Search

Background: HIV-exposed uninfected (HEU) infants are a growing population with potentially poor health outcomes. We evaluated morbidity and mortality in HEU formula-fed infants enrolled in the NICHD HPTN 040/PACTG 1043 trial., Methods: Infectious morbidity, mortality and undernutrition were evaluated within a cohort of 1000 HEU infants enrolled between April 2004 and April 2010 in Brazil (n = 766) and South Africa (n = 234) as part of the NICHD/HPTN 040 trial of 3 different antiretroviral regimens to decrease intrapartum HIV vertical transmission., Results: Twenty-three percent of infants had at least 1 infectious serious adverse effect. Infants born to mothers with <12 years of education [adjusted odds ratio (AOR), 2.6; 95% confidence interval [CI], 1.2-5.9), with maternal viral load of >1,000,000 copies/mL at delivery (AOR, 9.9; 95% CI, 1.6-63.1) were more likely to have infectious serious adverse effects. At 6 months, the infant mortality rate per 1000 live births overall was 22 ± 2.6, 9.1 ± 1.8 in Brazil and 64.1 ± 3 in South Africa. Undernutrition and stunting peaked at 1 month of age with 18% having a weight-for-age Z score ≤-2, and 22% with height for Z score ≤-2. The likelihood of infant mortality was greater among infants born in South Africa compared with Brazil (AOR, 6.2; 95% CI, 2.5-15.8), high maternal viral load (AOR, 1.7; 95% CI, 1.01-2.9) and birth weight-for-age Z score ≤-2 (AOR, 5.2; 95% CI, 1.8-14.8)., Conclusions: There were high rates of undernutrition, stunting and infectious serious adverse effect in this study's formula-fed HEU population. Suppressing maternal HIV viral load during the peripartum period may be a modifiable risk factor to decrease infant mortality.

Background: Congenital cytomegalovirus (CMV) infection (cCMV) is an important cause of hearing loss and cognitive impairment. Prior studies suggest that HIV-exposed children are at higher risk of acquiring cCMV. We assessed the presence, magnitude and risk factors associated with cCMV among infants born to HIV-infected women, who were not receiving antiretrovirals during pregnancy., Methods: cCMV and urinary CMV load were determined in a cohort of infants born to HIV-infected women not receiving antiretrovirals during pregnancy. Neonatal urines obtained at birth were tested for CMV DNA by qualitative and reflex quantitative real-time polymerase chain reaction., Results: Urine specimens were available for 992 (58.9%) of 1684 infants; 64 (6.5%) were CMV-positive. Mean CMV load (VL) was 470,276 copies/ml (range: < 200-2,000,000 copies/ml). Among 89 HIV-infected infants, 16 (18%) had cCMV versus 42 (4.9%) of 858 HIV-exposed, uninfected infants (P < 0.0001). cCMV was present in 23.2% of infants with in utero and 9.1% infants with intrapartum HIV infection (P < 0.0001). Rates of cCMV among HIV-infected infants were 4-fold greater (adjusted OR, 4.4; 95% CI: 2.3-8.2) and 6-fold greater among HIV in utero-infected infants (adjusted OR, 6; 95% CI: 3-12.1) compared with HIV-exposed, uninfected infants. cCMV was not associated with mode of delivery, gestational age, Apgar scores, 6-month infant mortality, maternal age, race/ethnicity, HIV viral load or CD4 count. Primary cCMV risk factors included infant HIV-infection, particularly in utero infection., Conclusion: High rates of cCMV with high urinary CMV VL were observed in HIV-exposed infants. In utero HIV infection appears to be a major risk factor for cCMV in infants whose mothers have not received combination antiretroviral therapy in pregnancy.

