CMV infection in a cohort of HIV-exposed infants born to mothers receiving antiretroviral therapy during pregnancy and breastfeeding

Antiretroviral therapy has been shown to reduce rates of congenital CMV infection. Little information is available on the possible impact of antiretroviral therapy on postnatal breastfeeding-associated CMV infection acquisition. A cohort of 89 HIV-infected mothers and their children was studied. Women received antiretroviral therapy from week 25 of gestation until 6 months postpartum or indefinitely if meeting the criteria for treatment. All women were evaluated for CMV IgG presence and CMV DNA in breast milk. Children were tested for CMV infection by either the presence of IgM or the presence of CMV DNA in plasma at 1, 6 and 12 months and by the presence of IgG at 24 months. All mothers had high titers of CMV DNA in breast milk (5.7 log at Month 1 and 5.1 log at Month 6). Cumulative CMV infection rates were 60.3 % at Month 6, 69 % at Month 12 and 96.4 % at Month 24. There was a significant negative correlation between the duration of antiretroviral treatment during pregnancy and levels of CMV DNA in breast milk at Month 1 (P = 0.033). There was a trend for a correlation between high titers of CMV DNA in breast milk at 6 months and CMV infection at 6 months (P = 0.069). In this cohort, more than 95 % of the children had acquired CMV infection by 2 years of age. Besides breastfeeding, which played a major role, also horizontal transmission between 1 and 2 years was certainly relevant in determining CMV infection acquisition.

Virological Response and Drug Resistance 1 and 2 Years Post-Partum in HIV-Infected Women Initiated on Life-Long Antiretroviral Therapy in Malawi

The objective of this study was to determine the virological response and the possible emergence of drug resistance at 1 and 2 years postpartum in HIV-positive pregnant women enrolled under the Option B approach and meeting the criteria for treatment. In the study, women with baseline CD4(+) <350/mm(3) received a combination of stavudine, lamivudine, and nevirapine during pregnancy (from week 25 of gestation) and continued it indefinitely after delivery. HIV-RNA was measured at 12 and 24 months postpartum. Drug resistance mutations were assessed in those with HIV-RNA >50 copies/ml. Baseline resistance mutations were assessed in the entire cohort. A total of 107 women were studied. At baseline, resistance mutations were seen in 6.6% of the women. At 12 months, 26.7% of the women had >50 copies/ml and among them 12.9% had virological failure (HIV-RNA >1,000 copies/ml). At 24 months, detectable HIV-RNA was seen in 28.3% of the women and virological failure in 10.1% of the women. Resistance mutations (mainly non-nucleoside reverse transcriptase inhibitors mutations) were seen in 40% of the women with detectable HIV-RNA. Baseline mutations did not correlate with virological failure or the emergence of resistance at later time points. Virological failure 2 years postpartum and emergence of resistance were rare in this cohort of HIV-infected women. These findings are reassuring in the light of the new strategies for the prevention of mother-to-child HIV transmission, recommending life-long antiretroviral therapy administration.

Comparison of the Cepheid GeneXpert and Abbott M2000 HIV-1 real time molecular assays for monitoring HIV-1 viral load and detecting HIV-1 infection

Assessing treatment efficacy and early infant diagnosis (EID) are critical issues in HIV disease management. Point-of-care assays may greatly increase the possibility to access laboratory monitoring also in rural areas. Recently two new laboratory tests have been developed by Cepheid (Sunnyvale, California) the Xpert HIV-1 Viral Load for viral load determination and the Xpert HIV-1 Qualitative for early infant diagnosis. We conducted a study in Blantyre, Malawi, comparing the 2 methods versus the Abbott real time quantitative and qualitative assays, for viral load and EID respectively. We tested 300 plasma samples for viral load determination and 200 samples for infant diagnosis. HIV-1 RNA values of the 274 samples quantified by both assays were highly correlated (Pearson r=0.95, R(2)=0.90). In 90.9% of the cases the two methods were concordant in defining the HIV-1 RNA levels as detectable or undetectable. For EID, the Xpert HIV-1 Qualitative assay yielded the same identical results as the Abbott assay. Both the quantitative and the qualitative Xpert assays are promising tools to monitor treatment efficacy in HIV patients receiving treatment and for early diagnosis in HIV-exposed infants.

Drug resistance mutations 18 months after discontinuation of nevirapine-based ART for prevention of mother-to-child transmission of HIV in Malawi

OBJECTIVES

The objective of this study was to determine the prevalence of drug resistance mutations among HIV-positive women in Malawi 18 months after discontinuing nevirapine-based ART for the prevention of mother-to-child transmission.

