The helminth community of a population ofRattus norvegicusfrom an urban Brazilian slum and the threat of zoonotic diseases

Abstract

AbstractUrban slums provide suitable conditions for infestation by rats, which harbour and shed a wide diversity of zoonotic pathogens including helminths. We aimed to identify risk factors associated with the probability and intensity of infection of helminths of the digestive tract in an urban slum population ofRattus norvegicus. Among 299 rats, eleven species/groups of helminths were identified, of whichStrongyloidessp.,Nippostrongylus brasiliensisand, the human pathogen,Angiostrongylus cantonensiswere the most frequent (97, 41 and 39%, respectively). Sex interactions highlighted behavioural differences between males and females, as eg males were more likely to be infected withN. brasiliensiswhere rat signs were present, and males presented more intense infections ofStrongyloidessp. Moreover, rats in poor body condition had higher intensities ofN. brasiliensis. We describe a high global richness of parasites inR. norvegicus, including five species known to cause disease in humans. Among these,A. cantonensiswas found in high prevalence and it was ubiquitous in the study area – knowledge which is of public health importance. A variety of environmental, demographic and body condition variables were associated with helminth species infection of rats, suggesting a comparable variety of risk factors for humans.