A Review on Rift Valley Fever on Animal, Human Health and its Impact on Live Stock Marketing

Review Article

Austin Virol and Retrovirology. 2016; 3(1): 1020.

A Review on Rift Valley Fever on Animal, Human Health and its Impact on Live Stock Marketing

Kasye M, Teshome D*, Abiye A and Eshetu A

School of Veterinary Medicine, Wollo University, Ethiopia

*Corresponding author: Daniel Teshome Gebeyehu, School of Veterinary Medicine, Wollo University, Dessie, Ethiopia

Received: May 20, 2016; Accepted: June 23, 2016; Published: June 28, 2016


Rift Valley Fever (RVF) is an acute, mosquito-borne viral disease that has significant global threat to livestock marketing and on human health. The disease is caused by a virus of the genus Phlebovirus of family Bunyaviridae, a group of enveloped single stranded RNA viruses. A review of RVF was made with the objective of organizing information on the epidemiology and management of rift valley fever, and on its economic impacts related to livestock marketing. The disease is mostly confined in Africa but it also occurs in other parts like Saudi Arabia and Yemen. Even though clinical disease has never been occurred in Ethiopia, serological tests are gotten IgM positive for RVF. The transmission of RVF is primarily by the bites of the mosquitoes of several species. Man acquires the infection from the infected animals and insect bites. Diagnosis is confirmed by PCR, isolation of virus, demonstration of antibodies in the sera and histopathology of the liver. Immunization of animals, destruction of mosquitoes and restriction on the movement of animals during epizootic can help in the control of RVF.

Keywords: Economic impact; Rift valley fever; Vaccines; Vectors; Virus


The livestock sub-sector plays a vital role in national economy of many developed and developing countries. It profits the national gross domestic economy through benefits from cattle rearing, exporting of live animals and hide as well as skin; which all those earn huge amount of money for that country. However, many countries are not self-sufficient in livestock productions while livestock still remains an integral part of their national economy. The most important contribution and value of livestock’s are: source of food, drought power, social and cultural assets, source of income and means of transportation. The proportion of livestock in Ethiopia remained the largest figure in Africa until recent time but levels of production are one of the lowest [1].

The economic benefit derived from the livestock sector in Ethiopia is not commensurate with the potentials and the sub sector remained untapped [2]. Productivity of animals is poor; factors for the poor productivity of livestock in Ethiopia include: disease, poor nutrition, unimproved genotypes, inappropriate management, socio economic and institutional constraints [1]. The widely prevalent livestock diseases are major constraints to livestock exports. Livestock exports from Ethiopia are jeopardized by repeated bans in particular from the countries in Arabian Peninsula as carrying the risk of introducing number of trans-boundary livestock disease [2].

RVF is an acute febrile arthropod born viral diseases of sheep, goats, cattle as well as humans and presents in most countries of sub Saharan Africa. As a current threat of bioterrorism, it could appear in other parts of the world [3].

RVF was first reported in an outbreak of abortion and death in exotic wool sheep as well as illness in humans that occurred in the rift valley of Kenya after heavy rain fall in 1930-31. Out breaks since occurred in the high lands of Kenya at irregular intervals of 3-15 years [4]. But it exists and occurs as epizootics through sub Saharan Africa with recent extension into Egypt and Madagascar, Mauritania and most recent expansion to the Arabian Peninsula [5].

The most recent epizootics in East Africa region was in 1997- 1998 in the dried areas of North East Kenya and South West Somalia after a heavy El Nino associated rains. This cause’s human death and some livestock lose, particularly of camels, but more significantly disruption to livestock exportation to the Middle East from the Horn of Africa [6].

The epidemic of RVF in Horn of Africa in 1997/8 stimulated many countries, but most importantly the kingdom of Saud Arabia as the major trading partner, to instigate a ban on livestock imports from the region [2].

In Ethiopia during the same period, the heavy rain fall and attendant flooding affected Southern and South Eastern parts of the country bordering Somalia and Kenya. Veterinarian Field investigations carried out in Somalia region and Borena zone in 1998 have observed high level of usual abortion among livestock. Out of the samples collected two sera from small ruminants from Mustahil, just near the border with Somalia were found IgM positive to RVF [2].

The disease is currently an economical concern because of the cost associated with preventive measures in endemic areas, monitoring for introduction of disease in neighboring unaffected areas, and trade restriction on import and export to and from countries [7]. To understand RVF, make prevention and to be ready to take action in controlling, it is important to know the nature and epidemiology of the disease.

Therefore, the objectives of this seminar paper are, to review: