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Visceral Leishmaniasis Urbanization in the Brazilian Amazon Is Supported by Significantly Higher Infection Transmission Rates Than in Rural Area. Microorganisms 2022; 10:microorganisms10112188. [PMID: 36363780 PMCID: PMC9692416 DOI: 10.3390/microorganisms10112188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/24/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
This was an open cohort prospective study (2016−2018) that analyzed the prevalence and incidence rates of human Leishmania (L.) infantum chagasi-infection and the evolution of their clinical-immunological profiles in distinct urban and rural scenarios of American visceral leishmaniasis (AVL) in Pará State, in the Brazilian Amazon. These infection profiles were based on species-specific DTH/IFAT-IgG assays and clinical evaluation of infected individuals, comprising five profiles: three asymptomatic, Asymptomatic Infection [AI], Subclinical Resistant Infection [SRI], and Indeterminate Initial Infection [III]; and two symptomatic, Subclinical Oligosymptomatic Infection [SOI] and Symptomatic Infection [SI = AVL]. The two distinct scenarios (900 km away) were the urban area of Conceição do Araguaia municipality and the rural area of Bujaru municipality in the southeast and northeast of Pará State. Human populations were chosen based on a simple convenience sampling design (5−10% in each setting), with 1723 individuals (5.3%) of the population (32,464) in the urban area and 1568 individuals (8.9%) of the population (17,596) in the rural one. A serological survey (IFAT-IgG) of canine infection was also performed in both scenarios: 195 dogs in the urban area and 381 in the rural one. Prevalence and incidence rates of human infection were higher in the urban area (20.3% and 13.6/100 person-years [py]) than in the rural setting (14.1% and 6.8/100-py). The AI profile was the most prevalent and incident in both urban (13.4% and 8.1/100-py) and rural (8.3% and 4.2/100-py) scenarios, but with higher rates in the former. An III profile case evolved to SOI profile after four weeks of incubation and another to SI (=AVL) after six. The prevalence of canine infection in an urban setting (39.2%) was also higher (p < 0.05) than that (32%) in the rural zone. AVL urbanization in Pará State, in the Brazilian Amazon, has led to infection rates significantly higher than those in rural sites, requiring more intense control measures.
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Alves ML, Silva DTD, Spada JCP, Leonel JAF, Benassi JC, Pereira NWB, Vioti G, Alves-Martin MF, de Almeida Paula NF, Starke-Buzetti WA, de Sousa Oliveira TMF. Use of the intradermal leishmanin test (Montenegro skin test) for feline visceral leishmaniosis: Detection of cellular immunity. Exp Parasitol 2022; 239:108294. [DOI: 10.1016/j.exppara.2022.108294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 04/28/2022] [Accepted: 06/02/2022] [Indexed: 11/17/2022]
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Ibarra-Meneses AV, Corbeil A, Wagner V, Onwuchekwa C, Fernandez-Prada C. Identification of asymptomatic Leishmania infections: a scoping review. Parasit Vectors 2022; 15:5. [PMID: 34983616 PMCID: PMC8727076 DOI: 10.1186/s13071-021-05129-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/11/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Asymptomatic Leishmania infection may play an important role in the transmission of the parasite in endemic areas. At present there is no consensus on the definition of asymptomatic Leishmania infection, nor is there a safe and accessible gold standard test for its identification. METHODS This paper presents a scoping review to summarize definitions of asymptomatic Leishmania infection found in the literature, as well as to detail the approach (molecular, serological, cellular, and/or parasitological tests) used by researchers to identify this asymptomatic population. A scoping review of published and gray literature related to asymptomatic Leishmania infection was conducted; retrieved citations were screened based on predefined eligibility criteria, and relevant data items were extracted from eligible articles. The analysis is descriptive and is presented using tables, figures, and thematic narrative synthesis. RESULTS We conducted a screening of 3008 articles, of which 175 were selected for the full review. Of these articles, we selected 106 that met the inclusion criteria. These articles were published between 1991 and 2021, and in the last 5 years, up to 38 articles were reported. Most of the studies were conducted in Brazil (26%), Spain (14%), India (12%), Bangladesh (10%), and Ethiopia (7%). Of the studies, 84.9% were conducted in the immunocompetent population, while 15.1% were conducted in the immunosuppressed population (HIV, immunosuppressive drugs, and organ transplantation population). We report 14 different techniques and 10 strategies employed by researchers to define asymptomatic Leishmania infection in an endemic area. CONCLUSIONS The definition of asymptomatic Leishmania infection is not unified across the literature, but often includes the following criteria: residence (or extended stay) in a Leishmania-endemic area, no reported signs/symptoms compatible with leishmaniasis, and positive on a combination of serological, molecular, cellular, and/or parasitological tests. Caution is recommended when comparing results of different studies on the subject of asymptomatic infections, as the reported prevalence cannot be confidently compared between areas due to the wide variety of tests employed by research groups. More research on the importance of asymptomatic immunosuppressed and immunocompetent Leishmania-positive populations in leishmaniasis epidemiology is required.
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Affiliation(s)
- Ana Victoria Ibarra-Meneses
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, Saint Hyacinthe, Canada
| | - Audrey Corbeil
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, Saint Hyacinthe, Canada
| | - Victoria Wagner
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada.,The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, Saint Hyacinthe, Canada
| | - Chukwuemeka Onwuchekwa
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Christopher Fernandez-Prada
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada. .,The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, Saint Hyacinthe, Canada.
