Activities of Rifampin, Rifapentine and Clarithromycin Alone and in Combination against Mycobacterium ulcerans Disease in Mice

Deepak Almeida
Center for Tuberculosis Research
Division of Infectious Diseases
Johns Hopkins University School of Medicine
BaltimoreMarylandUnited States of America

Paul J Converse
Center for Tuberculosis Research
Division of Infectious Diseases
Johns Hopkins University School of Medicine
BaltimoreMarylandUnited States of America

Zahoor Ahmad
Center for Tuberculosis Research
Division of Infectious Diseases
Johns Hopkins University School of Medicine
BaltimoreMarylandUnited States of America

Kelly E Dooley
Center for Tuberculosis Research
Division of Infectious Diseases
Johns Hopkins University School of Medicine
BaltimoreMarylandUnited States of America

Division of Clinical Pharmacology
Johns Hopkins University School of Medicine
BaltimoreMaryland

United States of America

Eric L Nuermberger
Center for Tuberculosis Research
Division of Infectious Diseases
Johns Hopkins University School of Medicine
BaltimoreMarylandUnited States of America

Department of International Health
Johns Hopkins Bloomberg School of Public Health
BaltimoreMarylandUnited States of America

Jacques H Grosset
Center for Tuberculosis Research
Division of Infectious Diseases
Johns Hopkins University School of Medicine
BaltimoreMarylandUnited States of America

Activities of Rifampin, Rifapentine and Clarithromycin Alone and in Combination against Mycobacterium ulcerans Disease in Mice

Background: Treatment of Mycobacterium ulcerans disease, or Buruli ulcer (BU), has shifted from surgery to treatment with streptomycin(STR)+rifampin(RIF) since 2004 based on studies in a mouse model and clinical trials. We tested two entirely oral regimens for BU treatment, rifampin(RIF)+clarithromycin(CLR) and rifapentine(RPT)+clarithromycin(CLR) in the mouse model.Methodology/Principal Findings: BALB/c mice were infected in the right hind footpad with M. ulcerans strain 1059 and treated daily (5 days/week) for 4 weeks, beginning 11 days after infection. Treatment groups included an untreated control, STR+RIF as a positive control, and test regimens of RIF, RPT, STR and CLR given alone and the RIF+CLR and RPT+CLR combinations. The relative efficacy of the drug treatments was compared on the basis of footpad CFU counts and median time to footpad swelling. Except for CLR, which was bacteriostatic, treatment with all other drugs reduced CFU counts by approximately 2 or 3 log 10 . Median time to footpad swelling after infection was 5.5, 16, 17, 23.5 and 36.5 weeks in mice receiving no treatment, CLR alone, RIF+CLR, RIF alone, and STR alone, respectively. At the end of follow-up, 39 weeks after infection, only 48%, 26.4% and 16.3% of mice treated with RPT+CLR, RPT alone and STR+RIF had developed swollen footpads. An in vitro checkerboard assay showed the interaction of CLR and RIF to be indifferent. However, in mice, coadministration with CLR resulted in a roughly 25% decrease in the maximal serum concentration (Cmax) and area under the serum concentration-time curve (AUC) of each rifamycin. Delaying the administration of CLR by one hour restored Cmax and AUC values of RIF to levels obtained with RIF alone.Conclusions/Significance: These results suggest that an entirely oral daily regimen of RPT+CLR may be at least as effective as the currently recommended combination of injected STR+oral RIF.

Introduction

Mycobacterium ulcerans disease, also known as Buruli ulcer (BU), is the third most prevalent disease caused by mycobacteria [1]. It is characterized by deep and necrotizing skin ulcers with undermined edges resulting from the secretion by M. ulcerans of an immunosuppressive macrolide toxin, termed mycolactone [2]. It is predominantly found in scattered foci in tropical riverine and marshy regions throughout the world. In certain parts of Africa its prevalence may exceed 150/100,000 individuals [3].

Until 2004, the recommended treatment for BU was surgical excision and skin grafting [1]. However, experimental studies using the mouse footpad model demonstrated that the combination of rifampin (RIF) and an aminoglycoside was bactericidal for M. ulcerans [4,5,6,7]. Based on these findings and subsequent studies in humans [8,9] the daily administration of the streptomycin-rifampin (STR+RIF) combination for 2 months was recommended by the World Health Organization (WHO) for the treatment of BU [10]. Depending on the size, severity and location of the ulcer, additional surgical intervention with skin grafting was also recommended. Treatment with STR requires intramuscular injection, which is difficult and expensive to implement in resource-poor countries since it requires use of sterile needles and syringes to avoid infection with blood borne pathogens. Therefore, the development of an entirely oral regimen is desirable [11].

In vitro, M. ulcerans is susceptible to a limited number of oral antibiotics including fluoroquinolones and macrolides [12,13,14,15,16]. However, in the mouse model, the combination of clarithromycin (CLR), a bacteriostatic or weakly bactericidal drug against M. ulcerans, and RIF, which also has limited bactericidal activity [4,6] has not consistently shown efficacy similar to the standard STR+RIF regimen. Three mouse studies assessing the bactericidal activity and the relapse rate after treatment completion yielded conflicting results. In the first study [5], the oral combination was less effective than the standard aminoglycoside plus RIF combination whereas in the second and third [12,13] studies, both combinations appeared to be as effective as the STR+RIF controls. There is, therefore, a need to directly address the issue of oral antibiotic treatment of BU, both with RIF and CLR and with new treatment regimens including anti-BU drugs that may have improved activity. Rifapentine (RPT), a rifamycin derivative with a much longer half-life than RIF could be an ideal substitute. In the murine model of tuberculosis when substituted for RIF at 10 mg/kg in a daily regimen in combination with isoniazid and pyrazinamide, it shortened the duration of treatment necessary to achieve cure [17,18]. Such regimens are currently under evaluation in at least 3 Phase II trials for tuberculosis treatment. In a murine model of M. ulcerans disease, daily RPT at the lower dose of 5 mg/kg has also been shown to be as active as, or even more active than, daily RIF at 10 mg/kg [13].

In this study, we hypothesized that the use of daily RPT along with CLR would increase the efficacy of the rifamycin-CLR combination and help in the development of an entirely oral regimen for treatment of BU. We first demonstrated that there were no negative in vitro interactions of CLR and RIF (as a representative rifamycin) and then compared the efficacy of the RIF+CLR regimen to that of the RPT+CLR regimen using the STR+RIF standard regimen as control to determine whether daily RPT is a better substitute for daily RIF in the treatment of M. ulcerans disease in this murine model and whether daily RPT+CLR is also a better substitute for the standard daily STR+RIF combination.

Materials and Methods

Antimicrobials STR and RIF were purchased from Sigma (St. Louis, MO) and RPT was a gift from sanofi-aventis pharmaceuticals (Paris, France). CLR was a gift from Abbott Laboratories (Abbott Park, U.S.A.). Stock solutions of RIF, RPT and CLR were prepared in sterile 0.05% agarose solution and STR was prepared in sterile normal saline. All stock solutions were prepared weekly and were stored at 4uC. All antimicrobials were administered orally (by gavage) using an esophageal cannula, except STR which was given by subcutaneous injections.

