Mccormick jb, webb pa, krebbs jw, johnson km, smith es 1987b lassa fever. Rift valley fever rvf outbreaks have been associated with periods of. The disease affects domestic and wild pigs and can involve tick vectors. Nov 21, 20 rift valley fever rvf is an emerging zoonosis posing a public health threat to humans in africa. The epidemiology and clinical presentation of lassa fever. Epidemiologic and clinical features of lassa fever. Crump ja, morrissey ab, nicholson wl, massung rf, stoddard ra, et al. Acronyms 1q 0 infant mortality rate per 1,000 live births 4q 1 child mortality rate between exact age 1 and exact age 5 5q 0 underfive mortality rate per 1,000 live births act artemisinin combination therapy alu artemetherlumefantrine anc antenatal care arv antiretroviral therapy cdc centers for disease control and prevention. The temporal analysis demonstrated that the average proportions of pcr and antibodyelisa positive samples from the hunted wild boar remained below 3. A dengue outbreak in cape verde was recently reported 3,000 cases, and. These are thought to be the earliest known items concerning the pos sible role of monkeys in yellow fever epidemiology, and both episodes origi nated in trinidad. Showalter in this work, we construct and analyze a nonlinear reactiondiffusion epidemiology model consisting of two integral. Epidemiological analysis of bovine ephemeral fever in 2012.
It is endemic in parts of west africa including sierra leone, liberia, guinea and nigeria. Q fever, or query fever, is a zoonotic disease caused by the bacterium coxiella burnetii. Fever tuberculosis viruses zoonoses abstract background. Evaluation of the impact of malaria interventions on. Lassa fever is spread through direct contact with the. Prevent, detect, and control diseases of public health importance. Epidemiological analyses of african swine fever in the baltic.
Chikungunya fever, an arboviral disease that is caused. Epidemiological study of relapsing fever in north africa. Of the cases reported so far in the nigerian outbreak, the mortality rate is 43. Mar 16, 2017 viral hemorrhagic fevers vhfs are a group of febrile illnesses caused by rna viruses from several viral families.
These highly infectious viruses lead to a potentially lethal disease syndrome characterized by fever, malaise, vomiting, mucosal and gastrointestinal gi. The existing outbreak data was not compiled which is important for the provision of epidemiological information as a base for the health care systems, and to make possible preventive and curative measures for the coming dengue fever outbreak. Name at least two countries where lassa fever is endemic. Pdf epidemiological trends of lassa fever outbreaks and. Lassa fever lf, an acute viral haemorrhagic fever, is an endemic zoonotic viral infection in west africa countries with up to % case fatality rate. Efsa assisted four countries in the analysis of epidemiological data on african swine fever asf, collected until september 2017. Mccormick jb, webb pa, krebs jw, johnson km, smith e 1987 b a prospective study of the epidemiology and ecology of lassa fever. Mosquitoes capable of transmitting yellow fever exist in regions. Epidemiological notes in connection with the 1954 outbreak of.
Compared with nine reporting countries in the 1950s, today the geographic distribution includes more than 100 countries worldwide. The virus exhibits persistent, asymptomatic infection with. Since 2015, major increases in lassa fever attack rate and in the casefatality rate have occurred in this state. Highlights african swine fever is a highly contagious swine disease with severe socioeconomic consequences. Lassa fever, also known as lassa hemorrhagic fever lhf, is a type of viral hemorrhagic fever caused by the lassa virus.
Chikungunya virus chikv is the aetiological agent of the mosquitoborne disease chikungunya fever, a debilitating arthritic disease that, during the past 7. Clinical presentation of lassa fever cases during the hospital epidemic at zorzor, liberia, marchapril 1972. Epidemiologic investigations into outbreaks of rift valley. It is a disease of poor environmental sanitation and hence occurs in parts of the world where water supply is unsafe and sanitation is substandard. Firsthand clinical observations of hemorrhagic manifestations in ebola hemorrhagic fever in zaire.
Epidemiologyoccurs worldwide though less commonly in the tropics1. Etiology of severe nonmalaria febrile illness in northern. In edo state, nigeria, health researchers are collecting data on lassa fever to improve health education and protect people from getting infected. An integrated approach to the syndrome of fever in resourcelimited areas is needed to improve patient outcomes and to rationally target disease control efforts.
Neighboring countries are also at risk, as the animal vector for lassa virus, the multimammate rat mastomys natalensis is distributed throughout the region. Lassa fever, viral haemorrhagic fever, mastomys introduction lassa fever lf is an acute viral haemorrhagic illness that is caused by an arenavirus. Since november 2015, at least 10 states in nigeria have been affected by an outbreak of lassa fever, an acute viral disease that causes fever, muscle pain, hemorrhage and sometimes death. Yellow fever yf, an endemic mosquitoborne viral infection of humans and nonhuman primates in tropical regions of africa and south america, is currently an important cause of haemorrhagic feverrelated death worldwide, affecting as many as 200 000 persons annually in these regions monath, 2001. Dengue fever df is globally emerging mosquito born viral disease. Epidemiology of dengue fever in ethiopian somali region. Epidemiological notes in connection with the 1954 outbreak.
