Island-Wide Surveillance of Gastrointestinal Protozoan Infections on Fiji by Expanding Lymphatic Filariasis Transmission Assessment Surveys as an Access Platform

As part of lymphatic filariasis (LF) transmission assessment surveys (TAS) on Fiji, an island-wide assessment of gastrointestinal protozoan infection was performed through concomitant stool sample collections to investigate the distribution of the protozoan infection. All grade 1 and 2 students of 69 schools in the two main islands were targeted in two phases (one in the Western Division and the other in the Central and Northern, except Taveuni sub-Division of Northern), where fecal samples of 1,800 students were available for coproscopy using the formalin-ether-acetate concentration. The overall prevalence of Giardia infections was 1.6%, having 2.2% in Western and 0.8% in Central/Northern Divisions (P = 0.094). The school-level prevalence of giardiasis ranged from 0% to 15.4%, and hotspot analysis using the Getis-Ord Gi* method detected the special heterogeneity of giardiasis prevalence in schools around Lautoka (Z-score = 3.36, P value < 0.05), an area affected by Cyclone Kofi in February 2014. Any protozoan infection prevalence was 4.9% in Western and 4.4% in Central/Northern Divisions (P = 0.8254). Real-time polymerase chain reaction analysis to confirm the findings from a parasitological examination of a 10% stool archive in 95% ethanol from Western revealed an elevated prevalence of giardiasis up to 22.4%, the presence of Entamoeba histolytica, and the absence of Cryptosporidium parvum. Obtaining stool samples alongside LF TAS is a convenient access platform for cosurveillance of gastrointestinal protozoan infections and has pinpointed hitherto unknown hotspots of Giardia infections in urban city centers of Fiji. This calls for greater attention to apply tailored water, sanitation, and hygiene measures for the control of these parasites.