[Epidemiological studies on viral hepatitis among long-term sojourners in the developing countries and evaluation of...

It is known that acute viral hepatitis is very common among sojourners in developing countries. In order to conduct effective health control, epidemiological studies were made on viral hepatitis which occurred among Japanese staying in developing countries, and evaluations were carried out on preventive measures. The subjects of present study were a group of Japanese people staying in developing countries for two years. Mid year population of the group was 1732 in 1988. Period of the present study is ten years from 1979 to 1988. The study was conducted based on the reports from offices in each country, survey trips and serological studies on the subjects. In 1979, frequency of hepatitis A (HA) was very high showing 79% of total hepatitides. However after starting of inoculation of human immune serum globulin (ISG), the frequency of HA declined remarkably. Statistical significance was recognized in the efficacy of ISG. Among 35 cases of hepatitis B (HB) (34 males and 1 female), 2 derived from HBe antigen carrier while the remaining 34 were regarded as infected during their stay in developing countries. No cases of HB were recognized among those who received injections of HB vaccine. The rate of people whose HB marker turned positive during their stay is showing a tendency of increase (4.2% in 1987). The frequency of infection with HB virus is especially high in Asian and African countries where the carrier rates of native people were also high. Ten cases of non-A non-B hepatitis were recognized. Among them 7 were infected in Asia, 1 in Africa and 1 in Central America.(ABSTRACT TRUNCATED AT 250 WORDS)