In utero HIV infection in pregnancies complicated by tuberculosis in Durban, South Africa

Poor Obstetric and Infant Outcomes in Human Immunodeficiency Virus-Infected Pregnant Women With Tuberculosis in South Africa: The Tshepiso Study

Background

Before the wide availability of antiretroviral therapy (ART), tuberculosis and human immunodeficiency virus (HIV) disease among pregnant women resulted in poor maternal and neonatal outcomes, including high rates of mother-to-child transmission of both HIV and tuberculosis. We aimed to describe the impact of tuberculosis among HIV-infected mothers on obstetric and infant outcomes in a population with access to ART.

Methods

In this prospective cohort study, we followed up HIV-infected pregnant women with or without tuberculosis disease from January 2011 through January 2014 in Soweto, South Africa. Two controls were enrolled for each case patient, matched by enrollment time, maternal age, gestational age, and planned delivery clinic and followed up for 12 months after delivery.

Results

We recruited 80 case patients and 155 controls, resulting in 224 live-born infants. Infants of mothers with HIV infection and tuberculosis disease had a higher risk of low birth weight (20.8% vs 10.7%; P = .04), prolonged hospitalization at birth (51% vs 16%; P < .001), infant death (68 vs 7 deaths per 1000 births; P < .001), and tuberculosis disease (12% vs 0%; P < .001) despite appropriate maternal therapy and infant tuberculosis preventive therapy. HIV transmission was higher among these infants (4.1% vs 1.3%; P = .20), though this difference was not statistically significant. Obstetric outcomes in coinfected women were also poorer with higher risks of maternal hospitalization (25% vs 11%; P = .005) and preeclampsia (5.5% vs 0.7%; P = .03).

Conclusions

Tuberculosis in HIV coinfected pregnant women remains a significant threat to the health of both mothers and infants. Improving tuberculosis prevention and early diagnosis among pregnant women is critical.

Strategies for the prevention of mother to child transmission in Western countries: an update

BACKGROUND

During the last decades remarkable scientific advances have been made toward the prevention of HIV mother-to-child transmission, in particular in developed nations. The aim of this review was to analyze the latest findings and available international recommendations on the prevention of HIV mother-to-child transmission in high-income countries.

METHODS

We performed a literature search of the Cochrane Library, MEDLINE by PubMed and EMBASE from database inception through June 2014, using the following terms: HIV, mother-to-child transmission and mother-to-child-transmission prevention. All types of articles in the English language were included. US and available European guidelines were searched and included in the analysis.

RESULTS

One hundred fifty articles were selected for inclusion in this review.

CONCLUSIONS

Global epidemiology of HIV infection is rapidly evolving, in particular in high-resource countries. The interpretation of clinical and epidemiological studies is crucial for the development of evidence-based recommendations to guide the management of HIV mother-to-child transmission. Although significant progress has been made, heterogeneity between countries in specific interventions still exists, which may address future research.

The role of co-infections in mother-to-child transmission of HIV

In HIV-infected women, co-infections that target the placenta, fetal membranes, genital tract, and breast tissue, as well as systemic maternal and infant infections, have been shown to increase the risk for mother-to-child transmission of HIV (MTCT). Active co-infection stimulates the release of cytokines and inflammatory agents that enhance HIV replication locally or systemically and increase tissue permeability, which weakens natural defenses to MTCT. Many maternal or infant co-infections can affect MTCT of HIV, and particular ones, such as genital tract infection with herpes simplex virus, or systemic infections such as hepatitis B, can have substantial epidemiologic impact on MTCT. Screening and treatment for co-infections that can make infants susceptible to MTCT in utero, peripartum, or postpartum can help reduce the incidence of HIV infection among infants and improve the health of mothers and infants worldwide.

Host factors that influence mother-to-child transmission of HIV-1: genetics, coinfections, behavior and nutrition

Mother-to-child transmission (MTCT) is the most important mode of HIV-1 acquisition among infants and children and it can occur in utero, intrapartum and postnatally through breastfeeding. Great progress has been made in preventing MTCT through use of antiretroviral regimens during gestation, labor/delivery and breastfeeding. The mechanisms of MTCT, however, are multifactorial and remain incompletely understood. This review focuses on select host factors affecting MTCT, in particular genetic factors, coexisting infections, behavioral factors and nutrition. Whereas much emphasis has been placed on decreasing maternal HIV-1 viral load, an important determinant of MTCT, through use of antiretroviral agents, complementary focus on overall maternal health is often neglected. By addressing coinfections in mothers and infants, improving the mother's nutritional status and modifying risky behaviors and practices, not only is maternal and child health improved, but a direct benefit in reducing MTCT can be derived. The study of genetic variations in susceptibility to HIV-1 infection is rapidly evolving, and the future is likely to bring revolutionary changes in HIV-1 prevention by enhancing natural resistance to infection and by individually tailoring pharmacologic regimens.

