Factores de riesgo asociados a la transmisión de malaria en zona endemica de Córdoba, Colombia / Risk factors associated with the transmission of malaria in the endemic zone of Córdoba, Colombia

El objetivo del trabajo fue determinar factores de riesgo asociados a la transmisión de la malaria en el municipio de Puerto Libertador, Córdoba. Se realizó un estudio observacional analítico transversal, retrospectivo, con enfoque cuantitativo de casos de malaria de zonas rurales del municipio. La información se organizó en Excel, se describieron variables sociodemográficas, aspectos clínicos de los pacientes, de vivienda y ambientales y se realizó un análisis de riesgo para establecer asociación entre las variables y la malaria, además se clasificaron especies de anofelinos vectores y se utilizaron los softwares SatScan y QGis para identificar puntos calientes de malaria en la zona de estudio. Se incluyeron 170 casos de malaria, se identificó que 92% de los individuos carecen de servicio de recolección de basuras, 86,5% sin acueducto, más del 90% no utilizan angeos, repelentes, insecticidas o fumigaciones, se encontró asociación estadística significativa (OR>1) con las aguas estancadas, la falta de acueducto y agua continua como factores de riesgo de malaria; además se clasificaron cinco especies de mosquitos que estarían involucradas en la transmisión y se identificó un punto caliente compuesto por seis veredas del municipio. La malaria en el municipio de Puerto Libertador está asociada principalmente a problemáticas sociales, que se constituyen en factores de riesgo que favorecen la incidencia de esta enfermedad. En la zona de estudio la identificación de los mosquitos Anopheles y del punto caliente, permitirán orientar las medidas de control del vector y dirigir las intervenciones a las localidades focalizadas con mayor riesgo de malaria(AU)

The objective of the work was to determine risk factors associated with the transmission of malaria in the municipality of Puerto Libertador, Córdoba. A retrospective, cross-sectional analytical observational study was carried out, with a quantitative approach to malaria cases in rural areas of the municipality. The information was organized in Excel, sociodemographic variables, clinical aspects of the patients, housing and environmental variables were described, and a risk analysis was carried out to establish an association between the variables and malaria.In addition, vector anopheline species were classified and the SatScan and QGis software to identify malaria hot spots in the study area. 170 cases of malaria were included, it was identified that 92% of the individuals lack garbage collection service, 86.5% without aqueduct, more than 90% do not use angeos, repellents, insecticides or fumigations, a significant statistical association was found ( OR> 1) with stagnant water, lack of aqueduct and continuous water as risk factors for malaria; In addition, five species of mosquitoes that would be involved in the transmission were classified and a hotspot made up of six villages in the municipality was identified. Malaria in the municipality of Puerto Libertador is mainly associated with social problems, which constitute risk factors that favor the incidence of this disease. In the study area, the identification of Anopheles mosquitoes and the hotspot will make it possible to orient vector control measures and direct interventions to targeted localities with the highest risk of malaria(AU)

Flight tone characterisation of the South American malaria vector Anopheles darlingi (Diptera: Culicidae)

BACKGROUND Flight tones play important roles in mosquito reproduction. Several mosquito species utilise flight tones for mate localisation and attraction. Typically, the female wingbeat frequency (WBF) is lower than males, and stereotypic acoustic behaviors are instrumental for successful copulation. Mosquito WBFs are usually an important species characteristic, with female flight tones used as male attractants in surveillance traps for species identification. Anopheles darlingi is an important Latin American malaria vector, but we know little about its mating behaviors. OBJECTIVES We characterised An. darlingi WBFs and examined male acoustic responses to immobilised females. METHODS Tethered and free flying male and female An. darlingi were recorded individually to determine their WBF distributions. Male-female acoustic interactions were analysed using tethered females and free flying males. FINDINGS Contrary to most mosquito species, An. darlingi females are smaller than males. However, the male's WBF is ~1.5 times higher than the females, a common ratio in species with larger females. When in proximity to a female, males displayed rapid frequency modulations that decreased upon genitalia engagement. Tethered females also modulated their frequency upon male approach, being distinct if the interaction ended in copulation or only contact. MAIN CONCLUSIONS This is the first report of An. darlingi flight acoustics, showing that its precopulatory acoustics are similar to other mosquitoes despite the uncommon male:female size ratio, suggesting that WBF ratios are common communication strategies rather than a physical constraint imposed by size.

