Nursing and community rates of Mycobacterium tuberculosis infection among students in Harare, Zimbabwe.

BACKGROUND: African hospitals have experienced major increases in admissions for tuberculosis, but they are ill-equipped to prevent institutional transmission. We compared institutional rates and community rates of tuberculin skin test (TST) conversion in Harare, Zimbabwe. METHODS: We conducted a cohort study of TST conversion 6, 12, and 18 months into training among 159 nursing and 195 polytechnic school students in Harare. Students had negative TST results (induration diameter, < or =9 mm) with 2-step testing at the start of training. RESULTS: Nursing students experienced 19.3 TST conversions (increase in induration diameter, > or =10 mm) per 100 person-years (95% confidence interval [CI], 14.2-26.2 conversions per 100 person-years), and polytechnic school students experienced 6.0 (95% CI, 3.5-10.4) conversions per 100 person-years. The rate of difference was 13.2 conversions (95% CI, 6.5-20.0) per 100 person-years. With a more stringent definition of conversion (increase in the induration diameter of > or =10 mm to at least 15 mm), which is likely to increase specificity but decrease sensitivity, conversion rates were 12.5 and 2.8 conversions per 100 person-years in nursing and polytechnic school students, respectively (rate difference, 9.7 conversions per 100 person-years; 95% CI, 4.5-14.8 conversions per 100 person-years). Nursing students reportedly nursed 20,868 inpatients with tuberculosis during 315 person-years of training. CONCLUSIONS: Both groups had high TST conversion rates, but the extremely high rates among nursing students imply high occupational exposure to Mycobacterium tuberculosis. Intense exposure to inpatients with tuberculosis was reported during training. Better prevention, surveillance, and management of institutional M. tuberculosis transmission need to be supported as part of the international response to the severe human immunodeficiency virus infection epidemic and health care worker crisis in Africa.

HIV incidence and poverty in Manicaland, Zimbabwe: is HIV becoming a disease of the poor?

BACKGROUND: In Zimbabwe, socioeconomic development has a complicated and changeable relationship with HIV infection. Longitudinal data are needed to disentangle the cyclical effects of poverty and HIV as well as to separate historical patterns from contemporary trends of infection. METHODS: We analysed a large population-based cohort in eastern Zimbabwe. The wealth index was measured at baseline on the basis of household asset ownership. The associations of the wealth index with HIV incidence and mortality, sexual risk behaviour, and sexual mixing patterns were analysed. RESULTS: The largest decreases in HIV prevalence were in the top third of the wealth index distribution (tercile) in both men at 25% and women at 21%. In men, HIV incidence was significantly lower in the top wealth index tercile (15.4 per 1000 person-years) compared with the lowest tercile (27.4 per 1000 person-years), especially among young men. Mortality rates were significantly lower in both men and women of higher wealth index. Men of higher wealth index reported more sexual partners, but were also more likely to use condoms. Better-off women reported fewer partners and were less likely to engage in transactional sex. Partnership data suggests increasing like-with-like mixing in higher wealth groups resulting in the reduced probability of serodiscordant couples. CONCLUSION: HIV incidence and mortality, and perhaps sexual risk, are lower in higher socioeconomic groups. Reduced vulnerability to infection, led by the relatively well off, is a positive trend, but in the absence of analogous developments in vulnerable groups, HIV threatens to become a disease of the poor.

Uptake of workplace HIV counselling and testing: a cluster-randomised trial in Zimbabwe.

