TBE in Tunisia
Elyes Zhioua
ECDC risk status: imperiled country
(data as of end 2022)
History and current situation
Ixodes ricinus is principally located in oak forests, in humid to semi-humid microclimatic zones in Northwestern Tunisia.1 While I. ricinus is considered the main vector of tick-borne encephalitis virus (TBEV) in Europe, no reports concerning this arbovirus have been reported from North African countries. To date no human cases of tick-borne encephalitis (TBE) have been reported in Tunisia. Ticks were collected from the oak forest of EL Jouza, located in Northwestern Tunisia, by flagging and from grazing cattle during the period from November 2015 through February 2016, a period corresponding to the peak activity of only adult I. ricinus in Tunisia. I. ricinus was the most dominant tick species during winter. TBEV was detected in a pool of engorged I. ricinus collected from grazing cattle yielding a minimum field detection rate of 0.1%.2 The European subtype (TBE-EU) was detected. A serological survey was performed on grazing cattle where ticks were collected. Of a total of 96 sera tested by ELISA, no positive sera were detected. Recently, a cross-sectional study performed on sheep (N = 289) from Northern Tunisia showed that one sera was tested positive by sero-neutralization test, leading to an overall antibody prevalence of 0.38%.3 Despite the fact that no human TBE cases have been reported in Tunisia, the aforementioned results provide strong evidence that TBE is endemic in Northwestern Tunisia. To assess the risk of TBE, serological studies on Tunisian populations at high-risk such as farmers and forestry workers and active surveillance in Northwestern Tunisia are urgently needed.
Overview of TBE in Tunisia
| Table 1: Virus, vector, transmission of TBE in Tunisia | |
|---|---|
| Viral subtypes, distribution | Far Eastern subtype (TBEV-FE) |
| Reservoir animals | Information not available |
| Infected tick species (%) | I. ricinus |
| Dairy product transmission | Not documented |
| Table 2: TBE-reporting and vaccine prevention in Tunisia | |
|---|---|
| Mandatory TBE reporting | Not mandatory |
| Other TBE-surveillance | Not applicable |
| Special clinical features | Information not available |
| Available vaccines | Not applicable |
| Vaccination recommendations and reimbursement | No recommendations |
| Vaccine uptake by age group/ risk group/ general population | Data not available |
| Name, address/website of TBE National Reference Center | Not available |
Burden of TBE in Tunisia over time: no data available
Age and gender distribution of TBE in Tunisia: no data available
TBEV-isolation and TBE cases in Tunisia: no reported cases of TBE in the country
Contact:
elyes.zhioua@gmail.com
Citation:
Zhioua E. TBE in Tunisia. Chapter 12b. In: Dobler G, Erber W, Bröker M, Schmitt HJ, eds. The TBE Book. 6th ed. Singapore: Global Health Press;2023. doi:10.33442/26613980_12b36-6
References
- Zhioua E, Bouattour A, Hu CM, et al. Infection of Ixodes ricinus (Acari: Ixodidae) by Borrelia burgdorferi sensu lato in North Africa. J Med Entomol. 1999;36(2):216-218.
- Fares W, Dachraoui K, Cherni S, et al. Tick-borne encephalitis virus in Ixodes ricinus (Acari: Ixodidae) ticks, Tunisia. Ticks Tick Borne Dis. 2021;12(1):101606.
- Khamassi Khbou M, Romdhane R, Foughali AA, et al. Presence of antibodies against tick-borne encephalitis virus in sheep in Tunisia, North Africa. BMC Vet Res. 2020;16(1):441.