ABSTRACT
OBJECTIVE: The prevalence and distribution of hepatitis B virus (HBV) genotypes in Canada is not known. Genotypic analysis may contribute to a better understanding of HBV strain distribution and transmission risk. METHODS: HBV surface antigen (HBsAg) positive samples of acute (n = 152) and chronic (n = 1533) HBV submitted for strain analysis or reference genotype testing between 2006 and 2012 were analyzed. The HBsAg coding region was amplified to determine the HBV genotype by INNO-LiPA assay or sequence analysis. Single and multivariate analyses were used to describe genotypes' associations with known demographic and behavioral risk factors for 126 linked cases of acute HBV. RESULTS: Nine genotypes were detected (A to I), including mixed infections. Genotype C (HBV/C) dominated within chronic infections while HBV/D and A prevailed among acute HBV cases. History of incarceration and residing with a chronic HBV carrier or injection drug user were the most frequently reported risks for acute HBV infection. Over time, HBV/A increased among both acute and chronic infections, and HBV/C and HBV/D decreased among chronic infections. CONCLUSION: Chronic and acute HBV genotypes in Canada differ in the relative distribution and their associations with known risk factors, suggesting different routes of transmission and clinical progression of infection.
Subject(s)
Genotype , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B, Chronic/genetics , Acute Disease , Canada/epidemiology , Female , Hepatitis B, Chronic/epidemiology , Hepatitis B, Chronic/prevention & control , Humans , Male , VaccinationABSTRACT
In the Middle East, the major sources of lead exposure have been leaded gasoline, lead-contaminated flour from traditional stone mills, focal exposures from small battery plants and smelters, and kohl (blue color) in cosmetics. In 1998-2000, we measured blood lead (PbB) levels in children 2-6 years of age in Israel, Jordan, and the Palestinian Authority (n = 1478), using a fingerstick method. Mean (peak; percentage > 10 microg/dL) PbB levels in Israel (n = 317) , the West Bank (n = 344), Jordan (n = 382) , and Gaza (n = 435) were 3.2 microg/dL (18.2 ; 2.2%) , 4.2 microg/dL (25.7; 5.2%), 3.2 microg/dL (39.3; < 1%) , and 8.6 microg/dL (> 80.0; 17.2%), respectively. High levels in Gaza were all among children living near a battery factory. The findings, taken together with data on time trends in lead emissions and in PbB in children in previous years, indicate the benefits from phasing out of leaded gasoline but state the case for further reductions and investigation of hot spots. The project demonstrated the benefits of regional cooperation in planning and carrying out a jointly designed project.
Subject(s)
Cooperative Behavior , Lead/toxicity , Child , Child, Preschool , Environmental Exposure , Humans , Israel , JordanABSTRACT
BACKGROUND: Recent evidence suggests a global rise in adult tuberculosis (TB) cases associated with HIV/AIDS. The World Health Organization, the United States Centers for Disease Control and Prevention, and the Public Health Agency of Canada advocate universal screening of all TB cases for HIV. The contribution of HIV to the TB burden in Canada remains unclear. METHODS: A retrospective cohort study was conducted of all TB cases reported in Canada from 1997 to 1998. The aim was to determine the proportion of patients that had an HIV test on record, and of these, the number of patients infected with HIV. RESULTS: From 1997 to 1998, 3767 TB cases were reported to the national TB surveillance system. In the present study, 3416 case records (90.7%) were included. The number of cases with a record of an HIV test was 736 (21.5%), and of these, 41.2% were tested within one month of TB diagnosis. Among the 703 cases with known HIV test results, the prevalence of HIV infection was 14.7%. Cases with an HIV test on record were more likely to have one or more risk factors for HIV, and also were more likely to be male, aged 15 to 49 years, of Aboriginal ethnicity, and to have smear-positive TB and both pulmonary and extrapulmonary disease at the time of diagnosis. DISCUSSION: These results suggest that HIV testing of TB patients is not universal, but rather selective, and is likely based on perceived risk factors for HIV as opposed to TB diagnosis alone.