Composition and abundance of anopheline species according to habitat diversity in Mexico / Composición y abundancia de especies de anofelinos según la diversidad de hábitats en México

Abstract: Objective: To determine the abundance and geographic distribution of the main malaria vectors, which are influenced by habitat characteristics and ecological factors that directly impact adult density and the dynamics of malaria transmission in Mexico. Materials and methods: Samples of larvae were collected from 19 states in Mexico. Each larval habitat was characterized in situ determining the following parameters: water depth, turbidity, percentage of vegetation cover, amount of detritus, presence of algae, light intensity, type of vegetation, amount of predators, habitat stability, altitude, and hydrologic type. Results: A total of 21 687 larvae corresponding to 13 anopheline species were obtained from 149 aquatic habitats. The most abundant species were Anopheles pseudopunctipennis (52.91%), An. albimanus (39.14%) and An. franciscanus (5.29%). The multiple logistic regression analysis showed a negative association between An. pseudopunctipennis and water turbidity (ß=-1.342; Wald=6.122; p=0.013) and the amount of detritus (ß=-2.206; Wald=3.642; p=0.050). While in An. albimanus, there was a significant positive association with water turbidity (ß=1.344; Wald=4.256; p=0.039), a negative correlation was found with the altitude (ß=-3.445; Wald=5.407; p=0.020). The highest mosquito species diversity index was found in Chiapas (Fisher's α=1.20) and the lowest diversity in Chihuahua (Fisher's α=0.26). The greatest richness was found in streams (n=11). Conclusions: The two most abundant species were: An. albimanus and An. pseudopunctipennis. Detailed knowledge of the distribution and characteristics of their larval habitats will be useful for the effective implementation of control strategies in Mexico.

Resumen Objetivo: Determinar la abundancia y la distribución geográfica de los principales vectores de la malaria, las cuales están influenciadas por las características del hábitat y los factores ecológicos que afectan directamente la densidad de los adultos y la dinámica de la transmisión de la malaria en México. Material y métodos: Se obtuvieron muestras de larvas de 19 estados de México. Cada hábitat larvario se caracterizó in situ determinando los siguientes parámetros: profundidad del agua, turbidez, porcentaje de cobertura vegetal, cantidad de detritus, presencia de algas, intensidad de luz, tipo de vegetación, cantidad de depredadores, estabilidad del hábitat, altitud y tipo hidrológico. Resultados: Se identificaron un total de 21 687 larvas pertenecientes a 13 especies de anofelinos, de 149 hábitats acuáticos. Las tres especies más abundantes fueron Anopheles pseudopunctipennis (52.91%), An. albimanus (39.14%) y An. franciscanus (5.29%). El análisis de regresión logística múltiple mostró una asociación negativa para An. pseudopunctipennis y la turbidez del agua (ß=-1.342; Wald= 6.122; p=0.013) y la cantidad de detritus (ß=-2.206; Wald= 3.642; p=0.050). Para An. albimanus se encontró una asociación positiva significativa con la turbidez del agua (ß=1.344; Wald= 4.256; p=0.039) y una correlación negativa con la altitud (ß=-3.445; Wald=5.407; p=0.020). El índice de diversidad más alto se encontró en Chiapas (α de Fisher=1.20) y la diversidad más baja en Chihuahua (α de Fisher=0.26). La mayor riqueza se encontró en los arroyos (n=11). Conclusiones: Las dos especies más abundantes fueron An. albimanus y An. pseudopunctipennis. El conocimiento detallado de la distribución y características de sus hábitats larvales será útil para la implementación efectiva de las estrategias de control en México.

Malária na fronteira do Brasil com a Guiana Francesa: a influência dos determinantes sociais e ambientais da saúde na permanência da doença / Malaria in the borders between Brazil and French Guiana: social and environmental health determinants and their influence on the permanence of the disease

