HEPATITIS B ANTIGEN: REGIONAL VARIATION IN INCIDENCE AND SUBTYPE RATIO IN THE AMERICAN RED CROSS DONOR POPULATION1

Abstract

Dodd, R. Y. (Amer. Nat. Red Cross, Blood Research Lab., 9312 Old Georgetown Rd., Bethesda, Md. 20014) P. V. Holland, L. Y. Ni, H. M. Smith, and T. J. Greenwalt. Hepatitis B antigen: Regional variation in incidence and subtype ratio in the American Red Cross donor population. Am J Epidemiol 97: 111–115, 1973.—A study of 2,596,118 Red Cross blood donations taken between April and December 1971 has established 0.104% as the national incidence of hepatitis B antigen (HBAg) antigenemia among volunteer blood donors. Considerable and significant variations in incidence have been demonstrated both locally and on a broad regional basis. In addition, the national value for the ratio of the HBAg subtype ad to HBAg subtype ay was found to be 5.8:1; again with considerable regional variation. In general, northern regions demonstrated a low incidence of HBAg whereas high incidences were found in the southeast, or in densely populated urban areas. Low ad: ay ratios were noted in two northeastern states and in the northwestern region of the U.S. In the absence of detailed information on the geographic variation of donor populations detailed analysis of the basis for these variations is not possible.