HIV-1 concentrations in human breast milk before and after weaning.

Concentrations of HIV-1 RNA and DNA in mucosal compartments influence the risk of sexual transmission and mother-to-child transmission of HIV-1. Breast milk production is physiologically regulated such that supply is a function of infant demand, but whether demand also influences HIV-1 dynamics in breast milk is unknown. We tested whether minor and major changes in feeding frequency influence breast milk viral concentrations in 958 HIV-1-infected women and their infants followed, for 24 months during a trial in Lusaka, Zambia. Women were randomized to wean abruptly at 4 months or to continue breast-feeding for a duration of their own choosing. Two weeks after breast-feeding cessation (4.5 months), HIV-1 concentrations in breast milk were substantially higher (median RNA, 2708 copies/ml; DNA, 14 copies/ml) than if breast-feeding continued (median RNA, <50 copies/ml; DNA, <1 copy/ml; P < 0.0001). Among those continuing breast-feeding, HIV-1 concentrations in milk were higher if breast-feeding was nonexclusive (median RNA, 293 copies/ml; DNA, 2 copies/ml; P = 0.0006). Elevated milk viral concentrations after stopping breast-feeding explained higher than expected rates of late postnatal HIV transmission in those who weaned early. Changes in the frequency of breast-feeding peri-weaning and with nonexclusive breast-feeding influenced milk viral concentrations. This may explain the reduced risk of HIV-1 transmission associated with exclusive breast-feeding and why early weaning does not achieve the magnitude of HIV prevention predicted by models. Our results support continuation of maternal antiretroviral drug interventions over the full duration of time when any breast milk exposures may occur after planned weaning.

Detection of low levels of human immunodeficiency virus (HIV) may be critical for early diagnosis of pediatric HIV infection by use of dried blood spots.

We compared a DNA-based assay with a total nucleic acid-based assay for early detection of infant human immunodeficiency virus (HIV) infection. The codetection of DNA and RNA did not result in an overall higher sensitivity compared to that of DNA alone. Discordant results were associated with low levels of HIV DNA, indicating that the sample amount may be critical.

Mortality and virologic outcomes after access to antiretroviral therapy among a cohort of HIV-infected women who received single-dose nevirapine in Lusaka, Zambia.

OBJECTIVES: Single-dose nevirapine (SDNVP) for prevention of mother-to-child HIV transmission selects mutations conferring resistance to nonnucleoside reverse transcriptase inhibitor (NNRTI)-based therapy. We investigated mortality and virologic and clinical outcomes after introduction of antiretroviral treatment (ART) among a cohort of women given SDNVP. METHODS: When ART programs were introduced in 2004 in Lusaka, Zambia, we were completing a trial of infant feeding, which involved following HIV-infected women who received SDNVP between 2001 and 2005. Women still in follow-up or who could be contacted were evaluated for eligibility for ART (CD4 count <200 or <350 and World Health Organization stage >or=3) and started on NNRTI-based therapy if eligible. We compared mortality in the cohort of women before and after ART access, and examined, among women initiating ART, whether virologic response was better allowing a longer time to elapse between SDNVP and treatment initiation. RESULTS: In the cohort of 872 women, mortality more than halved after ART became available (relative hazard = 0.46, 95% confidence interval: 0.23 to 0.91, P = 0.03). Of 161 SDNVP-exposed women followed on NNRTI-based ART, 70.8% suppressed (viral load <400 copies/mL). Only 3 of 8 SDNVP-exposed women (37.5%) <6 months of starting therapy suppressed compared with 13 of 22 (59.1%) who started 6-12 months, 44 of 61 (72.1%) 12-24 months, and 54 of 70 (77.1%) >24 months after exposure (chi2 trend P = 0.01). CONCLUSIONS: Most SDNVP-exposed women respond well to NNRTI-based therapy, but there was an attenuation of therapy efficacy that persisted to 12 months after exposure. Women should be screened for ART eligibility during pregnancy and started on effective regimens before delivery.

Diminished human immunodeficiency virus type 1 DNA yield from dried blood spots after storage in a humid incubator at 37 degrees C compared to -20 degrees C.

Collecting whole blood on filter paper simplifies the processing, transport, and storage of specimens used for the diagnosis of human immunodeficiency virus type 1 (HIV-1) and other tests. Specimens may be collected in tropical or rural areas with minimal facilities for handling specimens. To compare simulated tropical conditions with freezer storage, we examined the stability of HIV-1 DNA in dried blood spots (DBS) stored in humid heat and at -20 degrees C. DBS were created by spotting 50-microl aliquots of whole blood on 903 filter paper. DNA was extracted from DBS at baseline and after 2, 6, or 12 months of storage at -20 degrees C or at 37 degrees C with approximately 85% humidity. The DNA was tested undiluted or diluted using the Amplicor HIV-1 DNA PCR (Roche), version 1.5. Each reaction was scored positive, negative, or indeterminate based on optical density. Results were compared between storage conditions and over time. A total of 1,832 reactions from 916 DBS were analyzed, including 100 DBS at baseline, 418 stored at -20 degrees C, and 398 stored at 37 degrees C. A chi-square test showed fewer positive reactions for DBS stored at 37 degrees C (55%) than for those stored at -20 degrees C (78%) (P < 0.0001). Samples stored at -20 degrees C showed little change in the probability of detection of HIV-1 DNA over time; the odds ratio (OR) was 0.93 after storage for 1 year. Samples stored at 37 degrees C demonstrated a significant change in detection at 1 year (OR, 0.29). We conclude that exposure of DBS to 37 degrees C and high humidity impaired the recovery of HIV-1 DNA from DBS, whereas DNA recovery was preserved when DBS were stored frozen.