Bacterial strain

A recent isolate of M. ulcerans from a Ghanaian patient, strain Mu1059 [19] provided by Dr. Pamela Small, was used for the study.

In vitro checkerboard study

To determine whether the RIF and CLR interaction is synergistic, indifferent or antagonistic, serial two-fold concentrations ranging from 0.125 to 2 mg/ml of both drugs alone and in combination were prepared in 7H11 agar+Oleic Acid-Albumin-Dextrose-Catalase (OADC) supplement. Eight-week-old colonies of Mu1059 from 7H11 agar plates were suspended in phosphatebuffered saline (PBS), briefly vortexed, and kept undisturbed for 30 minutes to allow larger particles to settle. The optical density at 600 nm of this suspension was adjusted to 1, and 500 ml of the appropriate dilutions were plated in duplicate on antibioticcontaining plates and control plates without antibiotic. Plates were incubated at 32uC, and final CFU counts were performed after 12 weeks. The MIC was defined as the lowest drug concentration to inhibit growth of at least 99% of CFU on drug-free control plates. The fractional inhibitory concentration (FIC) value of individual drugs was then calculated using the MIC of the drug alone and MIC of the drug in combination. The sums of the two FIC values were combined to give the SFIC value which was then used to determine whether synergism (SFIC#0.5), indifference SFIC (.0.5 to #4) or antagonism (SFIC.4) occurred between the antibacterial agents. All calculations were performed in accordance with current accepted standards [20,21,22].

Inoculum preparation for the in vivo study

For each infection, an aliquot of a twice-mouse-passaged Mu1059 strain stored at 280uC was thawed and inoculated in mouse footpads. Once the footpads were swollen to a lesion index of 2-3 (defined as inflammatory footpad/hind foot swelling) [5], mice were sacrificed and footpad tissue was harvested, minced and suspended in sterile PBS. The solution was vortexed briefly, allowed to stand for 30 minutes, and the supernatant was used for footpad infection. Prior to infection, the inoculum was checked qualitatively for acid-fast bacilli, serially diluted, and plated for CFU counts on Middlebrook selective 7H11 plates (Becton-Dickinson, Sparks, MD).

Mouse model, infection and treatment

The kinetic method developed by Shepard for assessing the activity of anti-leprosy drugs [4,5,6,23,24] was used to assess drug activity. In brief, 320 female BALB/c mice aged 4-to-6 weeks (Charles River, Wilmington, MA) were infected in the right hind footpad with 0.03 ml of the M. ulcerans suspension. After infection, mice were randomized to one of two control groups or one of six test groups. The control groups included untreated negative controls (n = 50), and mice treated with STR+RIF as positive controls (n = 55). The test groups included mice treated with each antibiotic alone, i.e., CLR (n = 30), STR (n = 25), RIF (n = 25), and RPT (n = 25), and the two-drug combinations RIF+CLR (n = 55) and RPT+CLR (n = 55). Ten mice from the untreated

Author Summary

Buruli ulcer (BU) is found throughout the world but is particularly prevalent in West Africa. Until 2004, treatment for this disfiguring disease was surgical excision followed by skin grafting, procedures often requiring months of hospitalization. More recently, an 8-week regimen of oral rifampin and streptomycin administered by injection has become the standard of care recommended by the World Health Organization. However, daily injections require sterile needles and syringes to prevent spread of blood borne pathogens and streptomycin has potentially serious side effects, most notably hearing loss. We tested an entirely oral regimen, substituting the long acting rifapentine for rifampin and clarithromycin for streptomycin. We also evaluated each drug separately. We found that rifapentine alone is as good as rifampin plus streptomycin, but the simultaneous addition of effective clarithromycin doses, at least in the mouse, reduces the activity of both rifampin and rifapentine, making it difficult to assess the efficacy of the oral regimens in the model. Studies of serum drug concentrations indicated that separating treatment times by one hour or reducing the clarithromycin dose to one active in humans should overcome this issue in experimental and clinical BU treatment, respectively.

Oral Therapy for Buruli Ulcer in Mice www.plosntds.org group were sacrificed the day after infection (D1) and 11 days later at treatment initiation (D11) to establish baseline CFU counts in the footpads. All mice were treated for 4 weeks, 5 days per week. The drugs were given at the following doses that are equivalent (similar AUC) to the human doses [25,26]: RIF 10 mg/kg, RPT 10 mg/kg, STR 150 mg/kg and CLR 100 mg/kg. On treatment completion, 5 mice from each group were sacrificed for quantitative CFU counts in the footpads and all of the remaining mice were kept without treatment to determine the time to footpad swelling.

For quantitative footpad CFU counts, each footpad was harvested after having been thoroughly disinfected with soap and sterile PBS followed by 70% alcohol swabs. The footpad tissue was homogenized by fine mincing and suspended in 2 ml sterile PBS. Appropriate dilutions were plated on selective 7H11 plates and incubated at 32uC for 12 weeks before CFU were enumerated. This study was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All animal procedures were approved by the Johns Hopkins Animal Care and Use Committee (protocol MO08M240) and conducted according to relevant national and international guidelines.

Assessment of treatment efficacy

The activity of each treatment was assessed in terms of CFU counts on treatment completion and median time to footpad swelling in treated mice compared with untreated control mice. CFU counts were performed by harvesting and homogenizing the footpad as described above and suspending each footpad in 2 ml PBS. Serial 10-fold dilutions were prepared and 0.5 ml of appropriate dilutions were plated in duplicate on 7H11 selective plates. The plates were then incubated at 32uC for 12 weeks before the CFU counts were made. Median time to footpad swelling was assessed by checking the footpads of mice every week for 39 weeks after infection. If the median time to footpad swelling in treated mice exceeded that in untreated mice by no more than the duration of the treatment, i.e. 4 weeks, then the treatment was considered to be bacteriostatic. Longer median time to swelling was indicative of bactericidal activity or prolonged post-antibiotic effect. Absence of swelling at the end of the follow-up period was indicative of sterilizing potential.

Pharmacokinetic studies of rifamycin-CLR combinations

Because we observed a negative antimicrobial interaction between both rifamycin derivatives and CLR in vivo, a series of single-dose pharmacokinetic (PK) studies were performed in BALB/c mice. In the first study mice were co-administered 100 mg/kg of CLR and RIF 10 mg/kg. One sample for PK analysis was collected per mouse at 1, 2, 4, 6, 9 or 16 hrs after dosing. From these data, composite concentration-time curves were developed and compared. Because RIF serum concentrations appeared to be diminished when the two drugs were dosed together, we conducted a second study in which mice received 10 mg/kg of RIF alone, 10 mg/kg of RIF followed by 100 mg/kg of CLR one hour later, or 10 mg/kg of RIF co-administered with a lower dose of CLR (10 mg/kg). In a third study we substituted RPT for RIF and assessed RPT serum concentrations in mice receiving 10 mg/kg of RPT alone, 10 mg/kg of RPT coadministered with 100 mg/kg of CLR, or 10 mg/kg of RPT followed 1 hour later by 100 mg/kg of CLR. In a fourth study we evaluated RPT serum concentrations after RPT 10 mg/kg was coadministered with CLR at 10 mg/kg. Serum samples were frozen at 280uC and shipped overnight on dry ice to the Infectious Disease Pharmacokinetics Laboratory, National Jewish Medical and Research Center, Denver, CO. Drug concentrations were determined using validated HPLC methods. PK parameters were calculated using non compartmental methods with Phoenix WinNonlin software, version 6.1.0 (Pharsight, Cary, NC).

