Molecular and serological investigation of infectious diseases in captive and free-range crab-eating fox (Cerdocyon thous – Linnaeus, 1776) from northeastern Brazil

Abstract

The aim of this study was to detect DNA and antibodies anti-Leishmania spp., Neospora caninum and Toxoplasma gondii in captive and free-range crab-eating fox (Cerdocyon thous) from northeastern Brazil. Twenty-five crab-eating foxes from different states of northeastern Brazil were sampled by this study. Blood samples were collected by cephalic or jugular vein punctures. The whole blood was submitted to PCR, and the sera samples to the serological analysis as follows: MAT for T. gondii, NAT for N. caninum, and ELISA for L. chagasi. The frequence of antibodies anti-T. gondii was 50% and 29.41% for free-range and captive wild canids, respectively. The frequence of antibodies anti-N. caninum observed by this study was 62.50% and 23.52% for free-range and captive wild canids, respectively. The frequence of antibodies anti-L. chagasi was 4.0% for captive wild canids. Co-infections cases were identified as follows: one captive wild canid seropositive for T. gondii and L. chagasi and two free-range animals seropositive for T. gondii and N. caninum. All PCR assays performed were negative for the pathogens analyzed. This study describes the presence of antibodies anti-T. gondii, N. caninum e L. chagasi in wild canids from northeastern Brazil and highlights the necessity of further studies on infectious diseases in free-range and captive wild canids.

New insights on severe clinical manifestations and deaths from visceral leishmaniasis in free-living crab-eating foxes (Cerdocyon thous) in Brazil

“…Molecular diagnosis by PCR identified L. infantum DNA in the animals assessed in our study and therefore confirms the occurrence of VL in foxes (Gontijo and Melo 2004). Likewise, some studies have already demonstrated the existence of a wild VL cycle, and the species C. thous as a potential reservoir for the parasite (Kruse et al 2004;Gomes et al 2007;Luppi et al 2008;Oliveira et al 2012;Ferreira et al 2013;Almeida et al 2018). Several factors can be associated with the occurrence of Leishmania among foxes.…”

“…Currently, it is estimated about 30,000 new cases of VL and more than 1 million new cases of CL annually (WHO 2020). Remarkable, domestic dogs are important hosts of Leishmania species and can maintain the disease transmission cycle (Almeida et al 2018). Despite several studies investigating the occurrence and clinical manifestations of leishmaniasis in dogs, there few studies that describe the clinical evolution of the disease in other canids in Brazil (Oliveira 2012;Nicolato et al 2013).…”

“…Interestingly, previous studies suggest that free-living crab-eating foxes infected with Leishmania rarely develop clinical symptoms and that, when they do, they have a milder clinical manifestation and, most of them, spontaneously heal (Fornazari & Langoni 2014;Santos 2015;Almeida et al 2018;Lima et al 2018). On the other hand, our findings demonstrate that the specimens evaluated herein developed VL severe form and evolved with death after progression of clinical signs.…”

A Systematic Review (1990–2021) of Wild Animals Infected with Zoonotic Leishmania

“…It was found to be infected with L. infantum or exposed to the parasite (positive serology) in several publications, some of which were clinical cases, and thus were not considered in this study. The percentage of infection varied widely among the studies when including more than one animal (4-75%), and exposure to the parasite was demonstrated by serology (i.e., ELISA, IFAT), while culture, microscopy of smears, PCR followed by sequencing and inoculation of hamsters were employed to detect the parasite [81][82][83][84][85][86][87][88][89]. Several organs and tissues tested positive via PCR: bone marrow, heart, lymph nodes, liver, lungs, skin and spleen.…”

Epidemiology of Leishmaniasis in Palestine

“…These animals are a significant risk factor predisposing humans to infection in the endemic regions. However, other candidates include foxes and jackals (Millan et al 2016;Shokri et al 2017;Almeida et al 2018).…”