BACKGROUND: HIV counselling and testing is a key component of both HIV care and HIV prevention, but uptake is currently low. We investigated the impact of rapid HIV testing at the workplace on uptake of voluntary counselling and testing (VCT). METHODS AND FINDINGS: The study was a cluster-randomised trial of two VCT strategies, with business occupational health clinics as the unit of randomisation. VCT was directly offered to all employees, followed by 2 y of open access to VCT and basic HIV care. Businesses were randomised to either on-site rapid HIV testing at their occupational clinic (11 businesses) or to vouchers for off-site VCT at a chain of free-standing centres also using rapid tests (11 businesses). Baseline anonymised HIV serology was requested from all employees. HIV prevalence was 19.8% and 18.4%, respectively, at businesses randomised to on-site and off-site VCT. In total, 1,957 of 3,950 employees at clinics randomised to on-site testing had VCT (mean uptake by site 51.1%) compared to 586 of 3,532 employees taking vouchers at clinics randomised to off-site testing (mean uptake by site 19.2%). The risk ratio for on-site VCT compared to voucher uptake was 2.8 (95% confidence interval 1.8 to 3.8) after adjustment for potential confounders. Only 125 employees (mean uptake by site 4.3%) reported using their voucher, so that the true adjusted risk ratio for on-site compared to off-site VCT may have been as high as 12.5 (95% confidence interval 8.2 to 16.8). CONCLUSIONS: High-impact VCT strategies are urgently needed to maximise HIV prevention and access to care in Africa. VCT at the workplace offers the potential for high uptake when offered on-site and linked to basic HIV care. Convenience and accessibility appear to have critical roles in the acceptability of community-based VCT.

Voluntary counseling and testing by nurse counselors: what is the role of routine repeated testing after a negative result?

Three hundred eighty-eight human immunodeficiency virus (HIV)-negative clients in Zimbabwe were retested at 3 months using 2 parallel rapid tests. One operator error (risk, 0.26%; 95% confidence interval, 0.0065%-1.4%) and no "true" seroconversions (upper 95% confidence limit, 0.96%) were detected. High-risk behavior was not significantly reduced. Policies recommending routine retesting need to be reconsidered.

Association of house spraying with suppressed levels of drug resistance in Zimbabwe.

BACKGROUND: Public health strategies are needed to curb antimalarial drug resistance. Theoretical argument points to an association between malaria transmission and drug resistance although field evidence remains limited. Field observations, made in Zimbabwe, on the relationship between transmission and multigenic drug resistance, typified by chloroquine, are reported here. METHODS: Periodic assessments of the therapeutic response of uncomplicated falciparum malaria to chloroquine in two selectively sprayed or unsprayed health centre catchments, from 1995 - 2003. Cross-sectional analysis of in vivo chloroquine failure events for five sites in relation to natural endemicity and spraying history. RESULTS: During selective house spraying, the chloroquine failure rate for the sprayed catchment decreased, such that, after four years, the odds of chloroquine failure were 4x lower than before start of spraying in the area (OR 0.2, 95% CI 0.07 - 0.75, p = 0.010, n = 100). Chloroquine failure odds for the sprayed area became 4x lower than contemporaneous failure odds for the unsprayed area (OR 0.2 95% CI 0.08 - 0.65, p = 0.003, n = 156), although the likelihood of failure was not significantly different for the two catchments before selective spraying started (OR 0.5, 95% CI 0.21 - 1.32; p = 0.170, n = 88). When spraying ended, in 1999, the drug failure odds for the former sprayed area increased back 4 fold by 2003 (OR 4.2, 95%CI 1.49 - 11.78, p = 0.004, n = 146). High altitude areas with naturally lower transmission exhibited a 6x lower likelihood of drug failure than low-lying areas (OR 0.16 95% CI 0.068 - 0.353, -2 log likelihood change 23.239, p < 0.001, n = 465). Compared to sites under ongoing annual spraying, areas that were last sprayed 3-7 years ago experienced a 4-fold higher probability of chloroquine failure (OR 4.1, 95%CI 1.84 - 9.14, -2 log likelihood change 13.956, p < 0.001). CONCLUSION: Reduced transmission is associated with suppressed levels of resistance to chloroquine and presumably other regimens with multigenic drug resistance. It seems the adoption of transmission control alongside combination chemotherapy is a potent strategy for the future containment of drug-resistant malaria.