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|
|Keywords:||Contact tracking, HIV/AIDS, Multi-drug resistance, South Africa, Tuberculosis|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be