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Cunha MA, Celeste BJ, Kesper N, Fugimori M, Lago MM, Ibanes AS, Ouki LM, Neto EAS, Fonseca FF, Silva MAL, Júnior WLB, Lindoso JAL. Frequency of Leishmania spp. infection among HIV-infected patients living in an urban area in Brazil: a cross-sectional study. BMC Infect Dis 2020; 20:885. [PMID: 33238943 PMCID: PMC7686951 DOI: 10.1186/s12879-020-05622-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 11/17/2020] [Indexed: 11/13/2022] Open
Abstract
Background There is little information about the frequency of Leishmania infection in asymptomatic people living with HIV (PLWH) and about the performance of laboratory diagnostic methods in coinfected patients in Latin America. The main objective of this study is to evaluate the frequency of Leishmania spp. infection in HIV-infected patients living in an urban area in Brazil. Methods To detect Leishmania infection, diagnostic tests were performed to detect anti-Leishmania antibodies (ELISA using Leptomonas seymouri antigens; ELISA using rK39 antigens; ELISA using rK28 antigens; indirect fluorescent-antibody test (IFAT); direct agglutination test (DAT)) and Leishmania DNA (polymerase chain reaction (PCR) with the target genes kDNA and ITS-1). Results The frequency of at least one positive test was 15%. For ELISA using Leptomonas antigens and IFAT, there was an association between CD4+ T lymphocyte counts and test positivity, with a higher positivity of these tests in more immunosuppressed patients (CD4+ T cell count < 200/mm3). Conclusions According to our data, there was a high prevalence of Leishmania spp. infections in this population living with HIV. Although there is the possibility of cross-reaction, some tests that are considered highly specific for the diagnosis of Leishmania infection were positive. There was also an association between the positivity of some tests studied and lower values of CD4+ T lymphocytes.
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Affiliation(s)
- M A Cunha
- Department of Infectious Diseases, Federal University of Rio Grande do Norte, Rua Cônego Monte, 110, Quintas, Natal/RN, Rio Grande do Norte, 59037-170, Brazil. .,Department of Infectious and Parasitic Diseases, University of São Paulo Medical School, Sao Paulo, Sao Paulo, Brazil.
| | - B J Celeste
- Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine of São Paulo, Sao Paulo, Sao Paulo, Brazil
| | - N Kesper
- Laboratory of Protozoology, Institute of Tropical Medicine of São Paulo, Sao Paulo, Sao Paulo, Brazil
| | - M Fugimori
- Laboratory of Seroepidemiology and Immunobiology, Institute of Tropical Medicine of São Paulo, Sao Paulo, Sao Paulo, Brazil
| | - M M Lago
- Outpatient sector, Emilio Ribas Institute for Infectious Diseases, Sao Paulo, Sao Paulo, Brazil
| | - A S Ibanes
- Outpatient sector, Emilio Ribas Institute for Infectious Diseases, Sao Paulo, Sao Paulo, Brazil
| | - L M Ouki
- Outpatient sector, Emilio Ribas Institute for Infectious Diseases, Sao Paulo, Sao Paulo, Brazil
| | - E A Simões Neto
- Department of Medicine Course, Federal University of Maranhão, Pinheiro, Maranhão, Brazil
| | - F F Fonseca
- Department of Diseases of Chronic Conditions and Sexually Transmitted Infections, Ministry of Health of Brazil, Brasília, Federal District, Brazil
| | - M A L Silva
- Parasitology, Aggeu Magalhães Research Center, Recife, Pernambuco, Brazil
| | - W L Barbosa Júnior
- Parasitology, Aggeu Magalhães Research Center, Recife, Pernambuco, Brazil
| | - J A L Lindoso
- Department of Infectious and Parasitic Diseases, University of São Paulo Medical School, Sao Paulo, Sao Paulo, Brazil.,Laboratory of Protozoology, Institute of Tropical Medicine of São Paulo, Sao Paulo, Sao Paulo, Brazil.,Outpatient sector, Emilio Ribas Institute for Infectious Diseases, Sao Paulo, Sao Paulo, Brazil
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Sosa-Ochoa W, Zúniga C, Chaves LF, Araujo Flores GV, Sandoval Pacheco CM, Ribeiro da Matta VL, Pereira Corbett CE, Tobias Silveira F, Dalastra Laurenti M. Clinical and Immunological Features of Human Leishmania (L.) infantum-Infection, Novel Insights Honduras, Central America. Pathogens 2020; 9:pathogens9070554. [PMID: 32664223 PMCID: PMC7399949 DOI: 10.3390/pathogens9070554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/01/2020] [Accepted: 07/07/2020] [Indexed: 11/16/2022] Open
Abstract
Leishmania (Leishmania) infantum is the etiological agent of both American visceral leishmaniasis (AVL) and non-ulcerated cutaneous leishmaniasis (NUCL) in Honduras. Although AVL is the most severe clinical form of infection, recent studies have shown that human immune response to parasite infection can result in a clinical-immunological spectrum. The overall prevalence rate of infection and clinical-immunological profiles of the L. (L.) infantum infection in Amapala municipality, South Honduras was determined. We examined 576 individuals with diagnosis based on combined ELISA (IgG/IgM) and DTH assays. We also used genus-specific kDNA PCR and Hsp70 PCR-RFLP for NUCL cases. Clinical evaluation found 82% asymptomatic and 18% symptomatic individuals. All symptomatic cases (n = 104) showing NUCL were positive for parasites. We identified L. (L.) infantum species in 100% of the skin lesion scrapings and in 90% of the blood samples from NUCL cases studied. A total of 320 asymptomatic individuals were exposed (ELISA+ and/or DTH+), providing an overall L. (L.) infantum prevalence of 73.6%. Clinical, parasitological, and immunological evaluations suggest seven infection profiles, three asymptomatic and four symptomatic. This represents the first report on clinical and immunological features of human L. (L.) infantum-infection in Amapala municipality, Honduras.
