Natural History of Cryptosporidiosis in a Birth Cohort in Southern India

• Published in: Clinical infectious diseases Vol. 64; no. 3; pp. 347 - 354
• Main Authors: Kattula, Deepthi, Jeyavelu, Nithya, Prabhakaran, Ashok D., Premkumar, Prasanna S., Velusamy, Vasanthakumar, Venugopal, Srinivasan, Geetha, Jayanthi C., Lazarus, Robin P., Das, Princey, Nithyanandhan, Karthick, Gunasekaran, Chandrabose, Muliyil, Jayaprakash, Sarkar, Rajiv, Wanke, Christine, Ajjampur, Sitara Swarna Rao, Babji, Sudhir, Naumova, Elena N., Ward, Honorine D., Kang, Gagandeep
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.02.2017
• Subjects: ARTICLES AND COMMENTARIES; Cohort Studies; Cryptosporidiosis - epidemiology; Cryptosporidiosis - immunology; Cryptosporidiosis - parasitology; Cryptosporidiosis - prevention & control; Cryptosporidium - classification; Cryptosporidium - genetics; Cryptosporidium - isolation & purification; Diarrhea; Diarrhea, Infantile - epidemiology; Diarrhea, Infantile - immunology; Diarrhea, Infantile - parasitology; Diarrhea, Infantile - prevention & control; Disease control; Disease prevention; Endemic Diseases; Feces - parasitology; Female; Humans; Immunoglobulin G - blood; Incidence; India - epidemiology; Infant; Infant, Newborn; Longitudinal Studies; Major; Male; Parasitic protozoa; Parturition; Poverty Areas; Prospective Studies; India; India, Vellore; cryptosporidiosis; birth cohort; children; diarrhea; natural history; India
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1093/cid/ciw730

Background. Cryptosporidium is a leading cause of moderate to severe childhood diarrhea in resource-poor settings. Understanding the natural history of cryptosporidiosis and the correlates of protection are essential to develop effective and sustainable approaches to disease control and prevention. Methods. Children (N = 497) were recruited at birth in semiurban slums in Vellore, India, and followed for 3 years with twice-weekly home visits. Stool samples were collected every 2 weeks and during diarrheal episodes were tested for Cryptosporidium species by polymerase chain reaction (PCR). Serum samples obtained every 6 months were evaluated for seroconversion, defined as a 4-fold increase in immunoglobulin G directed against Cryptosporidium gp15 and/or Cp23 antigens between consecutive sera. Results. Of 410 children completing follow-up, 397 (97%) acquired cryptosporidiosis by 3 years of age. PCR identified 1053 episodes of cryptosporidiosis, with an overall incidence of 0.86 infections per child-year by stool and serology. The median age for the first infection was 9 (interquartile range, 4–17) months, indicating early exposure. Although infections were mainly asymptomatic (693 [66%]), Cryptosporidium was identified in 9.4% of diarrheal episodes. The proportion of reinfected children was high (81%) and there was clustering of asymptomatic and symptomatic infections (P < .0001 for both). Protection against infection increased with the order of infection but was only 69% after 4 infections. Cryptosporidium hominis (73.3%) was the predominant Cryptosporidium species, and there was no species-specific protection. Conclusions. There is a high burden of endemic cryptosporidiosis in southern India. Clustering of infection is suggestive of host susceptibility. Multiple reinfections conferred some protection against subsequent infection.