# Evaluating the effectiveness and sustainability of a primary healthcare strategy to reduce the prevalence of strongyloidiasis in endemically infected Indigenous communities in Northern Australia

## TL;DR

A healthcare strategy using electronic records to test and treat strongyloidiasis in remote Indigenous communities significantly reduced infection rates over eight years.

## Contribution

A sustainable primary healthcare strategy integrating electronic health records to reduce strongyloidiasis prevalence in endemic communities.

## Key findings

- 84% of adults in four communities were tested for strongyloidiasis, reducing prevalence from 44% to 10%.
- 85% of treated cases with follow-up tests showed negative results, indicating effective treatment and monitoring.
- The intervention's benefits were sustained for four years after implementation ended.

## Abstract

Strongyloidiasis is endemic in many remote Indigenous communities in Australia. Early diagnosis, treatment, and follow-up of chronic strongyloidiasis can prevent life-threatening clinical complications and decrease transmission in these endemic communities. The aim of this paper is to evaluate the effectiveness and sustainability of a primary healthcare strategy designed to measure and reduce the prevalence of strongyloidiasis in four remote communities in northeast Arnhem Land.

The primary healthcare strategy was a prospective, longitudinal, health-systems intervention designed to integrate serological testing for chronic strongyloidiasis into the Indigenous preventive adult health assessment utilising the electronic health-record systems in four Aboriginal health services. Positive cases were recalled for treatment, and opportunistic follow-up serology after six months. Results were tracked using Strongyloides reports generated by the electronic health-record system. This paper describes the changes in prevalence, effectiveness of treatment, and reinfection during the implementation phase, 2012–2016. An improved Strongyloides electronic report was developed to evaluate the effectiveness and sustainability of the intervention to the end of 2020.

During the entire period 2012–2020, 84% (2390/2843) of the resident adults in the four communities were tested for strongyloidiasis at least once. Prevalence was reduced from 44% (1056/2390) ever-positive to 10% (232/2390) positive on their last test. Of positive, treated cases with a follow-up serology test, the last test was negative in 85% (824/967) of individuals. Point prevalence continued to decrease in each community four years after the end of the implementation phase.

The results provided practice-based evidence of a significant decrease in the prevalence of strongyloidiasis attributable to the strategy which could be replicated in other health services utilising electronic health-record systems. The final evaluation demonstrated the sustainability and ongoing benefits for endemically infected communities, and the key role that health services can play in strongyloidiasis prevention and control programs.

This primary healthcare strategy originated in an Aboriginal community-controlled health organisation in remote Northern Territory communities in Australia where strongyloidiasis is endemic. The goal was to prevent clinical complications and reduce prevalence of strongyloidiasis. Serological testing for chronic strongyloidiasis was integrated into the preventive adult health assessments in four Aboriginal health services. Positive cases were recalled for treatment, then follow-up serology after six months.

Data extracted from the electronic health record (EHR) system during the implementation phase, 2012–2016, measured changes in prevalence, treatment effectiveness, and reinfection. An evaluation in 2020 used an improved Strongyloides report to extract data from 2012–2020. This showed that 84% of the adult population in the four communities were tested for strongyloidiasis, with prevalence decreasing from 44% to 10%. Of treated cases with follow-up tests, 85% had negative results.

These results showed a significant reduction in the prevalence of strongyloidiasis, highlighting the effectiveness and sustainability of the intervention. The Strongyloides report provided a monitoring and ongoing surveillance tool that was accessible to clinicians, as well as de-identified reports for the local health board and communities. This research highlights the important role of health services in prevention and control programs for strongyloidiasis in endemic communities.