Statistical analysis

Survival analysis, with footpad swelling as the measurement, was performed using the Kaplan-Meier method [27]. The log rank test was used to determine the level of statistical significance when comparing survival curves of the different treatment groups with the control group. p values were two-tailed, and a value of p,0.05 was considered statistically significant. CFU counts were logtransformed before analysis. Culture-negative footpads were assigned a log value of 0. Group means for experimental treatment groups were compared with that of the standard treatment control by one-way analysis of variance with Dunnett's post-test. Paired ttests were also used to compare groups of equal size. All analyses were performed with GraphPad Prism version 4.01 (GraphPad, San Diego, CA).

Results

Checkerboard assay

The results of the checkerboard study are shown in table 1. They indicated that the interaction (SFIC = 0.75) between the two drugs was neither synergistic nor antagonistic and therefore was termed indifferent using the current guidelines [20,21,22].

CFU counts

The initial footpad suspension used for the inoculum contained 5.76 log 10 CFU per ml or 4.24 log 10 in the 0.03 ml that was inoculated per footpad. The next day (D1) 10 mice were sacrificed and the mean CFU count per footpad was 3.2960.41 log 10 . On initiation of treatment, 11 days after infection (D11), the mean CFU count in the 10 mice that were sacrificed was 3.3560.16 log 10 CFU, indicating that there was no substantial multiplication in the footpads during the first 11 days.

On treatment completion (Figure 1), 4 weeks later, the mean log 10 CFU count was 5.0160.62 in untreated control mice (W4 UT), demonstrating that M.ulcerans had multiplied well, increasing by about 2 log 10 in the footpads during the 4 weeks following treatment initiation, and suggesting a division time close to 4 days. In the positive control mice treated with STR+RIF, the mean log 10 CFU count was 0.7660.52, with one footpad out of the 5 harvested footpads culture-negative, underscoring the potent bactericidal activity of the STR+RIF combination against actively multiplying M. ulcerans. Among the test mice, the mean log 10 CFU count was 3.5460.18 in mice treated with CLR alone, a value similar to the 3.3560.16 log 10 value on treatment initiation, confirming the bacteriostatic activity of CLR against actively multiplying M. ulcerans. For other antibiotics alone or in Table 1. Checkerboard analysis for in-vitro interaction between clarithromycin (CLR) and rifampin (RIF).

Alone

Time to footpad swelling

After completing 4 weeks of treatment, mice were monitored on a weekly basis for footpad swelling. Time to median swelling in untreated mice was 5 weeks after infection (Figure 2). In accordance with the CFU counts on treatment completion, mice treated with CLR were the first to reach footpad swelling. But the median time to swelling was 16 weeks after infection, well beyond the 9 weeks that would have been expected after 4 weeks of treatment with a purely bacteriostatic drug added to the 5 weeks time to swelling in untreated control mice. CLR treatment is thus accompanied by a prolonged delay in footpad swelling possibly due to a significant post-antibiotic effect. Mice treated by CLR were followed by mice treated by RIF alone and STR alone, with median time to footpad swelling of 23.5 and 34 weeks, respectively. Only 26.3% of mice treated with RPT alone and 11.4% of the positive controls treated with STR+RIF developed footpad swelling at the end of the 8-month follow-up period after treatment completion, emphasizing the potent sterilizing effect of both regimens. The difference between RPT alone and STR+RIF was not statistically significant (p = 0. 33).

Surprisingly, as illustrated in Figure 2B, the time to footpad swelling was much shorter in mice treated with RIF+CLR (p,0.008) or RPT+CLR (p = 0.116) than in mice treated with RIF alone or RPT alone, respectively, suggesting antimicrobial or pharmacological antagonism between rifamycins and CLR in the mouse. Despite this antagonism, however, the RPT+CLR regimen caused a significantly greater (p = 0.0007) delay in footpad swelling than did RIF+CLR. Because the checkerboard study did not reveal antagonism between the two antimicrobials, the antagonism was likely to be due to pharmacokinetic drug-drug interaction as demonstrated below.

Impact of CLR administration on rifamycin pharmacokinetics

In the first PK study, as in the second and third PK studies, the experiments were performed as single and first-dose assessments, RIF (10 mg/kg) was either administered alone or co-administered with CLR (100 mg/kg). The mean AUC 0-16h and Cmax of RIF were 118.63618 mg*hr/ml and 11.9761.3 mg/ml, respectively, when RIF was administered alone, and 92.5627 mg*hr/ml and 8.4860.54 mg/ml, respectively, when RIF was co-administered with CLR ( Figure 3A), suggesting that CLR co-administration led to diminished RIF concentrations. In a second PK study, RIF (10 mg/kg) was administered alone, with CLR (100 mg/kg) given 1 hr later, or co-administered together with CLR at a lower dose of 10 mg/kg. The mean AUC 0-21h and Cmax of RIF were 123621 mg*hr/ml and 15.764.2 mg/ml, respectively, when RIF was administered alone, 133632 mg*hr/ml and 16.762.5 mg/ml, respectively, when CLR (100 mg/kg) was administered 1 hr after RIF, and 125622 mg*hr/ml and 15.561.2 mg/ml, respectively when RIF and CLR were co-administered at an equal dose of 10 mg/kg ( Figure 3B).

Similar observations were made in mice given RPT and CLR. The AUC 0-24h and Cmax of RPT were moderately decreased from 317.24625 mg*hr/ml and 18.1161.0 mg/ml, respectively, when RPT was given alone to 241.0960.37 mg*hr/ml and 13.0761.6mg/ml, respectively, when RPT was co-administered with CLR (100 mg/kg). Delaying administration of CLR (100mg/ kg) by 1 hr resulted in a RPT AUC 0-24h of 279.7060.47 mg*hr/ml and Cmax of 15.1461.7 mg/ml ( figure 4A). Reducing the dose of CLR to 10 mg/kg when co-administered with 10 mg/kg RPT resulted in RPT AUC 0-24h and Cmax values of 302.51628 mg*hr/ ml and 17.5261.1 mg/ml, respectively, similar to those of 324.23644 mg*hr/ml and 19.2461.6 mg/ml, respectively, obtained with RPT alone ( Figure 4B).

