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.

Advancement in Leishmaniasis Diagnosis and Therapeutics.

Leishmaniasis is a complex of clinical manifestations that affects thousands of people in the world each year according to WHO [...].

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.

Contribution of Leishmania braziliensis antigen-specific CD4+ T, CD8+ T, NK and CD3+CD56+NKT cells in the immunopathogenesis of cutaneous leishmaniasis patients: Cytotoxic, activation and exhaustion profiles.

The pathogenesis of cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is dictated mainly by the immune-mediated-tissue inflammation developed. The understanding of the immunological mechanisms that generate tissue damage or resolution of lesions is the key to the development of effective vaccine protocols and proper therapeutic schemes. It is clear that the specific immune response mediated by T cells is responsible for the beneficial outcome of the disease, however, the roles of CD4+ T, CD8+ T, NK and NKT cell subpopulations in immunopathogenesis of CL need to be elucidated. Peripheral blood cells from patients before, during and after the antimonial therapy, as well as healthy individuals (HI) were cultured with (LbAgS) or without (NS) L. braziliensis antigens (LbAg). Afterwards, the frequencies of LbAg-specific-cytotoxic CD8+ T, CD4+ T, NK and CD3+CD56+ NKT cells, as well as their activation and exhaustion profiles, were defined by flow cytometry. We observed higher frequencies of CD8+ T, NK and CD3+CD56+ NKT cells and lower frequencies of CD4+ T lymphocytes in LbAgS cell cultures from patients before treatment. The specific response to LbAg resulted in an expansion of cytotoxic-activated CD4+ T, CD8+ T, and NK cells, before and during treatment, indicating specificity in the response by these cells against L. braziliensis. Furthermore, comparing the differences of frequencies of cytotoxic-activated CD4+T, CD8+T, and NK cells, among before and during treatment patients and HI groups, we conclude that these cell populations are in charge of immune response elicited by antimonial therapy. Interestingly, we also observed that NK cells were induced by LbAg to an exhaustion profile during all clinical stages of the disease. The increased antigen-specific activation and cytotoxic activity are in line with the strong inflammatory response described in this disease, a likely cause of tissue damage. These findings reinforce the involvement of these distinct cytotoxic-activated cell populations in the immunopathogenesis of CL, showing a character of specificity in this immune response.

Geo-epidemiology and socioeconomic aspects of human sporotrichosis in the municipality of Duque de Caxias, Rio de Janeiro, Brazil, between 2007 and 2016.

BACKGROUND: Sporotrichosis is usually caused by the traumatic inoculation of pathogenic species of fungi of the genus Sporothrix. The most prevalent species in Brazil is Sporothrix brasiliensis, which is generally associated with transmission involving infected cats. Sporotrichosis is hyperendemic in the state of Rio de Janeiro and Duque de Caxias is one of the most affected municipalities. METHODS: This was a cross-sectional, geo-epidemiological and socioeconomic study of human sporotrichosis in the municipality of Duque de Caxias using geoprocessing information for the construction of thematic maps. RESULTS: Eight hundred and twenty-seven cases of sporotrichosis from Duque de Caxias were reported between 2007 and 2016, most of them in women from 25-59 years. The most affected areas had low per capita income and scarce supply of treated water. Human sporotrichosis expanded throughout the territory of the municipality over time. CONCLUSIONS: An increase in both the number of reported cases and their spatial distribution occurred throughout the studied decade. The concentration of the disease was more intense in areas with greater vulnerability of the population, expressed by low per capita income and deficient provision of basic sanitation services. Sporotrichosis requires measures to better control the disease in Duque de Caxias and in the state of Rio de Janeiro.

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.

CD3+CD4negCD8neg (double negative) T lymphocytes and NKT cells as the main cytotoxic-related-CD107a+ cells in lesions of cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis.

BACKGROUND: Cutaneous leishmaniasis (CL) is caused by Leishmania (Viannia) braziliensis, which infects dermal macrophages and dendritic cells, causing an intense immune-mediated-tissue inflammation and a skin ulcer with elevated borders that can heal spontaneously or after antimonial therapy. The resolution of lesions depends on an adaptive immune response, and cytotoxic cells seem to have a fundamental role in this process. The aim of this study is to better understand the role of cytotoxicity mediated mechanisms that occur during the immune response in the CL lesion milieu, considering distinct cytotoxic-related CD107a+ cells, such as CD8+, CD4+, CD4neg CD8neg (double-negative, DN) and CD4+CD8+ (double-positive, DP) T lymphocytes, as well as NK and NKT cells. METHODS: Lesion derived cells were assessed for T cell subpopulations and NK cells, as well as CD107a expression by flow cytometry. In addition, cytometric bead array (CBA) was used to quantify cytokines and granzyme B concentrations in supernatants from macerated lesions. RESULTS: Flow cytometry analyses revealed that NKT cells are the major CD107a-expressing cell population committed to cytotoxicity in CL lesion, although we also observed high frequencies of CD4+ and DN T cells expressing CD107a. Analysing the pool of CD107a+-cell populations, we found a higher distribution of DN T cells (44%), followed by approximately 25% of NKT cells. Interestingly, NK and CD8+ T cells represented only 3 and 4% of the total-CD107a+-cell pool, respectively. CONCLUSIONS: The cytotoxicity activity that occurs in the lesion milieu of CL patients seems to be dominated by DN T and NKT cells. These findings suggest the need for a reevaluation of the role of classical-cytotoxic NK and CD8+ T cells in the pathogenesis of CL, implicating an important role for other T cell subpopulations.

