Parasite species variation and impact of spatial displacement of the population on cutaneous leishmaniasis in Rio de Janeiro, Brazil.

BACKGROUND: Cutaneous leishmaniasis results from complex interactions between human beings, vectors and the environment. Parasitic species differ in epidemiological and geographical contexts. METHODS: We studied a retrospective cohort of 696 patients with cutaneous leishmaniasis treated at a reference centre in the state of Rio de Janeiro, Brazil, between 2000 and 2015. We analysed displacements due to work, leisure and migrations with identification of Leishmania species. RESULTS: The geographic distribution of autochthonous cases showed that >95% of infections occurred in urban areas. In the state of Rio de Janeiro, most cases were concentrated in the cities surrounding forest parks and nature conservation areas. The same applies to the city of Rio de Janeiro, where these infections occurred in the neighbourhoods surrounding some mountain and forest areas. The non-displacement group included 575 (82.6%) patients and the displacement group included 121 (17.4%) patients. Leishmania (Viannia) braziliensis predominated in both groups. Other species were found in the displacement group. CONCLUSIONS: The disordered urbanization of the state of Rio de Janeiro in recent decades has created conditions for the emergence of urban foci of transmission close to forest areas. Changes in the environment, movement of infected individuals and adaptation of sandflies may have contributed to this.

Anti-Brucella canis antibodies in dogs naturally infected with Leishmania infantum and associated histological alterations in the genital tract.

In canine visceral leishmaniasis, coinfections can aggravate the disease. Our aim was to investigate Brucella canis in dogs infected with Leishmania infantum. One hundred and six L. infantum-seropositive dogs were submitted to serology for B. canis, PCR for B. canis and L. infantum, and histopathological analysis of the genital tract. Anti-B. canis antibodies were detected in seven dogs whose clinical signs, L. infantum load and histological alterations were similar to those of seronegative animals. The circulation of anti-B. canis antibodies was low but demonstrates the exposure of dogs to this bacterium in a visceral leishmaniasis-endemic area.

Trypanosoma caninum, a new parasite described in dogs in Brazil: aspects of natural infection.

Trypanosoma caninum constitutes the most recent trypanosomatid species infecting dogs in Brazil. Due to the limited data available about this parasite, this study aims to disclose clinical and laboratory findings from 14 dogs naturally infected. The dogs were diagnosed during a cross-sectional survey in Cuiabá (Mato Grosso, Brazil) and followed up at an interval of 3, 6, and 12 mo in order to evaluate the clinical evolution and to investigate the parasite, the DNA, or both in different biological samples (intact skin, cutaneous scar, blood, bone marrow, and lymph node aspirate) by parasitological (culture and smear exam) and molecular (DNA-based tests) methods. Specific anti-T. caninum and anti-Leishmania antibody production was also evaluated. Ten of 14 dogs infected by T. caninum showed a good general state at the time of diagnosis, and this status did not vary during the follow-up. Anti-T. caninum and anti-Leishmania IgG antibodies were detected by IFAT in 10 and 2 animals, respectively. Concomitant infection by Leishmania chagasi was confirmed in 2 dogs, indicating an overlap of endemic areas in Cuiabá. Trypanosoma caninum (parasite or DNA) was found only in the intact skin in all animals examined. Our results suggest that T. caninum infection can be manifested as an asymptomatic case with low humoral immune response.