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

Abstract

Urban 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 of Rattus norvegicus. Among 299 rats, eleven species/groups of helminths were identified, of which Strongyloides sp., Nippostrongylus brasiliensis and, the human pathogen, Angiostrongylus cantonensis were 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 with N. brasiliensis where rat signs were present, and males presented more intense infections of Strongyloides sp. Moreover, rats in poor body condition had higher intensities of N. brasiliensis. We describe a high global richness of parasites in R. norvegicus, including five species known to cause disease in humans. Among these, A. cantonensis was 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.

Coinfection modifies carriage of enzootic and zoonotic parasites in Norway rats from an urban slum

“…was present in 97% of the rats (Carvalho‐Pereira et al. ), we investigated whether its mean intensity varied in the presence or absence of other parasite species, regardless of the simple association tests for presence. We found that the intensity of Strongyloides sp.…”

“…The demographic features of the Pau da Lima rat population have been described by Carvalho‐Pereira et al. ().…”

“…After investigating the effects of environmental and host biotic variables, optimizing models in stages (for full explanation, see Carvalho‐Pereira et al. ), we determined whether coinfection would contribute additional independent explanatory power to the models (Fig. B).…”

“…, Carvalho‐Pereira et al. ). Among the helminth community of Norway rat populations, nematodes account for the highest number of species (Kataranovski et al.…”

“…Moreover, Norway rats can harbor several other human pathogens, in isolation or concomitantly, including helminths (Alicata 1965, Hancke et al 2011, Costa et al 2014b, Carvalho-Pereira et al 2018). Among the helminth community of Norway rat populations, nematodes account for the highest number of species (Kataranovski et al 2010, Hancke et al 2011, Simões et al 2016).…”