Leishmania tarentolaeandLeishmania infantumin geckos from Mallorca Island, Spain
Authors: Martí-Carreras Joan , Espunyes Johan , Carrera-Faja Laura , Pasetto Carlotta , Amengual Maria Magdalena Alcover , Chavez-Fisa Sarah , Carrasco Marina , Roura Xavier , Francino Olga , Ferrer Lluís 
Published: February 2025

Leishmania infantumandLeishmania tarentolaeare two sympatric parasites of significant ecological and epidemiological interest in the Mediterranean basin. In this study, we investigated the prevalence ofL. infantumandL. tarentolaein two gecko species (Tarentola mauritanicaandHemidactylus turcicus) present on Mallorca Island, Spain, using duplex quantitative PCR. A total of 60 geckos were sampled across the island, including 54T. mauritanicaand sixH. turcicus. Tissue and blood samples were screened for both parasites, and generalized linear models were used to assess organ-specific infection patterns. The results revealed high prevalence rates inT. mauritanica, with 24/54 (44.44%) testing positive forL. infantumand 22/54 (40.74%) forL. tarentolae.Coinfection with both parasites was detected in 11/54 individuals (20.37%). In contrast,H. turcicusshowed a prevalence of 3/6 (50%) forL. infantumand 1/6 (16.66%) forL. tarentolae, with no coinfections detected, probably due to small sample size. Blood and heart tissues were more likely to harborL. infantumin geckos, whileL. tarentolaedisplayed no significant organ-specific predilection. These findings indicate thatT. mauritanicaandH. turcicusmay act as reservoir hosts for bothL. infantumandL. tarentolae. The shared vectors and overlapping transmission routes (e.g., vector-borne, oral, or gastrointestinal transmission) suggest that these gecko species could contribute to the maintenance ofLeishmaniatransmission cycles in the region. The high prevalence rates and frequent coinfections highlight potential ecological interactions between the two parasites. Furthermore, the cross-reactivity ofL. infantumserological tests withL. tarentolaereinforces the need for molecular methods to distinguish between these species. This study underscores the ecological importance of reptiles inLeishmaniatransmission and provides valuable data on the potential role of geckos in endemic areas like Mallorca.

Author Summary

Leishmaniosis is a disease caused by parasites that can infect both animals and humans. In Europe,Leishmania infantumis the main species responsible for the disease, with dogs acting as its primary host. However, recent research suggests that other animals, including reptiles, might also play a role in its spread. In this study, centered in wild geckos from Mallorca Island (Spain), we looked forL. infantumandLeishmania tarentolae, a related parasite mostly found in reptiles. Using quantitative PCR, we found that 44% ofTarentola mauritanicageckos carriedL. infantumand 41% carriedL. tarentolae. Additionally, we detected coinfection of both parasites in 20% of the geckos. The second gecko species we studied,Hemidactylus turcicus, was also infected but at lower rates, and no coinfections were found. These results suggest that geckos may host both parasites, potentially influencing their spread. SinceL. tarentolaehas been detected in dogs, and both parasites are found in the same environments, there could be alternative ways of transmission (e.g., dogs eating infected geckos). The high number of infections raises new questions about the role of reptiles in the disease cycle, the reliability of current diagnostic tests, and the need for further research to understand these connections.