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Werneck GL, Figueiredo FB, Cruz MDSPE. Impact of 4% Deltamethrin-Impregnated Dog Collars on the Incidence of Human Visceral Leishmaniasis: A Community Intervention Trial in Brazil. Pathogens 2024; 13:135. [PMID: 38392873 PMCID: PMC10892744 DOI: 10.3390/pathogens13020135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND In Brazil, human visceral leishmaniasis (HVL) is caused by the protozoan parasite Leishmania infantum, primarily transmitted by the sand fly Lutzomyia longipalpis, with dogs acting as the main urban reservoir. This study aims to evaluate the effectiveness of 4% deltamethrin-impregnated dog collars (DMC) on HVL incidence. METHODS This is a community intervention study carried out from 2012 to 2015 in the municipalities of Araguaína, State of Tocantins, and Montes Claros, State of Minas Gerais, Brazil. Two areas in each were randomly allocated to either (1) culling seropositive dogs + residual insecticide spraying (control area-CA) or (2) culling seropositive dogs + residual insecticide spraying + DMC fitted to dogs every six months for two years (intervention area-IA). Cases of HVL (n = 1202) occurring from 2008 to 2020 were identified from the Brazilian Reportable Diseases Information System and georeferenced to the control and intervention areas. The HVL cases from 2008 to 2012 were considered as occurring in the "pre-intervention" period. Those cases from 2013 to 2016 and from 2017 to 2020 were regarded as occurring in the "intervention" and "post-intervention" periods, respectively. We used a mixed-effects Poisson regression model to estimate the effectiveness of the intervention, comparing the changes from the pre-intervention period to the intervention and post-intervention periods in the control and intervention areas. RESULTS In Araguaína, there was a statistically significant reduction in the incidence of HVL in both the control and intervention areas, comparing both the intervention and post-intervention periods with the pre-intervention period. The intervention with DMC was significantly associated with a reduction in HVL when comparing the intervention and pre-intervention periods, yielding an effectiveness estimate of the DMC of 27% (IC95% 1-46%, p = 0.045). No differences were observed when comparing the pre- and post-intervention periods (p = 0.827). In Montes Claros, cases reduced in both the control and intervention areas from the pre-intervention period to the intervention period (p = 0.913). In the post-intervention period, the incidence increased in the control area, while cases continued to decrease in the DMC area (p = 0.188). CONCLUSIONS The use of DMC was associated with a reduction of 27% in the incidence of HVL during the period of DMC delivery, indicating that DMC is effective as an additional strategy for controlling visceral leishmaniasis in Brazil. However, no significant reduction associated with DMC was detected after the intervention period, suggesting that a control program based on the large-scale deployment of DMC might have to be maintained for more extended periods without interruption.
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Affiliation(s)
- Guilherme Loureiro Werneck
- Departament of Epidemiology, State University of Rio de Janeiro, Rio de Janeiro 20950-000, RJ, Brazil
- Instituto for Public Health Studies, Federal University of Rio de Janeiro, Rio de Janeiro 21941-630, RJ, Brazil
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Chiyo L, Dos Santos AG, de Souza AB, Rivas AV, Valle SB, Sevá ADP, Viana KF. Cross-sectional spatial and epidemiological analysis of canine visceral leishmaniasis cases in the triple border region, Brazil, Argentina and Paraguay, between 2015 and 2020. Acta Trop 2023; 239:106811. [PMID: 36608750 DOI: 10.1016/j.actatropica.2022.106811] [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: 11/09/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 01/05/2023]
Abstract
Visceral Leishmaniasis is one of the most important vector-borne zoonoses in the world. In 2013, the first autochthonous canine case of the disease in the state of Paraná, southern region of Brazil, was reported in Foz do Iguaçu, on the triple border between Brazil, Argentina and Paraguay. In 2015, the first human case was related. Once the endemic was confirmed, the Zoonoses Control Center (ZCC), an agency of the Municipal Health Department, started actions to implement the Human Visceral Leishmaniasis (HVL) Surveillance and Control Program (VLSCP), of the Ministry of Health. Between 2015 and 2020, 12,205 dog samples were analyzed for the diagnosis of the disease. A prevalence of 37.94% (4,630 samples) was found: 2016 had the highest prevalence, with 46.25%, and the year with the lowest prevalence was 2020, with 25.98%. Possible risk factors for dogs were analyzed, and the results obtained were: whether the request for the exam was performed by the ZCC was a significant protective factor, with a lower prevalence (37.5%) than dogs coming from private clinics (OR = 0.89, p-value = 0.016). Males were significantly more infected than females, with 41.1% and 35.7% positivity, respectively (OR = 1.24, p < 0.0001). Companion dogs and mixed breed dogs were significantly less affected than the other groups tested (OR = 0.44, p < 0.001; OR = 0.79, p = 0.012, respectively). The dogs' dark coat color was a significant risk factor with respect to the other color categories. Short and medium coat sizes were significantly considered risk factors, with 41.3% and 31.3% positivity. Long-haired dogs had only 22.7% positivity. In univariate analyses, giant, large and medium dogs were significantly more affected than small dogs. Dogs up to four years of age were significantly less affected than those in other age groups. There was a coincidence of human and canine cases in the spatial distribution. However, according to the literature, a higher incidence would be expected in humans, due to the high prevalence found in dogs. Therefore, further studies should be carried out to understand the dynamics of the disease in this region.
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Affiliation(s)
- Luciana Chiyo
- Universidade Federal da Integração Latino-Americana, Programa de Pós-graduação em Biociências, Foz do Iguaçu, Paraná, Brazil; Centro de Controle de Zoonoses, Prefeitura Municipal de Foz do Iguaçu, Foz do Iguaçu, Paraná, Brazil
| | - Angelo Gabriel Dos Santos
- Universidade Federal da Integração Latino-Americana, Programa de Pós-graduação em Biociências, Foz do Iguaçu, Paraná, Brazil
| | - Adrieli Barboza de Souza
- Universidade Federal da Integração Latino-Americana, Programa de Pós-graduação em Biociências, Foz do Iguaçu, Paraná, Brazil
| | - Açucena Veleh Rivas
- Universidade Federal da Integração Latino-Americana, Programa de Pós-graduação em Biociências, Foz do Iguaçu, Paraná, Brazil; Centro de Medicina Tropical da Tríplice Fronteira, Foz do Iguaçu, Paraná, Brazil
| | | | | | - Kelvinson Fernandes Viana
- Universidade Federal da Integração Latino-Americana, Programa de Pós-graduação em Biociências, Foz do Iguaçu, Paraná, Brazil.
