Antibody responses to Cryptosporidium antigen in HIV-positive patients in the Republic of Korea

Review of Successful Control of Parasitic Infections in Korea

Korea had been one of hyperendemic countries of human parasitic infections until 1970s. In 1966, the Law for the Prevention of Parasitic Diseases was enacted, and the nationwide anti-parasitic control program began in 1969. The initiation of the national program was supported financially by Japan. The program included screening of whole students in Korea and treatment of all egg positive cases twice a year, and ended in 1995. In addition to student program, deworming campaign was run in the community, and 8 national status surveys were implemented from 1971 to 2012. Whole helminth egg positive rate was 84.3% in 1971 and decreased to 2.6% in 2012. Ascaris and other intestinal nematodes, Paragonimus, Taenia, and intestinal protozoa had decreased significantly throughout the country, but Clonorchis sinensis and intestinal trematodes are still prevalent locally in endemic areas. Lymphatic filariasis had been endemic in Jeju-do and other southern islands but elimination was endorsed in 2008. The control of parasitic infection in Korea was successful with statistical prevalence data, which can be a benchmarking model. In conclusion, the successful control in Korea could be achieved by social agreement of the priority, professional guidelines and systematic approach with good anthelminthics supply, and simultaneous economic growth.

Systemic antibody responses to the immunodominant p23 antigen and p23 polymorphisms in children with cryptosporidiosis in Bangladesh

Cryptosporidium is a major cause of diarrhea in children in developing countries. However, there is no vaccine available and little is known about immune responses to protective antigens. We investigated antibody responses to p23, a putative vaccine candidate, in children in Bangladesh with cryptosporidiosis and diarrhea (cases) and uninfected children with diarrhea (controls), and p23 gene polymorphisms in infecting species. Serum IgM, IgG, and IgA responses to p23 were significantly greater in cases than controls after three weeks of follow-up. Cases with acute diarrhea had significantly greater serum IgA and IgM responses than those with persistent diarrhea, which suggested an association with protection from prolonged disease. The p23 sequences were relatively conserved among infecting species and subtype families. Although most children were infected with Cryptosporidium hominis, there was a cross-reactive antibody response to C. parvum antigen. These results support further development of p23 as a vaccine candidate.