Active tuberculosis case-finding among pregnant women presenting to antenatal clinics in Soweto, South Africa

BACKGROUND

Human immunodeficiency virus (HIV) and tuberculosis (TB) are among the leading causes of death among women of reproductive age worldwide. TB is a significant cause of maternal morbidity. Detection of TB during pregnancy could provide substantial benefits to women and their children.

METHODS

This was a cross-sectional implementation research study of integrating active TB case-finding into existing antenatal and prevention of mother-to-child transmission services in six clinics in Soweto, South Africa. All pregnant women 18 years of age or older presenting for routine care to these public clinics were screened for symptoms of active TB, cough for 2 weeks or longer, sputum production, fevers, night sweats, or weight loss, regardless of their HIV status. Participants with any symptom of active TB were asked to provide a sputum specimen for smear microscopy, mycobacterial culture and drug-susceptibility testing.

RESULTS

Between December 2008 and July 2009, 3963 pregnant women were enrolled and screened for TB, of whom 1454 (36.7%) were HIV-seropositive. Any symptom of TB was reported by 23.1% of HIV-seropositive and 13.8% of HIV-seronegative women (P < 0.01). Active pulmonary TB was diagnosed in 10 of 1454 HIV-seropositve women (688 per 100,000) and 5 of 2483 HIV-seronegative women (201 per 100,000, P = 0.03). The median CD4⁺ T-cell count among HIV-seropositive women with TB was similar to that of HIV-seropositive women without TB (352 versus 333 cells/μL, P = 0.85).

CONCLUSIONS

There is a high burden of active TB among HIV-seropositive pregnant women. TB screening and provision of isoniazid preventive therapy and antiretroviral therapy should be integrated with prevention of mother-to-child transmission services.

Maternal tuberculosis: a risk factor for mother-to-child transmission of human immunodeficiency virus

BACKGROUND

Maternal human immunodeficiency virus (HIV) RNA load, CD4 cell count, breast-feeding, antiretroviral use, and malaria are well-established factors associated with mother-to-child transmission (MTCT) of HIV; the role of maternal tuberculosis (TB), however, has not been well established.

METHODS

The study population was 783 HIV-infected Indian mother-infant pair participants in randomized and ancillary HIV-infected cohorts of the Six Week Extended-Dose Nevirapine (SWEN) Study, a study comparing extended nevirapine versus single-dose nevirapine, to reduce MTCT of HIV among breast-fed infants. Using multivariable logistic regression, we assessed the impact of maternal TB occurring during pregnancy and through 12 months after delivery on risk of MTCT.

RESULTS

Of 783 mothers, 3 had prevalent TB and 30 had incident TB at 12 months after delivery. Of 33 mothers with TB, 10 (30%) transmitted HIV to their infants in comparison with 87 of 750 mothers without TB (12%; odds ratio [OR], 3.31; 95% confidence interval [CI], 1.53-7.29; P = .02). In multivariable analysis, maternal TB was associated with 2.51-fold (95% CI, 1.05-6.02; P = .04) increased odds of HIV transmission adjusting for maternal factors (viral load, CD4 cell count, and antiretroviral therapy) and infant factors (breast-feeding duration, infant nevirapine administration, gestational age, and birth weight) associated with MTCT of HIV.

CONCLUSIONS

Maternal TB is associated with increased MTCT of HIV. Prevention of TB among HIV-infected mothers should be a high priority for communities with significant HIV/TB burden.

Maternal tuberculosis: a risk factor for mother-to-child transmission of human immunodeficiency virus

BACKGROUND

Maternal human immunodeficiency virus (HIV) RNA load, CD4 cell count, breast-feeding, antiretroviral use, and malaria are well-established factors associated with mother-to-child transmission (MTCT) of HIV; the role of maternal tuberculosis (TB), however, has not been well established.

METHODS

The study population was 783 HIV-infected Indian mother-infant pair participants in randomized and ancillary HIV-infected cohorts of the Six Week Extended-Dose Nevirapine (SWEN) Study, a study comparing extended nevirapine versus single-dose nevirapine, to reduce MTCT of HIV among breast-fed infants. Using multivariable logistic regression, we assessed the impact of maternal TB occurring during pregnancy and through 12 months after delivery on risk of MTCT.

