The research group Parasites and Health of Universitat de València (ParaSalut), leaded by full university Professor María Teresa Galán-Puchades, participates, together with the Laboratorios Lokímica and the Institute of Biotechnology of the University of Granada, in the multifocal project BCN Rats, led by Agència de Salut Pública de Barcelona (ASPB), which studies different zoosanitary, genetic and demographic variables of the sewage rat populations of Barcelona.

As result of the researches made in Barcelona, they have found out the new reservoir of Leishmaniasis in sewer rats, Rattus norvegicus. According to the results obtained, one in three of the first 100 rats analysed was parasitized by Leishmania infantum, detected in the spleen by a very sensitive quantitative PCR technique.

The leishmaniasis, an infectious zoonotic disease mainly affecting humans and dogs, which act as reservoirs, is endemic throughout the Mediterranean basin. The parasite is transmitted by the bite of the diptera vector insect of the genus Phlebotomus. Despite the prevention measures implemented in different cities, aimed at the vector, the reservoir (dog) and humans, leishmaniasis remains endemic. This epidemiological situation led to the suspicion of the existence of a hitherto unnoticed reservoir that could be responsible for maintaining the prevalence of Leishmania sp.

The findings of the BCN Rats project represent an advance in the knowledge of the epidemiology of leishmaniasis. Knowledge of the existence of a new reservoir, hitherto not considered in urban areas, will be an instrument in rodent and vector surveillance and control programmes. In this way, the fight against this parasitic disease, which, in cities, has been directed exclusively to the control of the only reservoir so far known, the dog, will be more effective.

Recently, the World Health Organization (WHO) and the Pan American Health Organization (PAHO) have held the first scientific meeting focused on the problem of rodents and better protection of human health, in a clear exercise of the concept 'One Health'. The main goal of the WHO initiative is to control potential outbreaks of rodent-borne diseases more effectively and in a comprehensive manner as rodents are associated with 40% of zoonoses (diseases transmitted between animals and humans).

The results obtained in the study were presented at the XXI Congress of the Spanish Society of Parasitology (SOCEPA) that took place in Pontevedra on 3-5 July, and have been published by the prestigious scientific journal of the Center for Diseases Control and Prevention, Atlanta, USA (CDC), Emerging Infectious Diseases, considered the first journal in the categories of both Infectious Diseases and Immunology according to the JCR (Journal Citation Reports).

The article, Leishmaniasis in Norway Rats in Sewers, Barcelona, Spain, is available here.