Tuberculosis And HIV Co-Infection
Tuberculosis And HIV
Despite close links between these two pathogens and increasing efforts to address both concurrently, uptake of screening policies linking HIV and TB has been slow.
Universal HIV testing for newly diagnosed TB cases and TB assessment for all newly diagnosed HIV cases has been recommended in Canada for over a decade. Despite this, evidence suggests that universal testing for HIV of new TB cases is not occurring.
A review of TB cases from 1997 and 1998 reported to the Canadian Tuberculosis Reporting System (CTBRS) found that the percentage of TB cases with a record of an HIV test was only 21.1%.
Several published Canadian studies have been conducted to determine the overlap that exists between TB and HIV. However, methodologies vary widely. Estimates of individuals with HIV or AIDS and active TB range from 1.6% to 5.8%. Studies conducted in Montreal and British Columbia estimated HIV infection among TB disease cases at 3.8% and 13.8% respectively.
The CTBRS study found that among those whose test results were known the prevalence of HIV infection was 15.0% (3% coinfection for the entire cohort). The CTBRS captures information on HIV coinfection for all TB cases reported in Canada. Between 1997 and 2004, the proportion of TB cases for which HIV status was known increased from 5.7% to 23.2%. In 2004, HIV status was reported for only 23% of cases, of which 15% were HIV seropositive.
In the unlikely event that these were the only coinfected cases, the overall coinfection rate would have been 4%. Additional epidemiologic information for coinfected TB cases cannot be determined from this system because of the paucity of the data. Information from other sources have identified two important subpopulations at greater risk of TB-HIV coinfection: Aboriginal peoples and new immigrants to Canada.