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Affiliation(s)
- Wilfredo Sosa-Ochoa
- Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo 01246-903, SP, Brazil; (W.S.-O.); (G.V.A.F.); (C.M.S.P.); (V.L.R.d.M.); (C.E.P.C.)
- Microbiology Research Institute, Universidad Nacional Autónoma de Honduras, Tegucigalpa 11101, Honduras
| | - Concepción Zúniga
- Department of Health Surveillance, University School Hospital, Tegucigalpa 11101, Honduras;
| | - Luis Fernando Chaves
- Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA), Tres Ríos 4-2250, Cartago, Costa Rica;
| | - Gabriela Venicia Araujo Flores
- Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo 01246-903, SP, Brazil; (W.S.-O.); (G.V.A.F.); (C.M.S.P.); (V.L.R.d.M.); (C.E.P.C.)
| | - Carmen Maria Sandoval Pacheco
- Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo 01246-903, SP, Brazil; (W.S.-O.); (G.V.A.F.); (C.M.S.P.); (V.L.R.d.M.); (C.E.P.C.)
| | - Vania Lúcia Ribeiro da Matta
- Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo 01246-903, SP, Brazil; (W.S.-O.); (G.V.A.F.); (C.M.S.P.); (V.L.R.d.M.); (C.E.P.C.)
| | - Carlos Eduardo Pereira Corbett
- Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo 01246-903, SP, Brazil; (W.S.-O.); (G.V.A.F.); (C.M.S.P.); (V.L.R.d.M.); (C.E.P.C.)
| | - Fernando Tobias Silveira
- Parasitology Department, Evandro Chagas Institute (Surveillance Secretary of Health, Ministry of Health), Belém 66090-000, PA, Brazil;
- Tropical Medicine Institute, Pará Federal University, Belém 66075-110, PA, Brazil
| | - Marcia Dalastra Laurenti
- Laboratory of Pathology of Infectious Diseases, Medical School, São Paulo University, São Paulo 01246-903, SP, Brazil; (W.S.-O.); (G.V.A.F.); (C.M.S.P.); (V.L.R.d.M.); (C.E.P.C.)
- Correspondence:
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Presence of anti-Leishmania antibodies in candidates for kidney transplantation. Int J Infect Dis 2020; 98:470-477. [PMID: 32645376 DOI: 10.1016/j.ijid.2020.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES Visceral leishmaniasis (VL) is a progressive disease that, left untreated, is typically fatal. The purpose of this investigation was to detect Leishmania sp. infection in hemodialysis patients who had received multiple blood transfusions at a private clinic in Campo Grande, Mato Grosso do Sul state, Midwest Brazil. METHODS Fifty randomly selected volunteers were interviewed for collection of demographic, socioeconomic, and epidemiological data. Indirect immunofluorescence (titers positive when ≥1:40) and rK39 immunochromatographic tests were employed for serological investigation. RESULTS Males predominated (60%). Age ranged from 20 to 77 years. Most subjects reported being on hemodialysis for at least one year (94%) and 84% were candidates for kidney transplantation, 67% of whom were on the waiting list. Leishmania sp. infection was detected in 32%. Contact with infected dogs was the only variable associated with infection. CONCLUSIONS Under immunocompromised conditions, VL is opportunistic and potentially fatal. Despite existing risks, screening for VL is not performed in asymptomatic donors and recipients. The detection of anti-Leishmania antibodies in these patients reinforces the need for infection screening before immunosuppressive treatment is initiated to reduce not only the risks of VL development and severity, but also mortality rates in cases of reactivation of latent infection.
