Role of antenatal plasma cytomegalovirus DNA levels on pregnancy outcome and HIV-1 vertical transmission among mothers in the University of Zimbabwe birth cohort study (UZBCS).

INTRODUCTION Despite being a leading infectious cause of childhood disability globally, testing for cytomegalovirus (CMV) infections in pregnancy is generally not done in Sub-Sahara Africa (SSA), where breastfeeding practice is almost universal. Whilst CMV and human immunodeficiency virus (HIV) are both endemic in SSA, the relationship between antenatal plasma CMV-DNA, HIV-1-RNA levels and HIV-1-mother to child transmission (MTCT) including pregnancy outcomes remains poorly described. METHODS Pregnant women at least 20 weeks' gestational age at enrolment were recruited from relatively poor high-density suburbs in Harare, Zimbabwe. Mother-infant dyads were followed up until 6 months postpartum. In a case-control study design, we tested antenatal plasma CMV-DNA levels in all 11 HIV-1 transmitting mothers, as well as randomly selected HIV-infected but non-transmitting mothers and HIV-uninfected controls. CMV-DNA was detected and quantified using polymerase chain reaction (PCR) technique. Antenatal plasma HIV-1-RNA load was quantified by reverse transcriptase PCR. Infants' HIV-1 infection was detected using qualitative proviral DNA-PCR. Predictive value of antenatal plasma CMV-DNAemia (CMV-DNA of > 50 copies/mL) for HIV-1-MTCT was analyzed in univariate and multivariate regression analyses. Associations of CMV-DNAemia with HIV-1-RNA levels and pregnancy outcomes were also explored. RESULTS CMV-DNAemia data were available for 11 HIV-1 transmitting mothers, 120 HIV-infected but non-transmitting controls and 46 HIV-uninfected mothers. In a multivariate logistic regression model, we found a significant association between CMV-DNAemia of > 50 copies/mL and HIV-1 vertical transmission (p = 0.035). There was no difference in frequencies of detectable CMV-DNAemia between HIV-infected and -uninfected pregnant women (p = 0.841). However, CMV-DNA levels were higher in immunosuppressed HIV-infected pregnant women, CD4   50 copies/mL correlated significantly with antenatal plasma HIV-1-RNA load (p = 0.002). CONCLUSION Antenatal plasma CMV-DNA of > 50 copies/mL may be an independent risk factor for HIV-1-MTCT and higher plasma HIV-1-RNA load, raising the possibility that controlling antenatal CMV-DNAemia might improve infant health outcomes. Further studies with larger sample sizes are warranted to confirm our findings.