[Serologic diagnosis and epidemiology of acute delta hepatitis in Indre-et-Loire].

A 6 years retrospective study (1981-1986) of 153 consecutive cases of HBsAg positive acute hepatitis was carried out to assess the prevalence of delta virus infections in the Indre-et-Loire a district of the Loire Valley in France. Diagnostic value of the various serum markers of delta infection, i. e. HDAg, anti-HD and anti-HD IgM, were evaluated using immunoenzyme assays. During the survey, 22 cases of delta hepatitis were diagnosed (12 co-infections, 10 superinfections). They all involved young adults, 21 of them were drug-addicts, and one young woman was the consort of a drug-addict. In Indre-et-Loire, delta virus infection was responsible for half of acute HBsAg positive hepatitis among drug-users in the last 3 years of our study. Clinical and biological features of acute delta hepatitis were compared to those of the other HBsAg positive hepatitis: two cases of fulminant hepatitis occurred among the 12 co-infections; 4 of 6 superinfection that could be followed up to 6 months developed biopsy-proven chronic active hepatitis. Delta Ag was found constantly during the first week of the disease, its disappearance was always followed by a seroconversion to anti-HD after four weeks. Anti-delta IgM was an inconstant and late marker: it was detected within the first 4 weeks in only one case (a co-infection); it persisted only in superinfections. Our study shows that delta Ag is an efficient serum marker for the early diagnosis of acute delta hepatitis.