Temporal distribution of positive results of tests for detecting Leishmania infection in stray dogs of an endemic area of visceral leishmaniasis in the Brazilian tropics: A 13 years survey and association with human disease

Abstract

Human visceral leishmaniasis occurs in periodic waves in endemic areas of Brazil. In this study we followed the prevalence of human visceral leishmaniasis and of Leishmania infantum infection in stray dogs of an endemic area of visceral leishmaniasis at periods of time between 1997 and 2010. Prevalence of human visceral leishmaniasis had two peaks (40 cases) in 1997 and 2006 with sharp declines to 2 cases in 2001 and to 5 cases in 2008. Similar fluctuations were also observed in the occurrence of positive spleen culture and anti-Leishmania serology in dogs, although the proportion of dogs with active spleen parasitism remained relatively high even in the periods of low prevalence of human disease. These observations support the notion that stray dogs may constitute a renewable source of parasites, capable of sustaining the persistence of the infection in urban areas, even in periods of low transmission by phlebotomines.

High frequency of visceral leishmaniasis in dogs under veterinary clinical care in an intense transmission area in the state of Tocantins, Brazil

“…were observed in 264 (40.7%) samples (Table 1). The prevalence of Leishmania in our sample population was greater than that observed in other studies where the same technique was used (ALMEIDA et al, 2010), and similar to the results observed in seroprevalence studies performed in other areas of Brazil where the infection is endemic (AMÓRA et al, 2006;FRAGA et al, 2012). In our study, the method used had a low sensitivity, which may indicate that the true prevalence may be detected by using more sensitive diagnostic methods (GOMES et al, 2008;SRIVASTAVA et al, 2011).…”

Severe Clinical Presentation of Visceral Leishmaniasis in Naturally Infected Dogs with Disruption of the Splenic White Pulp

“…In a recent survey of the prevalence of infection in stray dogs collected from the streets of Jequié, Bahia State, Brazil, as estimated by culture, serology, and LST (DNA techniques were not used), up to 87% of animals tested positive for infection [25]. For the sample used in this study, when qPCR was used in addition to those tests, the estimated prevalence reached 98%.…”

Immunotherapy and Immunochemotherapy in Visceral Leishmaniasis: Promising Treatments for this Neglected Disease

“…For example, 70% of the anthropozoonotic VL burden occurs in the Indian subcontinent (17), and a critical challenge is related to widespread resistance to pentavalent antimony; resistance rates approach 60% in Bihar, India (60). In Europe, Asia, Africa, and the Americas, where zoonotic cases are observed, the risk of human disease is well-known to be associated with canine infection rates (61). Another serious problem that mainly occurs with zoonotic VL is that canine treatment does not effectively lead to a parasitological cure since these animals are constant sources of infection for sand flies (36).…”