montreal , quebec , gnome qubec and the ministre de dveloppement economique , innovation et exportation du gouvernement du qubec . john white and marcel behr , both of mcgill university and dr suneil malik of the infectious disease program in the office of biotechnology , genomics and population health at the public health agency of canada for comments and suggestions on earlier drafts of this manuscript . this article provides a timely review of the burden imposed by tuberculosis in the canadian province of quebec . it reviews the existing literature on the epidemiology of tuberculosis in quebec using both government and literature sources . in so doing , this article provides public health policy makers with an invaluable and updated review of the current prevalence of tuberculosis amongst at risk population groups in the province of quebec . such information should be extremely helpful to planning current and future health intervention strategies designed to control and reduce the burden of illness posed by tuberculosis and to plan cost - effective and appropriate treatment and management options in an optimal manner . tuberculosis ( tb ) is an infectious disease caused by mycobacterium tuberculosis which typically affects the lungs . globally , the prevalence of tb has reached epidemic levels , particularly in the developing world . canada , by contrast , has one of the lowest incidences of tb in the world . tb rates in the province of quebec have been lower than the canadian average since 1986 , but remain higher amongst certain populations , notably the inuit and immigrants . this paper aims to highlight the epidemiological trends of tb in the province of quebec , particularly in regards to these two groups . throughout canada and quebec , tb is regarded as a reportable communicable disease and so official records provide a best estimate of the number of persons with tuberculosis in canada and quebec . active tb requires immediate medical attention although m. tuberculosis infection can persist in a latent form . while treatment is often effective , drug resistant strains are known to occur . co - infection with other diseases such as hiv further complicates the treatment of the disease and can increase the mortality and cost of treatment . there are many other risk factors for developing active tb from latent infection , including immunosuppressant conditions such as hiv and factors related to poverty such as alcoholism , drug abuse , and malnutrition . the incidence of tb is over ten times greater in the province of quebec among immigrants compared to canadian - born residents . the highest prevalence rates are among recent immigrants from countries with a high incidence of tb , notably haiti , india , china , vietnam , the philippines and the democratic republic of congo . the cost of treatment of tb in canada is a financial burden , averaging over $ 47,000 dollars per case annually . active tb requires isolation and in rare cases intensive care , especially among multiple drug resistant cases , which while rare are potentially very costly to the healthcare system . the rate among aboriginal populations is higher compared to non - indigenous canadian - born citizens . in quebec , the greatest incidences are among the inuit , where the incidence rates can approach 50 times that of the general population . while rates may be higher among non - inuit aboriginal canadians than the non - aboriginal population , the epidemiological trends within that group are not discussed due to the small number of cases , typically less than five per year . other risk factors such as an increased genetic susceptibility , a changing diet away from vitamin d rich traditional diet towards a more western diet , the increased prevalence of diabetes and smoking all potential contribute to high rates of tb amongst quebec s inuit population , especially those on reserves versus off reserves . nevertheless , while incidences are high , the low absolute numbers of quebec s inuit population mean that there are often less than 10 cases per year . in nunavik ( the region in northern quebec home to many inuit ) communities , however , the lack of appropriate diagnostic medical facilities requires flying infected individuals to the nearest hospital , greatly increasing the cost of diagnosis and treatment . this paper aims to document the current epidemiological trends of tuberculosis in the province of quebec , with the goal of informing decision - makers about the cost - effectiveness of intervention strategies to reduce morbidity and mortality associated with tuberculosis in at risk populations . a systematic literature review of tuberculosis epidemiology research in the province of quebec and canada was performed . the primary electronic database service used was pubmed , a service provided by the national institute of health in the usa that is the primary interface for searching the medline database . the following keyword searches were used to find documents in pubmed : tuberculosis quebec epidemiology , aboriginal tuberculosis canada , aboriginal tuberculosis quebec , inuit tuberculosis quebec , immigrant tuberculosis canada , immigrant tuberculosis quebec and incidence tuberculosis quebec . the terms incidence and prevalence yielded redundant results . only literature that explicitly described the incidence or prevalence of tuberculosis cases occurring in the province of quebec twenty - nine of 226 peer - reviewed publications were deemed relevant and used as a basis for statistical analysis . in addition , to the pubmed and medline electronic search engines , the cochrane database was searched with similar terms , but yielded nothing of use . in addition to the peer - reviewed literature , a fruitful source of data on the epidemiology of tuberculosis was to be found in reports compiled by the governments of canada and the province of quebec . the most useful sources of epidemiologic information on the incidence and prevalence of tuberculosis in the province of quebec are also summarised in table 1 . the agencies that provide such reports include : i ) health canada ; ii ) the public health agency of canada ( phac ) ; iii ) ministre de la sant et des services sociaux ( msss ) ; and iv ) institut national de sant publique du qubec ( inspq ) . the website of each organisation is searchable , and the keywords tuberculosis and tuberculose were used to locate official documents within each agency . the msss provided epidemiological reports of tb in the province of quebec for 2000 - 2003 and 2004 - 2007 . these reports give incidences of tb