Trends in interventions to reduce perinatal human immunodeficiency virus type 1 transmission in North Carolina

Perception on prevention of mother-to-child-transmission (PMTCT) of HIV among women of reproductive age group in Osogbo, Southwestern Nigeria

Introduction

The fastest growing group of adults living with human immunodeficiency virus (HIV), is women. As more women contract the virus, the number of children infected in utero, intra-partum, and during breastfeeding has been growing. This study assessed the knowledge and attitude of women of child bearing age towards the prevention of mother-to-child-transmission (PMTCT) of HIV.

Materials and methods

This is a descriptive cross sectional survey of 420 women of the reproductive age group (15–49 years) selected using a multistage sampling technique. Data were obtained using interviewer-administered, pretested, semistructured questionnaires. The data were analyzed using the Statistical Package for Social Sciences (SPSS) software version 15.

Results

A high level of awareness about HIV/acquired immunodeficiency syndrome (AIDS) was observed among the respondents (99.8%). The knowledge about MTCT and PMTCT of HIV was high, 92.1% and 91.4%, respectively. However, a significant portion (71.27%) of the study population had poor attitudes towards PMTCT of HIV.

Conclusion

Despite the high level of awareness of HIV/AIDS, and good knowledge about MTCT and PMTCT of HIV/AIDS among the respondents, the attitude towards PMTCT is poor. There is need for the involvement of the stakeholders in bridging the gap between knowledge and attitude of prevention of MTCT of HIV among women.

Trends in perinatal HIV prevention in New York City, 1994-2003

OBJECTIVES

We examined trends in perinatal HIV prevention interventions in New York City implemented during 1994 to 2003 to ascertain the success of the interventions in reducing perinatal transmission.

METHODS

We used data obtained from infant records at 22 hospitals. We used multiple logistic regression to analyze factors associated with prenatal care and perinatal HIV transmission.

RESULTS

We analyzed data for 4729 perinatally HIV-exposed singleton births. Of mothers with prenatal care data, 92% had prenatal care. The overall proportion who received prenatal care and were diagnosed with HIV before delivery was 86% in 1994 to 1996 and 90% in 1997 to 2003. Use of prenatal antiretrovirals among mothers who received prenatal care was 63% in 1994 to 1996 and 82% in 1997 to 2003. From 1994 to 2003, cesarean births among the entire sample increased from 15% to 55%. During 1997 to 2003, the perinatal HIV transmission rate among the entire sample was 7%; 45% of mothers of infected infants had missed opportunities for perinatal HIV prevention. During 1997 to 2003, maternal illicit drug use was significantly associated with lack of prenatal care. Lack of prenatal, intrapartum, and neonatal antiretrovirals; maternal illicit drug use; and low birthweight were significantly associated with perinatal HIV transmission.

CONCLUSIONS

Interventions for perinatal HIV prevention can successfully decrease HIV transmission rates. Ongoing perinatal HIV surveillance allows for monitoring the implementation of guidelines to prevent mother-to-child transmission of HIV and determining factors that may contribute to perinatal HIV transmission.

Nucleoside reverse transcriptase inhibitors (NRTIs)-induced expression profile of mitochondria-related genes in the mouse liver