Background: The presence of antiretroviral drug-associated resistance mutations (DRMs) may be particularly problematic in human immunodeficiency virus (HIV)-infected pregnant women as it can lead to mother-to-child transmission (MTCT) of resistant HIV strains. This study evaluated the prevalence and the effect of antiretroviral DRMs in previously untreated mother-infant pairs., Methods: A case-control design of 1:4 (1 transmitter to 4 nontransmitters) was utilized to evaluate DRMs as a predictor of HIV MTCT in specimens obtained from mother-infant pairs. ViroSeq HIV-1 genotyping was performed on mother-infant specimens to assess for clinically relevant DRMs., Results: One hundred forty infants acquired HIV infection; of these, 123 mother-infant pairs (88%) had specimens successfully amplified using ViroSeq and assessed for drug resistance genotyping. Additionally, 483 of 560 (86%) women who did not transmit HIV to infants also had samples evaluated for DRMs. Sixty-three of 606 (10%) women had clinically relevant DRMs; 12 (2%) had DRMs against >1 drug class. Among 123 HIV-infected infants, 13 (11%) had clinically relevant DRMs, with 3 (2%) harboring DRMs against >1 drug class. In univariate and multivariate analyses, DRMs in mothers were not associated with increased HIV MTCT (adjusted odds ratio, 0.8 [95% confidence interval, .4-1.5]). Presence of DRMs in transmitting mothers was strongly associated with DRM presence in their infants (P < .001)., Conclusions: Preexisting DRMs were common in untreated HIV-infected pregnant women, but did not increase the risk of HIV MTCT. However, if women with DRMs are not virologically suppressed, they may transmit resistant mutations, thus complicating infant management.

Background: Sexually transmitted infections (STIs) including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Treponema pallidum (TP), and cytomegalovirus (CMV) may lead to adverse pregnancy and infant outcomes. The role of combined maternal STIs in HIV mother-to-child transmission (MTCT) was evaluated in mother-infant pairs from NICHD HPTN 040., Methodology: Urine samples from HIV-infected pregnant women during labor were tested by polymerase chain reaction (PCR) for CT, NG, and CMV. Infant HIV infection was determined by serial HIV DNA PCR testing. Maternal syphilis was tested by VDRL and confirmatory treponemal antibodies., Results: A total of 899 mother-infant pairs were evaluated. Over 30% had at least one of the following infections (TP, CT, NG, and/or CMV) detected at the time of delivery. High rates of TP (8.7%), CT (17.8%), NG (4%), and CMV (6.3%) were observed. HIV MTCT was 9.1% (n = 82 infants). HIV MTCT was 12.5%, 10.3%, 11.1%, and 26.3% among infants born to women with CT, TP, NG or CMV respectively. Forty-two percent of HIV-infected infants were born to women with at least one of these 4 infections. Women with these infections were nearly twice as likely to have an HIV-infected infant (aOR 1.9, 95% CI 1.1-3.0), particularly those with 2 STIs (aOR 3.4, 95% CI 1.5-7.7). Individually, maternal CMV (aOR 4.4 1.5-13.0) and infant congenital CMV (OR 4.1, 95% CI 2.2-7.8) but not other STIs (TP, CT, or NG) were associated with an increased risk of HIV MTCT., Conclusion: HIV-infected pregnant women identified during labor are at high risk for STIs. Co-infection with STIs including CMV nearly doubles HIV MTCT risk. CMV infection appears to confer the largest risk of HIV MTCT., Trial Registration: NCT00099359.

Background: Sexually transmitted infections (STIs) in pregnancy such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) may lead to adverse infant outcomes., Methods: Individual urine specimens from HIV-infected pregnant women diagnosed with HIV during labor were collected at the time of infant birth and tested by polymerase chain reaction for CT and NG. Infant HIV infection was determined at 3 months with morbidity/mortality assessed through 6 months., Results: Of 1373 maternal urine samples, 277 (20.2%) were positive for CT and/or NG; 249 (18.1%) for CT, 63 (4.6%) for NG and 35 (2.5%) for both CT and NG. HIV infection was diagnosed in 117 (8.5%) infants. Highest rates of adverse outcomes (sepsis, pneumonia, congenital syphilis, septic arthritis, conjunctivitis, low birth weight, preterm delivery and death) were noted in infants of women with CT and NG (23/35, 65.7%) compared with NG (16/28, 57.1%), CT (84/214, 39.3%) and no STI (405/1096, 37%, P = 0.001). Death (11.4% vs. 3%, P = 0.02), low birth weight (42.9% vs. 16.9%, P = 0.001) and preterm delivery (28.6% vs. 10.2%, P = 0.008) were higher among infants of CT and NG-coinfected women. Infants who had any adverse outcome and were born to women with CT and/or NG were 3.5 times more likely to be HIV infected after controlling for maternal syphilis (odds ratio: 3.5, 95% confidence interval: 1.4-8.3). By adjusted multivariate logistic regression, infants born to mothers with any CT and/or NG were 1.35 times more likely to have an adverse outcome (odds ratio, 1.35; 95% confidence interval, 1.03-1.76)., Conclusions: STIs in HIV-infected pregnant women are associated with adverse outcomes in HIV-exposed infected and uninfected infants.

