# Notes on the threadworm Strongyloides fuelleborni (Nematoda: Strongyloididae) in vervet monkeys (Chlorocebus pygerythrus) and zoonotic strongyloidiasis in southern Malawi

## TL;DR

This study reports the first occurrence of Strongyloides fuelleborni in vervet monkeys in Malawi, highlighting a potential zoonotic risk.

## Contribution

First documentation of Strongyloides fuelleborni in vervet monkeys in Malawi and evidence of zoonotic potential.

## Key findings

- Strongyloides fuelleborni was confirmed in vervet monkey fecal samples from three of four locations in Malawi.
- Molecular identification confirmed the presence of Strongyloides fuelleborni, a first report in the region.
- The close proximity of vervet monkeys to humans suggests a tangible risk of zoonotic transmission.

## Abstract

We sought to ascertain whether zoonotic strongyloidiasis occurred in vervet monkeys (Chlorocebus pygerythrus), a non-human primate (NHP) species becoming increasingly common in Southern Malawi. Faecal collection took place in four locations: Nyala Park, a private wildlife reserve adjacent to a sugarcane plantation in Chikwawa District, and three public locations, each near tourist lodges in Mangochi District. Our sampling took place during July 2023, when 32 faecal samples were inspected with parasitological methods. After faecal culture, threadworm larvae were noted in both districts that were confirmed by molecular identification methods as Strongyloides fuelleborni, a first report for Malawi. Given the close spatial proximity of vervets with people, our findings affirm prior disease surveillance concerns of local zoonotic potential. We therefore encourage future targeted helminthological surveys for better local monitoring of strongyloidiasis in NHPs and people.

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•First report of Strongyloides fuelleborni in vervet monkeys in Malawi.•This threadworm was present at three of four faecal sampling locations.•We suggest there is a local tangible risk of zoonotic transmission.

First report of Strongyloides fuelleborni in vervet monkeys in Malawi.

This threadworm was present at three of four faecal sampling locations.

We suggest there is a local tangible risk of zoonotic transmission.