ABSTRACT
BACKGROUND: Visceral leishmaniasis results from complex interactions among humans, dogs and environment. Brazil accounts for 97% of cases in the Americas. METHODS: Twenty years (2001-2020) of the endemic disease in the state of Rio de Janeiro were studied. Incidence, lethality, sociodemographic and clinical characteristics were investigated, complemented with spatial methodologies (kernel and clusters). RESULTS: Ninety-seven human cases and 625 dogs were reported. Of the 92 cities, 22 were human endemic areas. The state had a low incidence level (0.6 per 100 000). Lethality was higher compared with the Brazilian average. More than 90% of infections occurred in urban areas. Most cases (66%) occurred in men. The predominant age groups were 0-4 y (28.7%) and 20-39 y (32.9%). Fever (89.5%), splenomegaly (83.2%) and hepatomegaly (76.8%) were the main clinical manifestations. Spatial analysis showed a displacement of the human endemic: in the first decade (2001-2010), cases were concentrated in the Metropolitan region, and in the second decade (2011-2020) in the Médio Paraíba region of the state. Most of the endemic area (56.4%) had canine infections without reported human cases. CONCLUSIONS: Disorderly urbanisation and precarious living conditions favour the transmission of the disease. Changes in the environment and migratory processes contribute to its expansion.
Subject(s)
Dog Diseases , Leishmaniasis, Visceral , Spatio-Temporal Analysis , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/veterinary , Brazil/epidemiology , Humans , Dogs , Male , Female , Animals , Child, Preschool , Adult , Infant , Incidence , Child , Dog Diseases/epidemiology , Young Adult , Adolescent , Middle Aged , Endemic Diseases , Infant, Newborn , AgedABSTRACT
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.
