When the male partner of a pregnant woman attends antenatal clinic visits with her and gets tested for HIV, there appears to be a reduced risk of HIV transmission to their infant and increased survival in the child according to a Kenyan study presented at IAS 2009 in Cape Town this week.
Although this study wasn’t designed to determine the specific male partner factors responsible, according to Adam Alusio, a doctoral student working with the University of Washington and the University of Nairobi, “we hypothesize this is because of greater financial, physical or emotional support to the mother that we may expect to find provided by [such] men.”
Background
Although the use of antiretroviral therapy (ART) can reduce vertical (mother to child) transmission of HIV to below 2%, in the absence of interventions, vertical transmission can lead to the HIV infection of 15-45% of infants born to HIV-infected mothers. In sub-Saharan Africa, HIV infection greatly increases the risk of child mortality, from one out of ten to one out of three.
As results from PEARL, another prevention of vertical transmission (PVT) study presented at IAS this year indicate, in order for the interventions to work, each mother-infant pair must negotiate a complex cascade of events (from coming into the clinic, being offered and accepting HIV testing, getting their results, getting ARVs, and so on) and the likelihood of a misstep somewhere along this pathway is quite high. This should hardly be surprising because many of the pregnant women attending the clinic have very little support.
However, in some settings there has been a concerted effort to involve male partners in this process. One study in Nairobi has reported that getting men in for HIV counselling and testing significantly improved the uptake of specific PVT interventions, such as nevirapine uptake and adherence as well as the avoidance of breastfeeding in order to avoid HIV transmission to the infant (Farquhar). Stemming from this work, the team in Kenya conducted this further study to determine whether male partner involvement would reduce vertical transmission and the HIV-free survival of the infant.
Between 1999 to 2003, the study enrolled 532 HIV-positive pregnant women at week 32 of gestation. Each woman was interviewed to gather data about her male partner and she was asked to invite him to attend clinics with them and to undergo HIV testing. Around 5% had no current partners and about 10% were lost to follow-up prior delivery. 456 women with one year of follow-up were included in the analysis.
Male partners of 140 women (31%) attended clinics. The median age of the male partner was 31, and they had been in relationships for a median of four years (range two to seven).
Several factors were independently associated with male partner attendance: prior disclosure of HIV status to the partners (138 of the women (99%); prior discussion of PVT interventions 76 (72%); and the male having previously tested for HIV — the latter was significant in a multivariate analysis.
One hundred and twenty-eight men had previously been tested for HIV: 91% of those attending antenatal clinic visits compared to 23% of the non-attending males (as reported by female study participants (adjusted odds ratio [AOR] 20.2%, 95% confidence interval [CI], 9.5-42.9, p<0.001).
During the course of the study, 75 of the 140 men (54%) also underwent HIV testing, and 42 men (56% of those tested) were found to be HIV-positive.
The mothers were seen with their infants monthly. Infant HIV status was determined via RNA and DNA polymerase chain reaction testing at birth and at one, three, six, nine and twelve months postpartum. Among the 400 live infants who were followed, 55 were HIV-positive at twelve months of age.
In an analysis that controlled for maternal viral load and infant feeding modality, twelve-month-old children of women whose male partners attended clinics were found to be much less likely than other twelve-month-old children to have HIV. There were 47 HIV infected infants among the 275 mother-child pairs where the male partner did not attend the antenatal clinic (17%), versus 8 infected infants among the 125 mother-child pairs where the male partner did attend the antenatal clinic (adjusted hazard ratio [aHR]=2.38; 95% CI 1.07-5.39). Lower transmission was also associated with previous male partner HIV testing (aHR, 2.62; 95% CI, 1.32 – 5.21).
The same male partner-related variables were associated with HIV-free survival. The twelve-month-old children of women whose partners attended clinics had 59% higher HIV-free survival rate than their counterparts (aHR, 0.41; 95% CI, 0.22 – 0.79; p = 0.07). Previous male partner HIV testing was associated with a comparable 12-month HIV-free infant survival rate (AHR, 0.47; 95% CI, 0.27 – 0.81; p = 0.006). Both findings reflect controlling for maternal viral load and breast milk exposure.
According to the abstract, there was also a 2.5-fold higher survival rate among HIV-negative infants whose mothers’ partners attended clinics in comparison to other HIV-negative infants (hazard ratio [HR], 0.38; 95% CI, 0.14 – 0.98; p = 0.045).
When researchers sought to identify factors related to male partner clinic attendance, they found associations with three variables: women’s disclosure of their HIV serostatus; discussion between partners about prevention of mother-to-child HIV transmission; and previous male partner HIV testing. Previous testing was the only variable found to be significant in multivariate analysis (AOR, 19.6; 95% CI, 9.6 – 40.0; p = < 0.001).
Implications and discussion
“These findings suggest that promotion or programmes aimed at increasing male partner attendance in antenatal clinics and offering greater testing and counseling services in these settings could not only improve infant health outcomes but probably has an ancillary benefit of increasing HIV testing, treatment and prevention among high risk discordant populations,” Alusio said in conclusion.
During the discussion, members of the audience pointed out that male partner involvement could be very important for HIV-negative mothers as well. A growing number of studies have indicated that pregnant and breastfeeding women are at much heightened risk of acquiring HIV, and women who become infected at this stage are unlikely to receive PVT and far more likely transmit the virus to their child.
Dr Nigel Rollins of WHO also pointed out that it is possible that these men may have been better partners and fathers as well, and that that could account for better outcomes. “In one community in South Africa, a study found that only 27% of children live in the same household, the same physical building as their father,” he said. He suggested that in addition to encouraging male partner testing and clinic attendance, that interventions should involve men in the care of their child.
Alusio noted that in his Kenyan study population over 95% of the women were in monogamous relationships. Translating these findings to southern Africa, where people are more likely to have multiple concurrent partnerships, may prove more challenging.
Further information
Farquhar C et al. Antenatal couple counselling increases uptake of interventions to prevent HIV-1 transmission. Journal of Acquired Immune Deficiency Syndromes. 37:1620–1626, 2004.