Congenital hearing impairment associated with rubella: lessons from Bangladesh.

Infection with rubella virus during pregnancy may cause fetal death or the multiple congenital fetal abnormalities that are known as congenital rubella syndrome (CRS). Studies have demonstrated that congenital hearing impairment is the most frequent abnormality associated with intrauterine rubella infection. In the present study, the first of its kind in Bangladesh, we investigated the presence of rubella antibody in hearing-impaired children in order to understand the possible role of rubella infection in the development of hearing impairment. A total of 198 hearing-impaired children and 200 children without hearing problems were studied. After taking a detailed history from the parents, blood samples were collected from both mothers and children; sera were subjected to enzyme-linked immunosorbent assay (ELISA) for anti-rubella IgG. Rubella antibody was detected in 74% of the hearing-impaired children and in 18% of those with normal hearing: this finding correlated with the presence of rubella antibody in the mothers (67%) of rubella seropositive hearing-impaired children. In contrast, we observed rubella antibody in only 14% of the mothers of the children without hearing problems. Consistent with the presence of antibody, 41% of the seropositive mothers who had hearing-impaired children gave a history of fever and rash during early pregnancy. Our study indicates a strong association between rubella infection and hearing impairment in Bangladeshi children. In addition, it also indicates that infection by rubella virus is common in Bangladesh: this suggests that priority should be given to implementing appropriate measures for the control of rubella.

Viral hepatitis: recent experiences from serological studies in Bangladesh.

Infections due to hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV) and hepatitis E (HEV) viruses are the major causes of hepatitis and are associated with significant morbidity and mortality in developing countries like Bangladesh. The present study was carried out to determine the prevalence of HBsAg, anti-HCV antibody, anti-HAV antibody and anti-HEV antibody in patients suspected of having infection by HBV, HCV, HAV and HEV, respectively. Antibody to HAV was detected in 39% of subjects investigated. HBsAg was identified in 19% of subjects. Antibody to HCV and HEV was detected in 13% and 53% subjects, respectively. Infection with HAV was very high among children < or = 6 years of age (100%). On the contrary, exposure to HEV was higher in adult persons > or => 30 years of age (52%) compared to that in children < or = 6 years of age who had 0% incidence. Our study clearly indicates a high prevalence of those viruses, particularly of enterically transmitted HAV and HEV in Bangladesh, which appeared to be a serious health problem in this developing country. Control measures should be taken on an urgent basis to prevent the spread of infections by these viruses.