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Marcolino Silva D, Passarella Teixeira AI, Sierra Romero GA. Socioeconomic Status of Guardians as a Risk Factor for Canine Visceral Leishmaniasis: A Cohort Study in an Endemic Area of the Federal District, Brazil. Am J Trop Med Hyg 2023; 108:328-334. [PMID: 36535251 PMCID: PMC9896338 DOI: 10.4269/ajtmh.21-1170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 07/17/2022] [Indexed: 12/23/2022] Open
Abstract
Current control measures of canine visceral leishmaniasis (CVL), a chronic and fatal zoonosis with potential transmission to humans, are not efficient enough to reduce its spread. The search for improved control measures should include studies of risk factors for infection and illness. This study aimed to identify the risk factors for CVL in an endemic locality of the Federal District, Brazil, from June 2016 to December 2018. Biologic samples and data on dog characteristics, owner household characteristics, and dog care were collected. A combination of serological and molecular tests was used to identify infected animals. The 248 dogs screened for inclusion were predominantly asymptomatic/oligosymptomatic. The baseline prevalence of infection was 27.5%. One hundred six of 162 susceptible dogs were monitored for an average period of 10.7 months. The estimated CVL incidence was 1.91 cases/100 dog-months. The multivariate analysis using a proportional Cox model included the potential risk factors, with P ≤ 0.25 in the univariate analyses. Greater purchasing power (hazard ratio [HR], 1.04; 95% CI, 1.01-1.06; P = 0.03) and paved yard (HR, 0.19; 95% CI, 0.13-1.01; P = 0.05) remained in the final model as risk and protection factors, respectively. The use of repellent collars in dogs was associated moderately (P = 0.08) with protection against CVL. Our findings reflect the challenge of identifying strong interventions for reducing CVL incidence. Increased owner wealth had a counterintuitive effect on CVL, making the intervention scenario more complex for a zoonosis traditionally associated with poverty.
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Affiliation(s)
- Debora Marcolino Silva
- Center for Tropical Medicine, University of Brasília, Brasília, Federal District, Brazil
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Huggins LG, Koehler AV, Gasser RB, Traub RJ. Advanced approaches for the diagnosis and chemoprevention of canine vector-borne pathogens and parasites-Implications for the Asia-Pacific region and beyond. ADVANCES IN PARASITOLOGY 2023; 120:1-85. [PMID: 36948727 DOI: 10.1016/bs.apar.2022.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Vector-borne pathogens (VBPs) of canines are a diverse range of infectious agents, including viruses, bacteria, protozoa and multicellular parasites, that are pernicious and potentially lethal to their hosts. Dogs across the globe are afflicted by canine VBPs, but the range of different ectoparasites and the VBPs that they transmit predominate in tropical regions. Countries within the Asia-Pacific have had limited prior research dedicated to exploring the epidemiology of canine VBPs, whilst the few studies that have been conducted show VBP prevalence to be high, with significant impacts on dog health. Moreover, such impacts are not restricted to dogs, as some canine VBPs are zoonotic. We reviewed the status of canine VBPs in the Asia-Pacific, with particular focus on nations in the tropics, whilst also investigating the history of VBP diagnosis and examining recent progress in the field, including advanced molecular methods, such as next-generation sequencing (NGS). These tools are rapidly changing the way parasites are detected and discovered, demonstrating a sensitivity equal to, or exceeding that of, conventional molecular diagnostics. We also provide a background to the armoury of chemopreventive products available for protecting dogs from VBP. Here, field-based research within high VBP pressure environments has underscored the importance of ectoparasiticide mode of action on their overall efficacy. The future of canine VBP diagnosis and prevention at a global level is also explored, highlighting how evolving portable sequencing technologies may permit diagnosis at point-of-care, whilst further research into chemopreventives will be essential if VBP transmission is to be effectively controlled.
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Affiliation(s)
- Lucas G Huggins
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia.
| | - Anson V Koehler
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
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Canine Leishmaniasis in an Endemic Area for Human Leishmaniasis in Nicaragua. J Trop Med 2022; 2022:5774296. [PMID: 36072825 PMCID: PMC9444458 DOI: 10.1155/2022/5774296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/20/2022] [Accepted: 08/17/2022] [Indexed: 12/02/2022] Open
Abstract
In this study, the frequency of canines infected with Leishmania spp. in an area endemic to leishmaniasis in humans was determined. A descriptive pilot study was conducted between the months of October and December 2020 on dogs from Rota, a community in the municipality of León, which included 45 specimens from the peridomestic area. Different variables from each specimen were monitored, such as age, sex, breed, body condition, and clinical characteristics, as well as information on the owners and cases of human leishmaniasis presented in less than 5 years. Blood samples were collected from the cephalic vein and peripheral blood was separated. A complete blood count (CBC) was performed using venous blood samples with ethylene diamine tetraacetic acid (EDTA), as well as a conventional PCR was applied for the detection of Leishmania spp. Amastigotes were found in 22% of venous or peripheral blood samples, whereas a high prevalence of 28.89% (95% CI: 14.53–43.24) was found by PCR. Only 1/12 of positive dogs in PCR presented dry exfoliative dermatitis, therefore, there was no significant difference (p ≥ 0.05), the age and sex of the dogs were also not factors associated with infection (p ≥ 0.05). This study reports for the first time the molecular detection of Leishmania in dogs in an endemic area of leishmaniasis in humans in Nicaragua. The high frequency of dogs infected with Leishmania suggests that they play an important role in the transmission cycle of human leishmaniasis.
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Alves GB, de Oliveira TCB, Rodas LC, Rozza DB, Nakamura AA, Ferrari ED, da Silva DRR, Moraes Dos Santos G, Calemes EB, Requena KAML, Nagata WB, Santos-Doni TR, Bresciani KDS. Efficacy of imidacloprid/flumethrin collar in preventing canine leishmaniosis in Brazil. Transbound Emerg Dis 2022; 69:e2302-e2311. [PMID: 35478434 DOI: 10.1111/tbed.14571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 04/11/2022] [Accepted: 04/24/2022] [Indexed: 12/01/2022]
Abstract
The Leishmania infantum (synonym, Leishmania chagasi) causes life-threatening infection, namely canine leishmaniosis (CanL), which is a chronic zoonosis prevalent in various countries and spread by the bite of the infected Lutzomyia female sandfly in South America. The objective of the study was to assess the effectiveness of a polymer matrix collar containing made up of 10% imidacloprid and 4.5% flumetrin for the prevention of canine leishmaniosis from the hyperendemic region falling under Araçatuba municipality (Brazil). The research included a total of 146 dogs chosen from 75 households. Test were initiaded via physical examination, weighing, and biological sample collection (blood, popliteal lymph node, and conjunctival swab) of these dogs was done in March 2018 (Day 0; GA, control = 69, GB, treated = 77) to initiate lab tests. Post-inclusion, the animals were monitored on the 120th, 240th, 360th, and 480th days, respectively. The usage of collars continued between 0 to 480 days before being substituted in second (D240) and fourth (D480) follow-up visits. On the whole, 25 dogs in GA (36.2 percent) and 3 in GB (3.9 percent) were found positive for L. infantum infection in a minimum of one diagnostic test used in the research. Therefore, the average collar effectiveness for protection from L. infantum infection was 89.2% (p < 0.01). In the last follow-up, the average incidence density rate for GA was 30.7%, whereas, for GB, it was 2.9%. The imidacloprid/flumethrin collars evaluated in the research were found to be safe and extremely efficient for the prevention of L. infantum infection through Lutzomyia species among the large population of dogs in highly prone endemic regions. This is a dependable and efficient technique aimed at reducing the occurrence and propagation of this illness among the population of canines, which would eventually reduce the human-health-related hazards. In Brazil, Lutzomyia spp. is a leading vector of the infection; thus, the collar can be used to limit infection in dogs and humans. The first trial was conducted in Brazil, including a 10% imidacloprid/4.5% flumethrin collar. In the initial assessment, the efficiency of the collar was 91.0% (D0 to D240). The effectiveness was 90.0% in the second assessment (D240 to D480). The mean effectiveness of the collar was 89.2% during the protection of dogs against L. infantum. The collar used for this evaluation was extremely useful and safe. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Thais Rabelo Santos-Doni
