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West Nile Virus (WNV) is an arbovirus transmitted by mosquito bite involving birds as reservoirs, humans and equines as accidental hosts. Eight distinct lineages (WNV-1 to WNV-8) have been identified: WNV-1 and WNV-2 infect humans and animals, and WNV-3 to WNV-8 have been identified only in vectors. WNV has been implicated in neuroinvasives infections, especially meningitis and encephalitis. Tunisia experienced three epidemics in 1997, 2003 and 2012. Serological studies on humans, equines and birds as well as the detection of the virus in the vector favour a fairly frequent circulation in the country. A new epidemic has been observed in Tunisia between August and November 2018. The obtained sequences of the VWN from Tunisia 2018 grouped in a distinct monophyletic group within the Mediterranean subtype in Cluster 1, with a maximum of 2% nucleotide divergence. These sequences were clearly distinct from the Tunisia 1997, which grouped with sequences mainly from USA in Cluster 2. This work reports the genetic characterization of the Tunisia 2018 strain in comparison with the previously identified strains in Tunisia and worldwide. The epidemic virus Tunisia 2018 was genetically close to the Mediterranean basin and Eastern Europe sequences but distinct from the Tunisia 1997 closely related to the American sequences.

IntroductionSARS-CoV2 serology testing is multipurpose provided to choose an efficient test. We evaluated and compared 4 different commercial serology tests, three of them had the Food and Drug Administration (FDA) approval. Our goal was to provide new data to help to guide the interpretation and the choice of the serological tests.MethodsFour commercial tests were evaluated: Cobas®Roche®(total anti-N antibodies), VIDAS®Biomerieux®(IgM and IgG anti-RBD antibodies), Mindray®(IgM and IgG anti-N and anti-RBD antibodies) and Access®Beckman Coulter®(IgG anti-RBD antibodies). Were tested: a positive panel (n=72 sera) obtained from COVID-19 confirmed patients and a negative panel (n=119) of pre-pandemic sera. Were determined the analytical performances and was drawn the ROC curve to assess the manufacturer’s threshold.ResultsA large range of variability between the tests was found. Mindray®IgG and Cobas® tests showed the best overall sensitivity 79,2%CI95%[67,9-87,8]. Cobas® showed the best sensitivity after D14; 85,4%CI95%[72,2-93,9]. The best specificity was noted for Cobas®, VIDAS®IgG and Access® IgG(100%CI95%[96,9-100]). Access® had the lower sensitivity even after D14 (55,5% CI95%[43,4-67,3]). VIDAS®IgM and Mindray®IgM tests showed the lowest specificity and sensitivity rates. Overall, only 43 out of 72 sera gave concordant results (59,7%). Retained cut-offs for a significantly better sensitivity and accuracy, without altering significantly the specificity, were: 0,87 for Vidas®IgM(p=0,01), 0,55 for Vidas®IgG(p=0,05) and 0,14 for Access®(p−4).ConclusionAlthough FDA approved, each laboratory should realize its own evaluation for commercial tests. Tests variability may raise some concerns that seroprevalence studies may vary significantly based on the used serology test.

Objective: A recently discovered non-A-E hepatitis virus has been designated as human Pegivirus (HPgV). HPgV is prevalent in high-risk groups such as patients with hepatitis C virus (HCV), and it is of interest for patients who are at risk for transmitted infections. The aim of this study was to evaluate the prevalence of HPgV as well as the genotype distribution among patients in the Tunisian population who are infected with HCV and also in multitransfused patients. Methods: A total of 144 patients were screened using RTPCR/nested PCR of the 5′-untranslated region (UTR); 14 cases were sequenced and phylogenetically analyzed. Results: Seven (14.9%) subjects from the multitransfused group and 7 (7.2%) patients infected with HCV, respectively, were found positive for HPgV RNA. Sequencing and phylogenetic analysis of the 14 cases revealed that genotype 2a was the main genotype circulating in Tunisian patients. Genotype 2b was found in the amplified samples of 2 HCV-infected patients. Conclusion: This study enriches the limited data on HPgV prevalence in Tunisia, and shows, for the first time, the molecular epidemiology of the circulating strains in this country.