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da Rocha ICM, Dos Santos LHM, Coura-Vital W, da Cunha GMR, Magalhães FDC, da Silva TAM, Morais MHF, Oliveira E, Reis IA, Carneiro M. Effectiveness of the Brazilian Visceral Leishmaniasis Surveillance and Control Programme in reducing the prevalence and incidence of Leishmania infantum infection. Parasit Vectors 2018; 11:586. [PMID: 30419944 PMCID: PMC6233359 DOI: 10.1186/s13071-018-3166-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/24/2018] [Indexed: 12/02/2022] Open
Abstract
Background Control strategies adopted by the Brazilian Visceral Leishmaniasis Surveillance and Control Programme (VLSCP) include identifying and culling seropositive infected dogs, early diagnosis and treatment of human cases, chemical control of the vector and population awareness. This study evaluated the effectiveness of the VLSCP on the prevalence and incidence rates of Leishmania infantum in children residing in areas under different VLSCP intervention times. Methods A quasi-experimental epidemiological study with a panel (two cross-sectional) and a concurrent cohort was performed in three areas of Belo Horizonte, southeast Brazil. The first cross-sectional study (I) was carried out with 1875 children, 478 of which were enrolled in the cohort study. In the second cross-sectional study (II), 413 additional children were included, totalizing 891 children. Laboratory diagnosis was performed by ELISA-rK39. Analyses included multilevel logistic and Poisson regression models. Results The incidence rates of L. infantum infection were: 14.4% in the area where VLSCP intervention was initiated in 2006 (AI2006); 21.1% in the area where intervention was initiated in 2008 (AI2008); and 11.6% in the area where intervention was initiated in 2010 (AI2010 - control area). A follow-up period of 24 months showed that the persons-time incidence rates in AI2006, AI2008, and AI2010 were: 6.2/100, 10/100, and 5.6/100 persons/24 months, respectively. The final prevalence rates of infection (cross-sectional II - in 2012), compared to the initial rates (cross-sectional I - in 2010), increased 83.7% in AI2006, 74.1% in AI2008, and decreased 5% in AI2010. Analysis of the effectiveness revealed that children residing in AI2008 are more likely to be infected (OR = 1.84; 95% CI: 1.06-3.23) and present a higher risk of infection (IRR = 1.76; 95% CI: 1.05-2.95) compared to those in AI2010. No statistically significant differences were observed in asymptomatic infection (OR and IRR) in AI2006 compared to AI2010. Conclusions The VLSCP was not effective at controlling L. infantum infection in areas where interventions had respectively been carried out for six and four years. However, it is unclear what the consequences in terms of human infection and diseases would be in the absence of the VLSCP. Efforts to improve the effectiveness of control measures remain a necessary priority. Electronic supplementary material The online version of this article (10.1186/s13071-018-3166-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Iara Caixeta Marques da Rocha
- Laboratório de Epidemiologia das Doenças Infecciosas e Parasitárias, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Secretaria Municipal de Saúde de Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil
| | - Letícia Helena Marques Dos Santos
- Laboratório de Epidemiologia das Doenças Infecciosas e Parasitárias, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Wendel Coura-Vital
- Departamento de Análises Clínicas, Pós-graduação em Ciências Farmacêuticas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.,Pós-graduação em Ciências Biológicas, Núcleo de Pesquisa em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Gisele Macedo Rodrigues da Cunha
- Laboratório de Epidemiologia das Doenças Infecciosas e Parasitárias, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Fernanda do Carmo Magalhães
- Laboratório de Epidemiologia das Doenças Infecciosas e Parasitárias, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Thais Almeida Marques da Silva
- Laboratório de Epidemiologia das Doenças Infecciosas e Parasitárias, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Instituto de Ensino e Pesquisa da Santa Casa Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil
| | | | - Edward Oliveira
- Laboratório de Pesquisas Clínicas, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Ilka Afonso Reis
- Departamento de Estatística, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mariângela Carneiro
- Laboratório de Epidemiologia das Doenças Infecciosas e Parasitárias, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. .,Pós-graduação em Ciências da Saúde: Infectologia e Medicina Tropical, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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Marques APC, Oliveira SMVL, Rezende GR, Melo DA, Fernandes-Fitts SM, Pontes ERJC, Bonecini-Almeida MDG, Camargo ZP, Mendes RP, Paniago AMM. Standardization and Prevalence of the Booster Phenomenon: Evaluation Using a Two-Step Skin Test with 43 kDa Glycoprotein in Individuals from an Endemic Region of Paracoccidioidomycosis. Mycopathologia 2017. [DOI: 10.1007/s11046-017-0159-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Carranza-Tamayo CO, Werneck GL, Romero GAS. Are opossums a relevant factor associated with asymptomatic Leishmania infection in the outskirts of the largest Brazilian cities? Braz J Infect Dis 2016; 20:119-26. [PMID: 26867473 PMCID: PMC9427581 DOI: 10.1016/j.bjid.2015.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/17/2015] [Indexed: 11/25/2022] Open
Abstract
A population survey was conducted to explore the prevalence and factors associated with Leishmania infection in the Fercal region of the Federal District. The Fercal region is a group of neighborhoods in Brasília in which the first cases of visceral leishmaniasis were described. Leishmania infection was established by a positive leishmanin test. Although other tests were performed in the study (an immunochromatographic assay (Kalazar detect®) and a molecular assay), only the leishmanin skin test provided sufficient results for the measurement of the disease prevalence. Data on the epidemiological, clinical and environmental characteristics of individuals were collected along with the diagnostic tests. After sampling and enrollment, seven hundred people from 2 to 14 years of age were included in the study. The prevalence of Leishmania infection was 33.28% (95% CI 29.87–36.84). The factors associated with Leishmania infection according to the multivariate analysis were age of more than seven years and the presence of opossums near the home. Age is a known factor associated with Leishmania infection; however, the presence of wild animals, as described, is an understudied factor. The presence of opossums, which are known reservoirs of Leishmania, in peri-urban areas could be the link between the rural and urban occurrence of visceral leishmaniasis in the outskirts of largest Brazilian cities, as suggested by previous studies.
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Affiliation(s)
- César Omar Carranza-Tamayo
- Núcleo de Medicina Tropical, Universidade de Brasília (UnB), Campus Universitário Darcy Ribeiro, Brasília, DF, Brazil.
