Epidemiology and serological detection of Rift Valley Fever disease in farm animals in southern Egypt

Hassan Y.A.H Mahmoud,Alsagher O Ali

doi:10.4102/ojvr.v87i1.1877

Hassan Y.A.H Mahmoud, Alsagher O Ali

Open Access

https://doi.org/10.4102/ojvr.v87i1.1877

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Abstract

In this study, the serological surveillance of Rift Valley Fever virus (RVFV) in southern Egypt was carried out for 460 serum samples collected from domestic animals (unvaccinated), including cattle, sheep, goat, camel and donkey reared in three different provinces (Qena, Luxor and Aswan). Enzyme linked immunosorbent assay (ELISA) was used to detect RVFV antibodies. The results showed that 97 out of 460 animals were positive by using blocking ELISA. The percentage of RVFV infection in cattle, sheep, goat, camel and donkey was 5.55%, 65.21%, 14.44%, 20.65% and 0%, respectively. Geographical distribution and breeding system were taken into consideration for RVFV infection in these animals. The most prevalent type of infection was identified in intensive breeding farms systems (27.63%), and then in individual breeding systems (11.68%). Qena had a higher infection rate of RVFV (23.55%), in comparison to Aswan and Luxor (20.65% and 14.14%, respectively). Marked seroprevalence recorded in this study indicates a high incidence of infection in sheep (65.21%) and camel (20.65%); this necessitates the application of more effective strategies to control these types of infections in Egypt. This study provides a concise picture about the RVFV disease in southern Egypt. We need more similar studies targeted to clarify the reliable epidemiological status of RVFV disease in southern Egypt and other localities.

Highlights

Rift Valley Fever (RVF) is a vector-borne viral disease caused by Rift Valley Fever virus (RVFV), a member of the Bunyaviridae family and Phlebovirus genus that primarily affects domestic ruminants, causing large epizootics with high mortality rates in young animals and abortions in affected dams (Mansfield et al 2015; Shabani et al 2015)
The disease occurrence follows the unusual trend of heavy rainfall leading to flooding, resulting in providing a conducive environment for dormant mosquito eggs infected by RVFV to hatch and become predominant mosquito populations that transmit virus to animals and subsequently from animals to humans (Shabani et al 2015)
The current study revealed that the seroprevalence of RVFV in camels was 21.11%; this result is considered as a high percentage of seropositivity, indicating camels act as reservoir for maintenance of RVFV and high precautions should be applied as camels are used in Egypt for meat and milk production and in Aswan and Luxor for entertainment

Summary

Introduction

Rift Valley Fever (RVF) is a vector-borne viral disease caused by Rift Valley Fever virus (RVFV), a member of the Bunyaviridae family and Phlebovirus genus that primarily affects domestic ruminants, causing large epizootics with high mortality rates in young animals and abortions in affected dams (Mansfield et al 2015; Shabani et al 2015). Multiple outbreaks were reported in several parts of Africa and the Middle East, notably in Egypt (1977, 2003) (Faye et al 2007; Sissoko et al 2009), Kenya (1997– 1998, 2006–2007) (Faye et al 2010), Saudi Arabia and Yemen (2000–2001) (Al-Hazmi et al 2003; Nabeth et al 2001), Sudan (2007, 2010) (Hassan et al 2011; Nabeth et al 2001), Mayotte (2008) (Sissoko et al 2009) and Mauritania (1987, 1993–1994, 1998, 2003, 2010, 2012) (Boushab et al 2015; Faye et al 2007; Nabeth et al 2001). RVFV infection is typically asymptomatic or causes influenza-like illness accompanied by fever and headache but occasionally leads to serious complications, such as haemorrhagic syndromes, retinitis, encephalitis and death (Adam, Karsany & Adam 2010; Al-Hazmi et al 2003; Mansfield et al 2015; Shabani et al 2015)

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