Tracking Progress Toward Elimination of Mother to Child Transmission of HIV in Zambia: Findings from the Early Infant Diagnosis of HIV Program (2009-2017).

BACKGROUND: We carried out analyses of early infant testing results at Livingstone Central Hospital in Zambia to assess time of testing, linkages to care and availability of test results for clinical decision making. METHODS: We abstracted data from registers of HIV-exposed infants who had dried blood spots cards (DBS) collected for DNA-PCR from January 2009 to December 2017. Only those tested from 2014 to 2017 had additional data which were used to estimate risk factors for mother-to-child HIV transmission using logistic regression models. RESULTS: DBS were collected from 2630 children. The proportion of HIV-positive tests decreased from 21% in 2009 to 2% in 2016 and 2017. Median turnaround time for results was 9 weeks (IQR: 5, 15) for HIV-negative, 7 weeks (IQR: 5, 13) for HIV-positive children. Only 2% of infants whose mothers took antiretroviral therapy (ART) were HIV positive, while 18% of infants whose mothers took short course antiretroviral drugs (ARVs) were infected. Infants of mothers who did not take ARVs had 9 times the odds of an HIV positive test (OR = 8.9, 95% CI: 3.6, 22.6). Infants of mothers who received short course ARVs were 40% less likely to get an HIV test within the first 2 months of life (OR = 0.6, 95% CI: 0.4, 0.9) compared to infants of mothers who received ART. Only 52% had a third test at median age 52 weeks (IQR: 50, 54). CONCLUSIONS: Long turnaround time for test results and low retention in care after the initial HIV test were critical challenges to clinical decision making.

Predictors of loss to follow-up among children on long-term antiretroviral therapy in Zambia (2003-2015).

BACKGROUND: Retention in care is critical for children living with HIV taking antiretroviral therapy (ART). Loss to follow-up (LTFU) is high in HIV treatment programs in resource limited settings. We estimated the cumulative incidence of LTFU and identified associated risk factors among children on ART at Livingstone Central Hospital (LCH), Zambia. METHODS: Using a retrospective cohort study design, we abstracted data from medical records of children who received ART between 2003 and 2015. Loss to follow-up was defined as no clinical and pharmacy contact for at least 90 days after the child missed their last scheduled clinical visit. Non-parametric competing risks models were used to estimate the cumulative incidence of death, LTFU and transfer. Cause-specific Cox regression was used to estimate the hazard ratios of the risk factors of LTFU. RESULTS: A total of 1039 children aged 0-15 years commenced ART at LCH between 2003 and 2015. Median duration of follow-up was 3.8 years (95% CI: 1.2-6.5), median age at ART initiation was 3.6 years (IQR: 1.3-8.6), 179 (17%) started treatment during their first year of life. At least 167 (16%) were LTFU and we traced 151 (90%). Of those we traced, 39 (26%) had died, 71 (47%) defaulted, 20 (13%) continued ART at other clinics and 21 (14%) continued treatment with gaps. The cumulative incidence of LTFU for the entire cohort was 2.7% (95% CI: 1.9-3.9) at 3 months, 4.1% (95% CI: 2.9-5.4) at 6 months and 14.1% (95% CI: 12.4-16.9) after 5 years on ART. Associated risk factors were: 1) non-disclosure of HIV status at baseline, aHR = 1.9 (1.2-2.9), 2) No phone ownership, aHR = 2.1 (1.6-2.9), 3) starting treatment between 2013 to 2015, aHR = 5.6 (2.2-14.1). CONCLUSION: Among the children LTFU mortality and default were substantially high. Children who started treatment in recent years (2013-2015) had the highest hazard of LTFU. Lack of access to a phone and non-disclosure of HIV-status to the index child was associated with higher hazards of LTFU. We recommend re-enforcement of client counselling and focused follow-up strategies using modern technology such as mobile phones as adjunct to current approaches.

Long-term survival outcomes of HIV infected children receiving antiretroviral therapy: an observational study from Zambia (2003-2015).

BACKGROUND: In 2017, 64% of children living with HIV in Zambia accessed Antiretroviral Therapy (ART). Despite expanded ART coverage, there is paucity of information on effectiveness of pediatric ART in reducing mortality. The aim of this research is to describe treatment outcomes, measure mortality rates and assess predictors of mortality among children receiving ART. METHODS: Using a retrospective cohort study design, we abstracted routinely collected clinical data from medical records of children from birth to 15 years old, who had received ART for at least 6 months at Livingstone Central Hospital in Southern Province Zambia, between January 2003 and June 2015. The primary outcome was death. Cause of death was ascertained from medical records and death certificates. Distribution of survival times according to baseline covariates were estimated using Kaplan Meier and Cox Proportional Hazards methods. RESULTS: Overall, 1039 children were commenced on ART during the study period. The median age at treatment initiation was 3.6 years (IQR: 1.3-8.6) and 520 (50%) children were female. Of these, 71 (7%) died, 164 (16%) were lost to follow-up, 210 (20%) transferred and 594 (56%) were actively on treatment. After 4450 person years, mortality rate was 1.6/100 (95% CI: 1.4-1.8). Mortality was highest during the first 3 months of treatment (11.7/100 (95% CI: 7.6-16.3). In multivariable proportional hazards regression, the adjusted hazards of death were highest among children aged < 1 year (aHR = 3.1 (95% CI: 1.3-6.4), compared to those aged 6-15 years, WHO stage 4 (aHR =4.8 (95% CI: 2.3-10), compared to WHO stage 1 and 2. In the sensitivity analysis to address bias due to loss to follow-up, mortality increased 5 times when we assumed that all the children who were lost to follow up died within 90 days of their last visit. CONCLUSION: We observed low attrition due to mortality among children on ART. Loss to follow-up was high (16%). Mortality was highest during the first 3 months of treatment. Children aged less than one year and those with advanced WHO disease stage had higher mortality. We recommend effective interventions to improve retention in care and early diagnosis of HIV in children.