- Institute of Agricultural Sciences (ICA), Federal University of Jequitinhonha and Mucuri Valleys (UFVJM), Avenida Universitários
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Gonçalves R, de Souza CF, Rontani RB, Pereira A, Farnes KB, Gorsich EE, Silva RA, Brazil RP, Hamilton JGC, Courtenay O. Community deployment of a synthetic pheromone of the sand fly Lutzomyia longipalpis co-located with insecticide reduces vector abundance in treated and neighbouring untreated houses: Implications for control of Leishmania infantum. PLoS Negl Trop Dis 2021; 15:e0009080. [PMID: 33534804 PMCID: PMC7886189 DOI: 10.1371/journal.pntd.0009080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 02/16/2021] [Accepted: 12/17/2020] [Indexed: 01/29/2023] Open
Abstract
Background The rising incidence of visceral leishmaniasis due to Leishmania infantum requires novel methods to control transmission by the sand fly vector. Indoor residual spraying of insecticide (IRS) against these largely exophilic / exophagic vectors may not be the most effective method. A synthetic copy of the male sex-aggregation pheromone of the key vector species Lutzomyia longipalpis in the Americas, was co-located with residual pyrethroid insecticide, and tested for its effects on vector abundance, hence potential transmission, in a Brazilian community study. Methods Houses within eight defined semi-urban blocks in an endemic municipality in Brazil were randomised to synthetic pheromone + insecticide or to placebo treatments. A similar number of houses located >100m from each block were placebo treated and considered as “True Controls” (thus, analysed as three trial arms). Insecticide was sprayed on a 2.6m2 surface area of the property boundary or outbuilding wall, co-located within one metre of 50mg synthetic pheromone in controlled-release dispensers. Vector numbers captured in nearby CDC light traps were recorded at monthly intervals over 3 months post intervention. Recruited sentinel houses under True Control and pheromone + insecticide treatments were similarly monitored at 7–9 day intervals. The intervention effects were estimated by mixed effects negative binomial models compared to the True Control group. Results Dose-response field assays using 50mg of the synthetic pheromone captured a mean 4.8 (95% C.L.: 3.91, 5.80) to 6.3 (95% C.L.: 3.24, 12.11) times more vectors (female Lu. longipalpis) than using 10mg of synthetic pheromone. The intervention reduced household female vector abundance by 59% (C.L.: 48.7, 66.7%) (IRR = 0.41) estimated by the cross-sectional community study, and by 70% (C.L.: 56.7%, 78.8%) estimated by the longitudinal sentinel study. Similar reductions in male Lu. longipalpis were observed. Beneficial spill-over intervention effects were also observed at nearby untreated households with a mean reduction of 24% (95% C.L.: 0.050%, 39.8%) in female vectors. The spill-over effect in untreated houses was 44% (95% C.L.: 29.7%, 56.1%) as effective as the intervention in pheromone-treated houses. Ownership of chickens increased the intervention effects in both treated and untreated houses, attributed to the suspected synergistic attraction of the synthetic pheromone and chicken kairomones. The variation in IRR between study blocks was not associated with inter-household distances, household densities, or coverage (proportion of total households treated). Conclusions The study confirms the entomological efficacy of the lure-and-kill method to reduce the abundance of this important sand fly vector in treated and untreated homesteads. The outcomes were achieved by low coverage and using only 1–2% of the quantity of insecticide as normally required for IRS, indicating the potential cost-effectiveness of this method. Implications for programmatic deployment of this vector control method are discussed. The predominant sand fly vector of the intracellular parasite Leishmania infantum, that causes human and canine visceral leishmaniasis in the Americas, is Lutzomyia longipalpis. Vector control tools to reduce transmission are needed. A sex-aggregation pheromone released by male Lu. longipalpis attracts female conspecifics which facilitates blood-feeding and transmission. This study, conducted in Brazil, quantifies the effects of community deployment of a synthetic version of the sex-aggregation pheromone, in a controlled-release dispenser, and co-located with lethal insecticide applied to a small area of the household compound or outbuilding wall. 50mg synthetic pheromone dispensers were used since they attracted substantially more vectors than 10mg dispensers. Deploying this novel lure-and-kill method to houses in eight replicate study blocks in two suburban endemic areas, demonstrated that it reduces vector numbers at both pheromone + insecticide treated houses, and neighbouring untreated houses. The presence of chickens (a known additional attraction to blood-seeking female Lu. longipalpis) increased the beneficial effects of the intervention. The method used only 1–2% of the quantity of insecticide necessary for IRS for an average sized house. The results demonstrate the efficacy and potential cost-effectiveness of this novel lure-and-kill control method.
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Affiliation(s)
- Raquel Gonçalves
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Cristian F. de Souza
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Reila B. Rontani
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Alisson Pereira
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Katie B. Farnes
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Erin E. Gorsich
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Rafaella A. Silva
- Núcleo de Medicina Tropical, Universidade de Brasilia, Brasília, Federal District, Brazil
- Ministério da Saúde, Departamento de Imunização e Doenças Transmissíveis, Secretaria de Vigilância em Saúde, Brasília, Federal District, Brazil
| | - Reginaldo P. Brazil
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - James G. C. Hamilton
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Bailrigg, Lancaster, Lancashire, United Kingdom
- * E-mail: (JH); (OC)
| | - Orin Courtenay
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
- * E-mail: (JH); (OC)
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da Silva WJ, Cardoso DT, Morais MHF, Carneiro M, Moraga P, Barbosa DS. Spatiotemporal patterns and integrated approach to prioritize areas for surveillance and control of visceral leishmaniasis in a large metropolitan area in Brazil. Acta Trop 2020; 211:105615. [PMID: 32621931 DOI: 10.1016/j.actatropica.2020.105615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/17/2020] [Accepted: 06/30/2020] [Indexed: 11/17/2022]
Abstract
Visceral leishmaniasis (VL) is a neglected disease with worldwide distribution. Brazil is the country with the largest number of cases in the Americas, and the state of Minas Gerais presents a high VL-related burden and a high case fatality rate. We aimed to analyse the spatial and spatiotemporal patterns of VL occurrence and to identify priority risk areas for surveillance and control in the metropolitan region of Belo Horizonte-MG, the third largest metropolitan area in Brazil. An ecological study was conducted considering all cases of VL in humans confirmed from 2006 to 2017. The crude and smoothed incidence rates were used to analyse the distribution patterns of the disease (dispersed, random, or clustered) based on global and local indicators of spatial association and space-time risk assessment. Positive spatial autocorrelation and spatial dependence were found between incidence rates. It was possible to observe a high concentration of VL cases in the metropolitan core area, with the identification of two high-risk clusters in strictly urban areas, showing an urban association with the disease. Ten municipalities were categorised as high risk for VL occurrence. Our results provide evidence for making decisions in surveillance programs, suggesting the prioritisation of the municipalities with more risk of transmission.
