Enzyme immunoassay detection of antigen-specific immunoglobulin g antibodies in longitudinal serum samples from patients with cryptosporidiosis.
Cryptosporidium parvum is a protozoan parasite that causes diarrheal illness in a wide range of mammalian hosts, including humans. Characteristic serum immunoglobulin G (IgG) antibody responses to antigens in the 27- and 17-kDa size ranges have been shown to develop after infection, and several enzyme-linked immunosorbent assay (ELISA) and Western blot assay formats have been used to measure these IgG levels in human serum. Using a collection of serial samples from laboratory-confirmed cryptosporidiosis patients, we compared the results obtained by using two new ELISAs with those obtained with two different Western blot assays. When assayed with the large-format Western blot, 97% of the 67 patients had a demonstrable antibody response on at least one occasion. The Cp23 ELISA correctly identified 93% of the samples that had a 27-kDa response by Western blot and 100% of the negative samples. The Triton antigen ELISA detected 77% of the samples that had a 17-kDa response by Western blot and 88% of the negative samples. The sensitivity of the Triton antigen assay was higher for samples collected between 16 and 92 days after the onset of symptoms (96%). The minigel-format Western blot did not compare favorably with the large-format blot for the detection of antibodies to the 27-kDa antigen (71% sensitivity). A half-life of about 12 weeks was estimated for antibodies to both the 27- and 17-kDa antigens. We believe the Cp23 and Triton antigen ELISAs will be useful in epidemiologic studies of the prevalence of Cryptosporidium infection in the population.
Priest
J W
JW
Division of Parasitic Diseases, Centers for Disease Control and Prevention, Mail Stop F-13, Building 23, Room 1025, 4770 Buford Highway N.E., Atlanta, Georgia 30341-3724, USA. jpriest@cdc.gov
Li
A
A
Khan
M
M
Arrowood
M J
MJ
Lammie
P J
PJ
Ong
C S
CS
Roberts
J M
JM
Isaac-Renton
J
J
D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis* / Q000276:immunology; D015153:Blotting, Western; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000453:epidemiology; D016785:Cryptosporidium parvum / Q000276:immunology* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008137:Longitudinal Studies; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies
D000953:Antigens, Protozoan; D007074:Immunoglobulin G