Faculty Bibliography

BACKGROUND:Direct measures of HIV incidence are needed to assess the population-level impact of prevention programs but are scarcely available in the subnational epidemic hotspots of sub-Saharan Africa. We created a sentinel HIV incidence cohort within a community-based program that provided home-based HIV testing to all residents of Namibia's Zambezi region, where approximately 24% of the adult population was estimated to be living with HIV. OBJECTIVE:The aim of this study was to estimate HIV incidence, detect correlates of HIV acquisition, and assess the feasibility of the sentinel, community-based approach to HIV incidence surveillance in a subnational epidemic hotspot. METHODS:Following the program's initial home-based testing (December 2014-July 2015), we purposefully selected 10 clusters of 60 to 70 households each and invited residents who were HIV negative and aged ≥15 years to participate in the cohort. Consenting participants completed behavioral interviews and a second HIV test approximately 1 year later (March-September 2016). We used Poisson models to calculate HIV incidence rates between baseline and follow-up and multivariable Cox proportional hazard models to assess the correlates of seroconversion. RESULTS:Among 1742 HIV-negative participants, 1624 (93.23%) completed follow-up. We observed 26 seroconversions in 1954 person-years (PY) of follow-up, equating to an overall incidence rate of 1.33 per 100 PY (95% CI 0.91-1.95). Among women, the incidence was 1.55 per 100 PY (95% CI 1.12-2.17) and significantly higher among those aged 15 to 24 years and residing in rural areas (adjusted hazard ratio [aHR] 4.26, 95% CI 1.39-13.13; P=.01), residing in the Ngweze suburb of Katima Mulilo city (aHR 2.34, 95% CI 1.25-4.40; P=.01), who had no prior HIV testing in the year before cohort enrollment (aHR 3.38, 95% CI 1.04-10.95; P=.05), and who had engaged in transactional sex (aHR 17.64, 95% CI 2.88-108.14; P=.02). Among men, HIV incidence was 1.05 per 100 PY (95% CI 0.54-2.31) and significantly higher among those aged 40 to 44 years (aHR 13.04, 95% CI 5.98-28.41; P<.001) and had sought HIV testing outside the study between baseline and follow-up (aHR 8.28, 95% CI 1.39-49.38; P=.02). No seroconversions occurred among persons with HIV-positive partners on antiretroviral treatment. CONCLUSIONS:Nearly three decades into Namibia's generalized HIV epidemic, these are the first estimates of HIV incidence for its highest prevalence region. By creating a sentinel incidence cohort from the infrastructure of an existing community-based testing program, we were able to characterize current transmission patterns, corroborate known risk factors for HIV acquisition, and provide insight into the efficacy of prevention interventions in a subnational epidemic hotspot. This study demonstrates an efficient and scalable framework for longitudinal HIV incidence surveillance that can be implemented in diverse sentinel sites and populations.

Background/UNASSIGNED:In 2015, Namibia implemented an Acceleration Plan to address the high burden of HIV (13.0% adult prevalence and 216 311 people living with HIV [PLHIV]) and achieve the UNAIDS 90-90-90 targets by 2020. We provide an update on Namibia's overall progress toward achieving these targets and estimate the percent reduction in HIV incidence since 2010. Methods/UNASSIGNED:Data sources include the 2013 Namibia Demographic and Health Survey (2013 NDHS), the national electronic patient monitoring system, and laboratory data from the Namibian Institute of Pathology. These sources were used to estimate (1) the percentage of PLHIV who know their HIV status, (2) the percentage of PLHIV on antiretroviral therapy (ART), (3) the percentage of patients on ART with suppressed viral loads, and (4) the percent reduction in HIV incidence. Results/UNASSIGNED:In the 2013 NDHS, knowledge of HIV status was higher among HIV-positive women 91.8% (95% confidence interval [CI], 89.4%-93.7%) than HIV-positive men 82.5% (95% CI, 78.1%-86.1%). At the end of 2016, an estimated 88.3% (95% CI, 86.3%-90.1%) of PLHIV knew their status, and 165 939 (76.7%) PLHIV were active on ART. The viral load suppression rate among those on ART was 87%, and it was highest among ≥20-year-olds (90%) and lowest among 15-19-year-olds (68%). HIV incidence has declined by 21% since 2010. Conclusions/UNASSIGNED:With 76.7% of PLHIV on ART and 87% of those on ART virally suppressed, Namibia is on track to achieve UNAIDS 90-90-90 targets by 2020. Innovative strategies are needed to improve HIV case identification among men and adherence to ART among youth.

INTRODUCTION: Children are important transmitters of influenza in the community and a number of non-pharmaceutical interventions (NPIs), including hand washing and use of hand sanitizer, have been recommended to mitigate the transmission of influenza, but limited information is available regarding schools' ability to implement these NPIs during an influenza outbreak. We evaluated implementation of NPIs during fall 2009 in response to H1N1 pandemic influenza (pH1N1) by New York City (NYC) public schools. METHODS: From January 25 through February 9, 2010, an online survey was sent to all the 1,632 NYC public schools and principals were asked to participate in the survey or to designate a school nurse or other school official with knowledge of school policies and characteristics to do so. RESULTS: Of 1,633 schools, 376(23%) accessed and completed the survey. Nearly all respondents (99%) implemented at least two NPIs. Schools that had a Flu Response Team (FRT) as a part of school emergency preparedness plan were more likely to implement the NPI guidelines recommended by NYC public health officials than schools that did not have a FRT. Designation of a room for isolating ill students, for example, was more common in schools with a FRT (72%) than those without (53%) (p<0.001). CONCLUSIONS: Implementing an NPI program in a large school system to mitigate the effects of an influenza outbreak is feasible, but there is potential need for additional resources in some schools to increase capacity and adherence to all recommendations. Public health influenza-preparedness plans should include school preparedness planning and FRTs.

Staphylococcus aureus organisms vary in the function of the staphylococcal virulence regulator gene agr. To test for a relationship between agr and transmission in S. aureus, we determined the prevalence and genetic basis of agr dysfunction among nosocomial methicillin-resistant S. aureus (MRSA) in an area of MRSA endemicity. Identical inactivating agr mutations were not detected in epidemiologically unlinked clones within or between hospitals. Additionally, most agr mutants had single mutations, indicating that they were short lived. Collectively, the results suggest that agr dysfunction is adaptive for survival in the infected host but that it may be counteradaptive outside infected host tissues