Less commonly there may be bleeding from the mouth or. Viral hemorrhagic fevers vhfs are a group of febrile illnesses caused by rna viruses from several viral families. Keep your home clean and tidy to discourage rats from entering 4. Rift valley fever rvf is an emerging zoonosis posing a public health threat to humans in africa. Clinical presentation is varied, mainly presenting with fever, malaise, abdominal discomfort, and nonspecific symptoms often confused with other causes. World health organization, 2000 that is, not published by merlin, as was stated. Lassa fever is one of the hemorrhagic fevers and may appear with signs and symptoms like ebola or marburg hemorrhagic fever viruses, and until these viruses are ruled out, suspected cases must be managed with infection control precautions to prevent contact with blood, body fluids, and contaminated surfaces. The causative agent, yellow fever virus yfv, is the prototype of the genus. Lassa fever, a new virus disease of man from west africa.
Barnett maxwell finland laboratory for infectious diseases, boston medical center, boston, massachusetts yellow fever continues to occur in regions of africa and south america, despite the availability of effective vaccines. Less commonly there may be bleeding from the mouth or gastrointestinal tract. The fever which has afflicted over 284 has killed about 154 nigerians from different parts of the country from august 2015 to. For 2016, eueea countries reported three cases of lassa fever. Many of those infected by the virus do not develop symptoms. Dec 02, 2016 dengue fever df is globally emerging mosquito born viral disease. Two hundred and eight patients 90% presented as fid, with n3 or without n75 hepatitis. When symptoms occur they typically include fever, weakness, headaches, vomiting, and muscle pains. Researching awareness, risk factors and seroprevalence of. Baseline mapping of lassa fever virology, epidemiology and. Clinical polymorphism is a main feature of q fever and, depending upon the geographic location, differences in its clinical picture have been described. Clinical and epidemiological characteristics of yellow. Dengue is the most important arthropodborne viral disease of public health significance.
Significant viral hemorrhagic fever and arboviruses 4 10 100. Nigeria may be battling the worst outbreak of lassa fever in history. The world health organization estimates that more than 2. In this article, we report an analysis of the epidemiologic and clinical aspects of the lf outbreak that occurred in nigeria during january 1may 6, 2018.
Lassa fever is an acute viral zoonotic illness caused by lassa virus, an arenavirus known to be responsible for a severe haemorrhagic fever characterised by fever, muscle aches, sore throat, nausea, vomiting and, chest and abdominal pain. Lassa fever epidemiology in nigeria implications for research pdf. She died approximately one week after the onset of symptoms. A research manual for south africa maintains the focus on epidemiology as a discipline and incorporates the changes in policy as well as new findings and research methodologies. Lassa fever from the ashanti region of ghana detected in october and december, 2011.
The nurse presumably acquired infection from an obstetrical patient residing in lassa. Lassa fever accounts for an estimated 200,000 to 500,000 cases and 5000 deaths yearly in west africa, particularly in sierra leone, nigeria, liberia and r epublic of guinea. The objective of this study was to determine the epidemiology, clinical features and prognosis of acute q fever in our area. In lassa fever endemic regions such as nigeria, a suspected case is defined 23 as an illness with onset of fever and no response to treatment of usual causes of fever in the ar ea and at.
The natural reservoir of the lassa virus is multimammate rat species known as mastomys natalencesis fisherhoch et al, 1995. The history of recognized human arenavirus infection in africa began in 1969 with the mysterious death of two medical missionaries and the nearfatal illness of a third frame et al. Incidence peaked in late summer to early autumn each year, which coincided with incidence rate. Epidemiologic and environmental risk factors of rift. Lassa fever is an animalborne, or zoonotic, acute viral illness. Since the steady rise in human cases which started in 2007, q fever has become a major public health problem in the netherlands with 2,357 human cases notified in the year 2009.
Clinical and epidemiological characteristics of yellow fever. Lasv was first isolated in 1969 from a missionary nurse who worked in a clinic in a small town, lassa, in northeastern nigeria. Sep 11, 2016 nigeria may be battling the worst outbreak of lassa fever in history. Cattle, sheep and goats are the primary domestic animal reservoirs, and the bacteria are excreted in high numbers in birth products, milk, urine and faeces.
