Epidemiology and geographical distribution of enteric protozoan infections in sydney, australia

Stephanie Fletcher; Graziella Caprarelli; Juan Merif; David Andresen; Sebastian Van Hal; Damien Stark; John Ellis

doi:10.4081/jphr.2014.298

Epidemiology and geographical distribution of enteric protozoan infections in sydney, australia

J Public Health Res. 2014 Aug 25;3(2):298. doi: 10.4081/jphr.2014.298. eCollection 2014 Jul 2.

Authors

Stephanie Fletcher¹, Graziella Caprarelli², Juan Merif³, David Andresen⁴, Sebastian Van Hal⁵, Damien Stark⁶, John Ellis¹

Affiliations

¹ The iThree Institute and School of Medical and Molecular Biosciences, University of Technology , Sydney.
² Division of IT, Engineering and the Environment, University of South Australia , Adelaide.
³ Microbiology Department, South Eastern Area Laboratory Service (SEALS), Prince of Wales Hospital , Rand wick.
⁴ Department of Microbiology, Children's Hospital Westmead , Darlinghurst, Australia.
⁵ Department of Microbiology, Liverpool Hospital , Darlinghurst, Australia.
⁶ Division of Microbiology, St. Vincent's Hospital , Darlinghurst, Australia.

Abstract

Background: Enteric protozoa are associated with diarrhoeal illnesses in humans; however there are no recent studies on their epidemiology and geographical distribution in Australia. This study describes the epidemiology of enteric protozoa in the state of New South Wales and incorporates spatial analysis to describe their distribution.

Design and methods: Laboratory and clinical records from four public hospitals in Sydney for 910 patients, who tested positive for enteric protozoa over the period January 2007 - December 2010, were identified, examined and analysed. We selected 580 cases which had residence post code data available, enabling us to examine the geographic distribution of patients, and reviewed the clinical data of 252 patients to examine possible links between protozoa, demographic and clinical features.

Results: Frequently detected protozoa were Blastocystis spp. (57%), Giardia intestinalis (27%) and Dientamoeba fragilis (12%). The age distribution showed that the prevalence of protozoa decreased with age up to 24 years but increasing with age from 25 years onwards. The geographic provenance of the patients indicates that the majority of cases of Blastocystis (53.1%) are clustered in and around the Sydney City Business District, while pockets of giardiasis were identified in regional/rural areas. The distribution of cases suggests higher risk of protozoan infection may exist for some communities.

Conclusions: These findings provide useful information for policy makers to design and tailor interventions to target high risk communities. Follow-up investigation into the risk factors for giardiasis in regional/rural areas is needed. Significance for public healthThis research is significant since it provides the most recent epidemiological update on the common enteric protozoa affecting Australians. It reveals that enteric protozoa cause considerable disease burden in high risk city dwellers, and provides the evidence base for development of targeted interventions for their prevention and control in high risk populations. The prevalence of enteric protozoa in this metropolitan setting underscores that microorganisms do not respect borders and that a collaborative approach is needed to contain the global spread of infectious diseases. Incorporating spatial analysis is valuable in providing a compelling picture of the geographical distribution of these often neglected diseases. Local and State Public Health departments can use this information to support further inves-

Keywords: Blastocystis; Giardia intestinalis; Sydney; enteric protozoa; epidemiology; geographical distribution.