OBJECTIVETo confirm the existence of an increased risk of complications from influenza A (H1N1)p among patients with diabetes.RESEARCH DESIGN AND METHODSUsing data from an enhanced influenza surveillance project in Montreal, Canada, and age/sex-specific population estimates of diabetes prevalence, we estimated the risk of hospitalization among persons with diabetes. Comparing hospitalized patients admitted or not to an intensive care unit (ICU), we estimated the risk of ICU admission associated with diabetes, controlling for other patient characteristics.RESULTSAmong 239 hospitalized patients with PCR-confirmed influenza A (H1N1)p, 162 (68%) were interviewed, of whom 22 had diabetes, when 7.1 were expected (prevalence ratio 3.10 [95% CI 2.04–4.71]). The odds ratio for ICU admission was 4.29 (95% CI 1.29–14.3) among hospitalized patients with diabetes compared to those without.CONCLUSIONSDiabetes triples the risk of hospitalization after influenza A (H1N1)p and quadruples the risk of ICU admission once hospitalized.

The development of PCR-based genotyping modalities (spoligotyping and mycobacterial interspersed repetitive unit-variable-number tandem repeat [MIRU-VNTR] typing) offers promise for real-time molecular epidemiological studies of tuberculosis (TB). However, the utility of these methods depends on their capacity to appropriately classify isolates. To determine the operating parameters of spoligotyping and MIRU-VNTR typing, we have compared results generated by these newer tests to the standard typing method, IS6110 restriction fragment length polymorphism, in analyses restricted to high-copy-number IS6110 isolates. Sensitivities of the newer tests were estimated as the percentages of isolates with identical IS6110 fingerprints that had identical spoligotypes and MIRU-VNTR types. The specificities of these tests were estimated as the percentages of isolates with unique IS6110 fingerprints that had unique spoligotypes and MIRU-VNTR types. The sensitivity of MIRU-VNTR typing was 52% (95% confidence interval [CI], 31 to 72%), and the sensitivity of spoligotyping was 83% (95% CI, 63 to 95%). The specificity of MIRU-VNTR typing was 56% (95% CI, 51 to 62%), and the specificity of spoligotyping was 40% (95% CI, 35 to 46%). The proportion of isolates estimated to be due to recent transmission was 4% by identical IS6110 patterns, 19% by near-identical IS6110 patterns, 33% by MIRU-VNTR typing, and 53% by spoligotyping. The low calculated specificities of spoligotyping and MIRU-VNTR typing led to misclassification of cases, inflated estimates of TB transmission, and low positive predictive values, suggesting that these techniques have unsuitable operating parameters for population-based molecular epidemiology studies.Tuberculosis (TB) molecular epidemiology exploits selected bacterial DNA targets to serve as markers for Mycobacterium tuberculosis strains. The most common method of DNA fingerprinting used is IS6110-based restriction fragment length polymorphism (RFLP). In a number of studies over the past decade, this modality has been validated for tracking TB transmission through two sets of observations. First, isolates from epidemiologically linked patients generally share identical or similar patterns (2, 3, 5). Second, matched RFLP patterns, when occurring among patients without known epidemiological links, are generally observed within groups with clear risk factors for TB transmission (1, 10, 13, 24).An important practical limitation of IS6110 RFLP is that results are usually obtained weeks to months after the initial diagnosis of TB. This limitation stems from the need to grow large numbers of bacteria to extract DNA of sufficient quantity and quality for RFLP analysis. Therefore, while useful for documenting transmission events, IS6110 RFLP often provides data once outbreaks are well established. In contrast, a number of PCR-based typing modalities have been recently developed, including spoligotyping and mycobacterial interspersed repetitive unit-variable-number tandem repeat analysis (MIRU-VNTR) typing, which offer...

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The economic burden of West Nile virus (WNV) infection is not known for Canada. We sought to describe the direct and indirect costs of WNV infection in the province of Quebec, Canada, up to 2 years after onset of signs and symptoms. We conducted a retrospective cohort study that included WNV cases reported during 2012 and 2013. For 90 persons infected with WNV, persons with encephalitis accounted for the largest proportion of total cost: a median cost of $21,332 per patient compared with $8,124 for West Nile meningitis (p = 0.0004) and $192 for West Nile fever (p<0.0001). When results were extrapolated to all reported WNV patients, the estimated total cost for 124 symptomatic cases was ≈$1.7 million for 2012 and that for 31 symptomatic cases was ≈$430,000 for 2013. Our study provides information for the government to make informed decisions regarding public health policies and infectious diseases prevention and control programs.

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