Gastrointestinal and ectoparasites from urban stray dogs in Fortaleza (Brazil): high infection risk for humans?

Abstract

Dogs are important definite or reservoir hosts for zoonotic parasites. However, only few studies on the prevalence of intestinal parasites in urban areas in Brazil are available. We performed a comprehensive study on parasites of stray dogs in a Brazilian metropolitan area. We included 46 stray dogs caught in the urban areas of Fortaleza (northeast Brazil). After euthanization, dogs were autopsied. Ectoparasites were collected, and the intestinal content of dogs were examined for the presence of parasites. Faecal samples were collected and analysed using merthiolate iodine formaldehyde concentration method. A total of nine different parasite species were found, including five endoparasite (one protozoan, one cestode and three nematode species) and four ectoparasite species (two flea, one louse and one tick species). In the intestinal content, 3,162 specimens of four helminth species were found: Ancylostoma caninum (prevalence, 95.7%), Dipylidium caninum (45.7%), Toxocara canis (8.7%) and Trichuris vulpis (4.3%). A total of 394 ectoparasite specimens were identified, including Rhipicephalus sanguineus (prevalence, 100.0%), Heterodoxus spiniger (67.4%), Ctenocephalides canis (39.1%) and Ctenocephalides felis (17.4%). In the faeces, intestinal parasites were detected in 38 stray dogs (82.6%), including oocysts of Giardia sp. (2.2%) and eggs of the nematode A. caninum (82.6%). Neither eggs nor larval stages of D. caninum, T. canis or T. vulpis were detected in dog faeces. Sensitivity of faecal examination for A. caninum was 86.4% (95% confidence interval, 72.0-94.3) but zero percentage for the other intestinal helminth species. Our data show that stray dogs in northeast Brazil carry a multitude of zoonotic ecto- and endoparasites, posing a considerable risk for humans. With the exception of A. caninum, sensitivity of faecal examination was negligible.

An epidemiological survey on intestinal helminths of stray dogs in Mashhad, North-east of Iran

“…The overall prevalence of intestinal helminths found in this study is 86 %, revealing a very high level of infection. Similar findings were also reported with intestinal helminths from Mashhad (91 %, Razmi et al 2006) and Chenaran (66 %, Beiromvand et al 2013) Klimpel et al 2010) and Nigeria (52.6 % in Nigeria, Okoye et al 2011) rather than to those typically seen in North Europe, where very low prevalence values are reported such as 6 % in Finland (Pullola et al 2006) and 9.4 % in Germany (Becker et al 2012). Generally, these results can be easily explained, as these animals have no health control measures and, because of their habits, they are exposed to natural infection more than owned dogs.…”

Occurrences of gastrointestinal parasites in fecal samples from domestic dogs in São Paulo, SP, Brazil

“…Given that this was the most prevalent nematode (7.1%; CI: 6.2-8.0%), and because the dogs' immunity has low effect on the development of this nematode, which can be found in both adult and young dogs, the efficacy of treatments can clearly be seen. Other surveys, conducted in different regions of Brazil on domestic and feral dogs (BLAZIUS et al, 2005;LABRUNA et al, 2006;BRESCIANI et al, 2008;KATAGIRI & OLIVEIRA-SEQUEIRA, 2008;OLIVEIRA et al, 2009;PRATES et al, 2009;KLIMPEL et al, 2010;FERREIRA et al, 2013), also found that Ancylostoma spp. had the highest prevalence.…”

“…D. caninum is another zoonotic agent (NEIRA et al, 2008;CABELLO et al, 2011) with worldwide prevalence. In many surveys on dogs and cats, the frequency of this parasite has been underestimated because the diagnosis is based on fecal flotation methods, which are inefficient to detect proglottids (KLIMPEL et al, 2010). The best means of detection is the observation of proglottids in the fecal samples (GENNARI et al, 1999).…”

Parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil: an approach in public health

“…Furthermore, a recent study performed in another tropical area reported the presence of A. lumbricoides, by polymerase chain reaction, in stool samples from dogs; this suggests the ingestion of human feces by these dogs 14 . Nevertheless, T. vulpis and D. caninum had also been described rarely in human infections 5,9 . Thus, based on the results presented, determining the source of environmental fecal contamination is not possible, since microscopic identification of eggs was the only survey method employed.…”

“…(hookworms), Toxocara canis, Cryptosporidium sp. and Giardia sp., as well as the high impact of these infections in public health 4,9,12,13 . Despite the large number of reports on zoonotic parasites in public parks, beaches and recreational areas, there is a lack of studies about these agents in restricted geographical areas, such as islands.…”