DOI: 10.5061/dryad.6djh9w0zr
title: Data from: National-level effectiveness of ART to prevent early mother to child transmission of HIV in Namibia

description: Background: 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. Methods: 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.
 Results: 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. Conclusion: 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.
description: We conducted a cross–sectional clinic-based survey assessing
 uptake of ART among HIV infected mothers and MTCT prevalence among their
 HIV exposed infants 4-12 weeks of age. We recruited caregivers (hereafter
 referred to as mothers) and their infants from those seeking routine
 immunization or postnatal care services in 60 selected public health
 facilities between August 2014 and February 2015.  We recruited caregivers
 (hereafter referred to as mothers) and their infants from those seeking
 routine immunization or postnatal care services in 60 selected public
 health facilities between August 2014 and February 2015.
 We trained nurses at site level to identify all potentially
 eligible mother-infant pairs and work with trained data collectors to
 complete a standardized screening and interview questionnaire. For those
 who met the inclusion criteria, and provided written consent to
 participate in the study, we used the standardized questionnaire to gather
 sociodemographic data, clinical, treatment, and feeding data from the
 mother-infant pair. In addition to interviewing the mother, some clinical
 information was extracted from the maternal ANC cards and the infant child
 health passports (maternal HIV status, maternal ART use, infant HIV
 exposure status, and infant ARV prophylaxis). Study
 nurses recorded infant HIV PCR tests and results in routine MOHSS clinic
 registers at each site. Confidential participant identification numbers
 were recorded in the study register(s) for infants/mothers enrolled in the
 study. The participant identification number was placed on the dried blood
 spot card, the laboratory request form, and the questionnaire. All
 interview data and laboratory results were collected on password protected
 smartphones and uploaded daily to a secure central database.
description: <b>Column headings</b>
 <b>M_group:</b><i> </i>Mother's age
 group Value of 1 indicates mother aged 19 years or
 less, value of 2 indicates mother aged of 20-24 years,  mother aged 25-29
 years, value 4 indicates mother aged 30-34 years, value 5  indicates
 mother aged 35-39 years, value 6 indicates mother aged 40-44 years,  value
 7 indicate mother aged 45-49 years and value 8 indicates mother aged 50+
 years. <b>M_ART: </b>Mother on
 antiretroviral therapy (ART) Value of 1 indicates
 mother is on ART, value of 2 means mother is not on ART, value of 98 means
 mother refused ART and value of 99 the response was indicated as ‘Don’t
 know’. <b>M_ART_WHEN</b>: When mother
 started taking antiretroviral therapy (ART) Value of 1
 indicates mother started taking ART before pregnancy with this infant,
 value of 2 means mother started taking ART during pregnancy with this
 infant, value of 3 indicates mother started taking ART after delivery of
 this infant and value of 99 means mother’s response is ‘Don’t know or
 cannot remember’. <b>INF_Pr</b>: Child
 given antiretroviral prophylaxis any time after delivery
 Value of 1 indicates child given nevirapine any time
 after delivery, value 2 means child not given nevirapine any time after
 delivery, value of 98 means mother ‘refused’ child to be given Nevirapine
 while 99 means mother’s response is ‘Don’t know’.
 <b>INF_R</b>: Infant laboratory HIV result
 Value of 1 means infant’s HIV result is negative and value of 2
 indicates infant’s HIV test result is positive.
 <b>Missing Data</b>: Missing data (not collected or
 no information provided by participant) are indicated with a
 ‘999’.