HIV testing at immunisation clinics: an opportunity to identify women and infants who are falling through the cracks?

Research from Malawi further strengthens the case for using infant immunisation clinics as a key site for maternal and early infant HIV diagnosis, the Nineteenth International AIDS Conference (AIDS 2012) heard last week in Washington DC.

Researchers who performed infant HIV testing at Malawian clinics where women brought their children for standard three-month immunisations concluded that immunisation – which has high uptake in many resource-limited settings – may serve as an important opportunity to diagnose previously undetected cases of HIV.

Throughout the world, prevention of mother-to-child transmission (PMTCT) programmes seek to support HIV-positive women’s health, minimise the risk of HIV transmission to infants and provide treatment to those infants who acquire the virus.

A major challenge in the PMTCT field is the difficulty of retaining at-risk women throughout the series of interventions that need to occur for good outcomes. These include timely presentation for antenatal care; HIV testing; the delivery of test results; the initiation of antiretroviral regimens for HIV-positive women; safe delivery; infant HIV testing; and the initiation of treatment in infants found to be HIV-positive.

Ideally, pregnant women who do not know their HIV status undergo testing early in pregnancy. Those found to be HIV-positive are advised to initiate antiretroviral therapy and take other measures to reduce the likelihood of transmitting HIV to their infants.

In reality, many cases of HIV among women and infants remain undiagnosed. Pregnant women may not seek antenatal care, or if they do, care providers may fail to make HIV testing available to them. In some settings, a considerable number of women who undergo HIV testing do not return to health care facilities to obtain the results.

Furthermore, it is entirely possible for a woman to become newly infected with HIV at any time during pregnancy or the breastfeeding period.

Previously reported research from Malawi has shown that when compared with early infant diagnosis carried out through under-fives clinics which see predominantly sick children, offering HIV testing at immunisation clinics dramatically increased the rate of HIV testing and return for test results.

The study presented at the conference was carried out at 53 immunisation clinics in four districts in Malawi. It enrolled 5544 mother-infant pairs. Researchers tested infant dried blood spots for HIV exposure to determine maternal HIV status, while also asking the mothers about their HIV status and HIV testing history.

A key finding was that in addition to the 561 infants whose test results were consistent with their mothers’ self-reported HIV-positive status, another 207 infants also tested positive for HIV exposure. The mothers of the infants in the second group, according to self-reports, had either never been tested for HIV or else tested HIV-negative before or during pregnancy.

In other words, testing infants in immunisation clinics resulted in a 37% increase in the number of mothers known to be HIV-positive.Almost four percent of the HIV-exposed infants had mothers who reported receiving an HIV-negative test result during pregnancy.