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Utilization of Hearing Aids by the Hearing-Impaired in Ghana

negative for HBsAg and anti-HBs with a prevalence of 4.9% (95% CI = 2.8-7.9). Thus, of the 491 Karen whose venous blood samples were collected, 220 were positive for any of the three markers of HBV infections with an overall exposure of 44.8% (95% CI = 40.4--49.2)(Table I). The prevalence of HBsAg (X2 for trend = 6.387, P = 0.0115), anti-HBs (X2 for trend = 25.76, P = 0.0000) and overall exposure to HBV (X2 for trend = 31.65, P = 0.0000) were found to increase linearly with age. The findings of the survey indicate that HBV infection is highly endemic among the Karen, with more than 44% of the population being exposed to this infection. 11.6% of the population screened was positive for HBsAg and this rate is significantly higher than the national average of 4.71%3. The overall exposure to HBV among children was 36.5%, which suggests the importance of transmission during childhood. Among the 24 children under-14 tested positive for HBsAg, five were under 5 years accounting for 20.8% of the chronic carriers in this age group. HBsAg positivity among the infants was 6.3%. These findings suggest transmission through vertical and horizontal modes in this community. These modes were also found to be important among other primitive tribes of these islands. HBsAg, anti-HBs positivity and overall exposure were found to increase linearly with age. These rates were found to be significantly higher among those aged 15 years or more which suggests that the older population is more frequently exposed to other known modes such as parenteral exposure to blood, sexual transmission, etc. Certain sociocultural practices like bloodletting, scarification, tattooing and orally processed food were found to be the probable reasons contributing to the higher prevalences observed among the aborigines worldwide", These practices could also be playing a role in transmission of HBV infection among the Karen. However, further sociocultural studies are needed. Hepatitis B is an important health problem among the tribes of these islands and a pilot study to vaccinate the susceptible individuals with indigenous hepatitis B vaccine has been initiated among the Nicobarese'. Considering the small number of Karen in these islands and high prevalence of HBV infection among them, it is necessary to extend the vaccination programme among them. M V Murhekar MD K M Murhekar MD S C Sehgal MD