1
|
Gonzalez-Daza W, Vivero-Gómez RJ, Altamiranda-Saavedra M, Muylaert RL, Landeiro VL. Time lag effect on malaria transmission dynamics in an Amazonian Colombian municipality and importance for early warning systems. Sci Rep 2023; 13:18636. [PMID: 37903862 PMCID: PMC10616112 DOI: 10.1038/s41598-023-44821-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 10/12/2023] [Indexed: 11/01/2023] Open
Abstract
Malaria remains a significant public health problem worldwide, particularly in low-income regions with limited access to healthcare. Despite the use of antimalarial drugs, transmission remains an issue in Colombia, especially among indigenous populations in remote areas. In this study, we used an SIR Ross MacDonald model that considered land use change, temperature, and precipitation to analyze eco epidemiological parameters and the impact of time lags on malaria transmission in La Pedrera-Amazonas municipality. We found changes in land use between 2007 and 2020, with increases in forested areas, urban infrastructure and water edges resulting in a constant increase in mosquito carrying capacity. Temperature and precipitation variables exhibited a fluctuating pattern that corresponded to rainy and dry seasons, respectively and a marked influence of the El Niño climatic phenomenon. Our findings suggest that elevated precipitation and temperature increase malaria infection risk in the following 2 months. The risk is influenced by the secondary vegetation and urban infrastructure near primary forest formation or water body edges. These results may help public health officials and policymakers develop effective malaria control strategies by monitoring precipitation, temperature, and land use variables to flag high-risk areas and critical periods, considering the time lag effect.
Collapse
Affiliation(s)
- William Gonzalez-Daza
- Programa do Pós-Graduação em Ecologia e Conservação da Biodiversidade, Departamento de Biociências, Universidade Federal de Mato Grosso, Cuiabá, MT, 78060-900, Brazil.
| | - Rafael Jose Vivero-Gómez
- Grupo de Microbiodiversidad y Bioprospección, Laboratorio de Biología Celular y Molecular, Universidad Nacional de Colombia Sede Medellín, Street 59A #63-20, 050003, Medellín, Colombia
- Programa de Estudio y Control de Enfermedades Tropicales-PECET, Universidad de Antioquia, Calle 62 No. 52-59 Laboratorio 632, Medellín, Colombia
| | | | - Renata L Muylaert
- Molecular Epidemiology and Public Health Laboratory, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Victor Lemes Landeiro
- Departamento de Botânica e Ecologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, MT, 78060-900, Brazil
| |
Collapse
|
2
|
Meireles ACA, da Silva LR, Simplício MF, de Lima AA, Rios FGF, de Menezes CA, Feitoza LHM, Julião GR. Anopheline diversity in urban and peri-urban malaria foci: comparison between alternative traps and seasonal effects in a city in the Western Brazilian Amazon. Malar J 2022; 21:258. [PMID: 36068530 PMCID: PMC9450372 DOI: 10.1186/s12936-022-04274-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 08/22/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Continuous vector surveillance and sustainable interventions are mandatory in order to prevent anopheline proliferation (or spread to new areas) and interrupt malaria transmission. Anopheline abundance and richness were evaluated in urban and peri-urban malaria foci at a medium-sized city in the Brazilian Amazon, comparing the protected human landing catch technique (PHLC) and alternative sampling methods over different seasonal periods. Additional information was assessed for female feeding behaviour and faunal composition. METHODS Anophelines were sampled bimonthly in four urban and peri-urban sites in the city of Porto Velho, state of Rondônia, Brazil. The average number of captured mosquitoes was compared between an PHLC (gold standard), a tent trap (Gazetrap), and a barrier screen by means of generalized linear mixed models (GLMM), which also included season and environment (peri-urban/urban) as predictors. RESULTS Overall, 2962 Anopheles individuals belonging to 12 species and one complex were caught; Anopheles darlingi represented 86% of the individuals. More mosquitoes were captured in the peri-urban setting, and the urban setting was more diverse. The model estimates that significantly more anophelines were collected by PHLC than by the Screen method, and Gazetrap captured fewer individuals. However, the Screen technique yielded more blood-engorged females. The peak hours of biting activity were from 6 to 7 p.m. in urban areas and from 7 to 8 p.m. in peri-urban areas. CONCLUSIONS Although peri-urban settings presented a greater abundance of anophelines, Shannon and Simpson diversities were higher in urban sites. Each technique proved to be useful, depending on the purpose: PHLC was more effective in capturing the highest anopheline densities, Gazetrap caught the greatest number of species, and the barrier screen technique captured more engorged individuals. There was no seasonal effect on Anopheles assemblage structure; however, a more diverse fauna was caught in the transitional season. Biting activity was more intense from 6 to 8 p.m., with a predominance of An. darlingi.
