Background A randomized controlled trial (RCT) has shown that male circumcision (MC) reduces sexual transmission of HIV from women to men by 60% (32%−76%; 95% CI) offering an intervention proven efficacy for reducing the spread HIV. We explore implications this finding promotion MC as a public health control in sub-Saharan Africa. Methods and Findings Using dynamical simulation models we consider impact on relative prevalence circumcised uncircumcised men. country level data MC, estimate...

Objective: An AIDS epidemic among older children and adolescents is clinically apparent in Southern Africa. We estimated the likely scale time course of survivors vertical HIV infection. Design: modelled demographic, prevalence, mother-to-child transmission child survival data to project burden two African countries at different stages severe epidemics. Using measured for children, we estimate that 64% HIV-infected infants are fast progressors with median 0.64 years 36% slow 16.0 years....

Recent data from antenatal clinic (ANC) surveillance and general population surveys suggest substantial declines in human immunodeficiency virus (HIV) prevalence Zimbabwe. We assessed the contributions of rising mortality, falling HIV incidence sexual behaviour change to decline prevalence.

Objective: To validate the BED capture enzyme immunoassay for HIV-1 subtype C and to derive adjustments facilitating estimation of incidence from cross-sectional surveys. Design: Laboratory analysis archived plasma samples collected in Zimbabwe. Methods: Serial 85 women who seroconverted during postpartum year were assayed by used estimate window period between seroconversion attainment a specified absorbance. incidences prior recruitment calculated applying technique HIV-1-positive at...

Abstract An island of 4·5 km 2 in Lake Kariba, Zimbabwe, was stocked with cattle and infested Glossina morsitans Westwood G. pallidipes Austen 1979. From February 1980 to April 1981, the tsetse populations, estimated by mark, release recapture, increased about ten times, contain 3000 males m. 2000 . May 1981 1983, six traps, carbon dioxide acetone as odour attractants, were used capture 0·1–0·3% per day population 1–4% population. Captured flies retained killed, or automatically sterilized...

The IgG capture BED enzyme immunoassay (BED-CEIA) was developed to detect recent HIV-1 infection for the estimation of incidence from cross-sectional specimens. mean time interval between seroconversion and reaching a specified assay cutoff value [referred here as recency period (ω)], an important parameter estimation, is determined some subtypes, but testing in more cohorts new statistical methods suggest need revised ω different subtypes. A total 2927 longitudinal specimens 756 persons...

Background In Uganda, Rhodesian sleeping sickness, caused by Trypanosoma brucei rhodesiense, and animal trypanosomiasis T. vivax congolense, are being controlled treating cattle with trypanocides and/or insecticides. We used a mathematical model to identify treatment coverages required break transmission when host populations consisted of various proportions wild domestic mammals, reptiles. Methodology/Principal Findings An Ro for was generalized allow tsetse feed off multiple species....

Human leukocyte antigen (HLA)-E and HLA-G molecules act as powerful modulators of the innate immune response. The present study shows that HLA-E(G) genetic variant (the HLA-E*0103 allele) alone is significantly (P = .001) associated with a 4.0-fold decreased risk human immunodeficiency virus 1 (HIV-1) infection in Zimbabwean women. Furthermore, women carrying combination protective homozygote HLA-G*0105N heterozygote genotypes had 12.5-fold HIV-1 .03), compared neither genotype. These...

Abstract The juvenile hormone mimic, pyriproxyfen, applied topically to female tsetse flies, Glossina morsitans Westwood and G. pallidipes Austen, effectively sterilizes them by arresting development of their offspring in the pupal stage. Between July November 1989, 41 odour baited traps treated with pyriproxyfen were deployed near Rekomitjie Research Station, Zambezi Valley, Zimbabwe, a 12.3 km 2 block woodland habitat m. pallidipes. Tsetse entering brushed against material dosed mg/cm then...