Resumo O objetivo deste artigo é analisar a influência dos determinantes socioambientais da saúde na incidência de malária por Plasmodium vivax na fronteira franco-brasileira. O estudo foi realizado entre 2011 e 2015, no município de Oiapoque (AP), na Amazônia brasileira. Foram incluídos na amostra 253 indivíduos de ambos os sexos, de 10 a 60 anos de idade. Houve predominância de 63,64% (161/253) de casos de malária em adultos do sexo masculino. A faixa etária mais acometida foi de 20 a 29 anos, com 30% (76/253); 84,6% (214/253) dos pacientes não concluíram o ensino médio, e 29,6% (75/253) não concluíram o ensino primário. No aspecto ambiental, houve correlação negativa entre as precipitações pluviométricas e a incidência da malária por P. vivax (p=0,0026). Em termos de mobilidade, constatou-se considerável proporção de migrantes provenientes dos estados do Pará e do Maranhão (55,73%; 141/253). Por fim, os dados apontaram que 31,23% (79/253) dos casos de malária foram importados da Guiana Francesa. Em síntese, a transmissão da malária na fronteira franco-brasileira envolve fatores ecológico-ambientais, biológicos e sociais que se expressam na elevada vulnerabilidade social da população que vive e circula na zona fronteiriça, favorecendo a ocorrência de surtos e a permanência da enfermidade.

Abstract This study analyzes the influence of socio-environmental health determinants on the maintenance of Plasmodium vivax malaria at the borders between French Guiana and Brazil. This study was carried out between 2011 and 2015 in the city of Oiapoque, Amapá, situated in the Brazilian Amazon region. The sample included 253 individuals of both sexes aged between 10 and 60 years. The disease was predominant in 63.64% (161/253) adult males. The most affected age group was 20 to 29 years old, with 30% (76/253). About 84.6% did not complete high school, while 29.6% (75/253) of the cases had not finished the first degree. Concerning the environmental aspect, negative correlation was observed between rainfall and the incidence of P. vivax malaria (p=0.0026). In terms of mobility, there was a considerable influx of migrants from the states of Pará and Maranhão, with 55.73% (141/253). Lastly, the data indicated that 31.23% (79/253) of malaria cases were imported from French Guiana. In summary, the transmission of malaria in these particular borders involved ecological, environmental, biological and social factors, which are expressed in the high social vulnerability of the population living and circulating in the border zone, favoring the occurrence of outbreaks and the maintenance of the disease.

The impact of imported malaria by gold miners in Roraima: characterizing the spatial dynamics of autochthonous and imported malaria in an urban region of Boa Vista

BACKGROUND The number of malaria cases in Roraima nearly tripled from 2016 to 2018. The capital, Boa Vista, considered a low-risk area for malaria transmission, reported an increasing number of autochthonous and imported cases. OBJECTIVES This study describes a spatial analysis on malaria cases in an urban region of Boa Vista, which sought to identify the autochthonous and imported cases and associated them with Anopheles habitats and the potential risk of local transmission. METHODS In a cross-sectional study at the Polyclinic Cosme e Silva, 520 individuals were interviewed and diagnosed with malaria by microscopic examination. Using a global positional system, the locations of malaria cases by type and origin and the breeding sites of anopheline vectors were mapped and the risk of malaria transmission was evaluated by spatial point pattern analysis. FINDINGS Malaria was detected in 57.5% of the individuals and there was a disproportionate number of imported cases (90.6%) linked to Brazilian coming from gold mining sites in Venezuela and Guyana. MAIN CONCLUSIONS The increase in imported malaria cases circulating in the west region of Boa Vista, where there are positive breeding sites for the main vectors, may represent a potential condition for increased autochthonous malaria transmission in this space.

Environmental and socioeconomic analysis of malaria transmission in the Brazilian Amazon, 2010-2015

ABSTRACT OBJECTIVE To analyze the environmental and socioeconomic risk factors of malaria transmission at municipality level, from 2010 to 2015, in the Brazilian Amazon. METHODS The municipalities were stratified into high, moderate, and low transmission based on the annual parasite incidence. A multinomial logistic regression that compared low with medium transmission and low with high transmission was performed. For each category, three models were analyzed: one only with socioeconomic risk factors (Gini index, illiteracy, number of mines and indigenous areas); a second with the environmental factors (forest coverage and length of the wet season); and a third with all covariates (full model). RESULTS The full model showed the best performance. The most important risks factors for high transmission were Gini index, length of the wet season and illiteracy, OR 2.06 (95%CI 1.19-3.56), 1.73 (95%CI 1.19-2.51) and 1.10 (95%CI 1.03-1.17), respectively. The medium transmission showed a weaker influence of the risk factors, being illiteracy, forest coverage and indigenous areas statistically significant but with marginal influence. CONCLUSIONS As a disease of poverty, the reduction in wealth inequalities and, therefore, health inequalities, could reduce the transmission considerably. Besides, environmental risk factors as length of the wet season should be considered in the planning, prevention and control. Municipality-level and fine-scale analysis should be done together to improve the knowledge of the local dynamics of transmission.

