Preterm birth among women living with HIV: impact of preconception cART initiation.

OBJECTIVE: To examine the risk of preterm birth (PTB) and small for gestational age (SGA) among women living with HIV compared to women without HIV. Secondary objectives were to explore the role of maternal immune activation (IA) and effect of cART timing on these outcomes. DESIGN: Prospective observational cohort. SETTING: Urban government-run clinic at Chawama Hospital in Lusaka, Zambia. PARTICIPANTS: 1481 women with and without HIV with singleton pregnancies enrolled before 26 weeks' gestation by ultrasound dating. METHODS: From August 2019 to November 2022, pregnant women were enrolled in a 1:1 ratio of HIV infection. Maternal baseline clinical factors were collected, as well as CD4, viral load and CD8 T-cell IA in women with HIV. Birth outcomes were also collected. The association of HIV-exposure and cART timing on outcomes was assessed by multivariable logistic regression. The independent role of IA was determined by mediation analysis. MAIN OUTCOME MEASURES: PTB (<37 weeks) and SGA. RESULTS: There were 38 fetal deaths and 1230 singleton live births. Maternal HIV infection was associated with PTB (AOR 1.60, 95%CI 1.11-2.32) and to a lesser extent SGA (AOR 1.29, 0.98-1.70). Maternal cART timing impacted these associations, with highest risk in women who started cART after conception (PTB AOR 1.77, 95%CI 1.09-2.87, SGA AOR 1.52, 95%CI 1.04-2.22). Maternal IA was not associated with PTB independent of HIV infection. CONCLUSIONS: HIV is associated with PTB. Risk of PTB and SGA was highest in women with HIV who started cART in pregnancy, a modifiable risk factor.

Single-test syphilis serology: A case of not seeing the forest for the trees.

INTRODUCTION: There have been few empirical studies for diagnostic test accuracy of syphilis using a sequence of rapid tests in populations with low prevalence of syphilis such as pregnant women. This analysis describes syphilis test positivity frequency among pregnant women at an antenatal clinic in Zambia using a reverse-sequence testing algorithm for antenatal syphilis screening. METHODS: Between August 2019 and May 2023, we recruited 1510 pregnant women from a peri-urban hospital in Lusaka, Zambia. HIV positive and HIV negative women were enrolled in a 1:1 ratio. Blood collected at recruitment from the pregnant mothers was tested on-site for syphilis using a rapid treponemal test. Samples that tested positive were further tested at a different laboratory, with rapid plasma reagin using archived plasma. RESULTS: Of the total 1,421 sera samples which were screened with a rapid treponemal test, 127 (8.9%) were positive and 1,294 (91.1%) were negative. Sufficient additional samples were available to perform RPR testing on 114 of the 127 (89.8%) RDT positive specimens. Thirty-one (27.2%) of these 114 were reactive by RPR and 83 (72.8%) were negative, resulting in a syphilis overtreatment rate of 3 fold (i.e, 84/114). Insufficient sample or test kit availability prevented any testing for the remaining 89 (5.9%) participants. CONCLUSION: Use of only treponemal tests in low prevalence populations, like pregnant women, subjects individuals with non-active syphilis to the costs and possible risks of overtreatment. The use of the dual treponemal and non-treponemal tests would minimize this risk at some additional cost.