Prevalence of hepatitis B virus infection among health care workers in a tertiary hospital in Tanzania.

BACKGROUND: Sub-Saharan Africa has a high prevalence of hepatitis B virus (HBV) infections. Health care workers (HCWs) are at high risk of contracting HBV infection through their occupation. Vaccination of HCWs against HBV is standard practice in many countries, but is often not implemented in resource-poor settings. We aimed with this cross-sectional study to determine HBV prevalence, HCW vaccination status, and the risk factors for HCWs contracting HBV infection in Tanzania. METHODS: We enrolled 600 HCWs from a tertiary Tanzanian hospital. Their demographics, medical histories, HBV vaccination details and risk factors for contracting blood-borne infections were collected using a standardized questionnaire. Serum samples were tested for HBV and hepatitis C virus (HCV) markers by ELISA techniques, PCR and an anti-HBs rapid test. HCWs were divided in two subgroups: those at risk of contracting HBV (rHCW 79.2%) via exposure to potentially infectious materials, and those considered not at risk of contracting HBV (nrHCW, 20.8%). RESULTS: The overall prevalence of chronic HBV infection (HBsAg+, anti-HBc+, anti-HBs-) was 7.0% (42/598). Chronic HBV infection was found in 7.4% of rHCW versus 5.6% of nrHCW (p-value = 0.484). HCWs susceptible to HBV (HBsAg-, anti-HBc-, anti-HBs-) comprised 31.3%. HBV immunity achieved either by healed HBV infection (HBsAg-, anti-HBc+, anti-HBs+) or by vaccination (HBsAg-, anti-HBc-, anti-HBs+) comprised 36.5% and 20.2%, respectively. 4.8% of participants had indeterminate results (HBsAg-, anti-HBc+, anti-HBc-IgM-, anti-HBs-). Only 77.1% of HCWs who received a full vaccination course had an anti-HBs titer >10 ml/U. An anti-HBs point-of-care test was 80.7% sensitive and 96.9% specific. There was a significantly higher risk for contracting HBV (anti-HBc+) among those HCW at occupational risk (rHCW) of older age (odds ratios (OR) in rHCW 3.297, p < 0.0001 vs. nrHCW 1.385, p = 0.606) and among those HCW being employed more than 11 years (OR 2.51, p < 0.0001***). HCV prevalence was low (HCV antibodies 1.2% and HCV-RNA 0.3%). CONCLUSIONS: Chronic HBV infection is common among Tanzanian HCWs. One third of HCWs were susceptible to HBV infection, highlighting the need for vaccination. Due to high prevalence of naturally acquired immunity against HBV pre-testing might be a useful tool to identify susceptible individuals.

'Cough-triggered' tuberculosis screening among adults with diabetes in Tanzania.

AIMS: Diabetes increases the risk of tuberculosis and the prevalence of diabetes is rising in tuberculosis-endemic regions such as sub-Saharan Africa. Resource-appropriate strategies for tuberculosis case finding among African adults with diabetes are needed. The aims of this study were to determine prevalence of tuberculosis and evaluate one screening strategy among adult Tanzanians with diabetes. METHODS: In this prospective cohort study, we evaluated a 'cough-triggered' strategy for tuberculosis case finding among adults with diabetes at our zonal hospital in Tanzania. All adults with diabetes and cough underwent further tuberculosis symptom assessment, and those with productive cough had sputum collected for microscopy and Mycobacterium tuberculosis culture. RESULTS: Between September 2011 and March 2012, 700 adults with diabetes attended our hospital. A total of 693 were enrolled, 121/693 (17.5%) had cough and 32/693 (4.6%) had at least two of the classic symptoms of tuberculosis. Of note, 87/121 (71.9%) of patients with cough could not produce sputum spontaneously. Nine patients were diagnosed with tuberculosis for a prevalence of 1299/100 000 (1.3%), sevenfold greater than the national average. CONCLUSIONS: Tuberculosis is common among Tanzanian adults with diabetes, but tuberculosis case finding is challenging because of the high prevalence of non-productive cough. This low-cost, 'cough-triggered' tuberculosis case-finding strategy may serve as a reasonable first step for improving tuberculosis screening among adults with diabetes in sub-Saharan Africa.

Predictors of tuberculosis in first 6 months after initiation of antiretroviral therapy: a case-control study.

SETTING: In Africa, 10% of human immunodeficiency virus (HIV) infected adults starting antiretroviral therapy (ART) die within the first year, and tuberculosis (TB) is the leading cause of death. OBJECTIVE: To investigate the predictors of ART-associated TB at an adult HIV clinic in Tanzania. DESIGN: In this nested case-control study, adults starting ART were screened for TB according to the World Health Organization protocol. Those not diagnosed with TB were observed for 6 months. Patients diagnosed with TB were defined as cases, and controls were selected from among the patients who did not develop TB using incidence density matching. RESULTS: Among the 2514 HIV-positive adults in our cohort, 72 (3%) were diagnosed with TB during the first 6 months of ART. By multivariate analysis, baseline characteristics predictive of TB were cough, fever and night sweats; 76% (55/72) of the cases had at least one of these symptoms at the time of starting ART. CONCLUSION: Overall, 75% of the patients who developed TB during the first 6 months of ART had TB symptoms at the time of starting ART. Improved TB diagnostics and/or better strategies for empirical anti-tuberculosis treatment are needed for patients with symptoms of TB at ART initiation.

High prevalence of distal sensory polyneuropathy in antiretroviral-treated and untreated people with HIV in Tanzania.

OBJECTIVES: To describe the prevalence of distal sensory polyneuropathy (DSP), a complication of both advanced HIV disease and of antiretroviral therapy (ART), amongst Tanzanians with HIV, on and off ART (including stavudine) with CD4 counts above and below 200 cells/µl. METHODS: We recruited participants attending ART clinic into four groups: >6 months ART exposure and (i) CD4 < 200 cells/µl or (ii) CD4 > 200 cells/µl (ART/CD4 < 200 and ART/CD4 > 200, respectively); ART-naïve and (iii) CD4 < 200 cells/µl or iv)CD4 > 200 cells/µl (noART/CD4 < 200 and noART/CD4 > 200, respectively). Primary outcome was DSP, as defined by presence of at least one symptom and one sign. RESULTS: Of 326 evaluable participants, 81 (32 men, median age 38 years, median CD4 142 cells/µl) were enrolled in the ART/CD4 < 200 group, 78 (17 men, median age 37 years, median CD4 345 cells/µl) in ART/CD4 > 200, 81 (30 men, median age 37 years, median CD4 128 cells/µl) in noART/CD4 < 200 and 86 (22 men, median age 33 years, median CD4 446 cells/µl) in noART/CD4 > 200. Numbness was the most commonly reported symptom. DSP prevalence ranged from 43.2% in ART/CD4 < 200 to 20.9% in noART/CD4 > 200. DSP was more common among men (adjusted odds ratio [aOR] 1.9, 95% confidence interval [CI] 1.2-3.3) and older participants (aOR 2.7, 95% CI 1.1-6.2 for age 40 + vs. <30 years). CONCLUSION: Distal sensory polyneuropathy is common amongst those attending this clinic, even those with no ART exposure and a CD4 count above 200 cells/µl. Stavudine and didanosine expose HIV-infected patients to an additional avoidable risk of DSP. Access to non-neurotoxic ART regimes as well as earlier HIV diagnosis and initiation of ART is needed.