Spatial-temporal distribution of visceral leishmaniasis in Rio de Janeiro, Brazil, 2001-2020: expansion and challenges.

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.

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.

Clinical features and therapeutic response in adult and pediatric patients with American tegumentary leishmaniasis in Rio de Janeiro.

BACKGROUND: American tegumentary leishmaniasis (ATL) is a neglected disease with wide territorial distribution. Knowledge is scarce in children and adolescents. This study aims to compare the clinical features and response to antimony treatment in pediatric and adult patients with cutaneous leishmaniasis. METHODS: A retrospective cohort study was performed with 659 patients who attended a reference centre in Rio de Janeiro, Brazil, from 2000 to 2015. The pediatric cohort consisted of 131 (20%) patients and the adult cohort consisted of 528 (80%) patients. RESULTS: The epidemiological profile, antimony therapeutic response and incidence of adverse events (AE) were different in the pediatric cohort compared with the adult cohort. Mucosal form was less frequent in the pediatric cohort (RR:0.49, p=0.011). Lesions in the head, neck and trunk were more frequent in the pediatric cohort (RR:1.49, p=0.043). The effectiveness of antimony treatment was superior in the pediatric cohort (88.3% vs 76.6%) with a shorter healing time (RR:0.49, p=0.009). Pediatric patients had lower proportions of moderate to severe AE compared with adults (RR:0.45, p=0.027). Clinical AE predominated in the adult cohort (RR:0.40, p=0.000) and laboratory AE in the pediatric cohort (RR:1.50, p=0.023). CONCLUSIONS: This study adds to the body of knowledge on differences that exist between different age groups in ATL.

Endemic tegumentary leishmaniasis in Brazil: correlation between level of endemicity and number of cases of mucosal disease.

The purpose of this study was to establish a correlation between the endemic level of tegumentary leishmaniasis in different regions of Brazil during 2002-2009 and the number of cases of mucosal or mucocutaneous leishmaniasis. The proportion of mucosal leishmaniasis was inversely correlated with prevalence of infection. In areas with a lower infection prevalence, the proportion of mucosal leishmaniasis increased (P < 0.05). The hypothesis of an Amazonian origin and dissemination through human migration is considered. Our results show that in regions with lower prevalence and endemically younger, the proportion of cases that evolve to the mucosal form is higher than in regions with higher prevalence and endemically older.