Background: Sexually transmitted infections (STIs) such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) can lead to adverse pregnancy and neonatal outcomes. The prevalence of STIs and its association with HIV mother-to-child transmission (MTCT) were evaluated in a substudy analysis from a randomized, multicenter clinical trial., Methodology: Urine samples from HIV-infected pregnant women collected at the time of labor and delivery were tested using polymerase chain reaction testing for the detection of CT and NG (Xpert CT/NG; Cepheid, Sunnyvale, CA). Infant HIV infection was determined by HIV DNA polymerase chain reaction at 3 months., Results: Of the 1373 urine specimens, 249 (18.1%) were positive for CT and 63 (4.6%) for NG; 35 (2.5%) had both CT and NG detected. Among 117 cases of HIV MTCT (8.5% transmission), the lowest transmission rate occurred among infants born to CT- and NG-uninfected mothers (8.1%) as compared with those infected with only CT (10.7%) and both CT and NG (14.3%; P = 0.04). Infants born to CT-infected mothers had almost a 1.5-fold increased risk for HIV acquisition (odds ratio, 1.47; 95% confidence interval, 0.9-2.3; P = 0.09)., Conclusions: This cohort of HIV-infected pregnant women is at high risk for infection with CT and NG. Analysis suggests that STIs may predispose to an increased HIV MTCT risk in this high-risk cohort of HIV-infected women.

Background: Untreated syphilis during pregnancy is associated with spontaneous abortion, stillbirth, prematurity and infant mortality. Syphilis may facilitate HIV transmission, which is especially concerning in low- and middle-income countries where both diseases are common., Methods: We performed an analysis of data available from NICHD/HPTN 040 (P1043), a study focused on the prevention of intrapartum HIV transmission to 1684 infants born to 1664 untreated HIV-infected women. This analysis evaluates risk factors and outcomes associated with a syphilis diagnosis in this cohort of HIV-infected women and their infants., Results: Approximately, 10% of women (n=171) enrolled had serological evidence of syphilis without adequate treatment documented and 1.4% infants (n=24) were dually HIV and syphilis infected. Multivariate logistic analysis showed that compared with HIV-infected women, co-infected women were significantly more likely to self-identify as non-white (adjusted odds ratio [AOR] 2.5, 95% CI: 1.5-4.2), to consume alcohol during pregnancy (AOR 1.5, 95% CI: 1.1-2.1) and to transmit HIV to their infants (AOR 2.1, 95% CI: 1.3-3.4), with 88% of HIV infections being acquired in utero. As compared with HIV-infected or HIV-exposed infants, co-infected infants were significantly more likely to be born to mothers with venereal disease research laboratory titers≥1:16 (AOR 3, 95% CI: 1.1-8.2) and higher viral loads (AOR 1.5, 95% CI: 1.1-1.9). Of 6 newborns with symptomatic syphilis, 2 expired shortly after birth, and 2 were HIV-infected., Conclusion: Syphilis continues to be a common co-infection in HIV-infected women and can facilitate in utero transmission of HIV to infants. Most infants are asymptomatic at birth, but those with symptoms have high mortality rates.

Mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) infection remains an important cause of new HIV infections worldwide, especially in low and middle-resource limited countries. Safety data from studies involving pregnant women and prenatal antiretroviral (ARV) exposure are still needed once these studies are often small and with a limited duration to assess adverse drug reactions (ADR). The aim of this study was to estimate the incidence of ADR related to the use of antiretroviral therapy (ART) in pregnant women in two referral centers in Rio de Janeiro State. A prospective study was carried out from February 2005 to May 2006. Women were classified according to their ART status during pregnancy diagnosis: ARV-experienced (ARTexp) or ARV-naïve (ARTn). Two hundred fourteen HIV-infected pregnant women were included: 36 ARTexp and 178 ARTn. ARTexp women have not experienced ADR. Among ARTn, 20.2% presented ADR. Incidence rate of ADR was 70.8 per 1000 person-months and the most common ADRs observed were: gastrointestinal (belly or abdominal cramps, diarrhea, nausea and vomit) in 16.3%, cutaneous (pruritus and rash) in 6.2%, anemia (2.2%) and hepatitis (1.7%). The frequency of obstetrical complications, pre-term delivery, low birth weight and birth abnormalities was low in this population. ADRs ranged from mild to moderate intensity, none of them being potentially fatal. Only in a few cases it was necessary to discontinue ART. In conclusion, the high effectiveness of ARV for HIV prevention of MTCT (PMTCT) overcomes the risk of ADR., (Copyright © 2014 Elsevier Editora Ltda. All rights reserved.)

