SEROEPIDEMIOLOGICAL STUDY OF AN ACUTE HEPATITIS-E OUTBREAK IN MOROCCO

This study clearly shows that hepatitis E virus (HEV) was the major ae tiological virus in an outbreak in the south of Morocco, in 1994. Acut e hepatitis E was diagnosed using recombinant antigen-based enzyme imm unoassays and reverse transcription polymerase chain reaction in 77.3% of patients. In the west of Morocco, 6.1% of controls were positive f or anti-HEV IgG. The anti-HEV prevalence in patients was significantly higher than that of controls (84.0% vs. 6.1%) (P<0.001). In healthy c ontacts residing in southern Morocco, 10.4% had anti-HEV IgG, indicati ng past HEV infection. Furthermore, HEV-specific IgM was associated wi th subclinical HEV infection in 9 contacts and was noted in 10 others who were convalescent. Faecal contamination of drinking water samples collected from the epidemic city was observed. It also appeared that p rimary infection with HEV accounted for more than 86% of the cases. A longitudinal study showed waning of anti-HEV antibodies in patients an d healthy contacts six months after the initial testing. Subclinical H EV infection was significantly prevalent in a paediatric population yo unger than 10 years (P<0.05). Our results also showed that anti-HEV Ig G in healthy contacts decreased significantly after 30 years of age (P <0.01), whereas the clinical acute HEV infection incidence increased s ignificantly with age (P<0.01). From this study, it appears that HEV i s present in both the west and the south of Morocco.