HSV-2 plays an important role in the acquisition of HIV among women. Efforts to implement known HSV-2 control measures, as well as identify additional measures to control HSV-2, are urgently needed to curb the spread of HIV.

CRF01_AE and subtype B have dominated the HIV-1 epidemic in Thailand since 1989. We reported a new circulating recombinant form of HIV-1, CRF15_01B, as well as other unique CRF01_AE/B recombinants among prevalent HIV infections in Thailand. We sought to study this challenging molecular picture through assessment of subtypes among recent HIV-1 seroconverters in northern Thai drug users. A total of 847 HIV-1 seronegative drug users (342 IDU and 505 non-IDU) were enrolled, from 1999 to 2002, in a prospective study; 39 HIV-1 incident cases were identified and characteristics were collected. The overall HIV-1 incidence rate was 2.54/100PY, but it was 10.0/100PY among male IDU. HIV was strongly associated with injection history; 38 of 39 seroconverters gave a history of IDU. A near full-length genome of HIV-1 was recovered by PCR amplification and sequenced from peripheral mononuclear cell extracted DNA of 38 seroconverters. Phylogenetic analysis revealed that 33 (86.8%) were CRF01_AE and 5 (13.2%) were CRF01_AE/B recombinants. These recombinants had different structure but shared some common breakpoints, indicating an ongoing recombination process. Recombinant infection increased with year of sampling (0 to 57.1%). The molecular epidemiology of HIV-1 among drug users in northern Thailand has thus entered a new era. CRF01_AE remains predominant while pure subtype B is becoming rare, and now a substantial component of the epidemic. These findings support the need for CRF01_AE and subtype B components in clade-matched vaccine strategies for Thai phase III trials. Ongoing molecular surveillance of circulating HIV-1 strains is imperative for the evaluation of HIV vaccine efficacy.

The authors sought to determine sociodemographic and sexual and drug use risk factors for HIV infection among drug users in northern Thailand adjacent to the Golden Triangle. The authors enrolled patients admitted for inpatient drug detoxification at one treatment center in northern Thailand and studied HIV risks and prevalence using an interviewer-administered questionnaire and serum collection with HIV pretest and posttest counseling. Between February 1, 1999 and January 31, 2000, 1865 patients admitted for opiate and methamphetamine dependence completed study procedures. Overall HIV prevalence was 10.3%: 30.0% among 513 injection drug users (IDUs) and 2.8% among non-IDUs (OR = 14.8, 95% CI: 10.2, 21.6). HIV seroprevalence was 2.4% among exclusive methamphetamine users (98% of whom are non-IDUs) and 3.4% among opium smokers. Injection drug use was the dominant risk factor in multivariate models. Although Thailand is widely recognized as having a successful national response to the heterosexual HIV epidemic, seroprevalence in IDUs remains high. Despite a sharp increase of non-IDUs admitted to the drug treatment center, HIV infection and risks remained high among IDUs in northern Thailand. HIV prevention campaigns need to focus on IDUs and to implement harm reduction strategies to reduce transmission to IDUs and further contain the HIV epidemic in Thailand.

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Objective To describe darunavir pharmacokinetics with once and twice daily dosing during pregnancy and postpartum in HIV-infected women. Design Women were enrolled in International Maternal Pediatric Adolescent AIDS Clinical Trials Network Protocol P1026s, a prospective, non-blinded study of antiretroviral pharmacokinetics in HIV-infected pregnant women that included separate cohorts receiving darunavir/ritonavir dosed at either 800 mg/100 mg once daily or 600 mg/100 mg twice daily. Methods Intensive steady-state 12 or 24 hour pharmacokinetic profiles were performed during the second trimester, third trimester and postpartum. Darunavir was measured using high performance liquid chromatography (detection limit: 0.09 μg/mL). Results Pharmacokinetic data were available for 64 women (30 once daily and 34 twice daily dosing). Median darunavir area under the concentration-time curve (AUC) and maximum concentration (Cmax) were significantly reduced during pregnancy with both dosing regimens compared to postpartum, while the last measurable concentration (Clast) was also reduced during pregnancy with once daily darunavir. Darunavir AUC with once daily dosing was reduced by 38% during the second trimester and by 39% during the third trimester. With twice daily dosing, darunavir AUC was reduced by 26% in both trimesters. The median (range) ratio of cord blood/maternal delivery darunavir concentration in 32 paired samples was 0.18 (range: 0 – 0.82). Conclusion Darunavir exposure is reduced by pregnancy. In order to achieve darunavir plasma concentrations during pregnancy equivalent to those seen in non-pregnant adults, an increased twice daily dose may be necessary. This may be especially important for treatment-experienced women who may have developed antiretroviral resistance mutations.