Analysis of Ebola Virus Outbreak in 2014
The 2013–present Western African Ebola virus disease (EVD) outbreak is the largest ever recorded with >28,000 reported cases. Ebola virus (EBOV) genome sequencing has played an important role throughout this outbreak; however, relatively few sequences have been determined from patients in Liberia, the second worst-affected country. There has been announced 140 EBOV genome sequences from the second wave of the Liberian outbreak and analyze them in combination with 782 previously published sequences from throughout the Western African outbreak.
In Africa, fruit bats are believed to be the natural hosts of Ebola virus. The virus is transmitted from wildlife to people through contact with infected fruit bats, or through intermediate hosts, such as monkeys, apes, or pigs that have themselves become infected through contact with bat saliva or faeces. People may then become infected through contact with infected animals, either in the process of slaughtering or through consumption of blood, milk, or raw or undercooked meat. The virus is then passed from person to person through direct contact with the blood, secretions or other bodily fluids of infected persons, or from contact with contaminated needles or other equipment in the environment.EVD, which has a case fatality rate of up to 90%, is a severe acute viral illness often characterized by the sudden onset of fever, intense weakness, muscle pain, headache, nausea and sore throat. This is followed by vomiting, diarrhoea, impaired kidney and liver function, and in some cases, both internal and external bleeding. Laboratory findings frequently include low white blood cell and platelet counts and elevated liver enzymes.
When the outbreak began to spread, the establishment of isolation facilities in the affected areas was one of the first and fundamental steps to control virus diffusion and to provide medical assistance to suspected and confirmed cases. WHO and the Global Outbreak Alert and Response Network (GOARN) deployed experts to support every step of the operational response: surveillance and epidemiology, infection prevention and control, case management, public information, and social mobilization [World Health Organization (WHO)]. Fast and precise diagnostic capability to identify infected patients was provided by different laboratories and organization, first of all the Institut Pasteur in Dakar, which deployed a mobile laboratory team in Guinea. WHO alerted all bordering countries to increase surveillance for symptoms consistent with viral hemorrhagic fever and started to train health and community workers to detect, notify, and manage suspected cases [World Health Organization (WHO) Global Alert and Response].
In fact, the Liberian public-sector primary healthcare system has made strides towards recovery from the 2014–2015 EVD outbreak. All primary healthcare indicators tracked have recovered to pre-EVD levels as of November 2016. Yet, for most indicators, it took more than 1 year to recover to pre-EVD levels. During this time, large losses of essential primary healthcare services occurred compared to what would have been expected had the EVD outbreak not occurred. The disruption of malaria case management during the EVD outbreak may have resulted in increased malaria cases. Large and sustained investments in public-sector primary care health system strengthening are urgently needed for EVD-affected countries.
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