This report is an overview of enterovirus epidemiology in Tunisia during a 12-year period from 1992 to 2003. A total of 4700 clinical samples were collected as part of the national poliovirus surveillance programme and the routine diagnostic programme for aseptic meningitis. Enterovirus detection was performed by isolation on cell culture according to World Health Organization recommended protocols. Serotype identification was performed by seroneutralization of the cytopathic effect using pools of specific antisera and sequencing in the VP1 region of the genome. Poliovirus isolates were assessed for their wild or vaccine-related origin by standard World Health Organization recommended methods (PCR, probe hybridization and ELISA). The results confirm the interruption of wild poliovirus circulation since 1995. A total of 236 non-polio enterovirus (NPEV) strains were isolated; seroneutralization allowed typing of 93 % (219 out of 236) of them. The antisera used allowed the identification of the most common enterovirus serotypes. The remaining 17 isolates were sequenced; 16 of them belonged to enterovirus serotypes that were not targeted by the antisera pools used. A total of 29 different serotypes of NPEV were detected in the country during the study period. Echoviruses of serotypes 6, 11 and 30 were the most frequently isolated, almost every year; other serotypes had a cyclic occurrence and others were detected during a limited period with very few isolates. The NPEV isolation rate varied from year to year but was steadily under 10 %, suggesting a relatively low prevalence of these viruses in comparison to that in other developing countries. A seasonal variation was also noted; the high transmission period starts in March and peaks in September–November. This study is the first report of the epidemiology of NPEV in Tunisia. These viruses are associated with various diseases and epidemiological data may help to clarify their impact on human health.

First multicenter study for risk factors for hepatocellular carcinoma development in North Africa

In Tunisia, country of intermediate endemicity for Hepatitis B virus (HBV) infection, most molecular studies on the virus have been carried out in the North of the country and little is known about other regions. The aim of this study was to determine HBV genotype and subgenotypes in Central-East Tunisia. A total of 217 HBs antigen positive patients were enrolled and determination of genotype was investigated in 130 patients with detectable HBV DNA. HBV genotyping methods were: PCR-RFLP on the pre-S region, a PCR using type-specific primers in the S region (TSP-PCR) and partial sequencing in the pre-S region.

Le virus West Nile (VWN) est un arbovirus dont la circulation est de plus en plus large dans le monde. Il est fréquemment responsable d’épidémies de méningites et de méningoencéphalites. En Tunisie, deux pics épidémiques ont été observés en 1997 et en 2003 ayant touché les régions du sahel tunisien. Peu de données sont disponibles quant à la circulation de ce virus dans les autres régions, d’où le but de cette étude. Au total, 1 854 sujets sains originaires de trois gouvernorats différents, Kairouan, Bizerte et Sfax, ont été étudiés. Les prélèvements ont été collectés durant la période allant de janvier à décembre 2007. Aucun cas d’infection à VWN n’a été rapporté antérieurement à Bizerte, et uniquement deux cas sporadiques à Kairouan; Sfax par contre a été touché par les deux épidémies. Une recherche des anticorps spécifiques de type IgG a été faite par Elisa indirecte. La séroprévalence globale a été de 12,5 % avec répartition très variable selon les gouvernorats testés. Trois zones d’endémicité différente ont été retrouvées; forte à Kairouan (27,7 %), moyenne à Sfax (7,5 %) et faible à Bizerte (0,7 %). La séroprévalence a été significativement plus élevée chez les sujets âgés de plus de 40 ans à Kairouan. En conclusion, nos résultats montrent que leVWNprésente un risque réel en Tunisie; ce risque est présent non seulement dans les zones touchées par les épidémies antérieures mais aussi dans des gouvernorats qui sembleraient indemnes comme dans le cas de la région de Kairouan. Cela nous incite à instaurer une surveillance active, aussi bien à l’échelle humaine qu’animale, sur tout le territoire tunisien. West Nile virus (WNV) is an arbovirus classified into the family of Flaviviridae, genus Flavivirus. It is responsible for neurological diseases that occurred frequently as outbreaks and considered as an emerging infection in different regions of the world. In Tunisia, two outbreaks of meningoencephalitis due to this virus occurred, in 1997 and 2003. The virus circulation is studied only in Sahel, region affected by the two epidemics. The aim of this study is to determine if WNV is present in other regions of the country where, up to now, no data are available. A total of 1,854 sera collected from healthy patients were investigated by ELISA to detect specific IgG, during January to December 2007. Patients included are from three governorates: Kairouan, Bizerte, and Sfax. The governorate of Sfax (center of Tunisia) was affected by the two outbreaks, whereas only two cases were observed previously at Kairouan and no cases at Bizerte. Specific IgG were detected in 12.5% of studied population. This seroprevalence varied largely between the three governorates studied. Globally, three regions with different endemicity were described: high endemicity at Kairouan (27.7%), moderate at Sfax (7.5%), and low at Bizerte (0.7%). At Kairouan, the seroprevalence is significantly higher in individuals aged over 40. Our results suggest that WNV circulates in Tunisia; it has a high risk not only in regions affected by previous outbreaks but throughout the country. An active surveillance should be instituted in the country. It must target individuals, and animals, which can be vectors or reservoirs for the virus.