Analysis of serological responses to Cryptosporidium antigen among NHANES III participants.
OBJECTIVE
Sera from 1356 National Health and Nutrition Examination Survey (NHANES) III participants from seven primary sampling units were tested for serological responses to two Cryptosporidium antigen groups. Intensity of responses was compared by geographic area, age, sex, race/ethnicity, income, and hepatitis A seropositivity.


METHODS
Cryptosporidium seropositivity for the 15/17-kDa and the 27-kDa antigen groups were defined by the intensity of the responses. Conditional and unconditional logistic regression was used to identify significant risk factors.


RESULTS
Hispanics, blacks, and females had a higher seropositivity. Younger participants and those with higher income had a lower seropositivity. Being hepatitis A seropositive was strongly related to a weak serological response to the 27-kDa antigen group. Family size was unrelated to Cryptosporidium seropositivity. Significantly higher Cryptosporidium seropositivity was observed for three of the seven primary sampling units.


CONCLUSIONS
This study found significant geographical differences in the occurrence and the intensity of serological response. Strong serological responses to the 15/17-kDa antigen occurred more commonly in blacks and Hispanics, individuals not having high incomes, and in older age groups.
Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA. ffrost@lrri.org
Floyd J
FJ
Frost
Timothy B
TB
Muller
Rebecca L
RL
Calderon
Gunther F
GF
Craun
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000917:Antibody Formation; D000953:Antigens, Protozoan / Q000097:blood* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000208:ethnology / Q000276:immunology; D003458:Cryptosporidium / Q000276:immunology*; D005006:Ethnicity; D005260:Female; D005843:Geography; D006306:Health Surveys; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D014481:United States / Q000453:epidemiology; D014881:Water Supply / Q000592:standards
D000953:Antigens, Protozoan