Further data on HBs subtypes: geographical distribution

1123 HBs antigens from silent carriers of different parts of Europe, Africa and Asia were subtyped and classed in the eight categories previously described: a1y(w1), a2yl(w2), a2(3)y(w3), a3y(w4), ayr, a2ld(w2), a3d(w4) and adr: We have showed that w can be subdivided into the system of a subdeterminants, but for the present time, we do not know if r is a fifth subdeterminant of a. Subtyping was performed by CIEP and by ID using antisera from guinea pigs and goats immunized with selected HBs antigens. With these 8 categories it is possible to greatly increase our knowledge about the geographical distribution of HBs antigen: in Africa six areas can be distinguished: North Africa with a predominance of a2ly(w2) (75%) and with none a3y(w4); areas between North and West Africa where a2ly(w2) and a3y(4) represent respectively 62.8% and 25.7%; West Africa with a great predominance of a3y(w4) (84.5%); Central Africa with less a3y(w4) (53.4%), appearance of a2ld(w2) (8.7%) and presence of a2ly(w2) (37%); East Africa appears to be especially a2ld(w) (only 3 sera from Burundi); South Africa with a great predominance of a2ld(w2) (86%) and with ay subtype represented by a2(3)y(w3), very exceptional in the other parts of Africa. In France, The Netherlands, Hungary, a2ld(w) subtype is predominant, respectively 73.3%, 74% and 63%, a2(3)y(w3) is the main ay subtype in France and the only one in The Netherlands whereas in Hungary the same amount of a2ly(w) and a2(3)(w) is encountered. In Rumania, Italy and Greece, a great predominance of ay subtype is found (80%): a2ly(w2) is predominant in Rumania (66%) and Italy (as in North Africa) whereas a weak predominance of a2(3)y(w3) over a2ly(w2) is found in Greece. In the Antilles, 75% of a2ld(w2) are encountered. In the Far East, a great predominance of adr is found in Laos, Japan and Thailand (100% and 84% respectively) but no adr is encountered in Vietnam where 8 a1y(w1) and 1 ayr are found of of 11 HBs sera. This a1y(w1) subtype has also been found, although infrequently, in some countries of Africa. Among French people who have lived in Africa, many examples are found which show that the HBs subtype is related to the country and does not seen to depend on the host. Among the French who have been contaminated in Indochina all are carriers of adr HBsAg and none exhibits an a1y(w1) subtype.