Objectives: To describe the access to the interventions for the prevention of Human Immunodeficiency Virus (HIV) mother to child transmission and mother to child transmission rates in the outskirts of Rio de Janeiro, from 1999 to 2009., Methods: This is a retrospective cohort study. Prevention of HIV mother to child transmission interventions were accessed and mother to child transmission rates were calculated., Results: The study population is young (median: 26 years; interquartile range: 22.0-31.0), with low monthly family income (40.4% up to one Brazilian minimum wage) and schooling (62.1% less than 8 years). Only 47.1% (n=469) knew the HIV status of their partner; of these women, 39.9% had an HIV-seronegative partner. Among the 1259 newborns evaluated, access to the antenatal, intrapartum and postpartum prevention of HIV mother to child transmission components occurred in 59.2%, 74.2%, and 97.5% respectively; 91.0% of the newborns were not breastfed. Overall 52.7% of the newborns have benefited from all the recommended interventions. In subsequent pregnancies (n=289), 67.8% of the newborns received the full package of interventions. The overall rate of HIV vertical transmission was 4.7% and the highest annual rate occurred in 2005 (7.4%), with no definite trend in the period., Conclusions: Access to the full package of interventions for the prevention of HIV vertical transmission was low, with no significant trend of improvement over the years. The vertical transmission rates observed were higher than those found in reference services in the municipality of Rio de Janeiro and in the richest regions of the country., (Copyright © 2014. Published by Elsevier Editora Ltda.)

Objective: To evaluate cases of mother-to-child transmission of HIV-1 at multiple sites in Latin America and the Caribbean in terms of missed opportunities for prevention., Methods: Pregnant women infected with HIV-1 were eligible for inclusion if they were enrolled in either the NISDI Perinatal or LILAC protocols by October 20, 2009, and had delivered a live infant with known HIV-1 infection status after March 1, 2006., Results: Of 711 eligible mothers, 10 delivered infants infected with HIV-1. The transmission rate was 1.4% (95% CI, 0.7-2.6). Timing of transmission was in utero or intrapartum (n=5), intrapartum (n=2), intrapartum or early postnatal (n=1), and unknown (n=2). Possible missed opportunities for prevention included poor control of maternal viral load during pregnancy; late initiation of antiretrovirals during pregnancy; lack of cesarean delivery before labor and before rupture of membranes; late diagnosis of HIV-1 infection; lack of intrapartum antiretrovirals; and incomplete avoidance of breastfeeding., Conclusion: Early knowledge of HIV-1 infection status (ideally before or in early pregnancy) would aid timely initiation of antiretroviral treatment and strategies designed to prevent mother-to-child transmission. Use of antiretrovirals must be appropriately monitored in terms of adherence and drug resistance. If feasible, breastfeeding should be completely avoided. Presented in part at the XIX International AIDS Conference (Washington, DC; July 22-27, 2012); abstract WEPE163., (Copyright © 2012. Published by Elsevier Ireland Ltd.)

