Cryptosporidium species subtypes and associated clinical manifestations in Indian patients

Aim: Present hospital based study was carried out at our tertiary care centre with an aim to study the distribution of Cryptosporidium species subtypes in patients with complaints of diarrhea. Background: Cryptosporidium species are one of the important causative agents of parasitic diarrhea, amongst which Cryptosporidium hominis (C.hominis) and Cryptosporidium parvum (C.parvum) are the two major species that are associated with human cryptosporidiosis. Methods: Four hundred and fifty (n=450) diarrheic patients complaining of different types of diarrhea were enrolled in the present study. Both microscopic and molecular diagnostic methods were used for the detection as well as for identification of Cryptosporidium species and its speciation and subtyping. Results: Forty one (n=41) and forty three (n=43) patients were positive for Cryptosporidium species by microscopy and Polymerase chain reaction (PCR) assay respectively. Of these 43 cases, 70% (30/43) were identified as C. hominis and 21% (9/43) was as C. parvum, 7% (3/43) was as Cryptosporidium felis (C.felis) and 2% (1/43) as Cryptopsoridium viatorum (C. viatorum) respectively . Upon subtyping of C. hominis and C. parvum, 16 subtypes belonging to 8 different subtype families could be identified. The frequency of different families were Ia (13%, 5/39), Ib (15%, 6/39), Id (18%, 7/39), Ie (30%, 12/39) and IIa (5%, 2/39), IIc (8%, 3/39), IId (8%, 3/39) and IIe (3%, 1/39). Conclusion: Our study results strongly suggest and reinforces the fact that most of the human cryptosporidiosis is anthroponotic and we expect that present molecular epidemiological data will provide more insight to unravel the changing clinical paradigm of human cryptosporidiosis at large.