| | - Guilherme Loureiro Werneck
- Departamento de Epidemiologia, Instituto de Medicina Social, Universidade Estadual do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
| | - Gustavo Adolfo Sierra Romero
- Núcleo de Medicina Tropical, Universidade de Brasília (UnB), Campus Universitário Darcy Ribeiro, Brasília, DF, Brazil
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Furtado AS, Nunes FBBDF, Santos AMD, Caldas ADJM. Análise espaço-temporal da leishmaniose visceral no estado do Maranhão, Brasil. CIENCIA & SAUDE COLETIVA 2015; 20:3935-42. [DOI: 10.1590/1413-812320152012.01672015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Resumo Este estudo analisou a distribuição espaço-temporal dos casos de leishmaniose visceral (LV) no estado do Maranhão, no período de 2000 a 2009. A partir do número de casos notificados, foram elaborados mapas temáticos para demonstrar a evolução da distribuição geográfica da doença no estado. Utilizou-se o método MCMC para estimação dos parâmetros do modelo bayesiano espaço-temporal para a identificação das áreas de risco. De 2000 a 2009, foram notificados 5.389 casos de leishmaniose visceral, distribuídos em todas as 18 Unidades Regionais de Saúde do estado, com as maiores incidências em: Caxias, Imperatriz, Presidente Dutra e Chapadinha. As Unidades Regionais de Saúde com maiores riscos relativos por biênio foram: Caxias e Barra do Corda (2000-2001), Imperatriz e Presidente Dutra (2002-2003), Imperatriz e Caxias (2004-2005), Presidente Dutra e Codó (2006-2007), e Imperatriz e Caxias (2008-2009). Houve uma considerável expansão geográfica da LV no Maranhão, sendo necessária a adoção de medidas mais eficazes de prevenção e controle da doença no estado.
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Pinheiro MPG, Silva JHT, Cavalcanti KB, de Azevedo PRM, de Melo Ximenes MDFF. Ecological interactions among phlebotomines (Diptera: Psychodidae) in an agroforestry environment of northeast Brazil. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2013; 38:307-316. [PMID: 24581360 DOI: 10.1111/j.1948-7134.2013.12045.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 08/16/2013] [Indexed: 06/03/2023]
Abstract
Phlebotomine vectors transmit parasites and can cause visceral leishmaniasis (VL) or cutaneous leishmaniasis (TL). Phlebotomine females are hematophagous but need to ingest carbohydrates, possibly promoting the development of protozoan parasites in their digestive tract. The present study evaluated the species composition and abundance across several habitats in a metropolitan landscape, as well as associations among phlebotomines, plants, and local climatic parameters. Three consecutive monthly collections were carried out in an Atlantic Forest fragment, using CDC light traps in peridomestic areas and cashew, coconut, and mango tree. plantations. Eight species of phlebotomine were captured: Evandromyia evandroi, Lutzomyia longipalpis, Psathyromyia shannoni, Sciopemyia sordellii, Evandromyia walkeri, Psychodopygus wellcomei, Nyssomyia whitmani, and Nyssomyia intermedia, primarily from the forest environment. L. longipalpis was confirmed as a species adapted to anthropic environments, while P. wellcomei was shown to be predominately forest-dwelling. Phlebotomines exhibited diversified food consumption patterns in relation to carbohydrate sources. They fed on both native and exotic species of arboreal and shrubby vegetables and gramineous plants.
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Affiliation(s)
- Marcos Paulo Gomes Pinheiro
- Department of Microbiology and Parasitology, Entomology Laboratory, Department of Statistics, Federal University of Rio Grande do Norte, Natal, RN, Brazil
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Moura GS, Santos AMD, Aquino DMCD, Silva AAMD, Caldas ADJM. Factors associated with asymptomatic infection in family members and neighbors of patients with visceral leishmaniasis. CAD SAUDE PUBLICA 2013; 28:2306-14. [PMID: 23288063 DOI: 10.1590/s0102-311x2012001400009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 08/30/2012] [Indexed: 11/22/2022] Open
Abstract
This study analyzed factors associated with asymptomatic Leishmania chagasi infection in family members and neighbors of patients with visceral leishmaniasis (VL). A cross-sectional study was conducted with 361 individuals in the counties comprising Ilha de São Luís (São Luís Island) in Maranhão State, Brazil. The Montenegro skin test (MST) and serology by enzyme-linked immunosorbent assay (ELISA) were performed to detect infection. Odds ratios (OR) and prevalence ratios (PR) and their 95% confidence intervals (95%CI) were estimated by multilevel logistic regression and Poisson regression, respectively. The rates of positive reactions were 71.3% for MST and 9.7% for ELISA. The variable associated with infection according to MST was living in the same household as the index case (PR = 1.36; 95%CI: 1.03-1.78). According to ELISA, the statistically significant variables were: living in the county of Raposa (OR = 3.56; 95%CI: 1.24-10.19) and living in the same household as the index case (OR = 2.70; 95%CI: 1.19-6.08). Family members of individuals with LV are at increased risk of infection. Priority control measures should target these families.
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Affiliation(s)
- Germano Silva Moura
- Programa de Pós-graduaçãoem Saúde Coletiva, Universidade Federal doMaranhão, São Luís, Brasil.
