Prevalence of microcephaly and Zika virus infection in a pregnancy cohort in Kenya, 2017–2019

Abstract

Background Zika virus (ZIKV), first discovered in Uganda in 1947, re-emerged globally in 2013 and was later associated with microcephaly and other birth defects. We determined the incidence of ZIKV infection and its association with adverse pregnancy and fetal outcomes in a pregnancy cohort in Kenya. Methods From October 2017 to July 2019, we recruited and followed up women aged ≥ 15 years and ≤ 28 weeks pregnant in three hospitals in coastal Mombasa. Monthly follow-up included risk factor questions and a blood sample collected for ZIKV serology. We collected anthropometric measures (including head circumference), cord blood, venous blood from newborns, and any evidence of birth defects. Microcephaly was defined as a head circumference (HC) < 2 standard deviations (SD) for sex and gestational age. Severe microcephaly was defined as HC < 3 SD for sex and age. We tested sera for anti-ZIKV IgM antibodies using capture enzyme-linked immunosorbent assay (ELISA) and confirmed positives using the plaque reduction neutralization test (PRNT90) for ZIKV and for dengue (DENV) on the samples that were ZIKV neutralizing antibody positive. We collected blood and urine from participants reporting fever or rash for ZIKV testing. Results Of 2889 pregnant women screened for eligibility, 2312 (80%) were enrolled. Of 1916 recorded deliveries, 1816 (94.6%) were live births and 100 (5.2%) were either stillbirths or spontaneous abortions (< 22 weeks of gestation). Among 1236 newborns with complete anthropometric measures, 11 (0.9%) had microcephaly and 3 (0.2%) had severe microcephaly. A total of 166 (7.2%) participants were positive for anti-ZIKV IgM, 136 of whom became seropositive during follow-up. Among the 166 anti-ZIKV IgM positive, 3 and 18 participants were further seropositive for ZIKV and DENV neutralizing antibodies, respectively. Of these 3 and 18 pregnant women, one and 13 (72.2%) seroconverted with antibodies to ZIKV and DENV, respectively. All 308 samples (serum and urine samples collected during sick visits and samples that were anti-ZIKV IgM positive) tested by RT-PCR were negative for ZIKV. No adverse pregnancy or neonatal outcomes were reported among the three participants with confirmed ZIKV exposure. Among newborns from pregnant women with DENV exposure, four (22.2%) were small for gestational age and one (5.6%) had microcephaly. Conclusions The prevalence of severe microcephaly among newborns in coastal Kenya was high relative to published estimates from facility-based studies in Europe and Latin America, but little evidence of ZIKV transmission. There is a need for improved surveillance for microcephaly and other congenital malformations in Kenya.

Seroconversion and seroprevalence of TORCH infections in a pregnant women cohort study, Mombasa, Kenya, 2017–2019

“…A second subset of 285 participants who had both an enrollment specimen and a delivery specimen available were tested for the 10 TORCH pathogens to determine seroconversion rates. ZIKV-positive specimens were excluded from this study analysis and previously published [ 2 ]. A total of 62 (13.4%) of the women were ≤ 20 years old, 333 (71.9%) were between the ages of 21–35 years old, and 68 (14.7%) were > 35 years old.…”

“…We conducted a study on ZIKV among pregnant women in Mombasa, Kenya. This ZIKV pregnancy cohort study was designed to detect active transmission of ZIKV and determine if infection during pregnancy with the African strain of ZIKV caused adverse birth outcomes [ 2 ]. Using this pregnancy cohort study, we conducted a secondary analysis to determine the presence of other TORCH pathogens (excluding ZIKV) and their association with adverse birth outcomes.…”

Abordagem Interprofissional Na Compreensão Da Evolução Da Mortalidade Por Câncer De Mama Em Mulheres Jovens: Perspectivas Para Aprimorar a Política De Atenção Oncológica

“…No existen evidencias de detección de virus Zika en suero en este grupo de mujeres por RT-qPCR, solo se han detectado anticuerpos IgM contra Zika en embarazadas de Kenia (Osoro et al, 2022) y en líquido amniótico a través de RT-qPCR y secuenciación metagenómica viral de nueva generación en mujeres embarazadas de Brasil, lo cual refuerza la posible asociación entre este virus y los casos de microcefalia en neonatos en Brasil, ya que el virus atraviesa la barrera placentaria (Calvet et al, 2016). Interesantemente, no hay evidencias en la literatura sobre la detección de estos virus en saliva en este grupo de mujeres, no obstante, la utilidad de este fluido en la detección de virus Zika recientemente ha sido reportada en 18 de 22 pacientes de Nueva Caledonia y Guayana Francesa (Fraiture et al, 2021); lo que sugiere la capacidad potencial de las muestras no invasivas para abarcar un mayor número de casos infectados que las muestras invasivas (Humaidi et al, 2021).…”

mTOR signaling regulates Zika virus replication bidirectionally through autophagy and protein translation

“…The majority of ZIKV‐infected individuals are asymptomatic or have febrile symptoms, but severe neurological symptoms can also manifest 2 . Moreover, mother‐to‐fetus transmission results in the severe birth defect microcephaly, indicating that ZIKV can pass through placental and blood‒brain barriers 3 . As a member of the Flaviviridae family, ZIKV is a single positive‐stranded RNA virus with an 11 kb genome encoding three structural proteins, including envelope protein (E), capsid protein (C) and precursor membrane protein (prM), and seven nonstructural proteins (NSs) 4 .…”