Serological evidence of Rift Valley fever in domestic ruminants in Tunisia underlines the need for effective surveillance

Background: Rift Valley fever (RVF) is an infectious zoonotic disease infecting, mainly, domestic ruminants and causing significant economic and public health problems. RVF is a vector-borne disease transmitted by mosquitoes.Aim: In this work, we tried to seek any RVF virus circulation in Tunisia.Methods: Thus, we investigated 1,723 sera from different parts of Tunisia, collected in 2009 and 2013–2015 from sheep, goats, cattle, and dromedaries. All sera were assessed using enzyme-linked immunosorbent assay techniques.Results: Eighty-seven sera were detected positive and 11 doubtful. All of them were investigated by the virusneutralization technique (VNT), which confirmed the positivity of three sera.Conclusion: This is the first case of RVF seropositive confirmed by the VNT in Tunisian ruminants. Such a result was expected considering the climate, entomology, and geographic location of the country. Further investigations must enhance our findings to understand the RVF epidemiologic situation better and implement risk-based surveillance programs and effective control strategies

Epizootic haemorrhagic disease virus circulation in Tunisia

Epizootic haemorrhagic disease virus (EHDV) was detected for the first time in Tunisia and in other Northern African countries in 2006.The objective of the present study was to investigate whether EHDV circulated in Tunisian livestock beforeand after the officially-reported outbreak of 2006.Thus, serum samples from cattle and dromedaries collected in different time periods (before and after 2006) and from different regions of Tunisia were screened for the presence of EHDV antibodies. Serological investigations conducted on cattle and dromedary sera collected in 2000 and 2001 demonstrated no virus circulation on these dates. However, viral circulation was evidenced in 2012 and 2013, although no EHDV cases were officially reported in these years. Serum-neutralization assessed on few ELISA positive samples, confirmed the presence of antibodies against EHDV serotype 6, which was the serotype involved in the EHDV outbreak in the Maghreb region in 2006