New hepatitis B surface antigen subtypes inside the ad category.

In addition to the 10 HBs Ag subtypes already described, 2 new subtypes were defined by using the q determinant. Exceptions to the rule generally accepted were found in that the q determinant was only lacking in HBs Ag/adw4. These exceptions occurred in adw and adr categories. These 2 new subtypes are adw q positive and adr q negative. Out of 98 HBs Ag/adw4 from silent carries and patients from different parts of the world, mainly from France (79), 6 were found q positive. 3 out of these 6 cases came from Montpellier (South of France) and another 3 from Germany. The 92 other cases were found q negative. Further studies will be necessary to better know the location of this new subtype adw4 q positive, but it seems to be present only in certain parts of Europe. Out of 86 HBs Ag/adr from silent carriers from Asia (58), Oceania (17), France (10, most of them contaminated in Asia) and Réunion (1), 10 were found q negative. All these 10 cases were detected in Oceania, 2 out of 2 in carriers from New Caledonia and 8 out of 13 from French Polynesia. The new subtype adr q negative seems localized in Melanesia and Polynesia and absent from Asia. These 2 new markers of hepatitis B virus will allow better epidemiological and geographical studies.