Natural History of Cryptosporidiosis in a Longitudinal Study of Slum-Dwelling Bangladeshi Children: Association with Severe Malnutrition

Poonum S Korpe,Carol Gilchrist,Rashidul Haque,Sarah E Petri,Feiyang Niu,Daniel Reichman,William A Petri,Mamun Kabir,Jennie Z Ma,Miao Lu,Priya Duggal,Cristian Valencia,Gagandeep Kang

doi:10.1371/journal.pntd.0004564

Abstract

BackgroundCryptosporidiosis 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.Methodology/Principal FindingsThis 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.Conclusions/SignificanceCryptosporidium 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.

Highlights

Diarrheal disease is the second leading cause of death in children under age five worldwide, with cryptosporidiosis estimated to be second only to rotavirus as the leading cause of moderate-to-severe diarrhea [1,2,3]
Cryptosporidium species are responsible for a large proportion of global burden of diarrhea
This study describes the natural history of cryptosporidiosis in a birth cohort of impoverished Bangladeshi children

Summary

Introduction

Diarrheal disease is the second leading cause of death in children under age five worldwide, with cryptosporidiosis estimated to be second only to rotavirus as the leading cause of moderate-to-severe diarrhea [1,2,3]. Cryptosporidium infection has been associated with longer duration of diarrhea and 2–3 times higher mortality in young children [6,7]. Immune-compromised adults, including those with HIV/AIDS or on immunosuppressive drugs, are at increased risk [8,9,10]. Young children, especially those with malnutrition, are more vulnerable, presumably due to lack of acquired immunity, the biological mechanism is not clear [11,12,13,14,15,16]. We describe the natural history of Cryptosporidium spp. infection in a birth cohort of children in Bangladesh and evaluate for association with malnutrition

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