ABSTRACT
Seven years after the declaration of the first epidemic of Ebola virus disease in Guinea, the country faced a new outbreak-between 14 February and 19 June 2021-near the epicentre of the previous epidemic1,2. Here we use next-generation sequencing to generate complete or near-complete genomes of Zaire ebolavirus from samples obtained from 12 different patients. These genomes form a well-supported phylogenetic cluster with genomes from the previous outbreak, which indicates that the new outbreak was not the result of a new spillover event from an animal reservoir. The 2021 lineage shows considerably lower divergence than would be expected during sustained human-to-human transmission, which suggests a persistent infection with reduced replication or a period of latency. The resurgence of Zaire ebolavirus from humans five years after the end of the previous outbreak of Ebola virus disease reinforces the need for long-term medical and social care for patients who survive the disease, to reduce the risk of re-emergence and to prevent further stigmatization.
Subject(s)
Disease Outbreaks , Ebolavirus/genetics , Ebolavirus/isolation & purification , Hemorrhagic Fever, Ebola/epidemiology , Hemorrhagic Fever, Ebola/virology , Models, Biological , Animals , Democratic Republic of the Congo/epidemiology , Disease Outbreaks/statistics & numerical data , Ebolavirus/classification , Female , Guinea/epidemiology , Hemorrhagic Fever, Ebola/transmission , High-Throughput Nucleotide Sequencing , Humans , Male , Persistent Infection/virology , Phylogeny , Survivors , Time Factors , Viral Zoonoses/transmission , Viral Zoonoses/virologyABSTRACT
BACKGROUND: The Expanded Program on Immunisation has made it possible to prevent more than 3 million deaths in children under 5 years. The objectives of this study were to estimate the vaccination coverage of children from 0 to 59 months and identify factors associated with incomplete vaccination coverage. METHODS: A cross-sectional study was carried out in a dispensary in Conakry, Guinea between January and February 2020. Sociodemographic and vaccination information was collected from mothers of 380 randomly select children aged 0 to 59 months. Information on immunisation coverage was gathered from records vaccination cards and maternal reports. Logistic regression was used to identify factors independently associated with incomplete immunisation coverage. RESULTS: Most (66.5%) children aged < 12 months were up-to-date with their vaccinations. Factors associated with incomplete vaccination in this age group included: unavailability of vaccination cards (adjusted odds ratio [aOR] 7.58; 95% confidence interval [CI]: 2.56-22.44) and lack of prenatal consultation attendance (aOR 2.93; 95% CI: 1.15-7.48). In contrast only 19.8% (95% CI: 13.9-26.7) of children aged 12-59 months were fully immunised. Factors associated with incomplete vaccination coverage in children aged 12-59 months included high birth order (aOR 10.23; 95% CI: 2.06-19.43), and lack of prenatal consultation attendance (aOR 5.34; 95% CI: 1.48-19.23). CONCLUSION: Child immunisation coverage is low in Guinea. These results highlight the need to develop strategies based on an integrated approach to overcome obstacles to childhood immunisation in Guinea.
ABSTRACT
The recent Zaire Ebola virus (EBOV) outbreak in West Africa illustrates clearly the need for additional studies with humans and animals to elucidate the ecology of Ebola viruses (EBVs). In this study, we developed a serological assay based on the Luminex technology. Nine recombinant proteins representing different viral regions (nucleoprotein [NP], 40-kDa viral protein [VP40], and glycoprotein [GP]) from four of the five EBV lineages were used. Samples from 94 survivors of the EBOV outbreak in Guinea and negative samples from 108 patients in France were used to calculate test performance for EBOV detection and cross-reaction with other Ebola virus lineages. For EBOV antibody detection, sensitivities of 95.7%, 96.8%, and 92.5% and specificities of 94.4%, 95.4%, and 96.3% for NP, GP, and VP40, respectively, were observed. All EBOV-negative samples that presented a reaction, except for one, interacted with a single antigen, whereas almost all samples from EBOV survivors were simultaneously reactive with NP and GP (90/94) or with NP, GP, and VP40 (87/94). Considering as positive for past EBOV infection only samples that reacted with EBOV NP and GP, sensitivity was 95.7% and specificity increased to 99.1%. Comparing results with commercial EBOV NP and GP enzyme-linked immunosorbent assays (ELISAs; Alpha Diagnostic, San Antonio, TX), lower sensitivity (92.5%) and high specificity (100%) were observed with the same positivity criteria. Samples from EBOV survivors cross-reacted with GP from Sudan Ebola virus (GP-SUDV) (81.9%), GP from Bundibugyo Ebola virus (GP-BDBV) (51.1%), GP from Reston Ebola virus (GP-RESTV) (9.6%), VP40-SUDV (76.6%), and VP40-BDBV (38.3%). Overall, we developed a sensitive and specific high-throughput serological assay, and defined an algorithm, for epidemiological surveys with humans.
Subject(s)
Antibodies, Viral/blood , Antigens, Viral/immunology , Ebolavirus/immunology , Hemorrhagic Fever, Ebola/diagnosis , Serologic Tests/methods , Africa , Cross Reactions , France , Humans , Sensitivity and SpecificityABSTRACT
Ninety-eight semen specimens were obtained for Ebola virus (EBOV) RNA screening from 68 men in Guinea during the convalescent phase of EBOV infection. Ten samples from 8 men were positive for EBOV up to 9 months after onset of the disease, with decreasing trends in the proportion of positive samples and the level of viral RNA. Safe sex practices should be observed after discharge from treatment centers.