Collapse
Affiliation(s)
- Anne Caroline Alves Meireles
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil. .,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil.
| | - Lucas Rosendo da Silva
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil.,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil.,INCT-EpiAmO - National Institute of Epidemiology of Western Amazônia, Porto Velho, RO, Brazil
| | - Marlon Ferreira Simplício
- Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Alzemar Alves de Lima
- Centro de Pesquisa em Medicina Tropical de Rondônia, CEPEM-RO, Porto Velho, RO, 76812-329, Brazil.,Centro Universitário São Lucas, Porto Velho, RO, 76805-846, Brazil
| | - Flávia Geovana Fontineles Rios
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil.,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Carla Augusta de Menezes
- Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Luiz Henrique Maciel Feitoza
- Postgraduate Program in Experimental Biology (PGBIOEXP), Federal University of Rondônia (UNIR), BR-364, Km 9.5, Porto Velho, RO, 78900-550, Brazil.,Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil
| | - Genimar Rebouças Julião
- Laboratory of Entomology, Oswaldo Cruz Foundation, FIOCRUZ Rondônia, Porto Velho, RO, 76812-245, Brazil.,INCT-EpiAmO - National Institute of Epidemiology of Western Amazônia, Porto Velho, RO, Brazil
| |
Collapse
|
3
|
Noden BH, Cote NM, Reiskind MH, Talley JL. Invasive Plants as Foci of Mosquito-Borne Pathogens: Red Cedar in the Southern Great Plains of the USA. ECOHEALTH 2021; 18:475-486. [PMID: 34613506 DOI: 10.1007/s10393-021-01562-8] [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: 10/05/2020] [Revised: 09/10/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
West Nile virus (WNV) is the most significant mosquito-borne disease affecting humans in the United States. Eastern redcedar (ERC) is a native encroaching plant in the southern Great Plains that greatly alters abiotic conditions and bird and mosquito populations. This study tested the hypotheses that mosquito communities and their likelihood of WNV infection differ between ERC and other habitats in the southern Great Plains of the United States. We found support for our first hypothesis, with significantly more Culex tarsalis and Culex erraticus in ERC than deciduous and grass habitats. Mosquito communities in Central Oklahoma were more diverse (21 species) than western Oklahoma (11 species) but this difference was not associated with vegetation. Our second hypothesis was also supported, with significantly more WNV-infected Culex from ERC in both regions, as was our third hypothesis, with significantly more Culex tarsalis and Culex pipiens collected in ERC than other habitats in urban areas. The connection of mosquito-borne disease with invasive plants suggests that land management initiatives can affect human health and should be considered in light of public health impact. Evidence from other vector-borne disease suggests invasive plants, both in the Great Plains and globally, may facilitate the transmission of vector-borne pathogens.