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Affiliation(s)
- Wellington Junior da Silva
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Diogo Tavares Cardoso
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Maria Helena Franco Morais
- Belo Horizonte Health Department, Avenida Afonso Pena 2336, 30130-012, Belo Horizonte, Minas Gerais, Brazil
| | - Mariângela Carneiro
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Paula Moraga
- Department of Mathematical Sciences, University of Bath, North Rd, Claverton Down, BA2 7AY, Bath, United Kingdom
| | - David Soeiro Barbosa
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil; London School of Hygiene and Tropical Medicine, University of London, Keppel St, Bloomsbury, WC1E 7HT, London, United Kingdom.
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Bourdeau P, Rowton E, Petersen C. Impact of different Leishmania reservoirs on sand fly transmission: Perspectives from xenodiagnosis and other one health observations. Vet Parasitol 2020; 287:109237. [PMID: 33160145 PMCID: PMC8035349 DOI: 10.1016/j.vetpar.2020.109237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022]
Abstract
Leishmania has biologically adapted to specific phlebotomine sand flies through long co-evolution. The ability of Leishmania spp. to bind to sand fly midgut allows each Leishmania species to propagate and differentiate into infectious promastigotes and be transmitted. Sand fly feeding upon a mammalian host is the first step towards being infected and a host of Leishmania. Once deposited into the skin, host susceptibility to infection vs. ability to mount a sterilizing immune response predicts which hosts could be reservoirs of different Leishmania spp. Materials, in addition to parasites, are expelled during sand fly during feeding, including salivary antigens and other factors that promote local inflammatory responses. These factors aid visceralization of infection increasing the likelihood that systemic infection is established. Any environmental factor that increases sand fly biting of a particular host increases that host's role in Leishmania transmission. First descriptions of reservoir species were based on association with local human disease and ability to observe infected leukocytes on cytology. This approach was one pathogen for one reservoir host. Advances in sensitive molecular tools greatly increased the breadth of mammals found to host Leishmania infection. Visceralizing species of Leishmania, particularly L. infantum, are now known to have multiple mammalian hosts. L. donovani, long been described as an anthroponotic parasite, was recently identified through molecular and serologic surveys to have additional mammalian hosts. The epidemiological role of these animals as a source of parasites to additional hosts via vector transmission is not known. Current evidence suggests that dogs and other domestic animals either control infection or do not have sufficient skin parasitemia to be a source of L. donovani to P. argentipes. Further xenodiagnosis and characterization of skin parasitemia in these different hosts is required to more broadly understand which Leishmania spp. hosts can be a source of parasites to sand flies and which ones are dead-end hosts.
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Affiliation(s)
- Patrick Bourdeau
- Laboratoire de Dermatologie, Parasitologie et Mycologie, ONIRIS, Ecole Nationale Veterinaire, Agroalimentaire et de l'Alimentation Nantes-Atlantique, Nantes, France; Immunology Program, Department of Internal Medicine and Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Edgar Rowton
- Walter Reed Army Institute of Research, Silver Spring, MD, USA; Immunology Program, Department of Internal Medicine and Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Christine Petersen
- Walter Reed Army Institute of Research, Silver Spring, MD, USA; Department of Epidemiology, College of Public Health, USA; Center for Emerging Infectious Diseases, Coralville, IA, 52241, USA; Immunology Program, Department of Internal Medicine and Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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Yimam Y, Mohebali M. Effectiveness of insecticide-impregnated dog collars in reducing incidence rate of canine visceral leishmaniasis: A systematic review and meta-analysis. PLoS One 2020; 15:e0238601. [PMID: 32881961 PMCID: PMC7470253 DOI: 10.1371/journal.pone.0238601] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/19/2020] [Indexed: 02/07/2023] Open
Abstract
Canines are proven reservoir hosts of Leishmania infantum, the causative agent of human zoonotic visceral leishmaniasis, and therefore domestic dogs play a central role in transmitting the disease to humans. Studies on the effect of insecticide-impregnated dog collars for controlling canine visceral leishmaniasis (CanL) have been increasing; however, meta-analysis has not been conducted. This study assessed the effectiveness of insecticide-impregnated dog collars for preventing CanL. We searched (PubMed, Web of Science, Scopus, Embase, Ovid Medline(R), and Cochrane library), from inception until 2 May 2020. Two authors independently performed articles screening and data extraction. We applied the RoB 2.0 tool to evaluate the risk of bias in randomized trials, while the ROBINS-I tool was used for non-randomized trials. I-squared statistics(I2) and funnel plot and Egger’s test, respectively, were used to assesses heterogeneity between studies and publication bias. Relative Risk (RR) and 95% Confidence Interval (CI) were calculated using the random-effects model in Stata 14 software. Out of 242 citations identified, 14 studies comprising 3786 collared dogs and 3428 uncollared dogs were eligible for meta-analysis. The use of deltamethrin-impregnated dog collars(DMC) showed an overall effectiveness of 54% (95%CI: 35–65%, I2 = 63.2%, P = 0.002) in decreasing incidence of CanL, while 10% imidacloprid and 4.5% flumethrin collars provided an overall effectiveness of 90% (95%CI: 80–96%, I2 = 0.0%, P = 0.376). DMC efficacy stratified by follow-up duration was estimated to be 58% (RR = 0.42, 95%CI: 0.20–0.87), 54% (RR = 0.46, 95%CI: 0.31–0.68), 53% (RR = 0.47, 95%CI: 0.29–0.82) for follow-up periods of 5 to 6 months, 1 year and 2 years, respectively. The current evidence indicates that using insecticide-impregnated dog collars can reduce the risk of CanL caused by L. infantum. Therefore, insecticide-impregnated dog collars could be a viable alternative for inclusion as a public health measure for controlling CanL.
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Affiliation(s)
- Yonas Yimam
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Department of Biology, Faculty of Natural and Computational Sciences, Woldia University, Woldia, Ethiopia
- * E-mail:
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Centers for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences, Tehran, Iran
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11
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Alves EB, Figueiredo FB, Rocha MF, Castro MC, Werneck GL. Effectiveness of insecticide-impregnated collars for the control of canine visceral leishmaniasis. Prev Vet Med 2020; 182:105104. [PMID: 32759025 DOI: 10.1016/j.prevetmed.2020.105104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 02/06/2023]
Abstract
Visceral leishmaniasis is a neglected tropical disease widely distributed worldwide. In Brazil, the control measures adopted in the last decades have not been able to prevent the spread of the disease. This study aimed to evaluate the effectiveness of a population-based intervention using 4% deltamethrin-impregnated dog collars on the incidence of canine visceral leishmaniasis. A community intervention study was carried out in two areas of the city of Montes Claros, State of Minas Gerais, Brazil. In the control area, the preventive measures recommended by the Brazilian Program for Surveillance and Control of Visceral Leishmaniasis were implemented (culling of infected dogs and vector control with residual insecticides). In the intervention area, deltamethrin-impregnated collars were fit to domiciled dogs, in addition to the above mentioned preventive measures. At the beginning of the study, a census survey was carried out among domiciled dogs to detect the prevalence of L. infantum infection. Dogs found seronegative at recruitment were longitudinally followed-up to evaluate the incidence of infection. Monitoring of canine infection (control and intervention areas) and replacement of collars (intervention area) occurred through sequential surveys at 12, 18, and 24 months after the initial survey. At each survey, dogs were tested, and the owner answered a questionnaire about the general characteristics of the animal. Multilevel logistic regression models were used to test the effect of collars on the risk of canine infection, with households considered as aggregation units. Associations were expressed as odds ratios (OR) and respective 95% confidence intervals (95%CI). The prevalence of infection in the initial survey was 9.7% and 9.9% in the intervention and control areas, respectively (p = 0.732). Among a total of 20,477 dogs participating in the study, 9,770 were seronegative at recruitment. The cumulative incidence of infection was 4.1% in the intervention area and 7.9% in the control area (p < 0.001). In the multivariable analysis, the risk of infection was 52% lower in the intervention area as compared to the control area (OR = 0.48, 95%CI:0.39-0.59), after adjusting for the number of dogs in the house, period of recruitment, time of dog ownership, and age, sex, length of fur and breed. The use of 4% deltamethrin-impregnated dog collars was effective in reducing the incidence of canine leishmaniasis. Cost-effectiveness studies are recommended before the incorporation of collars in the arsenal of control measures of the Brazilian Program for Surveillance and Control of Visceral Leishmaniasis.
