Hepatitis type E in a French population: detection of anti-HEV by a synthetic peptide-based enzyme-linked immunosorbent assay.

Four synthetic peptides were used to develop an ELISA for detecting hepatitis type E infections. Antibodies to HEV were detected in 54 of 64 patients present during two outbreaks previously recognized as being due to hepatitis E virus. Those patients included French soldiers stationed in Chad at the time, and Algerian civilians residing in Algeria and considered as positive controls. Anti-HEV were also detected in 3 out of 74 cases of sporadic non-A, non-B, non-C hepatitis in France, and in 2 out of 150 anti-HAV-IgM-positive sporadic cases, also in France, but in none of 278 healthy adults from the general French population. Among a total of 34 anti-HEV-positive cases in French subjects, 32 were shown to be associated with travel outside of western Europe; in two cases, however, HEV transmission appeared to have taken place in Europe. Using this ELISA, a rapid drop in anti-HEV antibodies to undetectable levels following the acute phase of the disease was observed in a high proportion of the infected subjects. Thus, the present test would appear to be more suitable for diagnostic purposes than for epidemiological investigations.

Familial clustering of hepatitis B virus infections and prevention of perinatal transmission by immunization with a reduced number of doses in an area of intermediate endemicity (Tunisia).

Hepatitis B surface antigen (HBsAg) was detected in 3.3% of 7162 pregnant Tunisian women tested and HBeAg in 9.6% of the HBsAg-positive mothers. Family members of 46 of these HBsAg-positive mothers (33 husbands and 61 children aged 1-6 years) were investigated for the presence of HBV markers. HBsAg was detected in 21% of the children and 18% of the husbands. Fifty children born to HBsAg-positive mothers received hepatitis B vaccine at birth, at the age of 2-3 months and at the age of 9 months. After immunization, anti-HBs were detected in 92% of them with an anti-HBs geometric mean titre of 415 mIU ml-1. Compared with the HBsAg carrier state in older siblings, the protective efficacy was estimated to be 60%. It was 100% for infants born to HBeAg-negative mothers, but only 31% for those born to HBeAg-positive mothers. For a better efficacy, the schedule of the EPI needs to be modified to include an immunization session at 1 month of age.

High prevalence of mutations at codon 249 of the p53 gene in hepatocellular carcinomas from Senegal.

In hepatocellular carcinoma, mutation within the p53 gene occurs mainly at codon 249 and its frequency has been associated with exposure to aflatoxin. As Senegal is a country where liver cancer incidence is one of the highest in the world and where people are highly exposed to aflatoxin, we screened 15 liver cancer samples from this country for mutation at codon 249 of the p53 gene. Non-tumoral DNA from the patients showed a wild type genotype. Mutation at codon 249 of the p53 gene was detected in 10 of the 15 tumour tissues tested (67%). This frequency of mutation in codon 249 of the p53 gene is the highest described. These results confirmed that there is an association between countries of high aflatoxin intake and a high frequency of mutation in codon 249 of p53 gene, and that HBV alone does not contribute to these base changes.

Mapping of linear B cell epitopes on open reading frames 2- and 3-encoded proteins of hepatitis E virus using synthetic peptides.

Hepatitis E virus (HEV) is the causative agent of non-A, non-B hepatitis which is transmitted by the fecal-oral route and occurs principally in the form of large epidemics and outbreaks in developing countries. Two overlapping synthetic peptides corresponding to overlapping DNA sequences of the ORF 3 of HEV genome were found to be immunoreactive with sera from patients involved in two epidemics of enterically transmitted non-A, non-B hepatitis. The results suggested the existence of two distinct epitopes. The four synthetic peptides representing these two epitopes from Burma and Mexico strains of hepatitis E virus, were used to investigate anti-HEV reactivities. HEV antibodies were detected in 84-88% of HEV-infected individuals according to the peptide used. The results suggest that a peptide-based ELISA can provide an accurate tool for the diagnosis of acute hepatitis type E.

Detection of hepatitis B virus DNA by polymerase chain reaction in vaccinated and non-vaccinated Senegalese children.

An hepatitis B immunization programme was initiated in Senegal in 1978, and infants included in this controlled study have been followed for a period of 2-12 years after immunization. During this period HBV infections have been observed both in vaccinated and non-vaccinated infants. The polymerase chain reaction was used to search for HBV DNA sequences in the sera of 153 children with evidence of serum markers of past or present HBV replication. Amplified HBV DNA sequences were detected in 93% of the HBsAg positive individuals, in 58% of those only positive for antiHBc antibodies and in 7.8% of antiHBs and antiHBc positive infants. The results confirm the high efficiency and long-lasting effectiveness of HB vaccine.