Malaria and fish farming in the Brazilian Amazon Region: a strengths, weaknesses, opportunities, and threats analysis

Abstract INTRODUCTION: The fish farming program in Acre is as an alternative program to generate income and employment and has promising regional, national, and international markets. While the economic importance of fish farming in the Jurua Region is clear, one must address its contribution to increase malaria transmission. METHODS This was a qualitative study. The answers of the 16 key informants were organized into the following: (1) the healthcare services structure; (2) conscience, perception, and behaviors; and (3) socioeconomic and political issues. Each answer was classified as weaknesses, strengths, opportunities, and threats. RESULTS Regarding healthcare services, the frequency of household visits was reduced, and subjects presenting with malaria symptoms were required to visit a healthcare unit to be diagnosed and treated. Regarding individual's conscience, perception, and behavior, malaria was considered an insignificant disease, and a large proportion of the population were engaged in health practices that put them at risk in contacting with malaria vectors. Regarding political and economic issues, there were economic and infrastructure barriers for the development of a productive activity, and the insufficient credit or formalization of their properties prevented their access to governmental incentives and the financial market. CONCLUSIONS Support to fish farmers for low-cost inputs was not observed, and appropriate knowledge regarding the impact of the absence of maintenance and abandonment of fish tanks was insufficient. Moreover, insufficient healthcare services prevented not only the treatment of individuals with malaria but also the control of this disease.

Chicken eggs as a surveillance tool for malaria and leishmaniasis vector presence

Abstract INTRODUCTION: Malaria and leishmaniases are transmitted by vectors during blood-feeding. Vector-infected animals develop antibodies against the vector's saliva. This study evaluated IgY antibody detection in the chicken eggs exposed to bites from Migonemyia migonei, Lutzomyia longipalpis and Anopheles aquasalis. METHODS: We used ELISA to quantify the antibody levels in the sera and exposed chicken eggs. RESULTS: High IgY levels were observed following immunization; furthermore, higher reactivity was observed in the eggs and species-specific immune response was observed post final immunization. CONCLUSIONS: Chicken eggs can be used as sentinels to surveil vector saliva antibodies.

Current vector control challenges in the fight against malaria in Brazil

Abstract In Brazil, malaria is an important public health problem first reported in 1560. Historically, fluctuations in malaria cases in Brazil are attributed to waves of economic development; construction of railroads, highways, and hydroelectric dams; and population displacement and land occupation policies. Vector control measures have been widely used with an important role in reducing malaria cases. In this review article, we reviewed the vector control measures established in the Brazilian territory and aspects associated with such measures for malaria. Although some vector control measures are routinely used in Brazil, many entomological and effectiveness information still need better evidence in endemic areas where Plasmodium vivax predominates. Herein, we outlined some of the needs and priorities for future research: a) update of the cartography of malaria vectors in Brazil, adding molecular techniques for the correct identification of species and complexes of species; b) evaluation of vector competence of anophelines in Brazil; c) strengthening of local entomology teams to perform vector control measures and interpret results; d) evaluation of vector control measures, especially use of insecticide-treated nets and long-lasting insecticidal nets, estimating their effectiveness, cost-benefit, and population acceptance; e) establishment of colonies of malaria vectors in Brazil, i.e., Anopheles darlingi, to understand parasite-vector interactions better; f) study of new vector control strategies with impacts on non-endophilic vectors; g) estimation of the impact of insecticide resistance in different geographical areas; and h) identification of the relative contribution of natural and artificial breeding sites in different epidemiological contexts for transmission.

Do climate changes alter the distribution and transmission of malaria? Evidence assessment and recommendations for future studies

Abstract Malaria, a mosquito-borne infectious disease, is considered a significant global health burden. Climate changes or different weather conditions may impact infectious diseases, specifically those transmitted by insect vectors and contaminated water. Based on the current predictions for climate change associated with the increase in carbon dioxide concentrations in the atmosphere and the increase in atmospheric temperature, the Intergovernmental Panel on Climate Change predicts that in 2050, malaria may threaten some previously unexposed areas worldwide and cause a 50% higher probability of malaria cases. Climate-based distribution models of malaria depict an increase in the geographic distribution of the disease as global environmental temperatures and conditions worsen. Researchers have studied the influence of changes in climate on the prevalence of malaria using different mathematical models that consider different variables and predict the conditions for malaria distribution. In this context, we conducted a mini-review to elucidate the important aspects described in the literature on the influence of climate change in the distribution and transmission of malaria. It is important to develop possible risk management strategies and enhance the surveillance system enhanced even in currently malaria-free areas predicted to experience malaria in the future.