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Factors associated with visceral leishmaniasis in the americas: a systematic review and meta-analysis. PLoS Negl Trop Dis 2013; 7:e2182. [PMID: 23638203 PMCID: PMC3636096 DOI: 10.1371/journal.pntd.0002182] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 03/17/2013] [Indexed: 01/30/2023] Open
Abstract
Background Still today, more than 30 years after the beginning of the process of visceral leishmaniasis' urbanization, there is little knowledge about the risk factors for its occurrence, despite their relevance to the control and understanding of disease dynamics. The present study is the first systematic review with meta-analysis about factors associated with Leishmania infantum infection in humans in the Americas. Methods and Findings After searching different databases, consultations to the reference lists of articles and to experts in the field, 51 studies were reviewed. Theoretical discussions or meta-analysis of p-values or of effect sizes were used to pool information about each variable. The Q test and the I2 statistic were used to assess heterogeneities among the studies. Male sex was associated with visceral leishmaniasis in studies which used the leishmanin skin test for diagnosis and in those where the outcome was the clinical disease; the opposite occurred when serological diagnosis was applied. Younger individuals were less frequently infected than adults, but were more prone to illness. Although with different levels of evidence and of heterogeneity, the presence of dogs at home, higher dog seropositivity in nearby areas, lower socioeconomic status and highly vegetated areas were associated with L. infantum infection. This was not noticed for the presence of chickens in the house and with nutritional status. Susceptibilities to bias and limitations in the analysis and in the description of results were often identified in the studies analyzed. Conclusions Results showed the existence of consistent patterns for some of the factors analyzed and should be taken into account in developing more effective and well-targeted control measures. Studies must be conducted in new areas of the continent, with improved methodological quality and prioritizing the investigation of the patterns identified and their causes, as well as variables for which knowledge is poor. Visceral leishmaniasis (VL) is the most severe clinical form of leishmaniasis. In the Americas, VL is a zoonosis caused by the protozoan parasite Leishmania infantum, an intracellular micro-organism transmitted to humans through the bite of female phlebotomine sand flies. The domestic dog is considered the main reservoir and human beings are dead-end hosts. The disease occurs in 12 countries of the New World and Brazil accounts for 90% of the reported cases. The factors associated with infection are only partially understood, making harder understanding the disease dynamics and the development of effective and well-targeted control measures. Our work is the first systematic review with meta-analysis about factors associated with human visceral leishmaniasis in the Americas. It provides an organization of the available information, the description of more accurate data on the role of each of the factors studied, the evaluation of possible causes of heterogeneity in the results of the studies as well as the analysis of the quality of publications and limitations in the existing knowledge. The results of this study might be useful in the definition of which and where target interventions should be delivered, and for guiding researchers towards the development of future studies of better methodological quality.
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Guerra-Silveira F, Abad-Franch F. Sex bias in infectious disease epidemiology: patterns and processes. PLoS One 2013; 8:e62390. [PMID: 23638062 PMCID: PMC3634762 DOI: 10.1371/journal.pone.0062390] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 03/25/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Infectious disease incidence is often male-biased. Two main hypotheses have been proposed to explain this observation. The physiological hypothesis (PH) emphasizes differences in sex hormones and genetic architecture, while the behavioral hypothesis (BH) stresses gender-related differences in exposure. Surprisingly, the population-level predictions of these hypotheses are yet to be thoroughly tested in humans. METHODS AND FINDINGS For ten major pathogens, we tested PH and BH predictions about incidence and exposure-prevalence patterns. Compulsory-notification records (Brazil, 2006-2009) were used to estimate age-stratified ♂:♀ incidence rate ratios for the general population and across selected sociological contrasts. Exposure-prevalence odds ratios were derived from 82 published surveys. We estimated summary effect-size measures using random-effects models; our analyses encompass ∼0.5 million cases of disease or exposure. We found that, after puberty, disease incidence is male-biased in cutaneous and visceral leishmaniasis, schistosomiasis, pulmonary tuberculosis, leptospirosis, meningococcal meningitis, and hepatitis A. Severe dengue is female-biased, and no clear pattern is evident for typhoid fever. In leprosy, milder tuberculoid forms are female-biased, whereas more severe lepromatous forms are male-biased. For most diseases, male bias emerges also during infancy, when behavior is unbiased but sex steroid levels transiently rise. Behavioral factors likely modulate male-female differences in some diseases (the leishmaniases, tuberculosis, leptospirosis, or schistosomiasis) and age classes; however, average exposure-prevalence is significantly sex-biased only for Schistosoma and Leptospira. CONCLUSIONS Our results closely match some key PH predictions and contradict some crucial BH predictions, suggesting that gender-specific behavior plays an overall secondary role in generating sex bias. Physiological differences, including the crosstalk between sex hormones and immune effectors, thus emerge as the main candidate drivers of gender differences in infectious disease susceptibility.
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Affiliation(s)
- Felipe Guerra-Silveira
- Instituto Leônidas e Maria Deane – Fiocruz Amazônia, Manaus, Amazonas, Brazil
- School of Medicine, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil
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Bigeli JG, Oliveira Júnior WPD, Teles NMM. Diagnosis of Leishmania (Leishmania) chagasi infection in dogs and the relationship with environmental and sanitary aspects in the municipality of Palmas, state of Tocantins, Brazil. Rev Soc Bras Med Trop 2012; 45:18-23. [DOI: 10.1590/s0037-86822012000100005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 08/08/2011] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION: The aim of the present study was to identify the presence of Leishmania (Leishmania) chagasi infection in dogs in the City of Palmas, Tocantins, Brazil, using the PCR technique to list the hot spots of infected dogs in the city and associate their occurrence to significant environmental changes at capture sites. METHODS: DNA was extracted from blood of dogs, and the PCR were performed with primers RV1/RV2. After screening the population studied, the regions of the city that had the highest occurrence of canine infection were detected. These sites were visited, and ecological parameters denoting anthropogenic disturbance were evaluated. RESULTS: Some important features were listed in the regions visited, such as low urbanization, lack of public collection of sewage, limited garbage collection, vacant lots with tall vegetation, decaying organic matter, and, most importantly, the occurrence of stray dogs and poultry in homes. CONCLUSIONS: The methodology for screening the population was very efficient, especially in evaluating a large number of individuals in a short time, with a high degree of automation. The results indicate an association between the observed parameters and the occurrence of infection in dogs. The model presented in the city is ideal for studies of disease progression and expansion and for the evaluation of control measures adopted for canine VL.