in the province of quebec for various demographic groups and regions and were the primary source of data in this study . health canada , through phac , releases a yearly report on tb epidemiology in canada . reports are available online from 1996 to 2009 . these were used to provide additional information about tb in canada and the province of quebec that were not covered by the msss documents . several databases were used to gather demographic information about the overall population including ; the quebec census , quebec demographics database , circumpolar socioeconomic database and nunavik statistics program . demographic data beyond that were provided by individual papers based on these sources . as this was a systematic literature review of existing published literature , no ethical approval was required to complete this research project . the number of cases and incidence of tb in the province of quebec in 2009 is summarised in table 2 . the data for this table are compiled from the 2009 health canada report on tuberculosis . as can be seen , the incidence of tb in the province of quebec has been decreasing ( pearson s coefficient : -0.96 , p<0.01 ) since the 1980s and was below 3 cases per 100,000 in 2007 ( figure 1 ) . this includes the general population as well as immigrants ( pearson s coefficient : -0.81 , p<0.01 ) ( figure 2).while the incidence was low overall in the province of quebec , it was over 14 per 100,000 among immigrants in 2007 ( figure 2 ) . the percentage of tb cases that occurred amongst immigrants rose steadily in canada from 1985 to 2005 ( figure 2 ) , recently exceeding 50% and accounted for 62% of all cases in 2008 . the increase in the proportion of cases in quebec that occur in immigrants , approximately 0.7 percent per year , is statistically significant ( pearson s coefficient : 0.70 , p<0.01 ) . montreal is home to a large immigrant population and its proportion of immigrant cases is higher than the rest of the province : rivest et al . reported that from 1992 to 1995 , 77.9% of cases in montreal were among immigrants and that the incidence of tb in various immigrant groups reflects that in their home countries . the rivest paper also provides a table of the incidence of tb in montreal for immigrants from various regions , which is not reported in the official document . while the proportion of tb cases among immigrants has been increasing , the total number of cases has been decreasing . in addition to an increased incidence among immigrants , the inuit community in the province of quebec also experiences a high rate of tuberculosis . in 2007 , the incidence among inuit in the province of quebec was over 100 per 100,000 . while rates are decreasing over time among other groups , examining epidemiological data ( figure 3 ) suggests tuberculosis rates may be increasing among inuit nationwide ( pearson s coefficient : 0.67 , p<0.01 ) but there is no clear trend in quebec ( pearson s coefficient : 0.55 , p>0.02 ) . while government data is available from the mid 1990s , historical data may be used to examine the epidemiology of tb among the inuit in canada in prior decades . in the 1970s the mean incidence among the inuit was 168 per 100,000 , while during the period from 1995 to 2005 the mean incidence was 65 per 100,000 . enarson reports a reduction in incidence of 16% per year among the inuit in the early 1970s , but the trend slowed towards the end of the decade . nguyen et al . reports a fluctuating incidence of tb in nunavut throughout the 1990s . it is ascertained that the fluctuating rates observed from 1996 to 2009 are not a new trend . among non - indigenous canadians , tb rates generally increase with age with the highest rates among those older than 65 ( figure 4 ) . among immigrants , a bimodal distribution is seen with respect to age , with most cases occurring in young adults and a second peak in incidence among the elderly . the peak among young adult immigrants is not necessarily due to an increased susceptibility to tb in that group , but rather that new immigrants are mostly in that age group and many immigrants are diagnosed within two years of their arrival . the age distribution of inuit cases in quebec was bimodal , similar to that observed in immigrant cases . this is reported both by the sssq reports in the 2000s and by nguyen et al . in the 1990s . this may be explained by the fact that population of nunavik is considerably younger compared to that of the province of quebec . in general , the rate of tb with respect to age increases more strongly among men than women . while there is significant variation among children due to the small numbers , the relative incidence between sexes among children varies from year to year due to the small number of cases . among adults the greater rate among older men compared to older women has also been observed by holmes et al . , who have advanced two hypotheses for this trend : that adult men spend more time outside the house than women , or that female cases are under - reported due to differences in skin test efficacy . there does not appear to be a great difference between canadian and immigrant sex trends , although the immigrant population tends to display more gender parity . the results presented paint a clear picture : while quebec generally has low and falling tuberculosis rates , two groups suffer higher rates of the disease : immigrants and the inuit . canada is one of several countries with a low rate of tb that has a greater incidence rate among indigenous and immigrant populations . watkins et al . examined tuberculosis epidemiology among immigrants in canada and australia and found that immigrant groups in both countries suffer rates that mirror those of their home countries , similar to the conclusions of rivest et al . in quebec . french et al . found that in the united kingdom , 67% of tb cases were among immigrants , with an incidence rate of 88 per 100,000 , much greater than among immigrants in canada or in the province of quebec ( typically 20 per 100,000 ; figure 2 ) . in comparison to the uk , the immigrant proportion of cases in quebec in 2001 - 2003 , talbot et al . in the united states found that between 29 and 40 percent of cases in the mid 1990s were among immigrants , with rates of 32.9 per 100,000 , higher than canada s rate during that same time period . other industrialized nations with an indigenous population also have greater rates of tuberculosis in those populations . the rate among aboriginal populations in australia is 6.6 per 100,000 , lower than among the inuit in quebec but