[Prevalence of anti-HCV antibodies and seroconversion incidence in five haemodialysis units in Morocco]. / Prévalence des anticorps anti-VHC et incidence de séroconversion dans cinq centres d'hémodialyse au Maroc.

Dialysis patients are among groups at risk for development of hepatitis C infection (HCV). The aim of the study was to evaluate the prevalence and the incidence of seroconversion for HCV in five haemodialysis units in Morocco. The study was conducted during the period from September 2003 to September 2004. We studied 303 patients (148 females), mean age 49+/-16 years; dialysis duration was higher than five years in 64% of the cases. The prevalence of HCV infection was evaluated by using a fourth generation enzyme immunoassays. In the seronegative patients, we performed anti-HCV tests at three and six months intervals and monthly testing of alanine aminotransferase (ALT) activity and assessment of anti-HCV tests if the ALT activity was elevated. Moreover, risk factors, such as blood transfusion, surgery and other invasive procedures were recorded. Seroprevalence of HCV was 68.3%. Among 85 patients who were tested negative for anti-HCV at the entry of the study, four (4.60%) seroconverted in six month (estimated incidence: 9.41 new cases per year). HCV seropositivity was associated with longer duration of dialysis (p=0.000), and previous blood transfusions (p=0.047). The follow-up of the ALT in the seronegative patients did not show any significant variation. In conclusion, the prevalence and incidence of HCV infection in haemodialysis units in Morocco are dramatically elevated. High incidence seropositivity suggested nosocomial transmission of HCV; the dialysis processes itself, and blood transfusions are important risk factors for HCV transmission in these patients.

Experimental transfection of Macaca sylvanus with cloned human hepatitis B virus.

Due to the absence of easily accessible animal models for the study of hepatitis B virus (HBV), the possibility of using Macaca sylvanus, a monkey originating from Morocco, North Africa, was investigated. Three monkeys were intrahepatically inoculated with a replication-competent head-to-tail HBV DNA plasmid dimer construct. The HBV surface antigen and HBV DNA were detected prior to alanine aminotransferase elevation in the serum of two of three HBV-inoculated monkeys at day 2 post-transfection and persisted for several weeks. This indicates that transfected animals developed markers of HBV infection. In addition, electron microscopy of the serum 3 weeks post-transfection showed the presence of virus particles whose shape and size were similar to complete 42 nm HBV Dane particles. Histological examination of liver tissues also revealed pathological changes not observed in uninfected controls, which strongly suggested acute hepatitis. HBV DNA was also detected by PCR in these monkey livers. Taken together, these results indicate that HBV can successfully replicate in this model and that M. sylvanus could be a potentially useful new primate model for the study of HBV replication.