RESUMO
BACKGROUND: In 2017, the Democratic Republic of the Congo (DRC) recorded its eighth Ebola virus disease (EVD) outbreak, approximately 3 years after the previous outbreak. METHODS: Suspect cases of EVD were identified on the basis of clinical and epidemiological information. Reverse transcription-polymerase chain reaction (RT-PCR) analysis or serological testing was used to confirm Ebola virus infection in suspected cases. The causative virus was later sequenced from a RT-PCR-positive individual and assessed using phylogenetic analysis. RESULTS: Three probable and 5 laboratory-confirmed cases of EVD were recorded between 27 March and 1 July 2017 in the DRC. Fifty percent of cases died from the infection. EVD cases were detected in 4 separate areas, resulting in > 270 contacts monitored. The complete genome of the causative agent, a variant from the Zaireebolavirus species, denoted Ebola virus Muyembe, was obtained using next-generation sequencing. This variant is genetically closest, with 98.73% homology, to the Ebola virus Mayinga variant isolated from the first DRC outbreaks in 1976-1977. CONCLUSION: A single spillover event into the human population is responsible for this DRC outbreak. Human-to-human transmission resulted in limited dissemination of the causative agent, a novel Ebola virus variant closely related to the initial Mayinga variant isolated in 1976-1977 in the DRC.
Assuntos
Surtos de Doenças , Ebolavirus/genética , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/epidemiologia , Adolescente , Adulto , República Democrática do Congo/epidemiologia , Ebolavirus/imunologia , Feminino , Doença pelo Vírus Ebola/transmissão , Doença pelo Vírus Ebola/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testes Sorológicos , Adulto JovemRESUMO
The international response to the evolving Ebola epidemic in eastern Democratic Republic of Congo (DRC) has had interim successes while facing ongoing difficulties. The outbreak has occurred in an area of intractable conflict among multiple armed groups at a time of contentious national elections. Despite porous international borders and considerable population movement, however, transmission has been confined to North Kivu and Ituri provinces. Factors potentially contributing to this containment include conduct of about 55 million screenings, surveillance of contacts (12,591 under surveillance currently), testing of 280 samples per day, provision of safe and dignified burials for most deaths, vaccination of high-risk people (112,485 vaccinated as of May 7, 2019), and medical treatment including four investigational therapies. Major challenges remain. Since late February 2019, a sharp rise in cases and increased transmission have been observed. These coincide with organized attacks by armed groups targeting response teams, deteriorating security, and the population's increasing distrust of the response effort. The risk of local and regional spread remains high given the high proportion of deaths occurring outside treatment facilities, relatively low proportions of new patients who were known contacts, ongoing nosocomial transmission, and persistent delays in detection and reporting. Stopping this epidemic will require the alignment of the principal political and armed groups in eastern DRC in support of the response.
