Freshwater turtles from wetlands can transmit Salmonella to humans
Professors from the University CEU Cardenal Herrera studied 200 specimens of freshwater turtles from eleven Valencian wetland areas, to determine the prevalence of Salmonella and Campylobacter in these animals, because of their potential risk of transmitting gastrointestinal diseases to humans, especially children. According to the results, published in the journal Plos One, 11% of the analysed specimens of freshwater turtles were found positive for Salmonella. However, Campylobacter was not detected in any of them. This is the first study to rule out terrapins as transmitters of campylobacteriosis to humans.
The research group has used specimens of the native Emys orbicularis and of the exotic species Trachemys scripta elegans, found in eleven wetlands of the Valencian Region (Spain), including the marshes of Pego-Oliva, Xeraco, Cabanes or Peníscola, among others. In eight of the eleven wetlands the researchers found terrapins carriers of the bacteria Salmonella with moderate prevalence but none with the Campylobacter bacteria.
As pointed out by Professor of Veterinary Clara Marín, who led the study, campylobacteriosis and salmonellosis are common infections in humans: there have been 212,064 cases of the first and 99,020 cases of the second registered in the European Union during last year. Moreover, both are the two most frequent zoonosis worldwide, and thus represent an important public health problem in many countries which are interested in designing methods of preventing transmission of these infections from animals to humans. Salmonella can cause human gastroenteritis and meningitis, especially in children and elderly. Complications of campylobacteriosis can lead to arthritis and other diseases.
While previous studies had confirmed the risk of transmitting Salmonella in the case of pet turtles, in higher percentages than those recorded in this research, there are few studies on wild ones. The project of the University CEU Cardenal Herrera is the first to extend the analysis to the prevalence of Campylobacter in these wild animals.
Another novel aspect of the study was the combination of three different samples. The work has shown that collecting water samples where the turtles have remained for 48 hours after capture is as effective as sacrificing them or taking swabs directly from the rectum. This finding is especially helpful for sampling protected species.
Professor Clara Marín, head of the research group "Improving food safety in the production system and its derivatives" at the Institute of Biomedical Sciences of the university, has directed the team composed of Sofía Ingresa Capaccioni, Sara González Bodí y Santiago Vega García. Francisco Marco Jiménez, from the Institute of Animal Science and Technology at the Universitat Politècnica de València, has also taken part in the study. This research was awarded best paper at the International Symposium on Freshwater Turtles Conservation held in May in Portugal, and has been funded by the Regional Government through the European Programme LIFE09.