Mitochondrial dysfunction has been implicated in the adverse effects of nucleoside reverse transcriptase inhibitors (NRTIs) used to treat HIV-1 infections. To gain insight into the mechanism by which NRTIs alter mitochondrial function, the expression level of 542 genes associated with mitochondrial structure and functions was determined in the livers of p53 haplodeficient (+/-) C3B6F1 female mouse pups using mouse mitochondria-specific oligonucleotide microarray. The pups were transplacentally exposed to zidovudine (AZT) at 240 mg/kg bw/day or a combination of AZT and lamivudine (3TC) at 160 and 100mg/kg bw/day, respectively, from gestation day 12 through 18, followed by continuous treatment by oral administration from postnatal day 1-28. In addition, AZT/3TC effect was investigated in wild-type (+/+) C3B6F1 female mice. The genotype did not significantly affect the gene expression profile induced by AZT/3TC treatment. However, the transcriptional level of several genes associated with oxidative phosphorylation, mitochondrial tRNAs, fatty acid oxidation, steroid biosynthesis, and a few transport proteins were significantly altered in pups treated with AZT and AZT/3TC compared to their vehicle counterparts. Interestingly, AZT/3TC altered the expression level of 153 genes with false discovery rate of less than 0.05, in contrast to only 20 genes by AZT alone. These results suggest that NRTI-related effect on expression level of genes associated with mitochondrial functions was much greater in response to AZT/3TC combination treatment than AZT alone.

Frequent detection of acute HIV infection in pregnant women

BACKGROUND

Universal prenatal HIV antibody testing, which does not detect acute HIV, is standard for pregnant women in the United States. Unrecognized HIV acquisition during pregnancy may result in higher rates of perinatal transmission.

OBJECTIVE

To determine the prevalence of acute (antibody-negative) HIV infection in pregnant women and to assess the potential for prompt initiation of antiretroviral therapy to prevent perinatal transmission.

METHODS

From 1 November 2002 to 30 April 2005, all publicly funded HIV testing sites participated in North Carolina's Screening and Tracing Active Transmission (STAT) Program, which retested all specimens that were HIV antibody negative for HIV RNA using specimen pooling. All patients with acute HIV infection were immediately traced for evaluation, confirmatory testing, counseling, and referral services. For this study, all pregnant women with acute HIV were immediately initiated onto antiretroviral therapy and followed prospectively for pregnancy outcomes.

RESULTS

During the study period, 443 women were HIV positive by antibody testing; 15 were HIV antibody negative but positive by RNA assay and of these five were pregnant at the time of testing. The pregnant women received antiretroviral drugs and delivered HIV-uninfected infants. Maternal testing records of all six HIV-infected infants born in North Carolina showed three mothers with chronic HIV infection and three HIV antibody negative at private prenatal testing facilities.

CONCLUSIONS

In resource-rich settings, a substantial proportion of residual perinatal transmission may be from HIV acquisition during pregnancy. Standard antibody tests miss acute HIV infection and so algorithms that include pooled HIV RNA testing may improve its detection and represent a further opportunity to prevent perinatal transmission.

Trends in a Cohort of HIV-infected pregnant women in Rio de Janeiro, 1996-2004

OBJECTIVE: To describe trends in sociodemographic, immunological and virological profiles and interventions to decrease the risk of mother-to-child HIV transmission. METHODS: Retrospective cohort study conducted at a tertiary institution in Rio de Janeiro, Brazil from January 1996 to December 2004. Analysis was performed by stratification in three time periods: 1996-1998 (P1), 1999-2001 (P2) and 2002-2004 (P3). RESULTS: In 9 years, 622 pregnancies occurred. Complications included: maternal mortality 0.3%, stillbirths 2.5%, miscarriages 0.6%, neonatal mortality 1.1%, prematurity 9.9%, low birth weight (LBW) 16.5%, congenital malformations 2.2%. The number of HIV-infected pregnant patients grew threefold over time reflecting increased prevalence of disease and patient identification. HIV diagnosis before pregnancy increased from 30% in P1 to 45% in P3. The proportion of pregnant women receiving highly active antiretroviral therapy increased from none (P1) to 88% (P3) with a significant trend towards women delivering at undetectable viral loads in later years despite a higher frequency of advanced disease. Scheduled cesarean deliveries increased from 35% in P1 to 48% in P3. Perinatal transmission rates were 2.4% with a decline from 3.5% in P1 to 1.6% in P3. Neonatal outcomes tended to remain constant or improve with time. A slight rise in LBW and congenital malformations were observed. CONCLUSIONS: During the observational period, HIV+ pregnant women presented with more advanced disease and lower socio-economic status. However, improved management of HIV-infected patients (associated with increased identification and increased availability of treatment) resulted into very low transmission rates similar to those of developed countries with overall improvement of patient outcomes.

