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Pre-exposure prophylaxis (PrEP) for prevention of HIV infection has demonstrated efficacy in randomized controlled trials as well as in demonstration projects. For PrEP implementation to result in significant reductions in HIV incidence for men who have sex with men (MSM) in the United States, sufficient access to PrEP care and continued engagement outside of demonstration projects is required. We report the results of a follow-up survey of 173 former participants from the Miami and San Francisco sites of the U.S. PrEP Demo Project, administered 4–6 months after study completion. Survey respondents continued to frequently access medical care and had a high incidence of sexually transmitted infections after completion of the Demo Project, indicating ongoing sexual risk behavior. Interest in continuing PrEP was high, with 70.8% indicating they were “very interested” in continuing PrEP. Among respondents, 39.9% reported continuation of PrEP following completion of the Demo Project, largely through their primary care providers and frequently at low or no cost. Variability in access and engagement was seen, with participants from the San Francisco site, those with medical insurance, and those with a primary care provider at the end of the Demo Project more likely to successfully obtain PrEP medication. Two respondents reported HIV seroconversion in the period between study completion and the follow-up survey. Additional effort to increase equitable access to PrEP outside of demonstration projects is needed to realize the potential impact of this evidence-based prevention intervention.

Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) egg development and its relation to environmental parameters is an understudied aspect of vector biology. Although several studies have illustrated the dramatic effects of temperature on egg development, egg hatching dynamics remain unclear. The objective of this study was to expose An. gambiae eggs to various temperatures for different lengths of time and determine the impact on egg development and hatching count. Batches of mosquito eggs (n = 30 eggs/replicate) were incubated under moist conditions at temperatures of 12, 22, 27, 33, and 42 degrees C for intervals of 1, 3, 7, and 10 days. After that, they were flooded with distilled water at 27 degrees C, and hatching counts were observed for up to 7 days. Mosquito eggs held at 22 and 27 degrees C had the highest overall mean hatching count. During early incubation periods, eggs held at 33 degrees C had hatching counts comparable to 22 and 27 degrees C, but counts decreased drastically during later incubation periods. Temperatures of 12 and 42 degrees C reduced mosquito egg viability, because few eggs hatched in these temperature regimes. Other experiments revealed that during early embryonic development, temperature had a major effect on the developing embryo, while later in embryonic development it had no dramatic effect. Microscopic observation of the An. gambiae embryo showed that extreme low and high temperatures affected the normal development of the embryo. A regression model was developed to describe the effect of incubation temperature and incubation period on egg hatching counts, which demonstrated that the optimum temperature for egg hatching ranges from 24 to 30 degrees C, irrespective of incubation period. The interaction between temperature and time period may have implications for dry-season survival and climate-based models of malaria risk.

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