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Ponte CB, Souza NC, Cavalcante MN, Barral AMP, Aquino DMCD, Caldas ADJM. Risk factors for Leishmania chagasi infection in an endemic area in Raposa, State of Maranhão, Brazil. Rev Soc Bras Med Trop 2011; 44:712-21. [DOI: 10.1590/s0037-86822011005000059] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 05/05/2011] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION: Infection with Leishmania chagasi is the most common clinical presentation for visceral leishmaniaisis in endemic areas. The municipality of Raposa is an endemic area in State of Maranhão, Brazil, and have had registration cases of visceral leishmaniasis disease. For this reason, a cross- sectional study was conducted to evaluate the risk factors for infection with L. chagasi detected by Montenegro skin test. METHODS: The sample comprised 96% of the inhabitants of the villages of Maresia, Pantoja, and Marisol located in the municipality of Raposa, corresponding to 1,359 subjects. Data were collected using a questionnaire. Univariate and multivariate logistic regression models were applied to evaluate the association between the variables studied and infection of L. chagasi. RESULTS: The variables associated with infection upon nonadjusted analysis were a straw roof, mud walls, floors of beaten earth, presence of sand flies inside or outside of the dwelling, and bathing outdoors. Adjusted analysis showed that the presence of sand flies inside/outside the dwelling was a risk factor, and age younger than 10 years was a protective factor against asymptomatic infection. CONCLUSIONS: The results highlight the extent to which precarious living conditions of the population strengthen the epidemiological chain of visceral leishmaniasis.
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Felipe IMA, Aquino DMCD, Kuppinger O, Santos MDC, Rangel MES, Barbosa DS, Barral A, Werneck GL, Caldas ADJM. Leishmania infection in humans, dogs and sandflies in a visceral leishmaniasis endemic area in Maranhão, Brazil. Mem Inst Oswaldo Cruz 2011; 106:207-11. [PMID: 21537682 DOI: 10.1590/s0074-02762011000200015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Accepted: 01/05/2011] [Indexed: 11/22/2022] Open
Abstract
Leishmania infection in humans, dogs and sandflies was examined in the endemic visceral leishmaniasis (VL) municipality of Raposa, state of Maranhão, Brazil. In this study, we examined Leishmania chagasi infection in the blood serum of both humans and Canis familiaris and the natural Leishmania sp. infection rate in the sandfly vector, Lutzomyia longipalpis. Enzyme-linked immunosorbent assay, indirect immunofluorescence reaction and polymerase chain reaction were performed to detect Leishmania infections in humans, dogs and sandflies, respectively. Overall, 186 out of 986 studied human beings were infected with L. chagasi parasites, representing an infection prevalence of 18.9%. An even higher infection rate was detected in dogs, where 66 (47.8%) out of 138 were infected. Among all Lu. longipalpis captured (n = 1,881), only 26.7% were females. The Leishmania infection frequency for the vector Lu. longipalpis was 1.56%. Remarkably, all infected sandflies were found in the peridomiciliary area. Furthermore, a high incidence of asymptomatic forms of VL in the human and canine populations was observed. The results of this study suggest autochthonous transmission of L. chagasi in this endemic area for visceral leishmaniasis because infection by Leishmania sp. was identified in all important elements of the transmission chain.
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Viana GMC, Nascimento MDSB, Diniz Neto JA, Rabelo EMF, Binda Júnior JR, Santos Júnior OM, Santos AC, Galvão CS, Guimarães RS. Anti-Leishmania titers and positive skin tests in patients cured of kala-azar. Braz J Med Biol Res 2010; 44:62-5. [PMID: 21103789 DOI: 10.1590/s0100-879x2010007500134] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Accepted: 10/29/2010] [Indexed: 11/21/2022] Open
Abstract
Visceral leishmaniasis (VL), also known as kala-azar, is an important public health problem. If not treated, virtually all clinically symptomatic patients die within months. The diagnosis is based on the Montenegro skin test (MST) and anti-Leishmania titers. Nevertheless, the time required for cured individuals living in a leishmaniasis-endemic area to present a positive skin test and negative anti-Leishmania serology is known. To determine the cellular and humoral immune response profile in relation to different times post-VL cure, a cross-sectional study was conducted on subjects from a kala-azar endemic area in Paço do Lumiar, MA, Brazil, on the basis of 1995-2005 notifications reported by the National Health Foundation/Regional Coordination of Maranhão. We visited cured individuals with a history of VL within the last 10 years. Seventy-four subjects (30 females) ranging in age from 1 to 44 years were included, all of them symptom free at the time of the study. A cellular immune response was observed in 73 (98.6%) subjects, whereas no significant antibody titers were detected by indirect immunofluorescence (IIF) in the sera of 69 (93.2%) cases. Ten years post-cure, 39 (52%) subjects had a positive MST and negative IIF reaction, while in one subject the skin and anti-Leishmania serology tests were negative. Two other subjects were positive in both tests 1 year after cure. These data suggest that a cellular immune response may still be present in subjects cured of VL regardless of post-cure time, and that the parasite persists in the host after clinical cure of the disease. This would explain the persistence of significant Leishmania sp antibody titers in some subjects after treatment.
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Affiliation(s)
- G M C Viana
- Departamento de Patologia, Universidade Federal do Maranhão, São Luís, MA, Brasil.
