heavy rains from typhoon haitang on july 16 , 2005 , caused mudslides and flooding in central and southern taiwan . clinical information was collected on a case record form . for each patient , demographic data , including location , clinical signs , underlying illness , laboratory data , radiologic images , antimicrobial drug therapy , and clinical outcome , were obtained from medical records . information about patients functional levels , recent exposure to mud or water before admission , and prior travel to southeast asia or australia was obtained by telephone from the patients or their families if such information was incomplete or not available on medical charts . the study was reviewed and approved by the institutional review board of chi - mei foundation medical center . forty oxidase - positive , nonfermentative , gram - negative bacilli grew in ashdown selective medium and showed characteristic dry , rough , blue - purple colonies . the paired primers used for pcr amplification were pma-1 ( 5-ctg tcg tcg acg gcc gt-3 ) and pma-2 ( 5-ggt tcg aga ccg ttt gcg-3 ) ( 13 ) . the amplicons , 190 bp , were sequenced by using an abi 3730 dna analyzer ( applied biosystems , foster city , ca , usa ) . these isolates showed 99% identity with the homologous region of b. pseudomallei atcc23343 in the genbank database . in addition to the 40 isolates obtained in 2005 , a total of 14 b. pseudomallei isolates from 14 sporadic cases were available for molecular typing , including 1 isolate found in 2000 , 4 in 2001 , 4 in 2002 , 1 in 2003 , and 4 in 2004 . only the first isolate from each case was studied . two genetically distinct b. pseudomallei strains isolated in northern taiwan ( 9 ) were used as reference strains . for pulsed - field gel electrophoresis ( pfge ) , digests were subjected to gel electrophoresis using the chef mapper system ( bio - rad laboratories , hercules , ca , usa ) with a bacteriophage  dna ladder . gels were stained with ethidium bromide , viewed under uv light , and analyzed by using the molecular analyst system ( bio - rad laboratories ) . a total of 37 ( 92.5% ) patients never traveled abroad , and 28 ( 70% ) denied recent contact with mud or dirty water before their illness . because 3 patients could not walk , infection by cutaneous contact with contaminated dirt or water was less likely . twenty - seven ( 67.5% ) patients had an underlying debilitating illness , predominantly diabetes mellitus ( 20 patients ) . the most common initial symptoms were fever ( 29 patients , 72.5% ) and cough ( 13 patients , 32.5% ) . relevant prodromes lasting < 72 hours before admission were noted in 25 ( 62.5% ) patients , and 13 ( 32.5% ) patients visited hospitals within 24 hours after onset of the illness , which suggests acute illness . this onset was 4 days after the arrival of typhoon haitang , which suggests an incubation period of 4 days . most patients ( 30 , 75% ) had b. pseudomallei bacteremia , and 20 of these patients had concomitant pleuropulmonary infections . of 10 ( 25% ) patients without bacteremia , pulmonary infections remained the predominant foci in 6 . xbai restriction profiles in pfge provide a level of resolution similar to that obtained with multilocus sequence typing for b. pseudomallei isolates ( 14 ) , but the discriminative sensitivity of spei was greater than that of xbai in differentiation of our b. pseudomallei isolates . thus , genotyping information obtained from pfge spei profiles is useful in epidemiologic studies . among the 54 isolates , 2 pfge genotypes ( types a and b ) were identified in spei macrorestriction profiles ( figure 1 ) . these genotypes were genetically distinct from the 2 reference isolates ( types c and d ) . genotypes a and b were found in isolates obtained as early as 2000 ( figure 2 ) . pulsed - field gel electrophoresis of dna from burkholderia pseudomallei isolates digested with spei from patients with melioidosis in taiwan . lane 1 , isolate from kaohsiung county , 2005 ( type a ) ; lane 2 , isolate from tainan county , 2005 ( type b ) ; lane 3 , isolate from northern taiwan ( type c ) ; lane 4 , isolate from northern taiwan ( type d ) . geographic distribution of 14 sporadic cases of melioidosis , 20002004 , and 40 clustered cases , 2005 , taiwan . two pulsed - field gel electrophoresis ( pfge ) genotypes ( types a and b ) of burkholderia pseudomallei were present in southern taiwan . melioidosis became a reportable disease in taiwan in 2000 ; through 2004 , the center for disease control in taiwan received reports of 43 cases of b. pseudomallei infections ( 15 ) . increased rainfall in conjunction with typhoon haitang was observed from july through september 2005 . at the end of september 2005 , a total of 40 cases of melioidosis were identified . from october 2005 through march 2006 , only 3 cases were identified , but these were not included in our study . in conclusion , after widespread flooding caused by a typhoon , an outbreak of melioidosis occurred in southern taiwan from july 2005 through september 2005 . two genotypic strains were found in clustered cases in 2005 and in sporadic cases found in tainan and kaohsiung counties in 2000 . these findings confirm that environmental sources of b. pseudomallei are likely present in southern taiwan and that melioidosis is endemic in this country .
from july through september 2005 , shortly after a typhoon , 40 cases of burkholderia pseudomallei infection ( melioidosis ) were identified in southern taiwan . 
 two genotypes that had been present in 2000 were identified by pulsed - field gel electrophoresis . 
 such a case cluster confirms that melioidosis is endemic to taiwan .