Serodiagnosis of cryptosporidiosis in Italian HIV-positive patients by means of an oocyst soluble antigen in an ELISA.
A sensitive, specific, and reproducible ELISA which incorporated an oocyst soluble antigen was used in order to detect specific Cryptosporidium immunoglobulins G and M in Italian HIV-positive patients. The soluble antigen was prepared from purified oocysts collected from experimentally infected calves. The serum working dilution was established at 1 in 50. Of parasitologically positive and HIV-positive patients, 95% showed specific IgG or IgM or both in their serum. Of HIV-positive patients, some of whom had diarrhoea of uncertain aetiology, 15.8% were found to have specific IgG. Both specific IgG and IgM were detected in the serum of an HIV-positive patient 1 year before the shedding of oocysts in the faeces. Sixteen (5.3%) of 300 presumed healthy people, positive for specific IgG, were all IgM-negative. Any significant cross-reactions with other parasitic infections were not observed. With a serum dilution greater than 1 in 25, only a low degree of positivity was observed with samples highly IgG-positive for Toxoplasma species. The ELISA showed a higher than expected prevalence of Cryptosporidium infection in Italian HIV-positive patients.
Gomez Morales
M A
MA
Laboratory of Parasitology, Istituto Superiore di Sanità, Rome, Italy.
Pozio
E
E
Croppo
G P
GP
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan; D003457:Cryptosporidiosis / Q000175:diagnosis*; D003458:Cryptosporidium / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007558:Italy; D012680:Sensitivity and Specificity
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M