Background. It is important, for drug-resistance surveillance, to identify human immunodeficiency virus type 1 (HIV-1) strains that have undergone antiretroviral drug selection.Methods. We compared the prevalence of protease and reverse-transcriptase (RT) mutations in HIV-1 sequences from persons with and without previous treatment with protease inhibitors (PIs), nucleoside RT inhibitors (NRTIs), and nonnucleoside RT inhibitors (NNRTIs). Treatment-associated mutations in protease isolates from 5867 persons and RT isolates from 6247 persons were categorized by whether they were polymorphic (prevalence, >0.5%) in untreated individuals and whether they were established drug-resistance mutations. New methods were introduced to minimize misclassification from transmitted resistance, population stratification, sequencing artifacts, and multiple hypothesis testing.Results. Some 36 established and 24 additional nonpolymorphic protease mutations at 34 positions were related to PI treatment, 21 established and 22 additional nonpolymorphic RT mutations at 24 positions with NRTI treatment, and 15 established and 11 additional nonpolymorphic RT mutations at 15 positions with NNRTI treatment. In addition, 11 PI-associated and 1 NRTI-associated established mutations were polymorphic in viruses from untreated persons.Conclusions. Established drug-resistance mutations encompass only a subset of treatment-associated mutations; some of these are polymorphic in untreated persons. In contrast, nonpolymorphic treatment-associated mutations may be more sensitive and specific markers of transmitted HIV-1 drug resistance.

Eosinophilic meningitis can be the result of noninfectious causes and infectious agents. Among the infectious agents, Angiostrongylus cantonensis and Gnathostoma spinigerum are the most common. Although angiostrongyliasis and gnathostomiasis are not common in the United States, international travel and immigration make these diseases clinically relevant. Both A. cantonensis and G. spinigerum infection can present as severe CNS compromise. Diagnoses of both infections can be challenging and are often clinical because of a paucity of serological assays readily available in the United States. Furthermore, there are conflicting recommendations about treatment for angiostrongyliasis and gnathostomiasis. To further explore the emerging nature of these helminthic infections, a case description and review of A. cantonensis and G. spinigerum infections are presented. The clinical severity of eosinophilic meningitis and diagnosis of these infections are highlighted.

Although TDR has increased significantly in this large cohort, many TDR strains are unlikely to influence the activity of currently preferred first-line ART regimens. The high proportion of DRMs associated with infrequently used regimens combined with the clustering of TDR strains suggest that some TDR strains are being transmitted between ART-naïve individuals.

Barriers to HIV preexposure prophylaxis (PrEP) use have not been well-characterized in people who became HIV-infected, all of whom could have benefited from PrEP. We invited members of Kaiser Permanente Northern California with an HIV diagnosis during 2014-2016, following a negative HIV test in the year prior to diagnosis, to complete a survey assessing barriers to PrEP use prior to HIV diagnosis. We used chi-square tests to identify factors associated with specific barriers, and Cochran-Armitage tests to assess trends in barriers by year of HIV diagnosis. Of 268 patients surveyed, 122 (46%) responded. Median age of respondents was 36, most (84%) were men who have sex with men, and 64% were of minority racial/ethnic background. Thirty-six (30%) had discussed PrEP with a provider, of whom 10 were diagnosed with HIV at PrEP intake. Overall, only 5 (4.1%) had used PrEP, and all 5 discontinued before diagnosis. Among all respondents, the most common barrier to PrEP use was lack of PrEP awareness (51%). Among those aware of PrEP, the most common barriers were cost/insurance concerns (36%) and perceived low risk for HIV (24%). Lack of PrEP awareness ranged from 39% among those aged 25-34 to 88% among those aged <25 (P=0.011), and from 33% among Hispanics to 69% among Blacks (P=0.055). Lack of PrEP awareness decreased from 61% of those diagnosed in 2014 to 37% in 2016 (P=0.032). Increasing awareness and affordability of PrEP, and facilitating accurate assessment of HIV risk, are critical to reducing missed opportunities for PrEP.

Overall STD screening increases were observed after this intervention that included didactic training on the urgency of STD screening needs for HIV+ MSM, a presentation of preintervention clinic STD screening data, and the implementation of self-reported sexual risk assessment. Additional efforts are needed to determine feasible ways to accurately assess the appropriateness of STD screening and success of interventions to improve STD screening.