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Affiliation(s)
- Erika Barretto Alves
- Programa de Pós-graduação em Saúde Coletiva, Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Fabiano Borges Figueiredo
- Fundação Oswaldo Cruz, Instituto Carlos Chagas, Laboratório de Biologia Celular, Curitiba, PR, Brazil.
| | - Marília Fonseca Rocha
- Universidade Estadual de Montes Claros, Centro de Ciências Biológicas e da Saúde, Departamento de Saúde Mental e Saúde Coletiva, Montes Claros, MG, Brazil; Secretaria Municipal de Saúde, Centro de Controle de Zoonoses, Programa de Controle das Leishmanioses, Montes Claros, MG, Brazil.
| | - Marcia C Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
| | - Guilherme L Werneck
- Programa de Pós-graduação em Saúde Coletiva, Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Lemann Visiting Scholar, David Rockefeller Center for Latin American Studies, Cambridge, Massachusetts, United States of America.
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12
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Silva Fernandes TL, Pereira-Filho AA, Nepomuneno DB, de Freitas Milagres T, Ferreira Malta LG, D'Ávila Pessoa GC, Koerich LB, Pereira MH, Araujo RN, Gontijo NDF, Viana Sant'Anna MR. Galactosamine reduces sandfly gut protease activity through TOR downregulation and increases Lutzomyia susceptibility to Leishmania. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 122:103393. [PMID: 32360958 DOI: 10.1016/j.ibmb.2020.103393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 04/01/2020] [Accepted: 04/13/2020] [Indexed: 06/11/2023]
Abstract
In sandflies, males and females feed on carbohydrates but females must get a blood meal for egg maturation. Using artificial blood meals, this study aimed to understand how galactosamine interferes with sandfly digestive physiology. We also used galactosamine to manipulate the digestive physiology of Lutzomyia longipalpis to investigate its influence on sandfly digestion and Leishmania development within their insect vectors. Galactosamine was capable to reduce Lu. longipalpis trypsinolytic activity in a dose-dependent manner. This effect was specific to galactosamine as other similar sugars were not able to affect sandfly trypsin production. An excess of amino acids supplemented with the blood meal and 15 mM galactosamine was able to abrogate the reduction of the trypsinolytic activity caused by galactosamine, suggesting this phenomenon may be related to an impairment of amino acid detection by sandfly enterocytes. The TOR inhibitor rapamycin reduces trypsin activity in the L. longipalpis midgut. Galactosamine reduces the phosphorylation of the TOR pathway repressor 4EBP, downregulating TOR activity in the gut of L. longipalpis. Galactosamine reduces sandfly oviposition, causes an impact on sandfly longevity and specifically reduces sandfly gut proteases whereas increasing α-glycosidase activity. The administration of 15 and 30 mM galactosamine increased the number of promastigote forms of Le. mexicana and Le. infantum in galactosamine-treated L. longipalpis. Our results showed that galactosamine influences amino acid sensing, reduces sandfly gut protease activity through TOR downregulation, and benefits Leishmania growth within the Lu. longipalpis gut.
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Affiliation(s)
- Tatiana Lima Silva Fernandes
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Adalberto Alves Pereira-Filho
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Denise Barguil Nepomuneno
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Tarcísio de Freitas Milagres
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Luccas Gabriel Ferreira Malta
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Grasielle Caldas D'Ávila Pessoa
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Leonardo Barbosa Koerich
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Marcos Horácio Pereira
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Ricardo Nascimento Araujo
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Nelder de Figueiredo Gontijo
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil
| | - Mauricio Roberto Viana Sant'Anna
- Laboratório de Fisiologia de Insetos Hematófagos, Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Pampulha, Belo Horizonte, Minas Gerais, Brazil.
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13
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Morais MHF, Sabroza PC, Pessanha JE, Sobral A. Visceral leishmaniasis control actions: epidemiological indicators for its effectiveness evaluation in a Brazilian urban area. CAD SAUDE PUBLICA 2020; 36:e00060219. [PMID: 32520123 DOI: 10.1590/0102-311x00060219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 11/19/2019] [Indexed: 11/22/2022] Open
Abstract
This research applies indicators concerning control of the visceral leishmaniasis canine reservoir in the city of Belo Horizonte, Minas Gerais State, Brazil. Data were obtained from the Zoonoses Control Information System (SCZOO) and the Brazilian Information System on Diseases of Notification (SINAN) database. First we analyzed (i) existing associations between canine epidemiological indicators, where the dependent variable was the canine seroprevalence A (2007 to 2013), and the independent variables were, as follows: canine seroprevalence B (2006 to 2012); percentage of positive dogs by ELISA test reagents that were not euthanized; the relationship between the human and canine population; canine population testing coverage by census surveys; and the years of study (2006 to 2013); (ii) then, we examined the association between human visceral leishmaniasis (HVL) cases between 2007 to 2013 and the mentioned variables related to dogs and years. Statistical analysis was done by a generalized linear model (GLM). One unit increases in canine seroprevalence B and canine seroprevalence A were associated to 13% and 12% increases in HVL rates, respectively. The increase in one human/dog ratio unit was associated with a 13% decrease in HVL rates. Canine seroprevalence, human/dog ratio and non-euthanasia of ELISA-reactive dogs in the environment were adequate indicators for analyzing the canine enzootic transmission and the occurrence of HVL cases.
