| Sumario: |
Excretory-secretory antigen (ESA) and adult somatic antigen (ASA) were obtained from adult worms of Paragonimus mexicanus. These antigens were characterized, tested and compared for its use in serodiagnosis of human paragonimiasis. Excretory-secretory proteins with 30 and 32.5 kDa and adult somatic proteins with 30 and 35 kDa molecular weight reacted consistently with all positive control sera, these proteins were determined as specific for detection of antibodies against P. mexicanus in human sera using immunoblotting. Adult somatic antigens were also used to prepare an intradermal test. In an indigenous community, 100 children were administered the intradermal test, 23 reacted positive. Excretory-secretory antigen immunoblot carried out with blood samples of the children detected 11 sera positive, while immunoblot with ASA detected 14 sera positive. Results of ESA immunoblot showed good correlation (0.86) with ASA immunoblot results, but both immunoblots showed moderate correlation (0.50 and 0.58) to the intradermal test. Although both antigens, seemed to be adequate for its use in serodiagnosis, we recommend the use of ESA for serological diagnosis of paragonimiasis in Costa Rica, since cross-reactions with other parasitic infection, especially with other trematode infections, did not occur. Furthermore, intradermal tests should be used for monitoring population at risk, and ESA immunoblot to confirm active infections of P. mexicanus.
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