Collapse
Affiliation(s)
- Bruce H Noden
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK, 74078, USA.
| | - Noel M Cote
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK, 74078, USA
| | - Michael H Reiskind
- Department of Entomology and Plant Pathology, North Carolina State University, 2310 Gardner Hall, Raleigh, NC, 27696, USA
| | - Justin L Talley
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK, 74078, USA
| |
Collapse
|
4
|
Johansen IC, Rodrigues PT, Tonini J, Vinetz J, Castro MC, Ferreira MU. Cohort profile: the Mâncio Lima cohort study of urban malaria in Amazonian Brazil. BMJ Open 2021; 11:e048073. [PMID: 34789490 PMCID: PMC8727682 DOI: 10.1136/bmjopen-2020-048073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 10/22/2021] [Indexed: 01/21/2023] Open
Abstract
PURPOSE This population-based open cohort study aims to investigate biological and sociodemographic drivers of malaria transmission in the main urban hotspot of Amazonian Brazil. PARTICIPANTS Nearly 20% of the households in the northwestern town of Mâncio Lima were randomly selected and 2690 participants were enrolled since April 2018. Sociodemographic, housing quality, occupational, behavioural and morbidity information and travel histories were collected during consecutive study visits. Blood samples from participants>3 months old were used for malaria diagnosis and human genetic studies; samples from participants with laboratory-confirmed malaria have been cryopreserved for genetic and phenotypic characterisation of parasites. Serology was introduced in 2020 to measure the prevalence and longevity of SARS-CoV-2 IgG antibodies. FINDINGS TO DATE Malaria prevalence rates were low (up to 1.0% for Plasmodium vivax and 0.6% for P. falciparum) during five consecutive cross-sectional surveys between April-May 2018 and October-November 2020; 63% of infections diagnosed by microscopy were asymptomatic. Malaria risk is heterogeneously distributed, with 20% study participants contributing 86% of the overall burden of P. vivax infection. Adult males are at greatest risk of infection and human mobility across the urban-rural interface may contribute to sustained malaria transmission. Local P. vivax parasites are genetically diverse and fragmented into discrete inbred lineages that remain stable across space and time. FUTURE PLANS Two follow-up visits, with similar study protocols, are planned in 2021. We aim to identify high-risk individuals that fuel onwards malaria transmission and represent a priority target for more intensive and effective control interventions. TRIAL REGISTRATION NUMBER NCT03689036.
Collapse
Affiliation(s)
| | | | - Juliana Tonini
- Parasitology, University of Sao Paulo, Sao Paulo, Brazil
| | - Joseph Vinetz
- Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Marcia C Castro
- Global Health and Population, Harvard School of Public Health, Boston, Massachusetts, USA
| | | |
Collapse
|
5
|
Fontoura PS, Silva MF, da Costa AS, Ribeiro FS, Ferreira MS, Ladeia-Andrade S, Tonini J, Rodrigues PT, Castro MC, Ferreira MU. Monthly biological larviciding associated with a tenfold decrease in larval density in fish farming ponds and reduced community-wide malaria incidence in northwestern Brazil. Parasit Vectors 2021; 14:445. [PMID: 34479606 PMCID: PMC8414731 DOI: 10.1186/s13071-021-04964-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 08/17/2021] [Indexed: 12/01/2022] Open
Abstract
Background Larvicides are typically applied to fixed and findable mosquito breeding sites, such as fish farming ponds used in commercial aquaculture, to kill immature forms and thereby reduce the size of adult malaria vector populations. However, there is little evidence suggesting that larviciding may suppress community-wide malaria transmission outside Africa. Here, we tested whether the biological larvicide VectoMax FG applied at monthly intervals to fish farming ponds can reduce malaria incidence in Amazonian Brazil. Methods This study was carried out in Vila Assis Brasil (VAB; population 1700), a peri-urban malaria hotspot in northwestern Brazil with a baseline annual parasite incidence of 553 malaria cases per 1000 inhabitants. The intervention consisted of monthly treatments with 20 kg/ha of VectoMax FG of all water-filled fish ponds in VAB (n ranging between 167 and 170) with a surface area between 20 and 8000 m2, using knapsack power mistblowers. We used single-group interrupted time-series analysis to compare monthly larval density measurements in fish ponds during a 14-month pre-intervention period (September 2017–October 2018), with measurements made during