Recovery of enteroviruses and poliovirus in Harare sewage using the bag-mediated filtration system at the introduction of the inactivated polio vaccine in Zimbabwe

Environmental surveillance is a sensitive method for detecting circulating virus in the absence of clinical cases and is important for monitoring progress for poliovirus (PV) eradication. This study used the bag-mediated filtration system (BMFS) to determine PV and enterovirus (EV) prevalence in sewage at the transition from oral polio vaccine type 2 (OPV2) use to inactivated polio vaccine (IPV) use in Zimbabwe, and examined the correlation between environmental surveillance results and vaccination coverage of OPV. A total of 18 BMFS samples from 6 sampling sites were analysed for the presence of EV and PV via direct RT-qPCR, direct ITD (intratypic differentiation), and the WHO algorithm. EV prevalence in Harare wastewater was 88.9% (16/18) using direct RT-PCR, 61.1% (11/18) using direct ITD, and 77.8% (14/18) using the WHO algorithm. Of the 18 samples analysed using the WHO algorithm, 10 samples (55.6%) were positive for Sabin-like PV type 3 (SL3). Of these 10 samples, 2 were also positive for non-polio enteroviruses (NPEV), resulting in a total of 6 (33.3%) samples positive for NPEV and 4 negative. The sensitivity of isolation in detecting EVs in sewage was 92.9% when comparing direct RT-qPCR results to the WHO algorithm. Using direct ITD, two high-density, low-income sampling sites were negative for SL3 and one low-density, high-income sampling point was negative for SL3 using the WHO algorithm. There was a strong association between relative EV concentration and the number of OPV3 vaccine recipients (r = 0.8590; p = 0.0284) in sampled areas. This study demonstrated the ability of BMFS to detect PVs circulating in Harare wastewater at the beginning of the OPV–IPV switch and can be used to monitor potential reintroduction of wild PV or vaccine-derived PVs from endemic areas

Human parasitic protozoa in drinking water sources in rural Zimbabwe and their link to HIV infection

OBJECTIVE: We aimed to perform a risk assessment in a rural setting, where drinking water is obtained from both protected and unprotected deep or shallow wells, boreholes and springs. Water is consumed untreated and this poses a risk of acquiring waterborne infections that may cause diarrhea. METHODS: The study included 113 study participants who volunteered in Chiweshe rural community (Musarara village) in Mashonaland Central Province in Zimbabwe. There were 34 (30%) males and 79 (70%) females with ages ranging from 2 to 89 years. HIV counseling was carried out at the communal meeting and testing was done at home visits. Stool and drinking water samples were collected from 104 subjects. Routine laboratory methods were used to examine for parasitic infections. RESULTS: Only 29 (25.7%) of participants were confirmed HIV positive using 2 rapid serology tests; eighty-four (74.3%) were negative. Diarrheic stool samples were observed in 17 (16.3%) participants and of these 5 (29.4%) were HIV seropositive. Several parasites were isolated from stool samples: G. duodenalis 6 (5.7%), E. histolytica/dispar 19 (18.2%), C. parvum, 8 (7.6%) and C. cayetanensis 23 (22.1%). Eleven out of 30 (36.6%) water bodies had protozoan parasites: G. duodenalis 2 (6.6%), E. histolytica 4 (13.3%), C. parvum 1 (3.3%), C. cayetanensis 3 (10%), E. coli 1 (3.3%). CONCLUSION: The water sources were being used without treatment and were shown to pose a risk for acquiring diarrheagenic protozoan parasites

Baseline Inflammatory Biomarkers Identify Subgroups of HIV-Infected African Children With Differing Responses to Antiretroviral Therapy

This article has been accepted for publication in Journal of Infectious Disease. Published by Oxford University Press.Background. Identifying determinants of morbidity and mortality may help target future interventions for human immunodeficiency virus (HIV)–infected children. Methods. CD4+ T-cell count, HIV viral load, and levels of biomarkers (C-reactive protein, tumor necrosis factor α [TNF-α], interleukin 6 [IL-6], and soluble CD14) and interleukin 7 were measured at antiretroviral therapy (ART) initiation in the ARROW trial (case-cohort design). Cases were individuals who died, had new or recurrent World Health Organization clinical stage 4 events, or had poor immunological response to ART. Results. There were 115 cases (54 died, 45 had World Health Organization clinical stage 4 events, and 49 had poor immunological response) and 485 controls. Before ART initiation, the median ages of cases and controls were 8.2 years (interquartile range [IQR], 4.4–11.4 years) and 5.8 years (IQR, 2.3–9.3 years), respectively, and the median percentages of lymphocytes expressing CD4 were 4% (IQR, 1%–9%) and 13% (IQR, 8%–18%), respectively. In multivariable logistic regression, cases had lower age-associated CD4+ T-cell count ratio (calculated as the ratio of the subject's CD4+ T-cell count to the count expected in healthy individuals of the same age; P < .0001) and higher IL-6 level (P = .002) than controls. Clustering biomarkers and age-associated CD4+ and CD8+ T-cell count ratios identified 4 groups of children. Group 1 had the highest frequency of cases (41% cases; 16% died) and profound immunosuppression; group 2 had similar mortality (23% cases; 15% died), but children were younger, with less profound immunosuppression and high levels of inflammatory biomarkers and malnutrition; group 3 comprised young children with moderate immunosuppression, high TNF-α levels, and high age-associated CD8+ T-cell count ratios but lower frequencies of events (12% cases; 7% died); and group 4 comprised older children with low inflammatory biomarker levels, lower HIV viral loads, and good clinical outcomes (11% cases; 5% died). Conclusions. While immunosuppression is the major determinant of poor outcomes during ART, baseline inflammation is an additional important factor, identifying a subgroup of young children with similar mortality. Antiinflammatory interventions may help improve outcomes.This work was supported by the Medical Research Council, the Department for International Development, the Wellcome Trust (grant 093768/Z/10/Z to A. J. P.), and ViiV Healthcare/GlaxoSmithKline (donation of drugs and funding of viral load assays)