Risk based serological survey of Rift Valley fever in Tunisia (2017-2018).

Rift Valley fever (RVF) has been reported in the sub-Saharan region of Africa, Egypt and Arabian Peninsula - Yemen and Saudi Arabia, over the past 20 years and is a threat to both the animal and human populations in Tunisia. Tunisia is considered as a high-risk country for the introduction of RVF due to the informal movements of diseased animals already reported in the neighboring countries. The objective of this study was to assess the status of RVF in small ruminants and camels in Tunisia. A risk-based serological survey was conducted to evaluate the presence of RVF based on spatial qualitative risk analysis (SQRA). Samples were collected from small ruminants (sheep and goats) (n = 1,114), and camels (n = 173) samples, belonging to 18 breeders in 14 governorates between November 2017 and January 2018. Samples were tested using an RVF specific multispecies competitive ELISA. Out of the 1,287 samples tested for the presence of RVF IgG antibodies by ELISA, only one positive sample 0.07% (1/1 287) was detected but not confirmed with the virus neutralization test (VNT) used for confirmation. So far, no RVF outbreaks have been reported in Tunisia and our study confirmed the absence of RVF in livestock up to January 2018. Further investigations are needed to confirm the RVF-free status of Tunisia today.

Seroprevalence and associated risk factors of Chlamydia abortus infection in ewes in Tunisia.

Enzootic abortion of ewes (EAE) caused by Chlamydia abortus is a disease of ruminants that results in serious economic losses in livestock industry. The zoonotic potential of the pathogen adds a public health concern on the efforts to control the disease. We report herein a cross-sectional study that was conducted during the lambing season (June and July) in Tunisia to estimate the seroprevalence of C. abortus infection in large sheep herds with abortion history. A total of 803 ewes were sampled and tested using indirect enzyme linked immunosorbent assay (iELISA). The overall apparent seroprevalence at herd and individual levels were 58 % (95 %CI = 39-74.5 %) and 6.6 % (95 %CI = 4.9-8.3 %), respectively. Significant risk factors investigated using univariate and multivariate analyses were history of infertility (OR = 5.7; 95 %CI = 3.05-10.66), the number of reproductive ewes (OR = 2.1; 95 %CI = 1.12-3.94), the control of new animals at introduction (OR = 4.35; 95 %CI = 2.46-7.68), the sharing of drinking water (OR = 2.18; 95 %CI = 1.22-3.9), the exchange of breeding males (OR = 2.56; 95 %CI = 1.003-6.54), the disposal of abortion materials without precaution (OR = 4.36; 95 %CI = 2.42-7.87), the lack of lambing barn (OR = 2.39; 95 %CI = 1.13-5.04), the non-application of hygienic post-abortion measures (OR = 10.35; 95 %CI = 5.28-20.26) and the manure management (OR = 11.35; 95 %CI = 3.26-39.48). To the best of our knowledge, this is the first sero-epidemiological survey conducted on an abortive disease in Tunisian ewes that investigated the risk factors of C. abortus infection.