2020 Ebola virus disease outbreak in Équateur Province, Democratic Republic of the Congo: a retrospective genomic characterisation.

BACKGROUND: The Democratic Republic of the Congo has had 15 Ebola virus disease (EVD) outbreaks, from 1976 to 2023. On June 1, 2020, the Democratic Republic of the Congo declared an outbreak of EVD in the western Équateur Province (11th outbreak), proximal to the 2018 Tumba and Bikoro outbreak and concurrent with an outbreak in the eastern Nord Kivu Province. In this Article, we assessed whether the 11th outbreak was genetically related to previous or concurrent EVD outbreaks and connected available epidemiological and genetic data to identify sources of possible zoonotic spillover, uncover additional unreported cases of nosocomial transmission, and provide a deeper investigation into the 11th outbreak. METHODS: We analysed epidemiological factors from the 11th EVD outbreak to identify patient characteristics, epidemiological links, and transmission modes to explore virus spread through space, time, and age groups in the Équateur Province, Democratic Republic of the Congo. Trained field investigators and health professionals recorded data on suspected, probable, and confirmed cases, including demographic characteristics, possible exposures, symptom onset and signs and symptoms, and potentially exposed contacts. We used blood samples from individuals who were live suspected cases and oral swabs from individuals who were deceased to diagnose EVD. We applied whole-genome sequencing of 87 available Ebola virus genomes (from 130 individuals with EVD between May 19 and Sept 16, 2020), phylogenetic divergence versus time, and Bayesian reconstruction of phylogenetic trees to calculate viral substitution rates and study viral evolution. We linked the available epidemiological and genetic datasets to conduct a genomic and epidemiological study of the 11th EVD outbreak. FINDINGS: Between May 19 and Sept 16, 2020, 130 EVD (119 confirmed and 11 probable) cases were reported across 13 Équateur Province health zones. The individual identified as the index case reported frequent consumption of bat meat, suggesting the outbreak started due to zoonotic spillover. Sequencing revealed two circulating Ebola virus variants associated with this outbreak-a Mbandaka variant associated with the majority (97%) of cases and a Tumba-like variant with similarity to the ninth EVD outbreak in 2018. The Tumba-like variant exhibited a reduced substitution rate, suggesting transmission from a previous survivor of EVD. INTERPRETATION: Integrating genetic and epidemiological data allowed for investigative fact-checking and verified patient-reported sources of possible zoonotic spillover. These results demonstrate that rapid genetic sequencing combined with epidemiological data can inform responders of the mechanisms of viral spread, uncover novel transmission modes, and provide a deeper understanding of the outbreak, which is ultimately needed for infection prevention and control during outbreaks. FUNDING: WHO and US Centers for Disease Control and Prevention.

Circulating angiogenic factors in singleton vs multiple-gestation pregnancies.

OBJECTIVE: Placental soluble fms-like tyrosine kinase-1 may contribute to the pathogenesis of preeclampsia. Here we describe alterations in serum angiogenic factor levels in women with multiple gestation pregnancies, a major preeclampsia risk factor. STUDY DESIGN: We collected serial serum specimens from 101 pregnant women at high preeclampsia risk between 22 and 36 weeks' gestation. Soluble fms-like tyrosine kinase-1 and placental growth factor were measured by enzyme-linked immunosorbent assay. Women who had preeclampsia or gestational hypertension develop were excluded. RESULTS: Maternal soluble fms-like tyrosine kinase-1 was higher in multiple gestation (n = 20) compared with high-risk singleton (n = 81) pregnancies for each gestational age range examined. Maternal placental growth factor was significantly higher in multiple vs high-risk singletons before 31 weeks' gestation, whereas the soluble fms-like tyrosine kinase-1/placental growth factor ratio was higher in multiple vs high-risk singletons after 27 weeks. CONCLUSION: Alterations in circulating angiogenic factors are present in women with multiple gestations and may contribute to higher preeclampsia risk in this population.