RESULTS

Of 783 mothers, 3 had prevalent TB and 30 had incident TB at 12 months after delivery. Of 33 mothers with TB, 10 (30%) transmitted HIV to their infants in comparison with 87 of 750 mothers without TB (12%; odds ratio [OR], 3.31; 95% confidence interval [CI], 1.53-7.29; P = .02). In multivariable analysis, maternal TB was associated with 2.51-fold (95% CI, 1.05-6.02; P = .04) increased odds of HIV transmission adjusting for maternal factors (viral load, CD4 cell count, and antiretroviral therapy) and infant factors (breast-feeding duration, infant nevirapine administration, gestational age, and birth weight) associated with MTCT of HIV.

CONCLUSIONS

Maternal TB is associated with increased MTCT of HIV. Prevention of TB among HIV-infected mothers should be a high priority for communities with significant HIV/TB burden.

High incidence of tuberculosis among HIV-infected infants: evidence from a South African population-based study highlights the need for improved tuberculosis control strategies

BACKGROUND

There are limited population-based estimates of tuberculosis incidence among human immunodeficiency virus (HIV)-infected and HIV-uninfected infants aged < or =12 months. We aimed to estimate the population-based incidence of culture-confirmed tuberculosis among HIV-infected and HIV-uninfected infants in the Western Cape Province, South Africa.

METHODS

The incidences of pulmonary, extrapulmonary, and disseminated tuberculosis were estimated over a 3-year period (2004-2006) with use of prospective representative hospital surveillance data of the annual number of culture-confirmed tuberculosis cases among infants. The total number of HIV-infected and HIV-uninfected infants was calculated using population-based estimates of the total number of live infants and the annual maternal HIV prevalence and vertical HIV transmission rates.

RESULTS

There were 245 infants with culture-confirmed tuberculosis. The overall incidences of tuberculosis were 1596 cases per 100,000 population among HIV-infected infants (95% confidence interval [CI], 1151-2132 cases per 100,000 population) and 65.9 cases per 100,000 population among HIV-uninfected infants (95% CI, 56-75 cases per 100,000 population). The relative risk of culture-confirmed tuberculosis among HIV-infected infants was 24.2 (95% CI, 17-34). The incidences of disseminated tuberculosis were 240.9 cases per 100,000 population (95% CI, 89-433 cases per 100,000 population) among HIV-infected infants and 14.1 cases per 100,000 population (95% CI, 10-18 cases per 100,000 population) among HIV-uninfected infants (relative risk, 17.1; 95% CI, 6-34).

CONCLUSIONS

This study indicates the magnitude of the tuberculosis disease burden among HIV-infected infants and provides population-based comparative incidence rates of tuberculosis among HIV-infected infants. This high risk of tuberculosis among HIV-infected infants is of great concern and may be attributable to an increased risk of tuberculosis exposure, increased immune-mediated tuberculosis susceptibility, and/or possible limited protective effect of bacille Calmette-Guérin vaccination. Improved tuberculosis control strategies, including maternal tuberculosis screening, contact tracing of tuberculosis-exposed infants coupled with preventive chemotherapy, and effective vaccine strategies, are needed for infants in settings where HIV infection and tuberculosis are highly endemic.

Perinatal tuberculosis and HIV-1: considerations for resource-limited settings

Tuberculosis is the commonest HIV-1-related disease and the most frequent cause of mortality in young women in endemic regions. Tuberculosis and HIV-1 are independent risk factors for maternal mortality and adverse perinatal outcomes, and in combination have a greater impact on these parameters than their individual effects. In referral health centres in southern Africa around one-sixth of all maternal deaths are due to tuberculosis/HIV-1 coinfection. One-third (37%) of HIV-1-infected mothers with tuberculosis are severely immunocompromised, with CD4 counts of fewer than 200 cells/microL compared with 14-19% in mothers recruited into major mother-to-child intervention trials in Europe. Babies born to mothers with tuberculosis/HIV-1 also have higher rates of prematurity, low birthweight, and intrauterine growth restriction. Transmission rates of HIV-1 from mother to infant are around 25-45% in resource-limited settings, while that for mother-to-child-transmission of tuberculosis is 15% within 3 weeks of birth. We highlight this emergent problem, and discuss the dilemmas associated with diagnosis and management of pregnant HIV-1-infected mothers with tuberculosis, and their newborn babies.