Abstract Flies attracted to odours from 500 11 kg of livestock were captured using electrified netting in the Zambesi Valley, Rhodesia. Catches male Glossina morsitans Westw., Tabanidae, Stomoxyinae and non-biting muscids reached maximum levels at odour concentrations produced by only 500–3500 livestock, but catches female G. both sexes pallidipes Aust. increased over whole range tested. With dose odour, up 7100 tsetse caught 3 h. The proportion tenerals was not affected concentration. Daily...

Background Several approaches have been used for measuring HIV incidence in large areas, yet each presents specific challenges estimation. Methodology/Principal Findings We present a comparison of estimates Kenya and Uganda using multiple methods: 1) Epidemic Projections Package (EPP) Spectrum models fitted to prevalence from antenatal clinics (ANC) national population-based surveys (NPS) (2003, 2007) (2004/2005); 2) survey-derived model infer age-specific between two sequential NPS; 3) an...

Tuberculosis transmission is determined by contact between infectious and susceptible individuals. A recent study reported a 4% annual risk of child tuberculosis infection in southern African township. model was used to explore the interactions prevalence adult infection, adult-to-child contacts, household ventilation, which could result such high infection.Number residents per incidence were derived from census community registers. Using Wells-Riley equation probability analyses adults with...

Background: Whereas HAART initiated at CD4 cell counts 351–450 cells/μl reduces mortality, compared with starting lower levels, there is currently no evidence for the advantages of initiating treatment greater than 450 cells/μl. Methods: Mortality hazard, as a function count, was estimated among postpartum HIV-positive women in Zimbabwe, using HIV-negative reference group. Results: within 24 months 54 times higher less 200 cells/μl, fell to 5.4 those 400–600 but little thereafter. For 600...

Background Quantifying the effects of climate change on entomological and epidemiological components vector-borne diseases is an essential part research, but evidence for such remains scant, predictions rely largely extrapolation statistical correlations. We aimed to develop a mechanistic model test whether recent increases in temperature Mana Pools National Park Zambezi Valley Zimbabwe could account simultaneous decline tsetse flies, vectors human animal trypanosomiasis. Methods findings...

A methodology is presented to facilitate a declaration that an area 'pest-free' following eradication campaign against insect pest. This involves probability models assess null trapping results and also growth help verify, waiting period, pests were not present when control was stopped. Two are developed calculate the of negative if in fact insects present. If this sufficiently low, then hypothesis rejected. The depend on knowledge efficiency attractiveness traps. To verify model, period...

The reduced capture history (RCH), compiled from complete histories of uniquely marked animals, for a given pooling interval contains the same information as would be obtained experiments where (i) single sample lasts duration interval; (ii) an identical batch mark is applied to animals captured in series samples carried out during interval. For stationary populations, biases are calculated RCH estimates all parameters Jolly-Seber (J-S) model. results verified using simulation. functions...

ABSTRACT. Growth rates of tsetse populations were estimated by calculating the dominant eigenvalues appropriate Leslie matrices. The individual effects four variables (pre‐adult and adult survival probability, interlarval period pupal duration), have been investigated varying each one over a wide range values, while other three are held constant. R , log growth rate, was found to vary approximately linearly with pre‐adult death rate; 1% change in rate causes 10‐fold R. varies fecundity...

Objective: To test whether post-partum vitamin A supplementation can reduce incident HIV among women and identify risk factors for incidence. Design: Randomized, placebo-controlled trial Methods: Between November 1997 January 2001, 14 110 were randomly administered 400 000 IU or placebo within 96 h post-partum. incidence was monitored 9562 HIV-negative women. Results: Cumulative 3.4% [95% confidence interval (CI), 3.0–3.8] 6.5% (95% CI, 5.7–7.4) over 12 24 months post-partum, respectively....

Objective: To estimate the proportion who test as recent infections by BED capture enzyme immunoassay (BED) among patients about to commence, and those receiving, antiretroviral therapy. Design: Cryopreserved plasma samples from HIV on national treatment (ART) rollout program at Tygerberg Hospital clinic, South Africa, were tested using assay. Participants: Five hundred five qualifying for ART included in this study. Method: All each patient BED. Basic demographic data, HIV-1 viral load, CD4...