[Use of highly sensitive methods of detecting hepatitis B virus markers for studying epidemic foci of hepatitis B].

Passive hemagglutination test (PHA) was found to detect HBsAg in the population living outside the hepatitis B virus foci 1.5-fold as frequently as counter immunoelectroosmophoresis technique, and anti-HBs by enzyme immunoassay 14-fold as frequently. As compared with normal population, the contacts in foci had 4-fold higher levels of HBsAg carrier state and twice as high rates of detection of anti-HBs. The total index of HBV infection in foci was 27.7%. The above materials considerably extend the concepts of HBV epidemiology. The regularity of the results obtained indicate the specificity and high sensitivity of PHA and EIA tests and suggests that they be used on a wider scale.