Rift Valley fever

2011 ◽  
Author(s):  
R. Swanepoel ◽  
J. T. Paweska
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Case Fatality ◽  
Febrile Illness ◽  
Horn Of Africa ◽  
Valley Fever ◽  
Domestic Ruminants ◽  
Inactivated Vaccines ◽  
Limited Scale ◽  
Haemorrhagic Disease

Rift Valley fever (RVF) is an acute disease of domestic ruminants in mainland Africa and Madagascar, caused by a mosquito borne virus and characterized by necrotic hepatitis and a haemorrhagic state. Large outbreaks of the disease in sheep, cattle and goats occur at irregular intervals of several years when exceptionally heavy rains favour the breeding of the mosquito vectors, and are distinguished by heavy mortality among newborn animals and abortion in pregnant animals. Humans become infected from contact with tissues of infected animals or from mosquito bite, and usually develop mild to moderately severe febrile illness, but severe complications, which occur in a small proportion of patients, include ocular sequelae, encephalitis and fatal haemorrhagic disease. Despite the occurrence of low case fatality rates, substantial numbers of humans may succumb to the disease during large outbreaks. Modified live and inactivated vaccines are available for use in livestock, and an inactivated vaccine was used on a limited scale in humans with occupational exposure to infection. The literature on the disease has been the subject of several extensive reviews from which the information presented here is drawn, except where indicated otherwise (Henning 1956; Weiss 1957; Easterday 1965; Peters and Meegan 1981; Shimshony and Barzilai 1983; Meegan and Bailey 1989; Swanepoel and Coetzer 2004; Flick and Bouloy 2005). In September 2000, the disease appeared in south-west Saudi Arabia and adjacent Yemen, and the outbreak lasted until early 2001 (Al Hazmi et al. 2003; Madani et al. 2003; Abdo-Salem et al. 2006). The virus was probably introduced with infected livestock from the Horn of Africa, and it remains to be determined whether it has become endemic on the Arabian Peninsula.

scholarly journals Rift Valley fever: a review

2020 ◽  
Vol 41 (1) ◽  
pp. 28
Author(s):  
John Bingham ◽  
Petrus Jansen van Vuren
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Febrile Illness ◽  
Viral Disease ◽  
Broad Host Range ◽  
Haemorrhagic Fever ◽  
Research Focus ◽  
Valley Fever ◽  
Domestic Ruminants

Rift Valley fever (RVF) is a mosquito-borne viral disease, principally of ruminants, that is endemic to Africa. The causative Phlebovirus, Rift Valley fever virus (RVFV), has a broad host range and, as such, also infects humans to cause primarily a self-limiting febrile illness. A small number of human cases will also develop severe complications, including haemorrhagic fever, encephalitis and visual impairment. In parts of Africa, it is a major disease of domestic ruminants, causing epidemics of abortion and mortality. It infects and can be transmitted by a broad range of mosquitos, with those of the genus Aedes and Culex thought to be the major vectors. Therefore, the virus has the potential to become established beyond Africa, including in Australia, where competent vector hosts are endemic. Vaccines for humans have not yet been developed to the commercial stage. This review examines the threat of this virus, with particular reference to Australia, and assesses gaps in our knowledge that may benefit from research focus.

scholarly journals Safety and efficacy of ChAdOx1 RVF vaccine against Rift Valley fever in pregnant sheep and goats

npj Vaccines ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Anna Stedman ◽  
Daniel Wright ◽  
Paul J. Wichgers Schreur ◽  
Madeleine H. A. Clark ◽  
Adrian V. S. Hill ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Febrile Illness ◽  
Neutralizing Antibody ◽  
High Titre ◽  
Valley Fever ◽  
Sheep And Goats ◽  
Pregnant Sheep ◽  
Human Use

Abstract Rift Valley fever virus (RVFV) is a zoonotic mosquito-borne virus that was first discovered in Kenya in 1930 and has since spread to become endemic in much of Africa and the Arabian Peninsula. Rift Valley fever (RVF) causes recurrent outbreaks of febrile illness associated with high levels of mortality and poor outcomes during pregnancy—including foetal malformations, spontaneous abortion and stillbirths—in livestock, and associated with miscarriage in humans. No vaccines are available for human use and those licensed for veterinary use have potential drawbacks, including residual virulence that may contraindicate their use in pregnancy. To address this gap, we previously developed a simian adenovirus vectored vaccine, ChAdOx1 RVF, that encodes RVFV envelope glycoproteins. ChAdOx1 RVF is fully protective against RVF in non-pregnant livestock and is also under development for human use. Here, we now demonstrate that when administered to pregnant sheep and goats, ChAdOx1 RVF is safe, elicits high titre RVFV neutralizing antibody, and provides protection against viraemia and foetal loss, although this protection is not as robust for the goats. In addition, we provide a description of RVFV challenge in pregnant goats and contrast this to the pathology observed in pregnant sheep. Together, our data further support the ongoing development of ChAdOx1 RVF vaccine for use in livestock and humans.

scholarly journals Severe Human Illness Caused by Rift Valley Fever Virus in Mauritania, 2015

