First report of pathogenic Leptospira in Sri Lankan bats: A potential reservoir risk?

Abstract Background Leptospirosis is a bacterial infection caused by spirochetes of the genus Leptospira . It affects both humans and animals, posing a significant public health threat worldwide. In Sri Lanka, leptospirosis causes annual outbreaks, particularly during the monsoon seasons. The disease is often difficult to diagnose and can have a high mortality rate. Bats are potential reservoirs for Leptospira in other countries. This study investigated the presence and diversity of Leptospira in bats inhabiting the Wavulgalge, a natural cave in Sri Lanka. Methodology/Principal Findings Using PCR and Sanger sequencing techniques, Leptospira borgpetersenii and Leptospira kirschneri were identified in Miniopterus fuliginosus and Rousettus leschenaultii bats. Out of 148 bat urine samples, 16 tested positive via RT-qPCR, with M. fuliginosus samples harboring L. borgpetersenii and one R. leschenaultii sample harboring L. kirschneri revealed by Sanger sequencing method. Conclusions/Significance These findings enhance the understanding of the zoonotic role of Sri Lankan bats in Leptospira transmission. Author Summary Leptospirosis is a bacterial disease that affects both humans and animals, particularly in tropical regions. It spreads through contact with water or soil contaminated by the urine of infected animals. In Sri Lanka, leptospirosis poses a significant public health challenge, with frequent outbreaks during the rainy season. However, while much research has focused on domestic animals as potential carriers, the role of bats in the transmission of this disease has not been fully explored. In this study, we investigated whether bats in Sri Lanka can act as carriers of Leptospira bacteria, which could contribute to the spread of leptospirosis to humans. We focused on a population of bats from the Wavulgalge cave and tested them for the presence of Leptospira using molecular methods. Our results provide the first evidence that Leptospira is present in Sri Lankan bats, highlighting their potential role as a reservoir for the bacteria. These findings are important because they suggest that bats, like rodents and livestock, could contribute to the spread of leptospirosis in Sri Lanka. Understanding which animals carry the bacteria helps inform public health strategies, allowing for more targeted surveillance and control measures. By including bats in these efforts, we can better prevent future outbreaks of leptospirosis and protect at-risk communities. This study also contributes to the broader understanding of how wildlife can influence human health, especially in tropical environments where human-animal interactions are common. Our work emphasizes the need for a One Health approach, which considers the connections between human, animal, and environmental health, to tackle neglected diseases like leptospirosis.