November 2018–October 2019 and shortly after the 12-month intervention (November 2019). We used interrupted time-series analysis with a comparison group to contrast the malaria incidence trends in VAB and nearby nonintervention localities before and during the intervention. Results Average larval densities decreased tenfold in treated fish farming ponds, from 0.467 (95% confidence interval [CI], 0.444–0.490) anopheline larvae per dip pre-intervention (September 2017–October 2018) to 0.046 (95% CI, 0.041–0.051) larvae per dip during (November 2018–October 2019) and shortly after the intervention (November 2019). Average malaria incidence rates decreased by 0.08 (95% CI, 0.04–0.11) cases per 100 person-months (P < 0.0001) during the intervention in VAB and remained nearly unchanged in comparison localities. We estimate that the intervention averted 24.5 (95% CI, 6.2–42.8) malaria cases in VAB between January and December 2019. Conclusions Regular larviciding is associated with a dramatic decrease in larval density and a modest but significant decrease in community-wide malaria incidence. Larviciding may provide a valuable complementary vector control strategy in commercial aquaculture settings across the Amazon. Graphical abstract ![]()
Collapse
Affiliation(s)
- Pablo S Fontoura
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil
| | - Marcos F Silva
- Multidisciplinary Center, Federal University of Acre, Cruzeiro do Sul, Brazil
| | - Anderson S da Costa
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil
| | - Francismar S Ribeiro
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil
| | - Marcílio S Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil
| | - Simone Ladeia-Andrade
- Laboratory of Parasitic Diseases, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, RJ, 21045-900, Brazil
| | - Juliana Tonini
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil
| | - Priscila T Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil
| | - Marcia C Castro
- Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo, SP, 05508-900, Brazil.
| |
Collapse
|
6
|
Rufalco-Moutinho P, Moura Kadri S, Peres Alonso D, Moreno M, Carrasco-Escobar G, Prussing C, Gamboa D, Vinetz JM, Mureb Sallum MA, Conn JE, Martins Ribolla PE. Ecology and larval population dynamics of the primary malaria vector Nyssorhynchus darlingi in a high transmission setting dominated by fish farming in western Amazonian Brazil. PLoS One 2021; 16:e0246215. [PMID: 33831004 PMCID: PMC8031405 DOI: 10.1371/journal.pone.0246215] [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: 01/09/2021] [Accepted: 03/23/2021] [Indexed: 11/21/2022] Open
Abstract
Vale do Rio Juruá in western Acre, Brazil, is a persistent malaria transmission hotspot partly due to fish farming development that was encouraged to improve local standards of living. Fish ponds can be productive breeding sites for Amazonian malaria vector species, including Nyssorhynchus darlingi, which, combined with high human density and mobility, add to the local malaria burden.This study reports entomological profile of immature and adult Ny. darlingi at three sites in Mâncio Lima, Acre, during the rainy and dry season (February to September, 2017). From 63 fishponds, 10,859 larvae were collected, including 5,512 first-instar Anophelinae larvae and 4,927 second, third and fourth-instars, of which 8.5% (n = 420) were Ny. darlingi. This species was most abundant in not-abandoned fishponds and in the presence of emerging aquatic vegetation. Seasonal analysis of immatures in urban landscapes found no significant difference in the numbers of Ny. darlingi, corresponding to equivalent population density during the rainy to dry transition period. However, in the rural landscape, significantly higher numbers of Ny. darlingi larvae were collected in August (IRR = 5.80, p = 0.037) and September (IRR = 6.62, p = 0.023) (dry season), compared to February (rainy season), suggesting important role of fishponds for vector population maintenance during the seasonal transition in this landscape type. Adult sampling detected mainly Ny. darlingi (~93%), with similar outdoor feeding behavior, but different abundance according to landscape profile: urban site 1 showed higher peaks of human biting rate in May (46 bites/person/hour), than February (4) and September (15), while rural site 3 shows similar HBR during the same sampling period (22, 24 and 21, respectively). This study contributes to a better understanding of the larvae biology of the main malaria vector in the Vale do Rio Juruá region and, ultimately will support vector control efforts.