Adherence to antiretrovirals by pregnant women (and postpartum women if breastfeeding) is crucial to effectively decrease maternal viral load and decrease the risk of mother-to-child transmission of HIV. Our objectives were to describe self-reported adherence to antiretrovirals during the antepartum (after 22 weeks of pregnancy) and postpartum periods (6-12 weeks and 6 months), and identify predictors of adherence among HIV-infected women enrolled and followed in a prospective cohort study from June 2008 to June 2010 at multiple sites in Latin America. Adherence was evaluated using the number of missed and expected doses during the 3 days before the study visit. At the pre-delivery visit, 340 of 376 women (90%) reported perfect adherence. This rate significantly decreased by 6-12 weeks (171/214 [80%]) and 6 months postpartum (163/199 [82%], p<0.01). The odds for less than perfect adherence at the pre-delivery visit was significantly higher for pregnant women with current tobacco use (odds ratio [OR]=2.9, 95% confidence interval [CI]: 1.46-6.14; p=0.0029). At 6-12 weeks postpartum, the probability of non-perfect adherence increased by 6% for each 1 year increase in age (OR=1.06, 95% CI: 1.00-1.12, p=0.0497). At 6 months postpartum, the odds of nonperfect adherence was higher for those who were currently using alcohol (OR=3.04, 95% CI: 1.34-6.90; p=0.0079). Although a self-report measure of adherence based on only 3 days may lead to overestimation of actual adherence over time, women with perfect adherence had lower viral loads and higher CD4 counts. Adherence to antiretrovirals decreased significantly postpartum. Interventions should target women at high risk for lower adherence during pregnancy and postpartum, including tobacco and alcohol users.

Background: The safety and efficacy of adding antiretroviral drugs to standard zidovudine prophylaxis in infants of mothers with human immunodeficiency virus (HIV) infection who did not receive antenatal antiretroviral therapy (ART) because of late identification are unclear. We evaluated three ART regimens in such infants., Methods: Within 48 hours after their birth, we randomly assigned formula-fed infants born to women with a peripartum diagnosis of HIV type 1 (HIV-1) infection to one of three regimens: zidovudine for 6 weeks (zidovudine-alone group), zidovudine for 6 weeks plus three doses of nevirapine during the first 8 days of life (two-drug group), or zidovudine for 6 weeks plus nelfinavir and lamivudine for 2 weeks (three-drug group). The primary outcome was HIV-1 infection at 3 months in infants uninfected at birth., Results: A total of 1684 infants were enrolled in the Americas and South Africa (566 in the zidovudine-alone group, 562 in the two-drug group, and 556 in the three-drug group). The overall rate of in utero transmission of HIV-1 on the basis of Kaplan-Meier estimates was 5.7% (93 infants), with no significant differences among the groups. Intrapartum transmission occurred in 24 infants in the zidovudine-alone group (4.8%; 95% confidence interval [CI], 3.2 to 7.1), as compared with 11 infants in the two-drug group (2.2%; 95% CI, 1.2 to 3.9; P=0.046) and 12 in the three-drug group (2.4%; 95% CI, 1.4 to 4.3; P=0.046). The overall transmission rate was 8.5% (140 infants), with an increased rate in the zidovudine-alone group (P=0.03 for the comparisons with the two- and three-drug groups). On multivariate analysis, zidovudine monotherapy, a higher maternal viral load, and maternal use of illegal substances were significantly associated with transmission. The rate of neutropenia was significantly increased in the three-drug group (P<0.001 for both comparisons with the other groups)., Conclusions: In neonates whose mothers did not receive ART during pregnancy, prophylaxis with a two- or three-drug ART regimen is superior to zidovudine alone for the prevention of intrapartum HIV transmission; the two-drug regimen has less toxicity than the three-drug regimen. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development [NICHD] and others; ClinicalTrials.gov number, NCT00099359.).

Background: Information is lacking on outcomes in HIV-infected Brazilian women with CD4(+) T-cell counts >200 cells/mm(3) who initiate HAART for the prevention of mother-to-child transmission, and discontinue after delivery., Methods: Clinical event rates after postpartum HAART discontinuation were calculated for all WHO stage 2-3 events, as well as for HIV progression warranting HAART re-initiation, defined by a WHO stage 4 event and/or CD4(+) T-cell decrease to ≤200 cells/mm(3). Predictors of the WHO stage 2-3 events and HIV progression outcomes were evaluated with Cox's proportional hazards models., Results: A total of 120 women were followed for a mean of 1.5 years after delivery. Overall, 26 women had 30 events as follows: 20 developed WHO stage 2-3 events, yielding an incidence rate of 13/100 person-years (PY; 95% CI 8-20); 10 developed HIV progression requiring HAART re-initiation (incidence ratio 6/100 PY, 95% CI 3-11). Among progressors, a single woman developed a WHO stage 4 clinical event and the remainder had CD4(+) T-cell decreases. Women who had baseline CD4(+) T-cell counts between 200-500 cells/mm(3) had a hazard ratio for WHO stage 2-3 events of 2.5 compared to women with baseline ≥500 cells/mm(3) (95% CI 1.0-6.3; P=0.05). The only significant predictor of HIV progression was baseline CD4(+) T-cell count (hazard ratio 0.99, 95% CI 0.98-0.99; P=0.02)., Conclusions: In this observational study, a baseline CD4(+) T-cell count <500 cells/mm(3) was associated with an increased risk of postpartum WHO stage 2-3 clinical events and HIV disease progression. Randomized studies are needed to further evaluate the effect of postpartum treatment discontinuation on maternal health.