seven times greater than the non - native population . in the united states the rate of tb among native americans is 6 per 100,000 , 5.4 times greater than among the white population , while in new zealand the maori experienced a tb rate that was 6.9 times greater than the non - indigenous population . in all these countries , the rates are several times lower than among the province of quebec s inuit population . the increased tuberculosis rates are a manifestation of a greater problem of poor indigenous health in well - developed countries , which durie claims is due to genetic vulnerability , socioeconomic disadvantage , resource alienation , and political oppression . while this may explain the global trend , it does not explain why the situation is so much worse among the inuit compared to other indigenous groups worldwide . one such factor is co - infection with hiv , a disease more common in immigrants . they report that 5.2% of people with aids in the province of quebec have had tb and 5.8% of those with active tb are hiv positive . they conclude that immigrants from hiv - stricken countries are significantly more likely to develop tb and that aids contributes significantly to the number of tb cases in the province of quebec . this is consistent with the fact that the most common country of origin for immigrants with tb in quebec is haiti , which has the third highest rate of hiv outside africa . , it was observed that one s socioeconomic stratum was an important risk factor for the incidence of tb . in addition , there is evidence that tuberculosis epidemiology is linked to vitamin d deficiency and thus it may be possible to reduce the incidence of the disease in at - risk populations with a supplementation program . vitamin d deficiency may help explain the disparity between men and women in quebec : selvaraj et al . found evidence that tuberculosis susceptibility is related to a mutation of the vitamin d receptor in men but not women . among other factors , the increased rate of tuberculosis among the quebec inuit may be due to vitamin d insufficiency , due to both the greater latitude of their communities and due to nutritional insufficiencies . this may be a factor explaining why tuberculosis rates are so much greater in quebec inuit than other indigenous populations , such as australian aborigines , who experience more sunlight . this paper was motivated by questioning the economic benefit of preventative measures against tuberculosis . to gauge these benefits , the financial burden of treating the disease the costs of tuberculosis care in canada are discussed by menzies in a report for the public health agency of canada ( phac ) . the average cost per active case in canada is $ 47,290 ( 2004 dollars ) . excluding expenditures such as research funding , the cost of treating an active case is $ 19,906 , while latent tb costs $ 845 per case . the drugs used to treat active tb range in cost from cdn $ 500 to cdn $ 1000 dollars , but rare cases of multiply resistant tb require drugs costing over cdn $ 50,000 dollars . however , costs in the northern territories were much higher than the national average , due to the higher incidences and wide geographic dispersion . many northern communities lack medical facilities and staff , and suspected tb patients and their families must be flown to a hospital . nunavik has similar human geography as nunavut , with the population distributed between several small villages , only one with a hospital . while the cost of treatment in quebec is $ 35,000 per tb case , it is over twice as high in nunavut . due to their similarities , the cost per case may be similarly high in nunavik although it was not explicitly reported . the increased rate of tuberculosis among the inuit in quebec may present an economic burden if not checked . peer reviewed and government documents were used to collate data about the epidemiology of tb in the province of quebec . overall , the incidence of tb is much higher among immigrants than the general population . the rates among the total population as well as among immigrants were found to be decreasing over time . the inuit suffer a much higher rate than either immigrants or the general population , but this fluctuates from year to year with no significant trend being observed . several factors including hiv , poverty , and vitamin d deficiency were investigated , as well as the potential economic burden of the disease .
the aim of this research was to conduct a thorough review on the literature of tuberculosis in canada and the province of quebec . to achieve this aim , 
 an exhaustive literature review of tuberculosis in the province of quebec was undertaken . 
 data was collected with the goal of creating an epidemiological and public health evidence base to forecast the spread of tuberculosis . 
 a keyword search strategy was used to find relevant articles from the peer - reviewed literature using the electronic search engine pubmed and a search of other relevant federal and provincial government databases . 
 twenty - nine peer - reviewed publications and twenty government reports containing information about the incidence or prevalence of tuberculosis in the province of quebec were included in the analysis . 
 an analysis of the data revealed that while tuberculosis rates have been decreasing in both canada and quebec with an overall incidence below 3 per 100,000 of population in 2007 , among immigrants and the inuit communities in quebec , the incidence and prevalence of the disease still remains high and reached 18 per 100,000 and 100 per 100,000 , respectively in 2007 . in general , while tuberculosis does not pose a significant burden to the general population , it does continue to affect certain sub - groups disproportionately , including select immigrants and inuit communities in quebec . 
 efforts to ensure that cost - effective healthcare interventions are delivered in a timely fashion should be pursued to reduce the associated morbidity and mortality of tuberculosis in the province of quebec.acknowledgmentsfunding for this research was provided to medmetrics inc . , by mcgill university , 
 montreal , quebec , gnome qubec and the ministre de dveloppement economique , innovation et exportation du gouvernement du qubec.the authors also wish to thank drs . 
 john white and marcel behr , both of mcgill university and dr suneil malik of the infectious disease program in the office of biotechnology , genomics and population health at the public health agency of canada for comments and suggestions on earlier drafts of this manuscript .