Evaluating respiratory cryptosporidiosis in pediatric diarrheal disease: protocol for a prospective, observational study in Malawi

Wongani Nyangulu,Wes Van Voorhis,Pui-Ying Iroh Tam

doi:10.1186/s12879-019-4380-x

Abstract

BackgroundCryptosporidium is among the most common causes of severe diarrhea in African children 0–23 months old. It is associated with excess mortality, stunting and malnutrition. The most common manifestation of cryptosporidium is intestinal diarrheal disease. However, respiratory cryptosporidiosis has been documented in up to a third of children presenting with diarrhea. It is unclear whether respiratory involvement is a transient phenomenon or a reservoir for gastrointestinal (GI) disease. This study aims to evaluate the role of respiratory cryptosporidiosis in pediatric diarrheal disease.MethodsThis is a prospective, observational study conducted at Queen Elizabeth Central Hospital (QECH) in Blantyre, Malawi. Young children aged 2–24 months hospitalized with diarrhea will be enrolled. Enrolled children will have induced sputum, nasopharyngeal (NP) swab and stool samples collected. All participants positive for cryptosporidium on sputum/NP/stool PCR testing will be followed up fortnightly after discharge from the hospital up to 8 weeks post-discharge. Sputum/NP/stool sample collection will be done at each visit. The primary outcomes will be presence of Cryptosporidium spp. in sputum/NP/stool. The secondary outcome will be presence of respiratory and GI symptoms, mortality and stunting. Ethical approval was obtained from the University of Malawi College of Medicine Research Ethics Committee (COMREC) and the Liverpool School of Tropical Medicine (LSTM) research ethics committee.DiscussionThe study began recruitment activities at QECH in February 2019. The protocol allows for expansion of recruitment to secondary sites within Blantyre and Chikwawa districts in the event that targets are not met at QECH. Study recruitment is expected to continue until early 2020.

Highlights

Cryptosporidium is among the most common causes of severe diarrhea in African children 0–23 months old
Respiratory cryptosporidiosis has been documented in up to a third of children presenting with diarrhea [5]; respiratory detection without intestinal involvement has been reported, raising the possibility of primary respiratory infection with Cryptosporidium spp., either by inhalation or by contact with fomites [6]
In a recent case control study of children who presented with diarrhea (≥ 3 loose stools within a 24 h period) to Queen Elizabeth Central Hospital (QECH), Cryptosporidium spp. (27.8%) was the third most common pathogen detected behind rotavirus (34.7%) and adenovirus (29.1%) among cases [7]

Summary

Introduction

Cryptosporidium is among the most common causes of severe diarrhea in African children 0–23 months old. It is associated with excess mortality, stunting and malnutrition. Respiratory cryptosporidiosis has been documented in up to a third of children presenting with diarrhea. Cryptosporidiosis is a cause of severe diarrhea [1], excess mortality [2, 3], and stunting, and is associated with malnutrition [4]. (27.8%) was the third most common pathogen detected behind rotavirus (34.7%) and adenovirus (29.1%) among cases [7] This is much higher than previous reports likely due to improved diagnosis using molecular methods (PCR) [7, 8]. The rainy season is associated with higher incidence of disease compared to the dry season but a study comparing Blantyre (urban) to Chikwawa (rural) did not show a significant difference in number of cases between urban and rural dwellers [8]

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