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Affiliation(s)
| | | | | | - Andrea Sobral
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
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14
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Canine serological survey and dog culling ant its relationship with human visceral leishmaniasis in an endemic urban area. BMC Infect Dis 2020; 20:401. [PMID: 32503461 PMCID: PMC7275440 DOI: 10.1186/s12879-020-05125-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 05/28/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Visceral leishmaniasis is an important but neglected disease that is spreading and is highly lethal when left untreated. This study sought to measure the Leishmania infantum seroprevalence in dogs, the coverage of its control activities (identification of the canine reservoir by serological survey, dog culling and insecticide spraying) and to evaluate its relationship with the occurrence of the disease in humans in the municipalities of Araçatuba and Birigui, state of São Paulo, Brazil. METHODS Information from 2006 to 2015 was georeferenced for each municipality and modeling was performed for the two municipalities together. To do this, latent Gaussian Bayesian models with the incorporation of a spatio-temporal structure and Poisson distribution were used. The Besag-York-Mollie models were applied for random spatial effects, as also were autoregressive models of order 1 for random temporal effects. The modeling was performed using the INLA (Integrated Nested Laplace Approximations) deterministic approach, considering both the numbers of cases as well as the coverage paired year by year and lagged at one and two years. RESULTS Control activity coverage was observed to be generally low. The behavior of the temporal tendency in the human disease presented distinct patterns in the two municipalities, however, in both the tendency was to decline. The canine serological survey presented as a protective factor only in the two-year lag model. CONCLUSIONS The canine serological coverage, even at low intensity, carried out jointly with the culling of the positive dogs, suggested a decreasing effect on the occurrence of the disease in humans, whose effects would be seen two years after it was carried out.
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15
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Teixeira AIP, Silva DM, de Freitas LRS, Romero GAS. A cross-sectional approach including dog owner characteristics as predictors of visceral leishmaniasis infection in dogs. Mem Inst Oswaldo Cruz 2020; 115:e190349. [PMID: 32348406 PMCID: PMC7184770 DOI: 10.1590/0074-02760190349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 02/11/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Visceral leishmaniasis (VL) is relevant for human and animal public health. Several factors have been associated with the risk of Leishmania infantum infection in dogs. However, dog owner characteristics have been rarely explored. OBJECTIVES To estimate the prevalence and to identify the associated factors for VL infection including dog owners characteristics. METHODS A cross-sectional study was conducted including dogs from an endemic canine visceral leishmaniasis (CVL) region in the Federal District, Brazil. The infection was detected using parasitological, serological, and molecular methods. The associated factors were identified through Poisson regression modelling. FINDINGS The prevalence of infection was 26.25% [95% confidence interval (CI): 20.05 to 33.57]. The associated factors were: short coat prevalence ratio (PR) = 2.33 (95% CI: 1.02 to 5.22); presence of backyard with predominance of soil and/or vegetation PR = 4.15 (95% CI: 1.35 to 12.77); and highest gross family income score PR = 2.03 (95% CI: 1.16 to 3.54). MAIN CONCLUSION This is the first study that relates higher socioeconomic status of dog owners as an independent factor associated with higher prevalence of VL infection, along with other strongly associated factors related to receptive environment for phlebotomines. Our findings strengthen the need for exploration of the biological and behavioural bases linking dog owner characteristics to the risk of canine infection in prospective cohort studies.
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Affiliation(s)
| | - Debora Marcolino Silva
- Universidade de Brasília, Faculdade de Medicina, Núcleo de Medicina Tropical, Brasília, DF, Brasil
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16
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Dantas-Torres F, Nogueira FDS, Menz I, Tabanez P, da Silva SM, Ribeiro VM, Miró G, Cardoso L, Petersen C, Baneth G, Oliva G, Solano-Gallego L, Ferrer L, Pennisi MG, Bourdeau P, Maia C, Otranto D, Gradoni L, Courtenay O, Costa CHN. Vaccination against canine leishmaniasis in Brazil. Int J Parasitol 2020; 50:171-176. [PMID: 32126240 DOI: 10.1016/j.ijpara.2020.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 12/29/2019] [Accepted: 01/02/2020] [Indexed: 12/13/2022]
Abstract
Prevention of canine Leishmania infantum infection is critical to management of visceral leishmaniasis in people living in endemic areas of Brazil. A bill (PL 1738/11), currently under consideration, proposes to establish a national vaccination policy against canine leishmaniasis in Brazil. However, there is no solid scientific evidence supporting the idea that this could reduce transmission from infected vaccinated dogs to sand flies to a level that would significantly reduce the risk of L. infantum infection or visceral leishmaniasis in humans. Thus, we advocate that insecticide-impregnated collars should the first line protective measure for public health purposes and that vaccines are applied on a case-by-case, optional basis for individual dog protection.
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Affiliation(s)
- Filipe Dantas-Torres
- Department of Immunology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, Brazil.
| | | | - Ingrid Menz
- Self-employed Veterinarian, Campinas, Brazil
| | | | - Sydnei Magno da Silva
- Department of Immunology, Microbiology and Parasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, Brazil
| | - Vitor Márcio Ribeiro
- Veterinary School, Pontifical Catholic University of Minas Gerais, Betim, Brazil
| | - Guadalupe Miró
- Department of Animal Health, Veterinary Faculty, Universidad Complutense de Madrid, Madrid, Spain
| | - Luís Cardoso
- Department of Veterinary Sciences, and Animal and Veterinary Research Centre, University of Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal
| | - Christine Petersen
- Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, United States
| | - Gad Baneth
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Gaetano Oliva
- Department of Veterinary Medicine and Food Production, University of Naples Federico II, Naples, Italy
| | - Laia Solano-Gallego
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Lluís Ferrer
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Maria Grazia Pennisi
- Department of Veterinary Sciences, University of Messina, Polo Universitario Annunziata, Messina, Italy
| | - Patrick Bourdeau
- Veterinary School of Nantes ONIRIS, University of Nantes, LUNAM, Nantes, France
| | - Carla Maia
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy
| | - Luigi Gradoni
- Unit of Vector-borne Diseases, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Orin Courtenay
- Zeeman Institute, and School of Life Sciences, University of Warwick, Coventry, United Kingdom
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17
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Moura CRLDP, Costa CHN, Moura RDD, Braga ARF, Silva VC, Costa DL. Cutaneous parasitism in patients with American visceral leishmaniasis in an endemic area. Rev Soc Bras Med Trop 2020; 53:e20190446. [PMID: 32130324 PMCID: PMC7094057 DOI: 10.1590/0037-8682-0446-2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/20/2020] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION: Visceral leishmaniasis (VL) represents a public health concern in several
areas of the world. In the American continent, VL transmission is typically
zoonotic, but humans with active VL caused by Leishmania
infantum are able to infect sandflies. Thus, individuals with
cutaneous parasitic infections may act as reservoirs and allow interhuman
transmission. Additionally, the skin may be responsible for reactivation of
the disease after therapy. This study’s objective was to evaluate cutaneous
parasitism in humans with VL in an American endemic area. METHODS: A cross-sectional hospital-based study was conducted in northeast Brazil
from October 2016 to April 2017. Biopsies of healthy skin for histopathology
and immunohistochemistry were performed prior to treatment in all study
patients. RESULTS: Twenty-two patients between the ages of five months to 78 years were
included in the study. Seven patients (31.8%) tested positive for HIV. Only
one patient had cutaneous parasitism, as confirmed by immunohistochemistry
prior to treatment. Parasitism was not detected after treatment. CONCLUSIONS: Cutaneous parasitism in the healthy skin of humans with visceral
leishmaniasis, although unusual, may be a source of infection for
phlebotomine sandflies.
