title: Natural History of Cryptosporidiosis in a Longitudinal Study of Slum-Dwelling Bangladeshi Children: Association with Severe Malnutrition.
abstract: Cryptosporidiosis is a common cause of infectious diarrhea in young children worldwide, and is a significant contributor to under-five mortality. Current treatment options are limited in young children. In this study, we describe the natural history of Cryptosporidium spp. infection in a birth cohort of children in Bangladesh and evaluate for association with malnutrition.
  
  
  
  This is a longitudinal birth cohort study of 392 slum-dwelling Bangladeshi children followed over the first two years of life from 2008 to 2014. Children were monitored for diarrheal disease, and stool was tested for intestinal protozoa. Anthropometric measurements were taken at 3-month intervals. A subset of Cryptosporidium positive stools were genotyped for species and revealed that C. hominis was isolated from over 90% of samples. In the first two years of life, 77% of children experienced at least one infection with Cryptosporidium spp. Non-diarrheal infection (67%) was more common than diarrheal infection (6.3%) although 27% of children had both types of infection. Extreme poverty was associated with higher rates of infection (chi-square, 49.7% vs 33.3%, p = 0.006). Malnutrition was common in this cohort, 56% of children had stunted growth by age two. Children with Cryptosporidium spp. infection had a greater than 2-fold increased risk of severe stunting at age two compared to uninfected children (odds ratio 2.69, 95% CI 1.17, 6.15, p = 0.019) independent of sex, income, maternal body-mass index, maternal education and weight for age adjusted z (WAZ) score at birth.
  
  
  
  Cryptosporidium infection is common (77%) in this cohort of slum-dwelling Bangladeshi children, and both non-diarrheal and diarrheal infections are significantly associated with a child's growth at 2 years of age.
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Poonum S
authors.initials: PS
authors.lastname: Korpe
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Rashidul
authors.initials: R
authors.lastname: Haque
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: Carol
authors.initials: C
authors.lastname: Gilchrist
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Cristian
authors.initials: C
authors.lastname: Valencia
authors.affiliation: Department of Statistics, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: Feiyang
authors.initials: F
authors.lastname: Niu
authors.affiliation: Department of Statistics, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: Miao
authors.initials: M
authors.lastname: Lu
authors.affiliation: Division of Biostatistics, Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: Jennie Z
authors.initials: JZ
authors.lastname: Ma
authors.affiliation: Department of Animal and Veterinary Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, United States of America.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Petri
authors.affiliation: Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Reichman
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Mamun
authors.initials: M
authors.lastname: Kabir
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Priya
authors.initials: P
authors.lastname: Duggal
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Virginia, Charlottesville, Virginia, United States of America.
authors.forename: William A
authors.initials: WA
authors.lastname: Petri
mesh_terms: D001459:Bangladesh / Q000453:epidemiology; D015331:Cohort Studies; D003457:Cryptosporidiosis / Q000150:complications* / Q000453:epidemiology* / Q000469:parasitology; D003458:Cryptosporidium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D003967:Diarrhea / Q000469:parasitology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007228:Infant Nutrition Disorders / Q000150:complications* / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D044342:Malnutrition / Q000150:complications* / Q000453:epidemiology*; D011204:Poverty Areas; D011446:Prospective Studies; D012307:Risk Factors