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Boushab Mohamed Boushab ◽  
Fatima Zahra Fall-Malick ◽  
Sidi El Wafi Ould Baba ◽  
Mohamed Lemine Ould Salem ◽  
Marie Roseline Darnycka Belizaire ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Neurological Complication ◽  
Clinical Signs ◽  
Febrile Illness ◽  
Signs And Symptoms ◽  
Epidemiological Surveillance ◽  
Enzyme Linked Immunosorbent Assay ◽  
Valley Fever

Abstract Background Rift Valley Fever epizootics are characterized by numerous abortions and mortality among young animals. In humans, the illness is usually characterized by a mild self-limited febrile illness, which could progress to more serious complications.Objectives. The aim of the present prospective study was to describe severe clinical signs and symptoms of Rift Valley Fever in southern Mauritania. Patients and methods Suspected cases were enrolled in Kiffa (Assaba) and Aleg (Brakna) Hospital Centers from September 1 to November 7, 2015, based on the presence of fever, hemorrhagic or meningoencephalitic syndromes, and probable contact with sick animals. Suspected cases were confirmed by enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR). Results There were thirty-one confirmed cases. The sex ratio M/F and the average age were 2.9 and 25 years old [range, 4-70 years old], respectively. Mosquito bites, direct contact with aborted or dead animals, and frequent ingestion of milk from these animals were risk factors observed in all patients. Hemorrhagic and neurological manifestations were observed in 81% and 13% of cases, respectively. The results of laboratory analysis showed high levels of transaminases, creatinine, and urea associated with thrombocytopenia, anemia, and leukopenia. All patients who died (42%) had a hemorrhagic syndrome and 3 of them had a neurological complication. Among the cured patients, none had neurologic sequelae. Conclusion The hemorrhagic form was the most common clinical manifestation of RVF found in southern Mauritania and was responsible for a high mortality rate. Our results justify the implementation of a continuous epidemiological surveillance.

scholarly journals High seroprevalence of Rift Valley fever phlebovirus in domestic ruminants and African Buffaloes in Mozambique shows need for intensified surveillance

2017 ◽  
Vol 7 (1) ◽  
pp. 1416248 ◽  
Author(s):  
Belisário Moiane ◽  
Lourenço Mapaco ◽  
Peter Thompson ◽  
Mikael Berg ◽  
Ann Albihn ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
High Seroprevalence ◽  
Valley Fever ◽  
Domestic Ruminants

Evaluation of a commercial competitive ELISA for the detection of antibodies to Rift Valley fever virus in sera of domestic ruminants in France

2009 ◽  
Vol 90 (1-2) ◽  
pp. 146-149 ◽  
Author(s):  
Catherine Cêtre-Sossah ◽  
Agnès Billecocq ◽  
Renaud Lancelot ◽  
Cédric Defernez ◽  
Jacques Favre ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Competitive Elisa ◽  
Fever Virus ◽  
Valley Fever ◽  
Domestic Ruminants

scholarly journals A Spatial Analysis of Rift Valley Fever Virus Seropositivity in Domestic Ruminants in Tanzania

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0131873 ◽  
Author(s):  
Calvin Sindato ◽  
Dirk U. Pfeiffer ◽  
Esron D. Karimuribo ◽  
Leonard E. G. Mboera ◽  
Mark M. Rweyemamu ◽  
...  
Keyword(s):  
Spatial Analysis ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Domestic Ruminants

scholarly journals Farm-Level Risk Factors of Increased Abortion and Mortality in Domestic Ruminants during the 2010 Rift Valley Fever Outbreak in Central South Africa

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 914
Author(s):  
Melinda K. Rostal ◽  
Sarah Cleaveland ◽  
Claudia Cordel ◽  
Lara van Staden ◽  
Louise Matthews ◽  
...  
Keyword(s):  
Risk Factors ◽  
South Africa ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Strong Support ◽  
Individual Risk ◽  
Valley Fever ◽  
Farm Level ◽  
Domestic Ruminants ◽  
Central South

(1) Background: Rift Valley fever (RVF) outbreaks in domestic ruminants have severe socio-economic impacts. Climate-based continental predictions providing early warnings to regions at risk for RVF outbreaks are not of a high enough resolution for ruminant owners to assess their individual risk. (2) Methods: We analyzed risk factors for RVF occurrence and severity at the farm level using the number of domestic ruminant deaths and abortions reported by farmers in central South Africa during the 2010 RVF outbreaks using a Bayesian multinomial hurdle framework. (3) Results: We found strong support that the proportion of days with precipitation, the number of water sources, and the proportion of goats in the herd were positively associated with increased severity of RVF (the numbers of deaths and abortions). We did not find an association between any risk factors and whether RVF was reported on farms. (4) Conclusions: At the farm level we identified risk factors of RVF severity; however, there was little support for risk factors of RVF occurrence. The identification of farm-level risk factors for Rift Valley fever virus (RVFV) occurrence would support and potentially improve current prediction methods and would provide animal owners with critical information needed in order to assess their herd’s risk of RVFV infection.

Sign in / Sign up

Export Citation Format

Share Document