Use of enhanced perinatal human immunodeficiency virus surveillance methods to assess antiretroviral use and perinatal human immunodeficiency virus transmission in the United States, 1999-2001

OBJECTIVE

Significant reductions in perinatal human immunodeficiency virus (HIV) transmission have been demonstrated in which the HIV-infected mothers and their HIV-exposed infants receive prenatal, intrapartum, and neonatal antiretroviral therapy.

STUDY DESIGN

We used data that were collected through the Enhanced Perinatal Surveillance system for HIV-exposed singleton births that occurred 1999-2001 in 24 sites.

RESULTS

The overall infant infection rate for the 3 years was 4.7%. Compared with zidovudine monotherapy, those patients who received zidovudine with other drugs that included a protease inhibitor and those who received zidovudine and other drugs with no protease inhibitor were less likely to have an infected infant (adjusted odds ratio, 0.4 [95% CI, 0.3-0.07]; adjusted odds ratio, 0.5 [95% CI, 0.3-0.8], respectively).

CONCLUSION

These data support the current treatment recommendations and show that infants were less likely to be infected when the mothers were given a prenatal antiretroviral therapy regimen that contained zidovudine with additional antiretroviral drugs with or without a protease inhibitor in addition to receiving antiretrovirals during delivery and neonatally.

Characteristics and management of HIV-1-infected pregnant women enrolled in a randomised trial: differences between Europe and the USA

BACKGROUND

Rates of mother-to-child transmission of HIV-1 (MTCT) have historically been lower in European than in American cohort studies, possibly due to differences in population characteristics. The Pediatric AIDS Clinical Trials Group Protocol (PACTG) 316 trial evaluated the effectiveness of the addition of intrapartum/neonatal nevirapine in reducing MTCT in women already receiving antiretroviral prophylaxis. Participation of large numbers of pregnant HIV-infected women from the US and Western Europe enrolling in the same clinical trial provided the opportunity to identify and explore differences in their characteristics and in the use of non-study interventions to reduce MTCT.

METHODS

In this secondary analysis, 1350 women were categorized according to enrollment in centres in the USA (n = 978) or in Europe (n = 372). Factors associated with receipt of highly active antiretroviral therapy and with elective caesarean delivery were identified with logistic regression.

RESULTS

In Europe, women enrolled were more likely to be white and those of black race were mainly born in Sub-Saharan Africa. Women in the US were younger and more likely to have previous pregnancies and miscarriages and a history of sexually transmitted infections. More than 90% of women did not report symptoms of their HIV infection; however, more women from the US had symptoms (8%), compared to women from Europe (4%). Women in the US were less likely to have HIV RNA levels <400 copies/ml at delivery than women enrolling in Europe, and more likely to receive highly active antiretroviral therapy, and to start therapy earlier in pregnancy. The elective caesarean delivery rate in Europe was 61%, significantly higher than that in the US (22%). Overall, 1.48% of infants were infected and there was no significant difference in the rate of transmission between Europe and the US despite the different approaches to treatment and delivery.

CONCLUSION

These findings confirm that there are important historical differences between the HIV-infected pregnant populations in Western Europe and the USA, both in terms of the characteristics of the women and their obstetric and therapeutic management. Although highly active antiretroviral therapy predominates in pregnancy in both settings now, population differences are likely to remain.

TRIAL REGISTRATION

NCT00000869.

Ultrasensitive p24 antigen assay for diagnosis of perinatal human immunodeficiency virus type 1 infection

We evaluated an ultrasensitive p24 antigen enzyme immunosorbent assay on 802 plasma specimens from 582 infants and children of 0 to 180 days of age. Overall sensitivity and specificity were 91.7% and 98.5%, respectively. After exclusion of infants of less than 7 days of age, the sensitivity and specificity were 93.7% and 98.3%, respectively.