Objective: To assess the feasibility of HIV rapid testing for pregnant women at maternity hospital admission and of subsequent interventions to reduce perinatal HIV transmission., Methods: Study based on a convenience sample of women unaware of their HIV serostatus when they were admitted to delivery in public maternity hospitals in Rio de Janeiro and Porto Alegre, Brazil, between March 2000 and April 2002. Women were counseled and tested using the Determine HIV1/2 Rapid Test. HIV infection was confirmed using the Brazilian algorithm for HIV infection diagnosis. In utero transmission of HIV was determined using HIV-DNA-PCR. There were performed descriptive analyses of sociodemographic data, number of previous pregnancies and abortions, number of prenatal care visits, timing of HIV testing, HIV rapid test result, neonatal and mother-to-child transmission interventions, by city studied., Results: HIV prevalence in women was 6.5% (N=1,439) in Porto Alegre and 1.3% (N=3.778) in Rio de Janeiro. In Porto Alegre most of women were tested during labor (88.7%), while in Rio de Janeiro most were tested in the postpartum (67.5%). One hundred and forty-four infants were born to 143 HIV-infected women. All newborns but one in each city received at least prophylaxis with oral zidovudine. It was possible to completely avoid newborn exposure to breast milk in 96.8% and 51.1% of the cases in Porto Alegre and Rio de Janeiro, respectively. Injectable intravenous zidovudine was administered during labor to 68.8% and 27.7% newborns in Porto Alegre and Rio de Janeiro, respectively. Among those from whom blood samples were collected within 48 hours of birth, in utero transmission of HIV was confirmed in 4 cases in Rio de Janeiro (4/47) and 6 cases in Porto Alegre (6/79)., Conclusions: The strategy proved feasible in maternity hospitals in Rio de Janeiro and Porto Alegre. Efforts must be taken to maximize HIV testing during labor. There is a need of strong social support to provide this population access to health care services after hospital discharge.

Background: The optimal neonatal antiretroviral (ARV) regimen for prevention of HIV mother-to-child transmission (MTCT) is unknown for infants born to mothers who receive no ARVs during pregnancy., Methods: As part of a protocol comparing the efficacy of 3 neonatal ARV regimens in preventing HIV-1 MTCT in neonates born to mothers who receive no prenatal treatment with ARVs, we devised a 3-dose nevirapine (NVP) regimen with the goal of maintaining the NVP plasma concentration >100 ng/mL (10 times the in vitro median inhibitory concentration of 10 ng/mL) during the first 2 weeks of life. NVP concentrations were measured in 14 newborns participating in a pharmacokinetics substudy during the second week of life and in single samples from 30 more newborns on day 10 to 14., Results: The median NVP elimination half-life was 30.2 hours (range: 17.8 to 50.3 hours). The NVP concentration remained greater than the target of 100 ng/mL in all samples collected through day 10 of life. By day 14, more than half of the newborns in the pharmacokinetic substudy had NVP levels <100 ng/mL, although only 1 neonate had no detectable NVP., Conclusion: Although this regimen failed to meet our 100-ng/mL target, it did maintain detectable NVP concentrations in nearly all newborns through the end of the second week of life and is to be used in the parent efficacy protocol.

Replication of the human immunodeficiency virus type 1 (HIV-1) isolate MN in CEM cells was less neutralized by the plasma from the mothers of infected children (MIC) in comparison with the plasma from the mothers of uninfected children (MUC). Significantly higher neutralization titres were observed for the sera from MUCs compared with MICs, and only the sera from MUC showed 100% neutralization of the HIV-1 MN strain. We suggest that a simple neutralization assay as described here could be useful in prognostic analyses.