Background: South Africa has a high prevalence of tuberculosis (TB), multi-drug resistant (MDR) TB and HIV-coinfected adults in whom TB is often diagnosed late in the course of disease, with resultant high mortality. Improved case-finding approaches for both TB and HIV are needed to reduce mortality and prevent transmission.
Methods: Two household case-finding studies were conducted in North West Province, South Africa. One enrolled household contacts of 725 newly diagnosed TB patients, the other enrolled 312 randomly-selected households. Participants were screened for TB using sputum smear and culture and offered voluntary counseling and testing (VCT) for HIV. TB symptom duration prior to enrollment and CD4 T-cell count at the time of HIV diagnosis were assessed. Clinic VCT registers were examined for comparison. A retrospective cohort study was conducted of all patients admitted for MDR treatment between 2000-2006 in the provincial MDR reference treatment hospital.
Results: Active case-finding detected a prevalence of 6016/100,000 cases of undiagnosed active TB in contacts of known TB cases (N=2837). 19% of contact households had ≥1 undiagnosed TB case. The prevalence of undetected TB in randomly selected persons (N=987) was 405/100,000, significantly lower (p<0.001). 165 (11%) of HIV-tested TB contacts and 76 (14%) of non-contacts tested positive. The adjusted mean symptom duration prior to TB diagnosis was 4.5 weeks longer in passively-detected TB cases than actively-detected (95% CI 3.1-5.3, p<0.001). Adjusted mean CD4 count at HIV diagnosis was over 200 cells/mm3 higher among actively-detected compared to passively-detected HIV (95°/0 CI 136-316, p<=0.001). Over 8 years, cure or treatment completion was achieved in 199 (61%) of patients treated for MDR. 46% of all MDR patients were HIV-infected and the risk of death during MDR treatment was more than twice as high for HIV-infected patients vs. those without HIV (adjusted hazard ratio 2.60,1)=0.001).
Conclusions: Targeted active case-finding in South Africa detects high rates of undiagnosed TB and HIV and is associated with accelerated time to diagnosis. Earlier diagnosis of MDR, especially in HIV-infected patients, is essential for improved survival and ART access should be facilitated for MDR patients.
|Commitee:||Beyrer, Chris, Rosenblum, Michael|
|School:||The Johns Hopkins University|
|Department:||Epidemiology (Infectious Diseases)|
|School Location:||United States -- Maryland|
|Source:||DAI-B 74/10(E), Dissertation Abstracts International|
|Subjects:||African Studies, Public health, Epidemiology, South African Studies|
|Keywords:||Contact tracking, HIV/AIDS, Multi-drug resistance, South Africa, Tuberculosis|
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