Persistence of nevirapine-resistant HIV-1 in women after single-dose nevirapine therapy for prevention of maternal-to-fetal HIV-1 transmission

Single-dose nevirapine (sdNVP) for prevention of mother-to-child transmission of HIV-1 can select nevirapine (NVP)-resistant variants, but the frequency, duration, and clinical significance of this resistance is not well defined. We used a sensitive allele-specific PCR assay to assess the emergence and persistence of NVP-resistant variants in plasma samples from 22 women with HIV-1 subtype C infection who participated in a study of sdNVP for prevention of mother-to-child transmission of HIV-1. The women were categorized into three groups on the basis of detection of NVP resistance by standard genotype analysis. Group 1 (n = 6) had NVP resistance detected at 2 and 6 mo after sdNVP, but not at 12 mo. Group 2 (n = 9) had NVP resistance detected at 2 mo, but not 6 mo. Group 3 (n = 7) had no NVP resistance detected at any time point. Allele-specific PCR analysis for the two most common NVP resistance mutations (K103N and Y181C) detected NVP-resistant variants in most (16 of 21) samples that were negative for NVP resistance by standard genotype, at levels ranging from 0.1% to 20% 1 yr after treatment. The frequency of NVP-resistant mutations decreased over time, but persisted above predose levels for more than 1 yr in > or = 23% of the women. These findings highlight the urgent need for studies assessing the impact of sdNVP on the efficacy of subsequent antiretroviral therapy containing NVP or other nonnucleoside reverse transcriptase inhibitors.

Transfer of antivirals across the human placenta

BACKGROUND

Viruses cross the placenta and infect the fetus. Antivirals are administered to pregnant women to protect them and the fetus against the viruses. It is necessary to know which antivirals cross the placenta and reach the fetal circulation in pharmacologically significant concentrations in order to plan antiviral therapy.

AIMS

This article reviews the literature on the placental transfer of antivirals against HIV. The review considers also the placental transfer of acyclovir and ganciclovir, which are used against the herpes simplex virus and the cytomegalovirus, respectively.

STUDY DESIGN

Firstly, a medline was performed with the following key words "placental transfer of antivirals". Secondly, a medline was performed with the key words "placenta transfer of..." followed by the name of a single antiviral and it was repeated for 20 antivirals. Thirdly, another medline was performed using the following key words "pharmacokinetics of antiviral in newborn" in order to collect those articles which describe in vivo transfer of antivirals. The literature was critically read and a written note was produced.

RESULTS

The literature on the placental transfer of antivirals includes studies in vitro perfusing the human placenta and studies performed in vivo in which the cord and maternal antiviral plasma concentrations are compared. Both the results obtained in vitro and in vivo show that the protease inhibitors poorly transfer the placenta because of their great molecular weight. With the exception of didanosine, the nucleoside reverse transcriptase inhibitors and nelfinavir, a non-nucleoside reverse transcriptase inhibitor, cross the placenta and the cord, and maternal plasma concentrations equilibrate.

CONCLUSIONS

In vitro and in vivo results are consistent with the view that the nucleoside reverse transcriptase inhibitors cross the human placenta and produce significant pharmacological concentrations in the fetal circulation. Nevirapine, the only studied non-nucleoside reverse transcriptase inhibitor, reach the equilibrium between the fetal and maternal concentration, whereas the protease inhibitors have a poor transfer across the human placenta.