Discussion

The main result of the present work is that RPT alone administered 5 days a week at a dose of 10mg/kg is at least as active in terms of bactericidal effect and as active in terms of relapse prevention as the standard combination of STR+RIF against experimental M.ulcerans disease in the mouse. Such a result is extremely promising for the future of M.ulcerans disease treatment because it suggests that an entirely oral treatment may be as active as the present regimen containing parenteral STR. However, RPT cannot be administered alone because of the risk of drug resistance resulting from monotherapy, and CLR is the oral companion drug of choice to combine with a rifamycin [28]. As CLR alone exhibited clear-cut bacteriostatic activity, an additive effect of the combination RPT+CLR and even RIF+CLR was expected. Unfortunately the co-administration of a rifamycin and CLR, both drugs given orally at doses equivalent to human doses on the basis of serum AUC, was less effective than each rifamycin alone in mice infected with M. ulcerans. As no antagonistic effect between RIF and CLR was exhibited in vitro in the checkerboard assay, the lesser in vivo effectiveness of the combination could not be related to a negative antimicrobial drugdrug interaction. Rather, it appears that the negative drug-drug interaction was pharmacokinetic in nature. Indeed, co-administration of a 10-mg/kg dose of RIF with a 100 mg/kg dose of CLR resulted in a 22% reduction of RIF AUC and a 29% reduction of RIF Cmax compared to administration of RIF alone. Similarly, Oral Therapy for Buruli Ulcer in Mice www.plosntds.org RPT 10 mg/kg given together with 100 mg/kg CLR resulted in a 24% and 28% reduction of the RPT AUC and Cmax, respectively, compared to RPT administered alone. When administration of 100mg/kg of CLR was delayed by one hour from RIF administration, the pharmacokinetic interaction became insignificant. Similarly, there were also no negative pharmacokinetic drug-drug interactions when mice were co-administered 10 mg/kg of RIF and 10 mg/kg of CLR. These results indicate that the co-administration of CLR and RIF negatively interacts with the blood levels of rifamycins in mice probably by interfering with their absorption or by another mechanism and that this drug interaction is dose-dependent. However, a recent study in humans showed that concomitant CLR did not impact the absorption rate constant, the Cmax, or the Tmax of RIF at steady state, indicating that, at clinically relevant doses (7.5 mg/kg of CLR and 10 mg/kg of RIF), CLR does not negatively affect the levels of rifamycins in humans [29].

Our findings illustrate the difficulties in designing experiments in the murine model that aim to instruct treatment of a human infectious disease and in interpreting their results.

In order to adequately assess in mice the antimicrobial potential of a given drug, that drug should be given at doses deemed equivalent to human doses. As, drugs are usually metabolized much more rapidly in mice than in humans, the drug doses in mice have to be increased to obtain similar drug exposure in mice as in humans [25,30]. That is the case for CLR [30,31]. But the dose of 100 mg/kg that is adequate in mice to assess the antimicrobial activity of CLR when the drug is used alone presents a problem when it is co-administered with 10 mg/kg of RIF, most likely by reducing the absorption of RIF. Therefore the fact that combinations of CLR and a rifamycin were less active than the corresponding rifamycin alone should be considered an experimental artifact, and both drugs should be administered separately, with an interval of no less than one hour between them. Oral Therapy for Buruli Ulcer in Mice www.plosntds.org Interestingly, the same phenomenon is observed in the experimental chemotherapy of tuberculosis for which RIF should be administered at least one hour before isoniazid and pyrazinamide to prevent a negative pharmacokinetic interaction in mice [32,33].

Although the negative pharmacokinetic interactions prevented a reliable assessment of the antimicrobial activity of the RIF+CLR and RPT+CLR combinations against experimental M.ulcerans disease in mice, they did not prevent assessment of each drug alone in reference to the positive controls receiving STR+RIF. Besides the promising potency of RPT, our study also emphasizes the peculiar prolonged delay in footpad swelling resulting from treatment with CLR in mice infected with M. ulcerans. Whatever its antimicrobial or immunomodulatory [34] nature, this delay in footpad swelling is favorable and supports the use of CLR in the treatment of Buruli ulcer.

Finally, it is important to note that, in our experimental model, drug activity was assessed during a 4-week period during which untreated animals had a 2 log 10 increase in CFU counts in their footpads. As expected, CLR exhibited bacteriostatic activity whereas other drugs exhibited bactericidal activity, especially RPT. But, very interestingly, even the most active drugs and drug regimens did not reduce the CFU counts by more than 3 log 10 in 4 weeks. This was much less than the 5-6 log 10 reduction in the CFU counts observed by Ji et al. [12,13,14] when treatment was initiated at the plateau phase of growth, i.e., when the organisms were no longer actively multiplying likely because of immune Figure 3. Effects of CLR administration on RIF concentrations. The reduction of serum RIF concentration by co-administered CLR is overcome by delayed CLR administration. RIF serum concentrations in mice after, A) RIF (10 mg/kg) given alone and co-administered with clarithromycin (CLR) (100 mg/kg), and; B) RIF given alone, with CLR (100 mg/kg) administered 1 hr later, or concurrently with CLR (10 mg/kg). doi:10.1371/journal.pntd.0000933.g003 Figure 4. Effect of CLR administration on RPT concentrations. The reduction of serum RPT concentrations by co-administered CLA is overcome by delayed CLR administration. RPT serum concentrations in mice after, A) RPT (10mg/kg) given alone; RPT (10 mg/kg) followed by clarithromycin (CLR) (100 mg/kg) administered 1 hr later; or RPT (10 mg/kg) and CLR (100 mg/kg) concurrently; and B) RPT (10 mg/kg) given alone versus co-administered with lower-dose CLR (10 mg/kg). doi:10.1371/journal.pntd.0000933.g004

Oral Therapy for Buruli Ulcer in Mice www.plosntds.org containment. In our experimental model because antibiotic treatment was initiated during the incubation phase of the disease, the reduction in the CFU counts and the time to foot pad swelling are measuring only the antimicrobial activity. When treatment is initiated at the plateau phase of growth, its effect is likely a mixture of antimicrobial activity, immune containment, and shutting down the enzymes involved in mycolactone production. It does not facilitate the assessment of the respective antimicrobial value of each drug regimen, even though it might better recapitulate the response of patients to antibiotic therapy. In the chemotherapy of BU, as in the chemotherapy of tuberculosis, the drug activity against actively multiplying organisms, usually termed bactericidal activity, is very different from the drug activity against organisms that are no longer actively multiplying, i.e., sterilizing activity. Consequently, the occurrence, magnitude, and duration of the antimicrobial effect depend on the experimental model used. The information provided by each model is therefore different yet complementary, and not at all contradictory.

