1. Natural History of Cryptosporidiosis in a Birth Cohort in Southern India
- Author
-
Jayanthi C. Geetha, Sitara Swarna Rao Ajjampur, Sudhir Babji, Rajiv Sarkar, Deepthi Kattula, Elena N. Naumova, Jayaprakash Muliyil, Karthick Nithyanandhan, Princey Das, Srinivasan Venugopal, Vasanthakumar Velusamy, Honorine D. Ward, Robin P. Lazarus, Prasanna S. Premkumar, Ashok D. Prabhakaran, Christine Wanke, Chandrabose Gunasekaran, Gagandeep Kang, and Nithya Jeyavelu
- Subjects
0301 basic medicine ,Microbiology (medical) ,Male ,medicine.medical_specialty ,Endemic Diseases ,030106 microbiology ,030231 tropical medicine ,diarrhea ,Cryptosporidium ,India ,Asymptomatic ,Serology ,Cohort Studies ,03 medical and health sciences ,Feces ,0302 clinical medicine ,children ,Interquartile range ,Internal medicine ,Poverty Areas ,Major Article ,Medicine ,Humans ,Longitudinal Studies ,Prospective Studies ,Seroconversion ,biology ,business.industry ,cryptosporidiosis ,Incidence (epidemiology) ,Incidence ,Infant, Newborn ,Parturition ,Infant ,birth cohort ,biology.organism_classification ,3. Good health ,Diarrhea ,Infectious Diseases ,natural history ,Immunoglobulin G ,Immunology ,Diarrhea, Infantile ,Female ,medicine.symptom ,business ,Cryptosporidium hominis - Abstract
Summary In an Indian birth cohort, we demonstrate a high and early burden of cryptosporidiosis by polymerase chain reaction and serology. Reinfection was common and infections clustered in a subset of children. Prior infection provided some protection against subsequent infection, but not disease., 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.
- Published
- 2016