Lethal outbreak of hepatitis B in a dental practice
F. E. Shaw Jr, C. L. Barrett, R. Hamm, R. B. Peare, P. J. Coleman, S. C. Hadler, H. A. Fields and J. E. Maynard
Between April 1, 1984, and Feb 1, 1985, nine cases of hepatitis B occurred
in the patients of a dentist practicing in a rural Indiana county
(population, 35,000). This was over 20 times the mean annual incidence for
the county in the previous decade. All of the patients had been treated by
the dentist two to five months before illness. Although the dentist had
never had hepatitis symptoms, his serum was positive for hepatitis B
surface antigen and hepatitis B e antigen and negative for anti-hepatitis B
core IgM antibody, indicating that he was probably a hepatitis B carrier.
Two patients (22%) died of fulminant hepatitis; the case-fatality ratio was
over ten times the reported US mean for hepatitis B. Using a case
definition based on anti-hepatitis B core IgM antibody positivity and
exposure to the dentist during a defined time period, a serosurvey of the
dentist's patients identified 15 asymptomatic cases (overall attack rate,
3.2%). Infection risk was related to the amount of trauma involved in the
cases' dental procedures. No cause was found for the unusual lethality of
the outbreak.
