# Serologic evidence of orthomarburgviruses and an orthoebolavirus in frugivorous Malagasy bats

## TL;DR

The study finds evidence of filoviruses in Malagasy bats, suggesting a new risk area for virus spillover.

## Contribution

Identifies Rousettus madagascariensis as a potential host for orthomarburgviruses in Madagascar.

## Key findings

- Seroreactivity to an orthoebolavirus related to Bundibugyo virus was detected in Malagasy bats.
- Ravn virus and Marburg virus seroprevalence rates were found in Rousettus madagascariensis.
- This is the first record of orthomarburgviruses in Madagascar.

## Abstract

Recent outbreaks of Marburg virus disease in regions of sub-Saharan Africa without prior record such as Ghana, Tanzania, Equatorial Guinea, and Rwanda challenge the current understanding of areas at-risk for filovirus spillover. The orthomarburgvirus host Rousettus aegyptiacus exists in these regions, and has a sister species, Rousettus madagascariensis, native only to the island of Madagascar. We expand on previous surveillance of frugivorous bats in Madagascar, and detect seroreactivity against an orthoebolavirus antigenically-related to Bundibugyo virus at 1.50–5.06% seroprevalence in Rousettus madagascariensis. Notably, we identify R. madagascariensis as an orthomarburgvirus-host species of interest in Madagascar, the first record of this virus genus on the island. We document seroprevalences of 15.36–29.78% for Ravn virus and 12.55–33.33% for Marburg virus in R. madagascariensis. These findings will guide future biosurveillance efforts to assess filovirus spillover risk in Madagascar.

The online version contains supplementary material available at 10.1186/s42522-025-00178-0.