Resume Objectif Cette etude avait pour but d’etudier les profils serologiques et moleculaires de l’infection delta chez des patients tunisiens. Patients et methodes Notre travail a porte sur 215 sujets antigene HBs (AgHBs) positifs, incluant 176 porteurs asymptomatiques issus de regions d’endemicite variables pour le virus de l’hepatite B (VHB) et 39 malades atteints d’hepatite B chronique et a serologie delta positive. Une recherche de l’antigene delta, des anticorps delta et de l’antigene HBe a ete effectuee chez tous les patients ; une recherche et un genotypage de l’ARN du virus de l’hepatite delta (VHD) ainsi qu’une recherche de l’ARN du VHB ont ete conduites chez les patients du second groupe. Resultats Douze sujets (6,8 %) sur 176 des porteurs asymptomatiques testes ont une serologie VHD positive. La prevalence a ete relativement plus elevee dans les localites de forte endemicite pour le VHB que dans celles d’endemicite moyenne ou faible. La moyenne d’âge des sujets delta positifs a ete de cinq ans superieure a celle de la population globale (30 ans versus 24,4 ans). Pour les malades a hepatite B chronique et a serologie delta positive, l’ARN du VHD a ete detecte chez 53,8 % des cas, une replication simultanee des deux virus VHB–VHD a ete observee chez 38,4 % des cas. Le genotype 1 a ete retrouve pour un des echantillons amplifies. Conclusions Les resultats de notre etude enrichissent les donnees encore tres limitees de la litterature sur la prevalence de l’infection par le VHD en Tunisie et sur l’epidemiologie moleculaire de souches circulantes.

Background Our aim is to detect the infection by Toscana virus (TOSV) and other Phleboviruses in the sera and cerebro-spinal fluid (CSF) of patients with meningitis in Tunisia. We examined various species of phlebotomus present in Tunisia to determine whether or not a direct relationship exists between cases of meningitis and the viruses circulating in the insect vectors. Methods Patients with the meningeal syndrome were tested for anti-TOSV IgM and IgG using an indirect Enzyme-Linked Immunosorbent Assay (ELISA) and for the presence of TOSV and other Phleboviruses using a RT-PCR test. An entomological study was carried out using CDC light traps to trap sandflies in different bioclimatic zones of Tunisia. Collected sandflies were tested by RT-PCR for the presence of TOSV and other Phleboviruses and subsequently by viral isolation on Vero cells. Results Of 263 patients were tested using ELISA of which 12.16% (n = 32/263) were IgM positive for anti TOSV. Of these 32 patients, 78% (n = 25/32) were IgG positive. 12.86% (n = 18/140) of the CSF samples tested by RT-PCR were positive for the Toscana virus. One CSF sample tested by RT-PCR revealed the presence of Sandfly Fever Sicilian Virus (SFSV). The Punique virus was identified in one sandfly pool. Conclusions This study confirms, for the first time, that TOSV is involved in a neurological disorder in North Africa. The incidence of this involvement in Tunisia conforms with observations made in other Mediterranean countries. Moreover, for the first time, a molecular approach was used to detect SFSV in a Tunisian patient displaying neurological symptoms. Electronic supplementary material The online version of this article (doi:10.1186/s12879-014-0598-9) contains supplementary material, which is available to authorized users.

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.

In an attempt to explain temporal and geographical rabies incidence fluctuations in Tunisia, a molecular epidemiological study of rabies virus (RV) was carried out. A panel of RV isolates from dogs, collected between 1992 and 2003, from different regions in Tunisia have been analysed by direct sequencing of PCR-amplified products coding for the nucleoprotein gene. New sequences have been compared to prototype sequences of Lyssavirus species and nine lineages of species 1. All Tunisian isolates belonged to species rabies virus and segregated into two rabies lineages geographically distinct: NCS lineage characterizing Northeast, Central and Northern areas of the country and NW lineage more restricted to the North-Western regions. Phylogenetic analyses showed that Tunisian RV clustered most closely to Africa 1a lineage: NCS lineage showed nucleic affiliation with isolates from Algeria and Morocco, whereas, NW lineage shared a strong relationship with Ethiopian and Sudanese strains.