GENOTYPING BY MULTIPLEX POLYMERASE CHAIN-REACTION FOR DETECTION OF ENDEMIC HEPATITIS-B VIRUS TRANSMISSION

A nested polymerase chain reaction (PCR) protocol was developed for ra pid genotyping of hepatitis B virus (HBV). During the first PCR round, a universal HBV primer pair was used to amplify the entire pre-S regi on of the HBV genome. Within the pre-S region, many nucleotide exchang es are observed. These are partly correlated to the serological hepati tis B surface antigen subtypes. Five additional subtype-specific prime rs were selected from that region which, together with two universal n on-group-specific primers, generated specific combinations of two to f our DNA fragments of defined sizes. By this approach, 55 hepatitis B s urface antigen-positive patients from a pediatric oncology unit in Ger many were analyzed. Fifty-four patients who had been infected within 2 years had an identical pattern in the multiplex PCR, suggesting a com mon source of infection and person-to-person transmission within the u nit. One child who was infected 5 years later had a different PCR patt ern and, therefore, must have been infected from a different source. F urthermore, 109 serum samples taken from pregnant Cameroonian women an d 25 serum samples from their babies taken 6 months after birth were a nalyzed. In one case, mother-to-infant transmission of the virus was d emonstrated. Apart from its role in epidemiological studies on HBV, mu ltiplex PCR may also be a useful tool for rapid genetic analysis in ot her fields if there is a moderate degree of sequence variation which e nables the design of specific primers.