Figure 1 .
1Reduction in footpad CFU counts with various treatment regimens. Mean CFU count from mouse footpads on the day after infection (Day1), the day of treatment initiation (D11), and after four weeks of: UT = no treatment, CLR = clarithromycin, RIF = rifampin, STR = streptomycin, RPT = rifapentine, The number of asterisks below the x-axis indicates the number of mice with negative footpad cultures. doi:10.1371/journal.pntd.0000933.g001

Figure 2 .
2Delay in footpad swelling in mice receiving different drug regimens. Kaplan-Meier curve depicting the percentage of mice free of footpad swelling during 39 weeks of follow-up after infection. The dotted vertical line shows the expected delay in time to swelling for a bacteriostatic drug. The dotted horizontal line indicates footpad swelling in 50% of mice. A) Single drug regimens: Effect of single drugs compared to the standard regimen STR+RIF. Rifapentine alone prevented relapse as well as the standard STR+RIF regimen and better than any other single drug. B) Combination drug regimens with a rifamycin6CLR: Effect of adding CLR to either RIF or RPT. CLR = clarithromycin; RIF = rifampin; RPT = rifapentine, STR = streptomycin. doi:10.1371/journal.pntd.0000933.g002
January 2011 | Volume 5 | Issue 1 | e933
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AcknowledgmentsWe thank Dr. Pamela Small, University of Tennessee, for providing us with the M. ulcerans 1059 strain, and Dr. Charles Peloquin for determination of rifamycin concentrations in serum.Author Contributions
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Human Resources for Health Alumni survey of Masters of Public Health (MPH) training at the Hanoi School of Public Health and 4 Advisor to Hanoi School of Public Health on Educational Development, Vietnam

Linh Cu Le -email@example.com
Department of Graduate Education
Hanoi School of Public Health
Vietnam

Quyen Tu Bui email@example.com
Department of Biostatistics
Hanoi School of Public Health
Vietnam

Ha Thanh Nguyen
Department of Graduate Education
Hanoi School of Public Health
Vietnam

Arie Rotem firstname.lastname@example.com
Email : Linh
Cu Le
Human Resources for Health Alumni survey of Masters of Public Health (MPH) training at the Hanoi School of Public Health and 4 Advisor to Hanoi School of Public Health on Educational Development, Vietnam
10.1186/1478-4491-5-24BioMed Central Page 1 of 9 (page number not for citation purposes) Research * Corresponding author
Background: 1) To elicit the opinions of the Public Health alumni of the MPH program; 2) To assess the applicability of the knowledge and skills acquired; 3) To identify the frequency of the public health competencies that the alumni performed.Methods:We requested 187 graduates to complete a self-administered questionnaire and conducted in-depth interviews with 8 alumni as well as a focus group discussion with 14 alumni.Results:In total 79.1% (148) of the MPH graduates completed and returned the questionnaire. Most alumni (91%) agreed that the MPH curriculum corresponded with the working requirements of public health professionals; and nearly all were satisfied with what they have learnt (96%). Most respondents said that the MPH program enabled them to develop relevant professional skills (95%) and that they were satisfied with the curriculum (90%). Notably fewer respondents (73%) felt that the MPH program structure was balanced and well designed. Most alumni (64.3%) were satisfied with Hanoi School of Public Health (HSPH) full-time lecturers; but even more (83%) were satisfied with visiting lecturers. The most commonly selected of the 34 pre-identified public health competencies were: applying computer skills (66.4%), planning and managing health programs (47.9%), communicating with the community and/or mobilizing the community to participate in health care (43.2%). Overall, the MPH alumni felt that HSPH emphasized research methods at the expense of some management and operational competencies. The most important challenges at work identified by the alumni were insufficient skills in: data analysis, decision making, inter-sectoral cooperation development, English language and training.Conclusion:The training program should be reviewed and revised to meet the needs of its graduates who enter diverse situations and positions. English language skills were identified as top priority for further emphasis. The training program should comply with a more advanced accreditation system and standards.

Introduction

Hanoi School of Public Health (HSPH) is a leading academic institution in Vietnam which provides training, conducts research, and informs the policies of the Ministry of Health in the broad area of public health. Among these tasks, training is considered to be the most important. In 1995, on direction of the Ministry of Health, the school started developing the Master of Public Health (MPH) program. Since 1996, it has been cooperating with many international experts in applying a pioneering approach in Vietnam entitled "Public health school without walls -PHSWOW", as an active member of the international PHSWOW network. Unlike traditional training programs in which field training and practice is poorly emphasized, the School's MPH program lasts two years, of which one is field-based. By 2006, seven cohorts had completed the program with a total of 187 MPH graduates. The initial program intake was about 20-25 students per year. Recently, the school's annual intake ranges from 40 to 50 MPH students including students from the Lao People's Democratic Republic and Cambodia.

During this period there has been one comprehensive evaluation of the training program carried out by an expert team supported by the Rockefeller fund at the end of 2000 [1]. The course manuals, academic staff and infrastructure were regarded as appropriate for MPH training and the field-based study in the second year was considered very practical. Qualitative interviews with six students of the school also reflected appreciation of the school's efforts to support the students. The students felt more confident and more knowledgeable about public health as a result of the training received.

In developing the training programs, HSPH referred to many professional documents and conducted several studies on core public health functions. A study conducted by HSPH in collaboration with the World Health Organization (WHO) identified the key public health functions that public health professionals at different levels are required to perform [2]. The research findings were used as a basis for developing training programs for MPH ensuring that the students' capacity fits the needs of their work. However, to date, it has not been verified that students were adequately prepared to perform key public health functions in practice.

Recently, HSPH has developed an educational development master-plan for the next 10 years. The focal point in the initial five year phase is the evaluation of the adequacy of training and initiation of quality management of all training programs. The current survey contributes to this evaluation by reviewing alumni perceptions of the MPH program at HSPH as well as their progress and career path. This is the first detailed review of MPH training programs in Vietnam. It offers an assessment of the alumni's acquired competencies in relation to a framework of the essential functions of public health.

A cross-sectional survey was conducted to: 1) Elicit opinions of the public health alumni on the MPH program; 2) Assess the relevance and adequacy of the knowledge and skills acquired during the program; 3) Identify the relative importance of a range of public health competencies performed by alumni in their present work situation.

Methods

Cross-sectional quantitative survey

The self-administered questionnaire was sent out to all MPH alumni of HSPH. Graduates who were studying or working abroad were contacted by e-mail. The research announcement and contents were presented on the website of the Department of Graduate training HSPH for reference. In total 148 graduates out of the total of 187 responded to the survey and returned a completed questionnaire (see [Additional file 1]).

Qualitative research

An in-depth interview was conducted with five MPH alumni who were working as lecturers at HSPH. These interviews served as a pre-test leading to revision of the questionnaire. Group discussions with 14 representatives from the seven MPH cohorts were conducted in the format of a workshop. Initially, we prepared a list of 21 alumni (including three members from each cohort) based on their current positions, gender and post/functions. Given the qualitative nature of this study and logistic constraints, we did not aim to select the participants on a random basis, but aimed to achieve thorough representation of the student body. Due to personal reasons, some of the alumni invited were not able to attend. The final 14 who attended were relatively representative of the cohorts: approximately two per cohorts, except for cohorts six and seven, who have just graduated, from which we had just one participant per cohort (more were invited, but were unable to attend). This was compensated by the fact that we did more in-depth interview with these cohorts, as described below. With regard to position and current job, the 14 alumni interviewed were quite representative. Twelve of them were working in public/government sector (including Ministry of Health offices, training institutions, research institutes, provincial health offices, preventive medicine center, etc.) and two were working for non governmental organizations (NGOs)/international organizations. Among these 14 alumni, 10 are from Hanoi, three are from other provinces in the northern part of Vietnam and one is from a central province. Within this mini workshop, structured group discussion and nominal group techniques were used to obtain information. This approach was adapted from other study methodologies [3,4].

