Hepatitis E virus (HEV) is an emerging disease. The genotype 1 and 2 are predominant in Asia and Africa, and are responsible for recurrent epidemics. Genotype 3 is the main genotype found in Europe and North America and is responsible for sporadic infections except for travel associated diseases.

HEV had a principally asymptomatic form. However, it was recently demonstrated that it could lead to a chronic form, especially in immunosuppressed patients. Moreover, in liver transplanted patients the infection could mimic a rejection and lead to the loss of the transplant. In other immunosuppressed patients, chronic hepatitis lead to cirrhosis and its well-known complications (ascitis, digestive hemorrhage, liver failure...). There is a lack of information about the prevalence of this disease.

In Canada the incidence of HEV infection was high (15-86% for liver transplanted children with liver tests disturbed). In Germany the prevalence was lower: 3,2% in liver & kidney transplanted children whereas 7,4% in control. It was shown in a retrospective study that in liver (and liver+kidney) transplanted children the prevalence in Lyon was around 8,3%.

This study will determined in a prospective approach the HEV prevalence in kidney, lung, heart and bone marrow transplanted children in Lyon.

Inclusion Criteria:

• <18 years old
• transplantation (heart, kidney, lung or bone marrow)
• protocol acceptance by family
• social security available

Exclusion Criteria:

• protocol rejection by family