National-level effectiveness of ART to prevent early mother to child transmission of HIV in Namibia

• Published in: PloS one 2020-11, Vol.15 (11), p.e0233341-e0233341
• Main Authors: Agabu, Andrew, Baughman, Andrew L, Fischer-Walker, Christa, de Klerk, Michael, Mutenda, Nicholus, Rusberg, Francina, Diergaardt, Dorothea, Pentikainen, Ndumbu, Sawadogo, Souleymane, Agolory, Simon, Dinh, Thu-Ha
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age; AIDS research; Anti-HIV Agents - therapeutic use; Antiretroviral agents; Antiretroviral drugs; Antiretroviral therapy; Babies; Biology and Life Sciences; Breast feeding; Breastfeeding & lactation; Caregivers; Children; Clinics; Confidence intervals; Consent; Deoxyribonucleic acid; Disease control; Disease prevention; Disease transmission; DNA; Drug therapy; Exposure; Female; Health aspects; Health facilities; HIV; HIV - isolation & purification; HIV Infections - drug therapy; HIV Infections - transmission; Human immunodeficiency virus; Humans; Immunization; Infant; Infant, Newborn; Infants; Infectious Disease Transmission, Vertical - prevention & control; Interviews; Laboratories; Male; Maternal and infant welfare; Maternal-fetal exchange; Medical tests; Medicine and Health Sciences; Mothers; Nurses; Patient outcomes; Pediatric HIV infections; People and Places; Postpartum Period; Pregnancy; Pregnancy Complications, Infectious - drug therapy; Pregnant women; Prevention; Prophylaxis; Public health; Questionnaires; Seroconversion; Sick role; Social services; Statistical analysis; Statistical methods; Vaccines; Womens health; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0233341

Namibia introduced the prevention of mother to child HIV transmission (MTCT) program in 2002 and lifelong antiretroviral therapy (ART) for pregnant women (option B-plus) in 2013. We sought to quantify MTCT measured at 4-12 weeks post-delivery. During Aug 2014-Feb 2015, we recruited a nationally representative sample of 1040 pairs of mother and infant aged 4-12 weeks at routine immunizations in 60 public health clinics using two stage sampling approach. Of these, 864 HIV exposed infants had DNA-PCR HIV test results available. We defined an HIV exposed infant if born to an HIV-positive mother with documented status or diagnosed at enrollment using rapid HIV tests. Dried Blood Spots samples from HIV exposed infants were tested for HIV. Interview data and laboratory results were collected on smartphones and uploaded to a central database. We measured MTCT prevalence at 4-12 weeks post-delivery and evaluated associations between infant HIV infection and maternal and infant characteristics including maternal treatment and infant prophylaxis. All statistical analyses accounted for the survey design. Based on the 864 HIV exposed infants with test results available, nationally weighted early MTCT measured at 4-12 weeks post-delivery was 1.74% (95% confidence interval (CI): 1.00%-3.01%). Overall, 62% of mothers started ART pre-conception, 33.6% during pregnancy, 1.2% post-delivery and 3.2% never received ART. Mothers who started ART before pregnancy and during pregnancy had low MTCT prevalence, 0.78% (95% CI: 0.31%-1.96%) and 0.98% (95% CI: 0.33%-2.91%), respectively. MTCT rose to 4.13% (95% CI: 0.54%-25.68%) when the mother started ART after delivery and to 11.62% (95% CI: 4.07%-28.96%) when she never received ART. The lowest MTCT of 0.76% (95% CI: 0.36% - 1.61%) was achieved when mother received ART and ARV prophylaxis within 72hrs for infant and highest 22.32% (95%CI: 2.78% -74.25%) when neither mother nor infant received ARVs. After adjusting for mother's age, maternal ART (Prevalence Ratio (PR) = 0.10, 95% CI: 0.03-0.29) and infant ARV prophylaxis (PR = 0.32, 95% CI: 0.10-0.998) remained strong predictors of HIV transmission. As of 2015, Namibia achieved MTCT of 1.74%, measured at 4-12 weeks post-delivery. Women already on ART pre-conception had the lowest prevalence of MTCT emphasizing the importance of early HIV diagnosis and treatment initiation before pregnancy. Studies are needed to measure MTCT and maternal HIV seroconversion during breastfeeding.