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Affiliation(s)
| | | | - Rafael de Deus Moura
- Universidade Federal do Piauí, Departamento de Medicina Especializada, Teresina, PI, Brasil.,Universidade Federal do Piauí, Hospital Universitário, Laboratório de Anatomia Patológica, Teresina, PI, Brasil
| | - Aline Reis Ferro Braga
- Universidade Federal do Piauí, Hospital Universitário, Laboratório de Anatomia Patológica, Teresina, PI, Brasil
| | | | - Dorcas Lamounier Costa
- Universidade Federal do Piauí, Instituto de Doenças Tropicais Nathan Portella, Teresina, PI, Brasil
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18
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Costa DNCC, Codeço CT, Bermudi PMM, Rodas LAC, Nunes CM, Hiramoto RM, Tolezano JE, Chiaravalloti Neto F. [Control of canine visceral leishmaniasis by euthanasia: estimated effect based on a survey and mathematical modeling]. CAD SAUDE PUBLICA 2020; 36:e00221418. [PMID: 32130320 DOI: 10.1590/0102-311x00221418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 08/14/2019] [Indexed: 02/08/2023] Open
Abstract
Visceral leishmaniasis is an emerging and neglected disease that is currently expanding to urban areas. The incidence of human disease is related to canine infection. Araçatuba and Birigui are municipalities (counties) in the state of São Paulo, Brazil, with 8-10% seroprevalence of canine infection and that employ control strategies targeting the canine reservoir, based on serological survey and culling of seropositive dogs. Using data from these control programs to parameterize mathematical models, this study assessed the efficacy of these activities. We estimated that current control is capable of reducing the incidence of canine visceral leishmaniasis (CVL) by approximately 20%. Assuming continuous control and three times the current serological survey activities in Araçatuba and Birigui, culling dogs with a positive CVL diagnosis would be effective for the control of canine infection. Although theoretically possible, in practice the control of CVL with the currently recommended strategies is insufficient, since it would require overcoming the difficulties in these activities, such as lack of material, human, and financial resources, besides associated ethical and legal issues.
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Affiliation(s)
| | | | | | | | - Cáris Maroni Nunes
- Faculdade de Medicina Veterinária de Araçatuba, Universidade Estadual Paulista, Araçatuba, Brasil
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19
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Gonçalves AAM, Leite JC, Resende LA, Mariano RMDS, Silveira P, Melo-Júnior OADO, Ribeiro HS, de Oliveira DS, Soares DF, Santos TAP, Marques AF, Galdino AS, Martins-Filho OA, Dutra WO, da Silveira-Lemos D, Giunchetti RC. An Overview of Immunotherapeutic Approaches Against Canine Visceral Leishmaniasis: What Has Been Tested on Dogs and a New Perspective on Improving Treatment Efficacy. Front Cell Infect Microbiol 2019; 9:427. [PMID: 31921703 PMCID: PMC6930146 DOI: 10.3389/fcimb.2019.00427] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/29/2019] [Indexed: 12/14/2022] Open
Abstract
Visceral leishmaniasis (VL), caused by digenetic protozoa of the genus Leishmania, is the most severe form of leishmaniasis. Leishmania infantum is one of the species responsible for VL and the disease caused is considered a zoonosis whose main reservoir is the dog. Canine visceral leishmaniasis (CVL) can lead to the death of the animal if left untreated. Furthermore, the available pharmocologial treatment for CVL presents numerous disadvantages, such as relapses, toxicity, drug resistance, and the fact treated animals continue to be reservoirs when treatment fails to achieve parasitological cure. Moreover, the available VL control methods have not been adequate when it comes to controlling parasite transmission. Advances in immune response knowledge in recent years have led to a better understanding of VL pathogenesis, allowing new treatments to be developed based on immune system activation, often referred to as immunotherapy. In fact, well-defined protocols have been described, ranging from the use of immunomodulators to the use of vaccines. This treatment, which can also be associated with chemotherapy, has been shown to be effective in restoring or inducing an adequate immune response to reduce parasitic burden, leading to clinical improvement. This review focuses on immunotherapy directed at dogs infected by L. infantum, including a literature review of what has already been done in dogs. We also introduce a promising strategy to improve the efficacy of immunotherapy.
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Affiliation(s)
- Ana Alice Maia Gonçalves
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Jaqueline Costa Leite
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Lucilene Aparecida Resende
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Reysla Maria da Silveira Mariano
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Patricia Silveira
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Otoni Alves de Oliveira Melo-Júnior
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Helen Silva Ribeiro
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Diana Souza de Oliveira
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Diogo Fonseca Soares
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Thaiza Aline Pereira Santos
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Alexandre Ferreira Marques
- Laboratory of Immuno-Proteome and Parasite Biology, Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | | | - Olindo Assis Martins-Filho
- Laboratory of Diagnostic and Monitoring Biomarkers, René Rachou Institute, FIOCRUZ-Minas, Belo Horizonte, Brazil
| | - Walderez Ornelas Dutra
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Denise da Silveira-Lemos
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Rodolfo Cordeiro Giunchetti
- Laboratory of Biology of Cell Interactions, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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20
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Courtenay O, Dilger E, Calvo-Bado LA, Kravar-Garde L, Carter V, Bell MJ, Alves GB, Goncalves R, Makhdoomi MM, González MA, Nunes CM, Bray DP, Brazil RP, Hamilton JGC. Sand fly synthetic sex-aggregation pheromone co-located with insecticide reduces the incidence of infection in the canine reservoir of visceral leishmaniasis: A stratified cluster randomised trial. PLoS Negl Trop Dis 2019; 13:e0007767. [PMID: 31652261 PMCID: PMC6834291 DOI: 10.1371/journal.pntd.0007767] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 11/06/2019] [Accepted: 09/09/2019] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To evaluate the efficacy of a synthetic sex-aggregation pheromone of the sand fly vector Lu. longipalpis, co-located with residual insecticide, to reduce the infection incidence of Leishmania infantum in the canine reservoir. METHODS A stratified cluster randomised trial was designed to detect a 50% reduction in canine incident infection after 24 months in 42 recruited clusters, randomly assigned to one of three intervention arms (14 cluster each): synthetic pheromone + insecticide, insecticide-impregnated dog collars, or placebo control. Infection incidence was measured by seroconversion to anti-Leishmania serum antibody, Leishmania parasite detection and canine tissue parasite loads. Changes in relative Lu. longipalpis abundance within households were measured by setting three CDC light traps per household. RESULTS A total 1,454 seronegative dogs were followed-up for a median 15.2 (95% C.I.s: 14.6, 16.2) months per cluster. The pheromone + insecticide intervention provided 13% (95% C.I. 0%, 44.0%) protection against anti-Leishmania antibody seroconversion, 52% (95% C.I. 6.2%, 74·9%) against parasite infection, reduced tissue parasite loads by 53% (95% C.I. 5.4%, 76.7%), and reduced household female sand fly abundance by 49% (95% C.I. 8.2%, 71.3%). Variation in the efficacy against seroconversion varied between trial strata. Equivalent protection attributed to the impregnated-collars were 36% (95% C.I. 14.4%, 51.8%), 23% (95% C.I. 0%, 57·5%), 48% (95% C.I. 0%, 73.4%) and 43% (95% C.I. 0%, 67.9%), respectively. Comparison of the two interventions showed no statistically consistent differences in their efficacies; however, the errors were broad for all outcomes. Reductions in sand fly numbers were predominant where insecticide was located (chicken and dog sleeping sites), with no evidence of insecticide-induced repellence onto humans or dogs. CONCLUSION The synthetic pheromone co-located with insecticide provides protection particularly against canine L. infantum parasite transmission and sand fly vector abundance. The effect estimates are not dissimilar to those of the insecticide-impregnated collars, which are documented to reduce canine infection incidence, human infection and clinical VL disease incidence, in different global regions. The trialled novel lure-and-kill approach is a low-cost potential vector control tool against ZVL in the Americas.