Are Neutrophil Extracellular Traps Playing a Role in the Parasite Control in Active American Tegumentary Leishmaniasis Lesions?

Neutrophil extracellular traps (NETs) have been described as a network of extracellular fibers composed by DNA, histones and various proteins/enzymes. Studies have demonstrated that NETs could be responsible for the trapping and elimination of a variety of infectious agents. In order to verify the presence of NETs in American tegumentary leishmaniasis (ATL) and their relationship with the presence of amastigotes we evaluated active cutaneous lesions of 35 patients before treatment by the detection of parasites, neutrophils (neutrophil elastase) and histones through immunohistochemistry and confocal immunofluorescence. Intact neutrophils could be detected in all ATL lesions. NETs were present in 27 patients (median 1.1; range from 0.1 to 23.5/mm2) with lesion duration ranging from one to seven months. NETs were in close proximity with neutrophils (r = 0.586; p = 0.0001) and amastigotes (r = 0.710; p = 0.0001). Two patterns of NET formation were detected: small homogeneously distributed networks observed in all lesions; and large structures that could be visualized at a lower magnification in lesions presenting at least 20% of neutrophils. Lesions presenting the larger NET formation showed high parasite detection. A correlation between NET size and the number of intact amastigotes was observed (p=0.02). As we detected an association between NET and amastigotes, our results suggest that neutrophil migration and NET formation could be stimulated and maintained by stimuli derived from the parasite burden/parasite antigen in the extracellular environment. The observation of areas containing only antigens not intermingled with NETs (elastase and histone) suggests that the involvement of these structures in the control of parasite burden is a dynamic process in which the formation of NETs is exhausted with the destruction of the parasites. Since NETs were also associated with granulomas, this trapping would favor the activity of macrophages in order to control the parasite burden.

Apoptosis and frequency of total and effector CD8+ T lymphocytes from cutaneous leishmaniasis patients during antimonial therapy.

BACKGROUND: Leishmaniasis is an important parasitic disease affecting millions worldwide. Human cutaneous leishmaniasis (CL) is endemic in Rio de Janeiro, Brazil, where is caused by Leishmania braziliensis. The adaptive immune response is accountable for the healing of CL and despite of key role of CD8+ T cells in this immune response little is known about the CD8+ T lymphocytes frequencies, apoptosis and antigen-responsive CD8+ T lymphocytes of CL patients during antimonial therapy. METHODS: Using flow cytometry, we examined total and effector CD8+ T cells from CL patients before (PBT), during (PDT) and after (PAT) treatment for apoptosis and frequencies upon isolation and after in vitro L. braziliensis antigens (LbAg)-stimulation culture. Besides, a correlation study between immunological findings and lesion size was done. RESULTS: PDT showed lower frequencies of total CD8+ T lymphocytes and higher levels of apoptosis of these cells, which were also observed following LbAg-stimulation culture. Regarding effector CD8+ T cells, high frequencies were observed in PDT, while lower frequencies were observed in PAT. Interestingly, PDT showed higher frequencies of apoptotic-effector CD8+ T lymphocytes. Similar results were seen after in vitro antigenic-stimulation assays. Correlation analysis showed that the greater the size of lesion, the smaller the frequency of effector CD8+ T lymphocytes in PDT and PAT, as well as a positive correlation between apoptotic-effector CD8+ T cells frequency and lesion size of PDT. CONCLUSIONS: Changes in effector CD8+ T-lymphocyte frequencies, during and after treatment, seem to represent a critical stage to generate an efficient immune response and suggest that these cells would be evolved in the triggering or in the resolution of lesion, under the influence of therapy. This hypothesis opens new perspectives to clarify controversial statements about the protective or deleterious role of CD8+ T cells in the cure or aggravation of CL and the new approach of evaluating patients during treatment proved to be of utmost importance for understanding the immune response in the healing process of human CL.

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.

Reaçäo reversa macular pós-alta e poliquimioterapia multibacilar / Reversal macular reaction after discharge and multidrug therapy for multibacillary leprosy

Sao apresentados três casos de pacientes portadores de formas multibacilares de hanseníase que apresentaram máculas hipocrômicas, em média seis meses após o término da poliquimioterapia/OMS para multibacilares (MB). Baseados nos exames baciloscópico, histopatológico e na evoluçao clínica favorável, com ou sem corticoterapia, firmou-se o diagnóstico de reaçao reversa macular, atípica, para estes casos. Discute-se este diagnóstico, em oposiçao à hipótese de recidiva de forma PB em pacientes inicialmente MB. Enfatíza-se a necessidade de uma correta caracterizaçao das lesoes de reaçao reversa pós-alta medicamentosa, evitando a reintroduçao terapêutica desnecessária.