Treatment of HIV infection in pregnant women: antiretroviral management options

Increasing rates of HIV infection in women worldwide, especially among those of childbearing age, reinforce the importance of understanding the management of HIV in pregnancy. Over the past decade, significant advances have been made in the prevention of vertical HIV transmission, including the use of single and combination antiretroviral therapy, elective caesarean section as the preferred mode of delivery and the elimination of breast feeding. Multiple clinical trials assessing antiretroviral therapy in pregnancy have been carried out worldwide. The first pivotal clinical trial, the AIDS Clinical Trials Group (ACTG) 076 study, was conducted in 1994 using a three-part zidovudine regimen. Despite the success of this regimen at decreasing rates of vertical transmission, it is not affordable in many developing countries. Consequently, many international clinical trials have concentrated on short-course antiretroviral regimens including zidovudine alone, zidovudine and lamivudine, and nevirapine alone. In the developed world, the management of nonpregnant HIV-infected individuals has also undergone significant advances and has implications for the management of HIV in pregnancy. A number of countries have participated in the development of guidelines for the management of HIV in pregnancy, which recommend that HIV-infected pregnant women should be offered combination antiretroviral therapy based on viral load and CD4+ cell count cut-offs used for individuals who are not pregnant, preferably with the inclusion of zidovudine. However, to maximise the benefits to their offspring, therapy is recommended at lower viral load thresholds than for nonpregnant adults. For antiretroviral-naive women, therapy is deferred until the second trimester because of the potential and uncertain risk of teratogenesis and the low risk of transmission during this period. Research has also found that maternal factors including viral load, immune status, chorioamnionitis, prematurely ruptured membranes and, to a lesser extent, intravenous drug use and smoking are associated with increased vertical transmission. These represent potentially modifiable risk factors that should be addressed before and throughout pregnancy. Despite the benefits of antiretroviral therapy to reduce HIV vertical transmission, its use can be complicated by known and unknown risks of toxicity to the mother, fetus or both as well as carrying the risk of developing drug-resistant virus. The latter can potentially compromise future treatment options for both the mother and child. Other important challenges include the use of antiretroviral drugs during pregnancy when the mother does not meet criteria for them for her own health, and balancing the relative risks and benefits of elective caesarean section at various degrees of viral load suppression. Clinicians managing HIV in pregnancy need to keep up to date with all the literature to provide optimal care, including counselling to allow mothers to balance the risks and benefits while deciding on treatment for both themselves and their children.

Subnanogram on-line column-switching liquid chromatographic–tandem mass spectrometric quantification method for nelfinavir and methoxyphenol metabolite M1 in rat plasma

A new on-line, rapid and sensitive column-switch LC/MS/MS method to measure nelfinavir (NFV), an HIV-1 protease inhibitor, and its major metabolite (M1) in rat plasma was developed. Rat plasma containing the analytes and the internal standard was treated with acetonitrile and the supernatant was processed through an on-line extraction and an analytical columns, with a column-switch device. ESI-LC/MS with multiple reaction monitors for appropriate analytes was performed. This assay gave a limit of quantitation (LOQ) of <1 ng/mL for the analytes with 5 min run time. The within-run and between-run precisions were <12 and <10%, respectively. This analytical method was successfully applied to a study to correlate changes in maternal and placental NFV plasma concentrations in rats following NFV exposure in utero.

Special considerations for the HIV-infected patient with preterm labor

It is essential that women admitted for PTL have a confidential review of maternal history and prenatal record for HIV serostatus. Combination ARV therapy should be continued during tocolysis of PTL and, if tocolysis fails, through delivery. Counseling and rapid HIV testing should be performed in the intrapartum or postnatal periods if the woman's serostatus has not been determined. Women identified as being HIV infected who are in labor should be treated with (1) ZDV in labor and for 6 weeks to the neonate, (2) NVP single dose to the mother in labor and single dose to the neonate, (3) ZDV-3TC in labor and to the neonate for 1 week, or (4) NVP (as above) and the ZDV regimen (as above). Cesarean delivery should be recommended to all women when the most recent viral load is greater than or equal to 1000 copies/mL or is unknown. Those charged with the care of HIV-infected pregnant women should make frequent use of the Public Health Service Website (http://www.aidsinfo.nih.gov), which provides a regularly updated, practical, and thorough guide to management of patients who have HIV.