Giardia lamblia infection increases risk of chronic gastrointestinal disorders.

Megan Dormond,Ramiro L Gutierrez,Chad K Porter

doi:10.1186/s40794-016-0030-0

Abstract

Background Giardia lamblia is a common parasitic cause of infectious gastroenteritis in the United States and the world and may be linked to an increased risk of chronic gastrointestinal (GI) disorders. We sought to assess the risk of several chronic GI disorders following Giardia infection among active duty US military personnel.MethodsThis study was designed as a retrospective cohort study in which active duty military personnel with documented G. lamblia infection were assessed for the subsequent risk of developing a chronic GI disorder including irritable bowel syndrome (IBS), dyspepsia and gastroesophageal reflux disease (GERD). Post-giardia chronic GI disorder risk was compared to risk in uninfected personnel matched on several demographic characteristics and medical encounter information. Data were obtained from the Defense Medical Surveillance System and exposures (1998–2009) with outcomes identified based on documented medical encounters with specific medical billing codes. Modified Poisson regression was used to evaluate the relationship between G. lamblia infection and chronic GI disorders.ResultsA total of 80 Giardia cases were identified for an estimated incidence of 0.55 cases per 100,000 person-years. Cases were matched to 294 unexposed subjects. After adjusting for important covariates, there was an increased risk of IBS (relative risk: 2.1, p = 0.03) associated with antecedent Giardia infection.ConclusionThese data add to a growing body of literature and demonstrate an increased risk of IBS after infection with G. lamblia.

Highlights

Giardia lamblia is a common parasitic cause of infectious gastroenteritis in the United States and the world and may be linked to an increased risk of chronic gastrointestinal (GI) disorders
A total of 80 giardiasis cases were identified for an estimated incidence of 0.55 per 100,000 person-years in males
Giardiasis cases were matched to 294 unexposed subjects for a total sample size of 374 subjects

Summary

Introduction

Giardia lamblia is a common parasitic cause of infectious gastroenteritis in the United States and the world and may be linked to an increased risk of chronic gastrointestinal (GI) disorders. In addition to the acute illness, giardiasis has been associated with an increased risk of several secondary or chronic health conditions and is known to cause small intestinal malabsorption [1] One such group of sequelae that has been increasingly associated with other enteric pathogens are functional gastrointestinal disorders (FGD). As a Dormond et al Tropical Diseases, Travel Medicine and Vaccines (2016) 2:17 group, these disorders are estimated to account for more than 11 million ambulatory care visits, equating to roughly four visits for every 100 persons in the United States [8] The pathoetiology of these disorders is poorly understood; several mechanisms have been implicated in producing symptoms including gut brain axis dysfunction, mucosal barrier disruption, gastrointestinal dysmotility, microbiota disturbances, inflammation, visceral hypersensitivity, diet, and genetic predisposition [8]

Methods

Results

Discussion

Conclusion