CROI 2015 Program and Abstracts

Abstract Listing

Oral Abstracts

Methods: Three household based surveys of individuals age 15 to 59 took place between September 2012 and November 2013 in Ndhiwa (Kenya), Chiradzulu (Malawi) and Mbolongwane/Eshowe (South Africa). Following consent, all individuals were interviewed and tested for HIV. Women reported their pregnancy and breastfeeding status and the result of their last HIV test. All individuals found HIV-positive were tested for viral load and CD4, regardless of the ART status. At the time of the survey, PMTCT option A was implemented in Kenya, B+ in Malawi and B in South Africa. Infection during PBF was defined as a positive-HIV test among a PBF woman who was unaware of her status and reported a negative HIV test during Ante Natal Care (ANC). Results: Among the 21,782 individuals eligible, 12,461 were women and of them, 11,550(92.7%) were included in the surveys. More women were PBF in Kenya (37.8%, 1,413/3,760) and in Malawi (33.8%, 1,444/4,275) than in South Africa (12.5%, 439/3,515). Among them, HIV prevalence ranged from 13.4% in Malawi to 22.2% in Kenya and 23.0% in South Africa. The proportion of PBF women with viral load<1,000copies/ml was higher in South Africa (63.4%;95%CI 65.5-72.3) and Malawi (72.3%; 95%CI 65.5-78.2) compare to Kenya (27.3%; 95%CI 22.5-72.3). Of the breastfeeding women with viral load >1,000copies/mL, 58.6% (95%CI 52.0-65.0) were not diagnosed for HIV at the time of the survey. This proportion was similar across sites (p=0.16). A total of 103(4.1%) breastfeeding women were infected during pregnancy or breastfeeding. This proportion was higher in Kenya (6.5%) than in South Africa (4.3%) and Malawi (1.9%). These new infections accounted for 37.5% (95%CI 31.5-44.4) of the HIV-positive breastfeeding women with viral load>1,000 copies/ml. Conclusions: Viral suppression at population level among PBF women ranged from 27 to 72%. Our analysis showed that the majority of HIV+ PBF women with viral load>1,000cp/mL were undiagnosed which could be partly due to infection after HIV testing at ANC. To identify those women and to prevent transmission or at least to ensure early diagnosis of their infants, repeated HIV-testing should be implemented until the end of breastfeeding. 33 Delayed HIV Detection in Infants Exposed to ARV Prophylaxis During Breastfeeding Caroline C. King 1 ; Julie A. Nelson 2 ; Carrie Ziemniak 3 ; Michael G. Hudgens 2 ; GeraldTegha 4 ; Charles S. Chasela 5 ; Denise J. Jamieson 1 ; Deborah Persaud 3 ; Charles M. van der Horst 2 ; Athena P. Kourtis 1 1 US Centers for Disease Control and Prevention (CDC), Atlanta, GA, US; 2 University of North Carolina at Chapel Hill, Chapel Hill, NC, US; 3 Johns Hopkins University, Baltimore, MD, US; 4 UNC Project, Lilongwe, Malawi; 5 University of Witwatersrand, Johannesburg, South Africa Background: We reported on the effectiveness of 28 weeks of infant nevirapine or maternal antiretrovirals in preventing HIV transmission during breastfeeding from a randomized trial of 2369 mother-infant pairs: the Breastfeeding, Antiretrovirals and Nutrition (BAN) study. After counseling on breastfeeding cessation and stopping the antiretroviral intervention, 28 infections were detected from 29 to 48 weeks: 13 on infant nevirapine arm (n=852), 9 on maternal ARV arm (n=849), and 6 on control arm (n=668). To determine whether the infections detected after 28 weeks occurred during the breastfeeding and antiretroviral intervention phase but had delayed detection on the antiretroviral arms, we performed ultrasensitive HIV testing on stored infant PBMC specimens. Methods: Infants in the BAN study were tested for HIV DNA via the Roche Amplicor 1.5 assay on whole blood at birth, 2, 12, 28 and 48 weeks, and, to narrow the window of transmission, dried blood spots from intervening visits were tested. For this substudy, ultrasensitive (droplet digital PCR) HIV testing was performed on infants with HIV infections first detected after 28 weeks and stored PBMC specimens at 24 weeks (n=9). Results: All three infants tested on the infant nevirapine arm had detectable HIV DNA at 24 weeks, compared to 2 of 4 infants on the maternal ARV and 1 of 2 on the control arms. For infants with detectable HIV at 24 weeks, the median delay in detection between the ultrasensitive and routine assays was 18.3 weeks for the nevirapine arm, 15.4 weeks for the maternal arm, and 9.4 weeks for the control arm. There were no significant differences in maternal viral load or reported antiretroviral adherence between arms for the 9 infants with ultrasensitive testing. None of the 3 infants on the nevirapine arm harbored de novo nevirapine resistance mutations. Ultrasensitive HIV DNA assay results on 9 infants who first tested HIV-positive by sensitive assay after reported breastfeeding cessation and stopping the postnatal ARV intervention by 28 weeks.

Oral Abstracts

* Infant HIV testing during the BAN Study follow-up was done on whole blood collected at birth, 2, 12, 28 and 48 weeks with a qualitative Roche Amplicor 1.5 DNA PCR assay (Roche Molecular Systems, Pleasanton, CA, USA). For positive infants, the window of HIV transmission was later narrowed by testing dried blood-spot specimens from interim visits for HIV DNA by Roche DNA assay or RNA using Gen-Probe Aptima HIV-1 assay. † Mutation seen in mother and infant. Conclusions: Using an ultrasensitive assay, extremely low HIV DNA concentrations were detected in 6 of 9 (66%) infants up to 22 weeks earlier than by standard testing . The prolonged inability to detect HIV DNA of routine sensitive assays in the context of postnatal ARV prophylaxis suggests that early antiretrovirals restrict HIV replication sufficiently to lead to missed diagnosis. Late detection of HIV infections also suggests that repeated virologic testing beyond the WHO recommendation of 6 weeks after breastfeeding cessation is warranted. Ultrasensitive testing may allow for earlier antiretroviral treatment, which might modify establishment of HIV reservoirs.

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CROI 2015