In addition to the mini workshop, eight in-depth interviews were conducted with MPH alumni (mainly from North Central and Central Coast provinces). Among these, four were males and four were females. We selected two alumni from the first cohort (one is now a senior lecturer in a medical school, one is a district hospital director), one from cohort four who is now working for an international organization, one alumni from cohort five who is now a teacher at a secondary medical school, one from cohort six who is working within the communication sector at provincial level, and three from cohort seven (one at secondary medical school, two at provincial health offices). The researchers travelled to these provinces to meet and interview four alumni, four others were interviewed during their visit to Hanoi.

The data was checked and entered using a data based programmed with Microsoft.NET tool, and managed in Microsoft Access 2003. Descriptive and bivariate analysis methods were applied, followed by multivariate techniques (including factor analysis.). For the results of indepth interviews thematic analysis was applied; the data from group discussions and interviews were analyzed based on the list of discussed topics and their prioritized order. Data analysis was carried out with SPSS, version 12.0.

Results

The majority of the alumni are now working in the northern part of the country (87%), mainly Hanoi (47.3% of the total sample). There are a few international students who have returned to their countries (two in Cambodia and four in the Lao People's Democratic Republic), and one alumnus is living in the United States of America. The overall response rate was 79.1% (148/187). Males accounted for 56.1% and females accounted for 43.9% of the sample. The current mean age of the alumni is 40.8 (41.5 in males and 39.8 in females). More than 57% of the alumni are in the age group 36-45. The mean age of MPH students at the beginning of their program is 35.3. No significant difference was evident in the mean age at enrolment when we compared across cohorts: . The majority of these alumni are working in preventive medicine public health sector (58.9%), 15% are working in curative medicine sector and the remainder are working in other health and non-health fields.

In general the alumni reported promotion to higher ranks after the training. Data showed that prior to MPH training, 59.3% of the alumni were at regular staff status (versus 43.9% currently), 24.8% were head of a department of an institution/organization (versus 31.1% currently), none of them were head of department at ministry level (versus 0.7% currently), and 8.3% of them were head of an institution/organization (versus 18.9% currently). It is difficult to claim that all promotion relates to their MPH training, but the qualitative interviews suggested that training made a major contribution to their career prospects.

The most frequent tasks that the alumni have to perform are: training (74.8%), preparing plans (72.1%), and conducting research (57.8%). The tasks that they perform least frequently are: evaluation and management of paraclinical services (18.4%) and providing clinical services (19.7%). Out of the alumni, 93% said that the tasks and functions they perform correspond well with what they learnt in the MPH program.

Identification of opinions of the public health alumni on the MPH program

In general, alumni were satisfied with the MPH program and the vast majority of them recognized that the program helped to improve their professional reputation, and that the design of the program corresponded with requirements of the practice reality ( Figure 1). "I usually encourage others to apply to study at HSPH because the study program is appropriate and very relevant to our work.... The training management at the School is very strict, they check our progress on a regular base and this is good for us. The field training supervision is very demanding, but it helps, it enables students to reach higher levels of learning. Studying here is very demanding, it's really a burden compared to other universities, but the quality is definitely much better. [FGD, female, MPH4] Table 1 indicates that some of the respondents thought that there was too much emphasis on epidemiology and research methodology (7.4% each). But these subjects were also ranked highest in the importance level of routine work (84.4% and 87.7%, respectively), just after basic computer application skills (92.5%). In contrast, the subjects that the alumni comment as "not emphasized enough" are: qualitative method (48% of the alumni), English (49.7%) and data analysis (46.6%).

The subjects which alumni suggested as least important in their work were rehabilitation, occupational health, maternal child health care and demography. This is not surprising since these are more specialized areas than general management of public health programs and many of the graduates are not assigned to work in these areas.

The alumni's comments in the open-ended section of the questionnaire are mainly related to the following issues: 1) the need for more data analysis training, scientific report writing, presentation/seminar skills for MPH students; 2) the need for more flexibility in relation to field work exercises and thesis topics, allowing students to do thesis at their work places; 3) the need for optional subjects and the modification of some "less important" subjects; 4) the need to develop specialized MPH tracks; 5) the need to improve the capacity of lecturers at HSPH, noting that many members of staff are still young and inexperienced.

The graduates in general indicated that they were proud to be HSPH alumni. They reported high confidence in performing public health activities and confidence in their ability to do research in particular. Overall they felt that they received a high quality of training with up-to-date knowledge with emphasis on practical skills. Key competencies and skills most frequently used and mentioned by the alumni were research skills, data analysis using statis-tical software, planning and evaluation, team work, communication skills and health education, problem solving, etc.

The respondents indicated that the overall structure of the MPH program was appropriate. However, they identified several areas that need to be modified. HSPH, in their view, should definitely move towards an accreditation and quality management system so that the students can accumulate their credits and transfer to other institutions. The MPH program should be clearly divided into core courses and optional (elective courses) to help develop "specialized MPH graduates". They identified emerging issues that could be developed into new optional courses such as: injury epidemiology, non-communicable diseases, and qualitative research methods especially particularly rapid appraisal (PRA).  The overall impression is that full time faculty members were well trained and applied active teaching methods. Part-time and guest lecturers were not regarded as high quality (though this view is not consistent with the quantitative data findings).

The English training at HSPH was considered "rather good" but very far from perfection. Respondents indicated that there was too much theory, and not enough practice or communicative lessons. The content of the course seems to be too "simple" and general and not sufficiently focused on the content and context of language used in Public Health.

Computer skills and data analysis appear to be a strength of MPH alumni. They highly appreciated those training courses at HSPH and showed significant confidence in relation to this area. However, they still expressed the need to study more data analysis skills and techniques.

Public speaking was considered a very important skill for MPH alumni. Their experiences showed that this is usually a weak point of public health professionals as a whole. Therefore, more attention should be given to this specific skill in MPH. The alumni also highly recommend HSPH to continue the weekly seminar for the students to prepare, present and talk in front of their classmates and teachers.

The alumni highly valued the field training component of the program. They all concluded that this is a must and that this experience helps them to considerably build up their own research capacity. The advantages of this component include: practicability, real-life experiences, hands-on teaching and learning and rigorous supervision during field work. In addition, many of the alumni suggested that HSPH should allow for the option of doing the field work in groups, instead of as individuals (first exercise of four months) with the second period of six months (field work exercise number two) leading to a thesis, done individually.