Collapse
Affiliation(s)
- Paulo Rufalco-Moutinho
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- * E-mail:
| | - Samir Moura Kadri
- Instituto de Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Diego Peres Alonso
- Instituto de Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Marta Moreno
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Gabriel Carrasco-Escobar
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Catharine Prussing
- Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Albany, NY, United States of America
- New York State Department of Health, Wadsworth Center, Albany, NY, United States of America
| | - Dionicia Gamboa
- Facultad de Ciencias y Filosofía, Departamento de Ciencias Celulares y Moleculares, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicinal Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicinal Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, Peru
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, United States of America
| | - Maria Anice Mureb Sallum
- Faculdade de Saúde Pública, Departamento de Epidemiologia, Universidade de São Paulo, São Paulo, Brazil
| | - Jan E. Conn
- Department of Biomedical Sciences, School of Public Health, State University of New York-Albany, Albany, NY, United States of America
- New York State Department of Health, Wadsworth Center, Albany, NY, United States of America
| | - Paulo Eduardo Martins Ribolla
- Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
- Instituto de Biotecnologia, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| |
Collapse
|
7
|
Johansen IC, Rodrigues PT, Ferreira MU. Human mobility and urban malaria risk in the main transmission hotspot of Amazonian Brazil. PLoS One 2020; 15:e0242357. [PMID: 33237945 PMCID: PMC7688137 DOI: 10.1371/journal.pone.0242357] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/30/2020] [Indexed: 11/22/2022] Open
Abstract
Malaria in the Amazon is often perceived as an exclusively rural disease, but transmission has been increasingly documented within and near urban centers. Here we explore patterns and causes of urban-to-rural mobility, which places travelers at risk of malaria in Mâncio Lima, the main malaria hotspot in northwestern Brazil. We also analyze rural-to-urban mobility caused by malaria treatment seeking, which poses an additional risk of infection to urban residents. We show that the rural localities most frequently visited by urban residents–typically farming settlements in the vicinity of the town–are those with the most intense malaria transmission and also the most frequent source localities of imported malaria cases diagnosed in the town. The most mobile urban residents are typically poor males 16 to 60-years old from multi-sited households who lack a formal job. Highly mobile residents represent a priority target for more intensive and effective malaria control interventions, that cannot be readily delivered to the entire community, in this and similar urbanized endemic settings across the Amazon.
Collapse
Affiliation(s)
- Igor C. Johansen
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo (SP), Brazil
- * E-mail: (ICJ); (MUF)
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo (SP), Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo (SP), Brazil
- * E-mail: (ICJ); (MUF)
| |
Collapse
|
8
|
Fontoura PS, da Costa AS, Ribeiro FS, Ferreira MS, Castro MC, Ferreira MU. Field Efficacy of VectoMax FG and VectoLex CG Biological Larvicides for Malaria Vector Control in Northwestern Brazil. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:942-946. [PMID: 31751448 DOI: 10.1093/jme/tjz220] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Indexed: 06/10/2023]
Abstract
Despite historical and contemporary evidence of its effectiveness, larval source management with insecticides remains little used by most malaria control programs worldwide. Here we show that environmentally safe biological larvicides under field conditions can significantly reduce anopheline larval density in fish farming ponds that have became major larval habitats across the Amazon Basin. Importantly, the primary local malaria vector, Anopheles darlingi Root (Diptera: Culicidae), feeds and rests predominantly outdoors, being little affected by interventions such as long-lasting insecticidal bed net distribution and indoor residual spraying. We found >95% reduction in late-instar density up to 7 d after the first application of VectoMax FG or VectoLex CG (both from Valent BioSciences), and up to 21 d after larvicide reapplication in fish ponds (n = 20) situated in the main residual malaria pocket of Brazil, irrespective of the formulation or dosage (10 or 20 kg/ha) used. These results are consistent with a substantial residual effect upon retreatment and support the use of biological larvicides to reduce the density of anopheline larvae in this and similar settings across the Amazon where larval habitats are readily identified and accessible.