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Silveira FT, Lainson R, Crescente JÂ, de Souza AA, Campos MB, Gomes CM, Laurenti MD, Corbett CE. A prospective study on the dynamics of the clinical and immunological evolution of human Leishmania (L.) infantum chagasi infection in the Brazilian Amazon region. Trans R Soc Trop Med Hyg 2010; 104:529-35. [DOI: 10.1016/j.trstmh.2010.05.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 05/05/2010] [Accepted: 05/05/2010] [Indexed: 11/17/2022] Open
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Crescente JAB, Silveira FT, Lainson R, Gomes CMC, Laurenti MD, Corbett CEP. A cross-sectional study on the clinical and immunological spectrum of human Leishmania (L.) infantum chagasi infection in the Brazilian Amazon region. Trans R Soc Trop Med Hyg 2009; 103:1250-6. [PMID: 19615710 DOI: 10.1016/j.trstmh.2009.06.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 06/17/2009] [Accepted: 06/17/2009] [Indexed: 11/24/2022] Open
Abstract
The objectives of this study were to identify individuals with symptomatic and/or asymptomatic infection due to Leishmania (L.) infantum chagasi; to study the two types of infection, both clinically and immunologically, and to determine the prevalence rate of infection at the beginning of the study. This was a cross-sectional study with a cohort of 946 individuals, of both genders, from the age of 1 year, living in the municipality of Barcarena, PA, Brazil, an area endemic for American visceral leishmaniasis (AVL). The leishmanin skin test (LST) and the indirect fluorescent test (IFAT), were used for the diagnosis of infection. One hundred and twenty cases of infection were diagnosed, with a prevalence rate of 12.6%; eight cases showed high seroreactivity (1280-10240, IgG) in IFAT and no LST reaction; four of these cases were typical AVL and four had subclinical oligosymptomatic infection. Using two immunological methods with a clinical examination of the infected individuals enabled the identification of five clinical-immunological profiles which may promote a better understanding of the interaction between L. (L.) i. chagasi and the human immune response: asymptomatic infection (AI) 73.4%; subclinical resistant infection (SRI) 15%; subclinical oligosymptomatic infection (SOI) 3%; symptomatic infection (AVL) 3% and indeterminate initial infection (III) 5%.
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Silveira FT, Lainson R, Pereira EA, de Souza AAA, Campos MB, Chagas EJ, Gomes CMC, Laurenti MD, Corbett CEP. A longitudinal study on the transmission dynamics of human Leishmania (Leishmania) infantum chagasi infection in Amazonian Brazil, with special reference to its prevalence and incidence. Parasitol Res 2008; 104:559-67. [PMID: 18936975 DOI: 10.1007/s00436-008-1230-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Accepted: 09/29/2008] [Indexed: 10/21/2022]
Abstract
This was a longitudinal study carried out during a period over 2 years with a cohort of 946 individuals of both sexes, aged 1 year and older, from an endemic area of American visceral leishmaniasis (AVL) in Pará State, Brazil. The object was to analyze the transmission dynamics of human Leishmania (Leishmania) infantum chagasi infection based principally on the prevalence and incidence. For diagnosis of the infection, the indirect fluorescent antibody test (IFAT) and leishmanin skin test (LST) were performed with amastigote and promastigote antigens of the parasite, respectively. The prevalence by LST (11.2%) was higher (p < 0.0001) than that (3.4%) by IFAT, and the combined prevalence by both tests was 12.6%. The incidences by LST were also higher (p < 0.05) than those by IFAT at 6 (4.7% x 0.6%), 12 (4.7% x 2.7%), and 24 months (2.9% x 0.3%). Moreover, there were no differences (p > 0.05) between the combined incidences by both tests on the same point surveys, 5.2%, 6.3%, and 3.6%. During the study, 12 infected persons showed high IFAT IgG titers with no LST reactions: five children and two adults developed AVL (2,560-10,120), and two children and three adults developed subclinical oligosymptomatic infection (1280-2560). The combined tests diagnosed a total of 231 cases of infection leading to an accumulated prevalence of 24.4%.
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Affiliation(s)
- Fernando T Silveira
- Parasitology Department, Evandro Chagas Institute (Surveillance Secretary of Health, Ministry of Health), Av. Almirante Barroso, 492, 66090-000, Belém, Pará State, Brazil.
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Gouvêa MV, Werneck GL, Costa CHN, de Amorim Carvalho FA. Factors associated to Montenegro skin test positivity in Teresina, Brazil. Acta Trop 2007; 104:99-107. [PMID: 17825238 DOI: 10.1016/j.actatropica.2007.07.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2006] [Revised: 05/27/2007] [Accepted: 07/27/2007] [Indexed: 11/16/2022]
Abstract
Visceral leishmaniasis (VL) is an emerging infectious disease of urban areas in Brazil. To better understand this process, we have studied the association between reaction to the Montenegro skin test (MST), and demographic, socioeconomic and environmental factors in an urban area with high force of transmission. Associations between variables were expressed by prevalence ratios and their respective 95% confidence intervals estimated by using Poisson regression models with robust variance. Higher prevalence of positivity to MST was detected among male and older participants, and among subjects who owned dogs for 3 or more years. Individuals with higher literacy and living in households with three or more persons showed lower prevalence of MST reaction. These results suggest that the identification of high-risk groups might be feasible and useful for targeting interventions.
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Affiliation(s)
- Marcus Vinicius Gouvêa
- Núcleo de Estudos de Saúde Coletiva, Universidade Federal do Rio de Janeiro e Departamento de Epidemiologia, Instituto de Medicina Social, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, Brazil
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