Hepatitis transmission among the Sioux Indians of South Dakota.
Hepatitis A continues to occur in cyclical community-wide epidemics on the Indian reservations of South Dakota. In June 1985 a population-based serosurvey for viral hepatitis involving 120 households was conducted at the Pine Ridge and Rosebud Sioux Indian reservations in South Dakota. The serosurvey was performed shortly after a large hepatitis A epidemic on the Pine Ridge reservation in 1983-84, and immediately before a large hepatitis A epidemic on the Rosebud reservation in 1985-86. The overall seroprevalence for antibodies to hepatitis A virus (anti-HAV) was 76.2 percent (Pine Ridge reservation 80.5 percent, Rosebud reservation 72.0 percent, relative risk = 1.12, 95 percent confidence interval = 1.01, 1.24). For age groups 0 to 4 years, 54.2 percent and 36.1 percent of children were seropositive at Pine Ridge and Rosebud, respectively. Seropositivity rose rapidly with age; by age 40, more than 90 percent of persons at both Pine Ridge and Rosebud were anti-HAV positive. Only 1.1 percent of persons tested were positive for hepatitis B markers. Anti-HAV seroprevalence rates in both communities are similar to rates observed in developing countries. The surprisingly high anti-HAV seroprevalence among young children at Rosebud, where clinical hepatitis A had been virtually absent in the previous seven years, indicates that high-grade silent transmission was taking place during the interepidemic period.
Shaw
F E
FE
Division of Viral and Rickettsial Diseases, Centers for Disease Control, Atlanta, GA 30333.
Shapiro
C N
CN
Welty
T K
TK
Dill
W
W
Reddington
J
J
Hadler
S C
SC
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology / Q000635:transmission*; D006508:Hepatitis Antibodies / Q000032:analysis; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006507:Hepatovirus / Q000276:immunology; D006801:Humans; D007198:Indians, North American; D007223:Infant; D008297:Male; D008875:Middle Aged; D013023:South Dakota / Q000453:epidemiology
D006508:Hepatitis Antibodies; D006514:Hepatitis B Surface Antigens