Lassa fever annual epidemiological report for 2016 en pdf275. Epidemiological analyses on african swine fever in the baltic countries and poland european food safety authority efsa, jose corti nas abrahantes, andrey gogin, jane richardson and andrea gervelmeyer abstract african swine fever virus asfv has been noti. Lassa fever is one of the hemorrhagic fever viruses like ebola virus, marburg virus, and others unlike ebola virus, lassa fever is not as contagious person to person, nor as deadly lassa virus is typically transmitted by the urine or feces of mastomys rats to humans. The only south african book dealing with epidemiology as a discipline. Each year more than 33 million people suffer from typhoid globally. During sporadic rvf outbreaks in 20082009 and widespread epidemics in 20102011, 302 laboratoryconfirmed human infections, including 25 deaths casefatality rate, 8% were identified. Coordinate surveillance systems to collect, analyse and interpret. Epidemiologic and environmental risk factors of rift valley fever in southern africa from 2008 to 2011 margaret m. Lassa fever lf is a zoonotic disease associated with acute and potentially fatal hemorrhagic illness caused by the lassa virus lasv, a member of the family arenaviridae. In collaboration with the asfaffected member states ms, efsa is updating the epidemiological analysis of asf in the european union which was carried out in 2015. An arenavirus was isolated from two of these patients and given the name of lassa virus after the town of lassa, nigeria, where the disease, known as lassa fever, occurred buckley et al. Epidemiological analyses of african swine fever in the. Lassa fever outbreaks have been confirmed across five west african countries, including nigeria, benin, sierra leone, togo, and burkina faso. The causative agent, yellow fever virus yfv, is the prototype of the genus flavivirus family flaviviridae.
Ongoing research confirms that abortion waves on dairy goat farms are the. Lassa fever lf is endemic to nigeria, where the disease causes substantial rates of illness and death. Arboviral disease, atmospheric dispersal modeling, bovine ephemeral fever, conditional autoregressive model, culicoides biting midges, epidemiology, japan, mosquito, spatial analysis, windborne spread background bovine ephemeral fever bef is an arboviral short for arthropodborne viral disease of cattle and water. Aetiology epidemiology diagnosis prevention and control references. Variation in genetic diversity helped understanding asf regional epidemiological patterns. Therefore understanding the epidemiology of causes of fever has important implications for management of febrile patients. The disease occurs now only in africa and central and south america, although historically, large outbreaks occurred in europe and north america.
Fever is among the most common symptoms of people living in africa, and clinicians are challenged by the similar clinical features of a wide spectrum of potential aetiologies. Ongoing research confirms that abortion waves on dairy goat farms are the primary source of infection for humans, primarily affecting people living close under 5 km. To summarize recent studies of fever aetiology in subsaharan africa focusing on causes other than malaria. Classical swine fever control epidemiology europe sus scrofa wild boar. Lassa fever is caused by a single stranded rna virus and is a disseminated systemic primary viral infection. Nov 08, 2017 efsa assisted four countries in the analysis of epidemiological data on african swine fever asf, collected until september 2017. Epidemiology and control of lassa fever springerlink.
Health workers may be infected by direct contact with blood, body fluids, urine, or stool of a patient with lassa fever. This video, the first in a twopart training series on lassa fever, provides an overview, describing the epidemiology and clinical presentation of the virus. Mission consisting of dr gaud and dr morgan proceeded to french north africa in november 1945 in order to study the epidemic of louseborne relapsing fever which, after 25 years quiescence, had spread rapidly through tunisia, algeria and morocco the last epidemics were in north africa between 1912 and 1915 and in french west africa between 1922 and 1925 during the. Epidemiology of lassa fever and factors associated with. The lassa virus is transmitted to humans mainly through handling rats, food or household items contaminated by rats urine and faeces. The yellow fever virus is a flavivirus with a 400year history. Common clinical featuressymptoms include sore throat, fever, vomiting, headache, malaise and rash on neck and chest classically a fine punctate erythema1. Regional epidemiological patterns involve different hosts and mechanisms of transmission. Epidemiological analyses on african swine fever in the baltic. Yf is a viral sepsis characterised most commonly by a sudden onset of fever and prostration. Many of these had not reported dengue for 20 or more years and several have no known history of the disease. Epidemiological trends of lassa fever outbreaks and insights for future control in nigeria article pdf available january 2017 with 2,184 reads how we measure reads.
Researching awareness, risk factors and seroprevalence of lassa fever in nigeria. Lassa fever outbreak hits nigeria infectioncontrol. Pathophysiology and treatment of lassa fever springerlink. Q fever annual epidemiological report 2016 2014 data. Scarlet fever causal agentgroup a betahaemolytic streptococci. Epidemiology of african swine fever virus sciencedirect. An epidemiology model suggested by yellow fever john r. These highly infectious viruses lead to a potentially lethal disease syndrome characterized by fever, malaise, vomiting, mucosal and gastrointestinal gi bleeding, edema, and hypotension. Dec 30, 2016 q fever, or query fever, is a zoonotic disease caused by the bacterium coxiella burnetii.
Epidemiological analyses on african swine fever in the. Yellow fever as an endemicepidemic disease and priorities for. From 1985 to 1999, consecutive cases of q fever, presented. Clinical presentation is varied, mainly presenting with fever, malaise, abdominal discomfort, and nonspecific symptoms often confused with other causes of febrile syndrome. Classical swine fever european livestock association. Mar 23, 2017 african swine fever virus asfv has been notified in the baltic countries and the eastern part of poland from the beginning of 2014 up to now.
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