PATIENTS AND METHODS

HIV-infected antiretroviral-naive (except for single-dose nevirapine) pregnant Malawian women receiving a nevirapine-based triple antiretroviral regimen from Week 25 of gestation until 6 months of breastfeeding were included in this analysis. Drug resistance was assessed in HIV-DNA 24 months post-partum and at baseline (before the initiation of treatment). In patients with resistance, the presence of mutations was also evaluated in the corresponding plasma samples.

RESULTS

Seven out of 42 (16.7%) women studied had archived drug resistance at Month 24 [six cases had NNRTI-associated mutations and two cases the M184I mutation]. In four cases, resistance mutations were already present at baseline (all NNRTI mutations). In three cases, there was an emergence of 'new' resistance (also present in the plasma in one case). Of the 35 women without resistance mutations at Month 24, only one subject had resistance mutations at baseline. Baseline resistance was significantly more common among women with mutations at 24 months compared with those harbouring a WT virus (4/7 versus 1/35, P < 0.001).

CONCLUSIONS

Among women who had discontinued drugs 6 months post-partum, only 3/42 (7.1%) had accumulated new resistance mutations in HIV-DNA 2 years after delivery. These findings are reassuring in terms of the safety of the Option B strategy for the prevention of HIV mother-to-child transmission.

Laboratory confirmation of clinically diagnosed malaria in a cohort of HIV-infected mothers and their children in Malawi

To avoid overdiagnosis, accuracy in the identification of true malaria cases is of critical importance. Samples (either whole blood, dried blood spots or plasma/serum) collected at the time of clinically diagnosed malaria episodes in a cohort of Malawian HIV-infected mothers and their children were retrospectively tested with the enzyme-linked immunosorbent assay (ELISA) for HRP-2 (histidine-rich protein 2) detection. There were 55 and 56 clinically diagnosed cases of malaria in mothers and children, respectively, with samples available for testing. Rates of laboratory-confirmed episodes were 20% (11 of 55) in mothers and 16.1% (9 of 56) in children. Hemoglobin was lower in children with confirmed malaria compared to those with clinical malaria diagnosis. The results of our study support the widespread use of rapid diagnostic tests.

Retention, transfer out and loss to follow-up two years after delivery in a cohort of HIV+ pregnant women in Malawi

In this study, we analysed in a cohort of pregnant women followed for two years the proportion of women remaining at the same clinic, those who transferred to other clinics, and those lost to follow-up. The possible determinants of the loss to follow-up were also assessed in a setting of postpartum discontinuation based on CD4+ count. A total of 311 pregnant women received antiretroviral therapy from week 25 of gestational age until six months postpartum (end of breastfeeding period), or indefinitely if meeting the criteria for treatment (baseline CD4+ <350 cells/mm(3)). Twenty-four months after delivery, six women had died, 247 were in active follow-up, 21 had transferred to another antiretroviral therapy clinic and 37 were lost to follow-up (rate of loss to follow-up 13%, 95% CI 9.1-16.9%). The presence of a baseline CD4+ count above 350 cells/mm(3) was associated with a ten-fold higher risk of loss to follow-up after six months of delivery (hazard ratio: 9.8, 95% CI 2.2-42.7, for baseline CD4 >350 cells/mm(3) versus baseline CD4+ count below 350 cells/mm(3), p = 0.002). This finding suggests that discontinuation of drugs when the risk of transmission has ceased can have a negative impact on the retention in care of these women.

Hepatitis B virus mother-to-child transmission among HIV-infected women receiving lamivudine-containing antiretroviral regimens during pregnancy and breastfeeding

The study included 309 HIV-infected pregnant women receiving a lamivudine-containing antiretroviral regimen from week 25 of gestational age until 6 months postpartum, during breastfeeding. Twenty-seven of them (8.7%) were hepatitis B virus surface antigen (HBsAg) positive; at baseline, hepatitis B virus (HBV) DNA levels >3 log(10) IU/mL (with a median level of 6.2 log(10) IU/mL) were found in 10 women, who at one, three and six months postpartum had median levels of 5.2 log(10) IU/mL, 4.5 log(10) IU/mL and 2.8 log(10) IU/mL, respectively. Twenty-four of the 30 breast milk samples evaluated had undetectable HBV DNA and the other six had values between 15 and 155 IU/mL. Median lamivudine concentrations were 1070 ng/mL in serum and 684 ng/mL in breast milk. Among the 24 HBV-exposed children with available samples, 16 always tested negative, four had a transient infection, one had an undetermined status and three (12.5%) first tested positive at Month 12 or Month 24. Among the children born to the HBV-uninfected mothers of the same cohort, the rate of HBsAg positivity at 12-24 months was 2% (4/196). Our finding of the absence of significative levels of HBV DNA in the breast milk of co-infected mothers supports the present recommendations for breastfeeding in HBV-infected women. Horizontal transmission can be hypothesized for the infections detected in children at 12-24 months. Children born to HBV-positive mothers remained at higher risk of postnatal HBV acquisition compared to those born to HBV-negative women.