Tracing defaulters in HIV prevention of mother‐to‐child transmission programmes through community health workers: results from a rural setting in Zimbabwe

Abstract

IntroductionHigh retention in care is paramount to reduce vertical human immunodeficiency virus (HIV) infections in prevention of mother-to-child transmission (PMTCT) programmes but remains low in many sub-Saharan African countries. We aimed to assess the effects of community health worker–based defaulter tracing (CHW-DT) on retention in care and mother-to-child HIV transmission, an innovative approach that has not been evaluated to date.MethodsWe analyzed patient records of 1878 HIV-positive pregnant women and their newborns in a rural PMTCT programme in the Tsholotsho district of Zimbabwe between 2010 and 2013 in a retrospective cohort study. Using binomial regression, we compared vertical HIV transmission rates at six weeks post-partum, and retention rates during the perinatal PMTCT period (at delivery, nevirapine [NVP] initiation at three days post-partum, cotrimoxazole (CTX) initiation at six weeks post-partum, and HIV testing at six weeks post-partum) before and after the introduction of CHW-DT in the project.ResultsMedian maternal age was 27 years (inter-quartile range [IQR] 23 to 32) and median CD4 count was 394 cells/µL3 (IQR 257 to 563). The covariate-adjusted rate ratio (aRR) for perinatal HIV transmission was 0.72 (95% confidence intervals [95% CI] 0.27 to 1.96, p=0.504), comparing patient outcomes after and before the intervention. Among fully retained patients, 11 (1.9%) newborns tested HIV positive. ARRs for retention in care were 1.01 (95% CI 0.96 to 1.06, p=0.730) at delivery; 1.35 (95% CI 1.28 to 1.42, p<0.001) at NVP initiation; 1.78 (95% CI 1.58 to 2.01, p<0.001) at CTX initiation; and 2.54 (95% CI 2.20 to 2.93, p<0.001) at infant HIV testing. Cumulative retention after and before the intervention was 496 (85.7%) and 1083 (87.3%) until delivery; 480 (82.9%) and 1005 (81.0%) until NVP initiation; 303 (52.3%) and 517 (41.7%) until CTX initiation; 272 (47.0%) and 427 (34.4%) until infant HIV testing; and 172 (29.7%) and 405 (32.6%) until HIV test result collection.ConclusionsThe CHW-DT intervention did not reduce perinatal HIV transmission significantly. Retention improved moderately during the post-natal period, but cumulative retention decreased rapidly even after the intervention. We showed that transmission in resource-limited settings can be as low as in resource-rich countries if patients are fully retained in care. This requires structural changes to the regular PMTCT services, in which community health workers can, at best, play a complementary role.

Outcomes of retained and disengaged pregnant women living with HIV in Uganda

“…Although our study did not have adequate power to detect differences in vertical transmission of HIV, our findings suggest that higher transmission in infants born to DW as compared to RW. Our estimates of HIV transmission among DW were higher than that reported in a study conducted among women who disengaged from care in Zimbabwe, where the observed estimates of 3.6% were reduced to 1.8% following a tracing program which used community workers to ensure that all HIV positive pregnant women were in care throughout the post-partum period [22]. Among the women retained in care, our estimates of vertical transmission are slightly lower than Uganda national estimates of 2.9% [42].…”

“…Several tracing studies have addressed the outcomes of non-pregnant adults who have become LTFU [18][19][20][21]. However, other than three studies from Zimbabwe, eSwatini and Malawi, there is a dearth of knowledge about the outcomes of pregnant women initiating ART who subsequently become LTFU [22][23][24]. Such outcomes may include estimates of HIV viral suppression, MTCT and care status among women who disengage from HIV care programs.…”

Effect of a Mentor Mother Programme on retention of mother-baby pairs in HIV care: A secondary analysis of programme data in Uganda

“…However, loss of clients along the PMTCT cascade is concerning because it is also a crucial period for ART initiation in HIV-infected infants [27]. Similar trends have been observed in other studies where retention was high during pregnancy but decreased rapidly in the postnatal period [28]. Other studies have reported cumulative retention rates of up to 80% six months postpartum [27–29].…”

Improving retention in antenatal and postnatal care: a systematic review of evidence to inform strategies for adolescents and young women living with HIV

“…Notably, only two papers presented age-disaggregated results [26,27] and one additional paper noted that age did not modify the study results [28]. Among all 37 papers evaluating at least one approach to increase retention, 18 demonstrated no effect on retention [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] and 19 reported a significant effect on retention [26][27][28][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62]. Notably, several papers reported significant improvements in retention at some time points but not at others; these are categorized as reporting a significant effect on retention.…”

“…One study was published during 2010 [30], but the remainder were published between 2014 and 2020. Cluster-randomized controlled trials were the most common study design [29,32,[34][35][36][37]39,40,43,47,[56][57][58], and the duration of follow-up across studies ranged from one month [28,30,33,61] to 36 to 60 months' postpartum [38], with two-thirds of studies following women through ≤6 months' postpartum [27,28,30,31,33,[35][36][37][39][40][41][43][44][45]47,48,50,[53][54][55][56][59][60][61][62]. Many studies were restricted to women who were not yet receiving ART when presenting for ANC or delivery, and 12 studies were restricted to women who were aged ≥18 years at enrolment in the study [26,28,29,…”