Hepatitis E virus genotypes 1 and 3 in wastewater samples in Tunisia
Hepatitis E represents an important public-health concern throughout the world. It is one of the leading causes of hepatitis in North Africa, Asia and the Middle East. In Tunisia, the true burden of HEV infection is still unknown. The objectives of the present study were to assess the occurrence of hepatitis E virus in Tunisia through the monitoring of urban sewage and to characterize the strains identified using molecular assays. A total of 150 sewage samples (raw and treated) were collected from three wastewater treatment plants located in the regions of Monastir and Mahdia and analyzed by nested RT-PCR using a qualitative assay targeting the methyltransferase gene in ORF1. Of these, only three samples (2 %) were found to be positive for HEV, one belonging to genotype 1 and two to genotype 3. The results of the present study indicate a low level of virus excretion among the Tunisian population. Both genotypes 1 and 3 are circulating in this country, however, possibly causing sporadic infections. The presence of the zoonotic genotype 3, known to be transmitted to humans mainly by swine and demonstrated in Tunisia for the first time in this work, raises the question of possible reservoir species, since pork products are not consumed in this country, pigs are not bred, and wild boar is not endemic. Further studies will be needed to gather information on the occurrence and diversity of HEV strains circulating among humans and animals in Tunisia, and on possible animal reservoirs.
KeywordsWild Boar Acute Hepatitis Basic Local Alignment Search Tool Wastewater Sample Sewage Sample
We thank Professor Herbert W. Virgin, Washington University (St. Louis, Missouri, United States) for providing the murine NoV stain used as sample process control.
The research leading to these results has received funding from the Italian National Centre for the Prevention and Control of Diseases (CCM), project – Hepatitis E Surveillance in Italy: an emerging disease in industrialized countries, and from the European Union’s Seventh Framework Programme for Research, Technological Development and Demonstration under Grant Agreement no. 278433-PREDEMICS.
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