Estudo da permeabilidade vascular pulmonar e das junções interendoteliais na malária experimental / Study of pulmonary vascular permeability and interendothelial junctions in experimental malaria

Infecções por Plasmodium spp. podem acarretar em complicações pulmonares (1 a 40% dos casos), que podem resultar no desenvolvimento da síndrome do desconforto respiratório agudo (SDRA). Esta síndrome é caracterizada por inflamação aguda, lesão do endotélio alveolar e do parênquima pulmonar, disfunção e aumento da permeabilidade da barreira alvéolo-capilar pulmonar e, consequente, formação de efusão pleural. Neste sentido, os mecanismos de regulação da permeabilidade das células endoteliais e as junções interendoteliais têm papel crítico na manutenção do endotélio pulmonar. O objetivo do estudo foi determinar precocemente o desenvolvimento da SDRA associada à malária por tomografia computadorizada por emissão de fóton único (SPECT/CT), além de identificar alterações nas junções interendoteliais das células endoteliais pulmonares primárias de camundongos DBA/2 (CEPP-DBA/2), após contato com os eritrócitos parasitados de Plasmodium berghei ANKA (EP-PbA). Os nossos resultados demonstraram que é possível identificar alterações na aeração pulmonar no 5° e 7° dia após a infecção e, consequentemente, diferenciar os animais que desenvolveriam SDRA daqueles que evoluiriam para hiperparasitemia (HP). Além disso, observamos em CEPP-DBA/2 que o contato direto com EP-PbA aumenta da abertura das junções interendoteliais e da permeabilidade vascular. Assim, avaliamos a diminuição da expressão das proteínas das junções interendoteliais que contribuem para o aumento da permeabilidade vascular, por imunofluorescência e Western Blot. Apesar da SDRA ter sido identificada há mais de 50 anos, ainda não se conhece formas de diagnóstico precoce e os mecanimos efetivos de desenvolvimento desta enfermidade, que permitam um tratamento efetivo e que evite a morte do paciente. Portanto, sugere-se que a técnica de SPECT/CT seja uma importante ferramenta de diagnóstico para identificação precoce de SDRA associado a malária

Infections by Plasmodium spp. can lead to pulmonary complications (1 to 40% of the cases), that can result in the development of acute respiratory distress syndrome (ARDS). This syndrome is characterized by the acute inflammation, injury of the alveolar endothelium and pulmonary parenchyma, dysfunction and increased permeability of the pulmonary alveolar-capillary barrier and, consequently, formation of pleural effusion. In this aspect, mechanisms of regulation of endothelial cell permeability and interendothelial junctions play a critical role in the maintenance of the pulmonary endothelium. The present study aimed to determine the early development of single-photon emission computed tomography (SPECT/CT) associated malaria ARDS in addition to identifying changes in the interendothelial junctions of the primary pulmonary endothelial cells of DBA/2 mice (CEPP-DBA/2) after contact with erythrocytes infected with Plasmodium berghei ANKA (EP-PbA). Our results demonstrated that is possible to identify changes in lung aeration on the 5th and 7th day after infection and, consequently, differentiate the animals that should develop ARDS from those that would evolve to hyperparasitemia (HP). In addition, we observed in CEPP-DBA/2 that direct contact with EP-PbA increases the opening of the interendothelial junctions and vascular permeability. Thus, we evaluated that decrease the expression of interendothelial junction proteins contribute to the increase of vascular permeability, by immunofluorescence and Western Blot. Although ARDS was identified more than 50 years ago, it is not yet known what forms of early diagnosis, and the effective mechanisms of development of this disease, that allow an effective treatment and that prevent the death of the patient. Therefore, it is suggested that the SPECT/CT technique is a valuable tool to promote the early identification of ARDS associated with malaria

Analytical validation of real-time quantitative PCR assays for optimum diagnosis of vivax malaria