Collapse
Affiliation(s)
- Pablo S Fontoura
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil
| | - Anderson S da Costa
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil
| | - Francismar S Ribeiro
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil
| | - Marcílio S Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil
| | - Marcia C Castro
- Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, MA
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil
| |
Collapse
|
9
|
Minimal genetic differentiation of the malaria vector Nyssorhynchus darlingi associated with forest cover level in Amazonian Brazil. PLoS One 2019; 14:e0225005. [PMID: 31725789 PMCID: PMC6855485 DOI: 10.1371/journal.pone.0225005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/25/2019] [Indexed: 12/05/2022] Open
Abstract
The relationship between deforestation and malaria in Amazonian Brazil is complex, and a deeper understanding of this relationship is required to inform effective control measures in this region. Here, we are particularly interested in characterizing the impact of land use and land cover change on the genetics of the major regional vector of malaria, Nyssorhynchus darlingi (Root). We used nextera-tagmented, Reductively Amplified DNA (nextRAD) genotyping-by-sequencing to genotype 164 Ny. darlingi collected from 16 collection sites with divergent forest cover levels in seven municipalities in four municipality groups that span the state of Amazonas in northwestern Amazonian Brazil: São Gabriel da Cachoeira, Presidente Figueiredo, four municipalities in the area around Cruzeiro do Sul, and Lábrea. Using a dataset of 5,561 Single Nucleotide Polymorphisms (SNPs), we investigated the genetic structure of these Ny. darlingi populations with a combination of model- and non-model-based analyses. We identified weak to moderate genetic differentiation among the four municipality groups. There was no evidence for microgeographic genetic structure of Ny. darlingi among forest cover levels within the municipality groups, indicating that there may be gene flow across areas of these municipalities with different degrees of deforestation. Additionally, we conducted an environmental association analysis using two outlier detection methods to determine whether individual SNPs were associated with forest cover level without affecting overall population genetic structure. We identified 14 outlier SNPs, and investigated functions associated with their proximal genes, which could be further characterized in future studies.
Collapse
|
10
|
Corder RM, Paula GA, Pincelli A, Ferreira MU. Statistical modeling of surveillance data to identify correlates of urban malaria risk: A population-based study in the Amazon Basin. PLoS One 2019; 14:e0220980. [PMID: 31398228 PMCID: PMC6688813 DOI: 10.1371/journal.pone.0220980] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/28/2019] [Indexed: 11/22/2022] Open
Abstract
Despite the recent malaria burden reduction in the Americas, focal transmission persists across the Amazon Basin. Timely analysis of surveillance data is crucial to characterize high-risk individuals and households for better targeting of regional elimination efforts. Here we analyzed 5,480 records of laboratory-confirmed clinical malaria episodes combined with demographic and socioeconomic information to identify risk factors for elevated malaria incidence in Mâncio Lima, the main urban transmission hotspot of Brazil. Overdispersed malaria count data clustered into households were fitted with random-effects zero-inflated negative binomial regression models. Random-effect predictors were used to characterize the spatial heterogeneity in malaria risk at the household level. Adult males were identified as the population stratum at greatest risk, likely due to increased occupational exposure away of the town. However, poor housing and residence in the less urbanized periphery of the town were also found to be key predictors of malaria risk, consistent with a substantial local transmission. Two thirds of the 8,878 urban residents remained uninfected after 23,975 person-years of follow-up. Importantly, we estimated that nearly 14% of them, mostly children and older adults living in the central urban hub, were free of malaria risk, being either unexposed, naturally unsusceptible, or immune to infection. We conclude that statistical modeling of routinely collected, but often neglected, malaria surveillance data can be explored to characterize drivers of transmission heterogeneity at the community level and provide evidence for the rational deployment of control interventions.
Collapse
Affiliation(s)
- Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: (RMC); (MUF)
| | - Gilberto A. Paula
- Department of Statistics, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil
| | - Anaclara Pincelli
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail: (RMC); (MUF)
| |
Collapse
|