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Affiliation(s)
- Orin Courtenay
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
- * E-mail: (OC); (JGCH)
| | - Erin Dilger
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Leo A. Calvo-Bado
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Lidija Kravar-Garde
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Vicky Carter
- School of Life Sciences, Institute of Science & Technology in Medicine, Keele University, Keele, Staffordshire, United Kingdom
| | - Melissa J. Bell
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Graziella B. Alves
- School of Life Sciences, Institute of Science & Technology in Medicine, Keele University, Keele, Staffordshire, United Kingdom
| | - Raquel Goncalves
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Muhammad M. Makhdoomi
- Zeeman Institute and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Mikel A. González
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Bailrigg, Lancaster, Lancashire, United Kingdom
| | - Caris M. Nunes
- Faculdade de Medicina Veterinária, Universidade Estadual Paulista (UNESP), Araçatuba, São Paulo, Brazil
| | - Daniel P. Bray
- School of Life Sciences, Institute of Science & Technology in Medicine, Keele University, Keele, Staffordshire, United Kingdom
| | - Reginaldo P. Brazil
- Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | - James G. C. Hamilton
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Bailrigg, Lancaster, Lancashire, United Kingdom
- * E-mail: (OC); (JGCH)
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21
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Silva SCPFE, Gomes LB, Carvalho PCFB, Santos AGRC, Borges LFNM, Oliveira CSF, Morais MHF, Pereira PLL, Amaral Haddad JP, Soares DFDM. Effectiveness of the mass use of deltamethrin-impregnated dog collars for preventing transmission of canine leishmaniasis by Lutzomyia spp.: A cluster randomized controlled trial. Prev Vet Med 2019; 171:104770. [PMID: 31536935 DOI: 10.1016/j.prevetmed.2019.104770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/21/2019] [Accepted: 09/03/2019] [Indexed: 11/25/2022]
Abstract
Visceral leishmaniasis (VL) is a zoonosis that greatly impacts public health, especially in developing countries. The effectiveness of deltamethrin-impregnated dog collars for preventing transmission of canine leishmaniasis (CanL) by the sand fly Lutzomyia spp. in countries with high incidence of the disease, such as Brazil, remains unknown. A cluster randomized controlled trial was carried out to evaluate the effectiveness of these collars in preventing infection of dogs with Leishmania infantum. Two areas were selected in a municipality endemic for VL in Brazil: an experimental area (EA) and a control area (CA). In both areas, blood samples were collected from dogs for detection of CanL. Seronegative dogs from the EA received collars impregnated with deltamethrin 4%. After six months, the dogs were retested for CanL and the incidence of the disease, the relative risk, and the effectiveness of collaring determined. In the baseline survey, 1020 dogs from the EA and 589 from the CA were examined. The prevalence calculated for EA was 4.41% (CI95% 3.27-5.91), and 7.13% (CI95% 5.25-9.59) for CA. In the second evaluation, 454 dogs from the EA and 292 from the CA were examined. The person-time incidence calculated for EA was 3.51% (CI95% 1.30-7.48), and for CA was 11.81% (CI95% 7.03-18.23). The difference between the calculated incidences was statistically significant (p = 0.009). The relative risk was 0.2972 (CI95% 0.1204-0.7339; p = 0.009), and the efficacy of the proposed measure was estimated in 70.27%. This report evaluated the effectiveness of the mass use of deltamethrin-impregnated dog collars in areas of transmission of VL by Lutzomyia spp. Collaring was able to protect dogs and may represent an effective strategy that could be implemented to control infection in both dogs and humans in Brazil and perhaps other countries where Lutzomyia spp. is the main vector of the disease.
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Affiliation(s)
| | - Laiza Bonela Gomes
- Departamento de Medicina Veterinária Preventiva, Escola de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Paloma Carla Fonte Boa Carvalho
- Departamento de Medicina Veterinária Preventiva, Escola de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | - Camila Stefanie Fonseca Oliveira
- Departamento de Medicina Veterinária Preventiva, Escola de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Pedro Lúcio Lithg Pereira
- Departamento de Medicina Veterinária Preventiva, Escola de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - João Paulo Amaral Haddad
- Departamento de Medicina Veterinária Preventiva, Escola de Medicina Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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22
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Courtenay O, Bazmani A, Parvizi P, Ready PD, Cameron MM. Insecticide-impregnated dog collars reduce infantile clinical visceral leishmaniasis under operational conditions in NW Iran: A community-wide cluster randomised trial. PLoS Negl Trop Dis 2019; 13:e0007193. [PMID: 30830929 PMCID: PMC6417739 DOI: 10.1371/journal.pntd.0007193] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 03/14/2019] [Accepted: 01/28/2019] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To assess the effectiveness of community-wide deployment of insecticide-impregnated collars for dogs- the reservoir of Leishmania infantum-to reduce infantile clinical visceral leishmaniasis (VL). METHODS A pair matched-cluster randomised controlled trial involving 40 collared and 40 uncollared control villages (161 [95% C.L.s: 136, 187] children per cluster), was designed to detect a 55% reduction in 48 month confirmed VL case incidence. The intervention study was designed by the authors, but implemented by the Leishmaniasis Control Program in NW Iran, from 2002 to 2006. RESULTS The collars provided 50% (95% C.I. 17·8%-70·0%) protection against infantile VL incidence (0·95/1000/yr compared to 1·75/1000/yr). Reductions in incidence were observed across 76% (22/29) of collared villages compared to pair-matched control villages, with 31 fewer cases by the end of the trial period. In 11 paired villages, no further cases were recorded post-intervention, whereas in 7 collared villages there were 9 new clinical cases relative to controls. Over the trial period, 6,835 collars were fitted at the beginning of the 4 month sand fly season, of which 6.9% (95% C.I. 6.25%, 7.56%) were lost but rapidly replaced. Collar coverage (percent dogs collared) per village varied between 66% and 100%, with a mean annual coverage of 87% (95% C.I. 84·2, 89·0%). The variation in post-intervention clinical VL incidence was not associated with collar coverage, dog population size, implementation logistics, dog owner compliance, or other demographic variables tested. Larger reductions and greater persistence in incident case numbers (indicative of transmission) were observed in villages with higher pre-existing VL case incidence. CONCLUSION Community-wide deployment of collars can provide a significant level of protection against infantile clinical VL, achieved in this study by the local VL Control Program, demonstrating attributes desirable of a sustainable public health program. The effectiveness is not dissimilar to the community-level protection provided against human and canine infection with L. infantum.
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Affiliation(s)
- Orin Courtenay
- Zeeman Institute, and School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Ahad Bazmani
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Paul D. Ready
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
| | - Mary M. Cameron
- London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom
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