Multisite study of cryptosporidiosis in children with diarrhea in India

Abstract

Cryptosporidium spp., a common cause of diarrhea in children, were investigated in the first multisite study in India. Diarrheal stools from hospitalized children aged <5 years from Delhi, Trichy, and Vellore were analyzed by microscopy, PCR-restriction fragment length polymorphism (RFLP), and/or sequencing at the small-subunit (SSU) rRNA and Cpgp40/15 loci for species determination and subgenotyping, respectively. Seventy of 2,579 (2.7%) children, 75% of whom were <2 years old, had cryptosporidial diarrhea as determined by microscopy. Genotyping and subgenotyping showed that Cryptosporidium hominis was the most commonly identified species (59/67 children), and subgenotypes Ie, Ia, Ib, and Id were common in all centers. A novel C. parvum subgenotype, IIn, was identified in Vellore. Meteorological analysis revealed a higher rate of cryptosporidial positivity during hotter and drier weather in Delhi.

FIG. 1.

Monthly distribution of cryptosporidial positivity rates and the meteorological parameters for the Delhi (A), Trichy (B), and Vellore (C) centers.

FIG. 1.

Monthly distribution of cryptosporidial positivity rates and the meteorological parameters for the Delhi (A), Trichy (B), and Vellore (C) centers.

FIG. 2.

Phylogenetic tree of sequences from a multisite study of cryptosporidial diarrhea in children in India compared to what was observed for known representative Cpgp40/15 subgenotypes. (The maximum likelihood method with PhyML and tree construction with TreeDyn were used with default settings in the Phylogeny.fr server [version 2]; the sequences for samples V416 and V640 were different from those for all other known subgenotypes and were named IIn.)

FIG. 3.

Cpgp40/15 subgenotypes of C. parvum identified in a multisite site on cryptosporidial diarrhea in India (M, 100-bp molecular weight marker; lanes 1 to 12, RFLP patterns observed following digestion with AluI [lanes 1 to 6] and with RsaI [lanes 7 to 12]; lanes 1 and 7, IIc; lanes 2 and 8, IId; lanes 3, 9, 4, and 10, IIm; lanes 5, 11, 6 and 12, IIn).