"Not only skills to do research but also skills to deal with problems that the research discovers, which means providing interventions, are necessary. The school is strong in training in research methodology. Thus its alumni can do research very well and confidently. However, they lack many practical skills, which cause difficulties for the alumni in designing and implementing intervention programs. In the second year, which is field-based, the focus is only identifying problems. Meanwhile, the next steps to solve the problems such as identifying resources, making intervention plan, and supervising the implementation of intervention are not emphasized.

When I return to work in the Department of Preventive Medicine, Ministry of Health (MOH), we mainly implement programs, not research. When I am asked to identify problems and

Subjects/topics Emphasis was given to this area in the MPH course (%) The importance in everyday work (%)

MPH alumni's perspective on public health skills and competencies

These 34 competencies were presented in four major groups: Public health management, Training, Research/ evaluation, and Leadership competencies ( Table 2). The detailed list of 34 competencies with frequency of how often the alumni practice and their confidence when performing these competencies is presented in [Additional file 2].

The data shows that competency number five (plan and manage health programs) is the most frequently performed by the alumni among the 10 public health management competencies (47.9% of them applied this competency very frequently), followed by monitor health problems and epidemics in the community (37%), and develop indicators and instruments to monitor community health (35.2%). The least frequently performed competency is evaluate and develop public health regulations (17.9%). Interestingly, the competency plan and manage health programs is the one that the vast majority of the alumni feel most confident about (96.9%). The next one is design health promoting interventions for the community (90.1%), followed by monitor health problems and epidemics in the community (88.5%).

With regard to the training competencies, it was found that about 38% of the alumni have provided training in public health very frequently and also about 38% of the alumni have to develop health-related capacity building plans and strategies as a frequent task. The level of confidence of the alumni in relation to providing training in public health and developing health-related capacity building plans and strategies is quite high (91.7% and 88%, respectively).

The next group composed 12 competencies/skills to conduct research and evaluation in public health. With regard to these competencies, apply computer skills successfully was the one that they most frequently performed (66.4%), followed by collect health information in a community (41.1%). It is noteworthy that only 36.5% of the alumni feel confident about using English effectively, and this is the lowest level of confidence among all 34 public health competencies. Thus, although almost 70% of the alumni confirmed that English is very important in their current work (66.2% of them replied that they sometimes need to use English, 22% need to use English very frequently), only 36.5% of the respondents feel confident about their English proficiency. Logistic regression analysis was conducted to explore the variables that relate to their 'confidence' in using English. After controlling for age, MPH cohorts, positions, levels of work (national, provincial, NGOs, etc.), working areas (health, nonhealth, etc.), and gender, the only factor found to be statistically related to the likelihood of not being confident in using English was the perception whether English was important or not (p < 0.001). Specifically, those who expressed their opinion that English was not (or minimally) important were actually 3.1 times more likely to be less confident in English, compared with their alumni counterparts who considered that English was important.

Regarding the fourth group of competency, leadership in public health, the competency that they perform most frequently is communicating with the community, mobilizing the community to participate in health care activities (43.2%). This is also the competency with which the highest percentage of alumni feels confident in (95.6%). At the opposite end, the one they performed least frequently and felt least confident about was work effectively within culturally diverse groups and settings.

MPH alumni's perspective on their current challenges at work

During the group discussions, alumni were requested to share their views and experiences concerning the current work they were undertaking. Importantly, we asked them to share the challenges that they were facing at their current work. Group nominal technique was used to explore this issue. The alumni admitted that they have to deal with several issues at work.

We used group nominal technique to sort out the most important challenges through the scoring process (Table  3). The top three challenges were: the lack of data analysis skills, lack of decision making skills and the difficulty in developing intersectoral cooperation (the same score of 17). The next concern was English proficiency and the fifth concern was training competency.

Discussion

The current distribution of the MPH alumni by geographic regions indicates that the MPH program at HSPH has provided public health education primarily for professionals from the northern part of Vietnam, with a lot of the alumni now working in Hanoi.

The comparison before and after MPH training shows a clear trend that the MPH graduates have gained certain promotions after their graduation. The proportion of alumni who worked for low level in health care sector (district and below) decreased while the proportion of those working for national level and international organizations increased after the MPH training. The percentage of alumni who have become head of the departments at institutions and head/deputy head of institutions has increased.

The overall structure of the MPH program appears to be satisfactory with one year of school-based and one year of practical/field-based education. However, there is a need to develop the curriculum geared towards a flexible approach, just like accredited MPH programs in developed countries, which allow students to study core (compulsory) and optional (elective) subjects. Suggestions concerning optional courses included: community-based rehabilitation, nutrition, disease prevention, occupational health and maternal child health care. There were some other themes that could be provided as elective subjects, such as project/program development, injury prevention, HIV/AIDS prevention, and non-communicable diseases. Alumni highlighted the importance for HSPH to move towards an accreditation and quality management system so that they could gain recognition for their studies by other institutions. In addition, alumni identified several areas they would like to study in more depth, includ- ing advanced data analysis skills, qualitative methods, and professional English. With regard to English proficiency, the alumni highly recommended that HSPH should provide more skills on using English as a tool to access public health scientific documents/references in English over the Internet, to summarize papers and reports in English.

The need to track the MPH program into (at least) two directions is clear. Most of the students indicated that research is not the only issue, and in most cases it is not the main task that they perform in routine work. Therefore, it is obvious that the research-component of the MPH program should be maintained, but to complement that, more practical/management-based components are required for the majority of MPH students. This could be the very first step of the development of more specialized MPH programs. Therefore, HSPH needs to immediately consider different tracking options. At least two tracks are needed: research-based (strong focus on research methodology) and program/practical-based (strong focus on project development and management).

In addition to existing academic subjects, some other skills are also very important. They include: scientific report writing, presentation/seminar skills, how to access information over the Internet, public speaking, and selfstudy competency, etc.

More flexibility in terms of field work exercise requirement and thesis topics is an emerging issue. The students would appreciate HSPH to allow them: 1) to implement the first field work exercise in groups rather than individuals; 2) to conduct thesis research at their work places, analyse secondary data, etc.

There is the need to improve the capacity of lecturers at HSPH, as many of the staff are still young and inexperienced. This would also link to the capacity building process at HSPH as well as the staff's academic requirement and staff evaluation process at HSPH. This also includes the criteria to screen, select and invite guest/visiting lecturers.

Some other academic skills newly identified as critical such as scientific report writing, presentation/seminar skills, information search over the Internet, public speaking, and self-study competency, have raised the issue of new subjects and coursework needed. Therefore, these topics should be discussed and assigned to specific academic departments and groups to develop and introduce to the students. In conjunction with this process, library and information services should also be reviewed and improved.

Conclusion

For the long-term strategy, HSPH should move forward an action plan of training quality assurance and quality control. This should initially address the following issues: capacity building for junior and inexperienced teaching staffs (with strong focus on pedagogy), staff performance evaluation regulations and processes, student's feedback and evaluation of teaching quality (at the end of each subject and at the end of the whole program) and learning materials reviews and modification/adaptation

The competency to plan and manage health programs is the most frequently performed by the alumni among the 10 public health management competencies. The next competencies are: monitor health problems and epidemics in the community and develop indicators and instruments to monitor community health. These findings suggest that the management and administrative workload is very crucial for MPH alumni. This finding is consistent with studies conducted in Australia where generic skills associated with report writing, project coordination and all aspects of planning and management also featured very highly [5,6].

As discussed above, the English capacity is of major concern for the MPH graduates. This issue is confirmed by the fact that few of the alumni said that they feel confident about using English effectively, and this is the lowest level of confidence among all 34 public health competencies.

Knowledge of English is regarded as important for further professional development and thus for promotion and career prospects.

As part of a long term strategy for educational development the HSPH should adopt a "comprehensive approach" using problem-based learning (or scenariobased learning) approaches, so that the "domains" of competencies can be better addressed.

"
The training program should include both core (mandatory) courses and elective courses. For example, because I conduct many training activities I need to learn more about training methodology, on the other hand, courses such as occupational health is not used in my job, which is really wasteful." [FGD, female, MPH5] "Advanced universities in the world have mandatory courses and elective courses in their training programs. Our School should follow them." [FGD, female, MPH2]General opinions of the Public health alumni on the MPH program (percent agree)Figure 1General opinions of the Public health alumni on the MPH program (percent agree).

corresponds with the working requirement of PH professionals MPH curriculum corresponds with the funtions that alum ni have to perform at work Alum ni satisfied with what they learnt at HSPH MPH program enables alumni to develop professional reputation The Alum ni sastified with the curriculum of the program Program provides up to date knowledge The program structure is balanced and well designed Alum ni satisfied with HSPH full tim e lecturer Alum ni satisfied with visiting lecturer Learning materials are rich and diversified

Table 1 :
1Alumni's perspective on specific subjects/topics (percent, n = 142)

Table 2 :
2The percentage of frequency of competencies performed by the MPH alumni3 most frequently performed
3 least frequently performed

1
2
3
1
2
3

Public health
management

Plan and manage
health programs
(47.9%)

Monitor health
problems and
epidemics in the
community (37%)

Develop indicators
and instruments to
monitor
community health
(35.2%)

Evaluate and
develop public
health regulations
(17.9%)

Describe the
health system
structure and the
drivers of health
system change
(25.3%)

Consult in making
public health
policies and plans
(25.3%)

Training
Provide training in
public health
(37.7%)

Develop health-
related capacity
building plans and
strategies (37.6%)

Monitor and
evaluate a training
program (33.8%)

Evaluate the health
human resource in
terms of quality,
quantity and need
(29%)
Research/
evaluation

Apply computer
skills successfully
in your work
(66.4%)

Collect health
information in a
community
(41.1%)

Assess and analyze
the health
situation of a
community
(35.6%)

Apply the
procedures of the
Ethics committee
in biomedical
studies (15.3%)

Apply qualitative
methods in public
health practice
(20.5%)

Use English
effectively in your
work (22.1%)

Leadership
Communicate
with the
community,
mobilizing the
community to
participate in
health care
activities (43.2%)

Facilitate group
work effective
(39.5%)

Use analytical,
critical thinking
and problem-
solving skills to
make decisions
effectively
(39.55%)

Work effectively
within culturally
diverse groups and
settings (26.7%)

Lobby leaders for
solving community
health problems
(28.8%)

Create multi
sectoral
cooperation to
solve community
health problems
effectively (29.3%)

Table 3 :
3The challenges of the MPH alumni in work settings, classified by competency groupsPublic health management
competencies

Teaching/training
competencies

Research/evaluation
competencies

Leadership competencies

-Lack of skills to evaluate health
programs at lower level

-Lack of skill to encourage student
to study
-Lack of skill to train subordinates
and lower-level health staff
-Poor self-study competency

-Lack of injury, health economic
research development skill
-Lack of data analysis skill
-Poor Public Health English
capacity
-Lack of skill to search for
information in the Internet

-Lack of policy advocacy skill
-Lack of group conflict solving skill
-Lack of skill to persuade and
explain to colleagues and leader
-Lack of skills to work in culturally
diverse settings
-Lack of skill to persuade and
explain to clients
-Lack of decision making skill
-Difficulty in creating intersectoral
cooperation

(page number not for citation purposes)
AcknowledgementsThis study was supported by the Dutch Government project to strengthen public health training at the Hanoi School of Public Health. The authors would like to thank the Hanoi School of Public Health leader board for their support and guidance.Competing interestsThe author(s) declare that they have no competing interests.Authors' contributionsLCL was responsible for the overall design and conduct of this study, the development of the questionnaire, the collection and interpretation of data, drafting the article, and editing of the final version.QTB was responsible for the development of the questionnaire and supported the data collection, the quantitative data analysis. http://www.human-resources-health.com/content/5/1/24 HTN was responsible for the coordination of this study, the development of the questionnaire, the data collection, qualitative data analysis.AR contributed to the conceptualization of the study, the development of the questionnaire, support the interpretation of the findings and editing of the final version.Additional materialAdditional file 1
PHSWOW External Evaluation Team of the Rockefeller Foundation: Report on a visit to the Hanoi School of Public Health. Hanoi, Vietnamdraft version. unpublishedPHSWOW External Evaluation Team of the Rockefeller Foundation: Report on a visit to the Hanoi School of Public Health, Hanoi, Vietnam 2000. (draft version, unpublished)

World Health Organization Western Pacific Region: Essential Public Health Functions -A three-country study in the Western Pacific Region. Report on the findings. Melbourne, Australia3National Public Health Partnership: National Delphi Study on Public Health Functions in Australia. manuscript unpublishedWorld Health Organization Western Pacific Region: Essential Public Health Functions -A three-country study in the Western Pacific Region 2003. 3. National Public Health Partnership: National Delphi Study on Public Health Functions in Australia: Report on the findings, Melbourne, Australia 2000. (manuscript unpublished)

The Victorian Consortium for Public Health: Student Survey for Victorian Consortium for Public Health. AustraliaManuscript unpublishedThe Victorian Consortium for Public Health: Student Survey for Victo- rian Consortium for Public Health. Australia 2004. (Manuscript unpub- lished)

Public health job vacancies--who wants what, where? Aust Health Rev. A Rotem, J C Dewdney, N A Mallock, T R Jochelson, 29Rotem A, Dewdney JC, Mallock NA, Jochelson TR: Public health job vacancies--who wants what, where? Aust Health Rev 2005, 29(2):226-234.

Identifying the competencies for Australian health professionals working in international health. H Akbar, P S Hill, A Rotem, I D Riley, A B Zwi, G C Marks, T Mark, Asia-Pacific Journal of Public Health. 172Akbar H, Hill PS, Rotem A, Riley ID, Zwi AB, Marks GC, Mark T: Identifying the competencies for Australian health profes- sionals working in international health. Asia-Pacific Journal of Public Health 2005, 17(2):99-103.