BACKGROUND The prompt diagnosis of plasmodial species for effective treatment prevents worsening of individual health and avoids transmission maintenance or even malaria reintroduction in areas where Plasmodium does not exist. Polymerase chain reaction (PCR) allows for the detection of parasites below the threshold of microscopic examination. OBJECTIVE Our aim was to develop a real-time PCR test to reduce diagnostic errors and increase efficacy. METHODS The lower limit of quantification and the linearity/analytical sensitivity to measure sensitivity or limit of detection (LoD) were determined. Intra-assay variations (repeatability) and alterations between assays, operators, and instruments (reproducibility) were also assessed to set precision. FINDINGS The linearity in SYBR™ Green and TaqMan™ systems was 106 and 102 copies and analytical sensitivity 1.13 and 1.17 copies/μL, respectively. Real-time PCR was more sensitive than conventional PCR, showing a LoD of 0.01 parasite (p)/μL. Reproducibility and repeatability (precision) were 100% for up to 0.1 p/μL in SYBR™ Green and 1 p/μL in TaqMan™ and conventional PCR. CONCLUSION Real-time PCR may replace conventional PCR in reference laboratories for P. vivax detection due to its rapidity. The TaqMan™ system is the most indicated when quantification assays are required. Performing tests in triplicate when diagnosing Plasmodium-infected-asymptomatic individuals is recommended to minimise diagnostic errors.

Novel molecular evidence of population structure in Anopheles (Kerteszia) bellator from Brazilian Atlantic Forest

Anopheles bellator is a primary malaria vector in the Atlantic Forest. Partial sequences of timeless and Clock genes were used to assess the genetic differentiation of five Brazilian populations, which showed strong population structure (e.g. high F ST values and fixed differences) in all pairwise comparisons between Bahia sample and the others from Paraná, São Paulo and Rio de Janeiro states. Also, the resulting phylogenetic trees clearly grouped the sequences from Bahia in a different cluster with high bootstrap values. Among southern and southeastern populations low levels of genetic differentiation were found suggesting a general stability of the genetic structure.

Prevalence of malaria relapse: systematic review with meta-analysis / Prevalência de recaída por malária: revisão sistemática com metanálise / Prevalencia de recaída por malaria: revisión sistemática con metaanálisis

ABSTRACT Objective: systematic review with a meta-analysis of the prevalence of malaria relapse. Method: it consisted in a search for cross-sectional studies, carried out in three databases, without application of filters. A total of 1,924 articles were identified, selected based on eligibility criteria. The selection was made in pairs from the reading of the titles, abstracts and text. The meta-analysis was performed with a statistical program. Results: a sample of 1,308 patients with malaria, ranging from 70 to 586 patients in the study. Relapse was estimated at 0.47%, with a 95% confidence interval and 99.04% of squared i. In the included studies, the prevalence of relapse ranged from 17.00% to 92.85%. The result of the meta-analysis is considered relevant, despite the heterogeneity. Conclusion: relapse is a phenomenon that can contribute to the maintenance of the endemicity of malaria in the world and to introduce it in non-affected areas. In addition, there is the need for advancement in the production of knowledge regarding this disease, to qualify the research methods on prevalence.

RESUMO Objetivo: realizar uma revisão sistemática com metanálise da prevalência de recaída por malária. Método: consistiu na busca por estudos transversais, realizada em três bases de dados, sem aplicação de filtros. Foram identificados 1.924 artigos, selecionados a partir de critérios de elegibilidade. A seleção foi realizada em par na sequência de leitura dos títulos, resumos e texto. A metanálise foi realizada com programa estatístico. Resultados: uma amostra de 1.308 pacientes com malária, variando de 70 a 586 pacientes nos estudo. A recaída foi estimada em 0,47%, com intervalo de confiança de 95% e i quadrado de 99,04%. Nos estudos incluídos, a prevalência de recaída variou de 17,00% a 92,85%. Considera-se o resultado da metanálise relevante, apesar da heterogeneidade. Conclusão: a recaída é um fenômeno que pode contribuir para a manutenção da endemicidade da malária no mundo, além de poder introduzi-la em áreas não afetadas. Além disso, há necessidade, para avanço na produção de conhecimento referente a essa doença, de qualificar os métodos de pesquisa sobre prevalência.

RESUMEN Objetivo: realizar una revisión sistemática con metaanálisis de la prevalencia de recaída por malaria. Método: consistió en la búsqueda por estudios transversales, realizada en tres bases de datos, sin aplicación de filtros. Fueron identificados 1.924 artículos, seleccionados a partir de criterios de elegibilidad. La selección fue realizada en pares en la secuencia de lectura de los títulos, resúmenes y texto. El metaanálisis fue realizado con un programa estadístico. Resultados: una muestra de 1.308 pacientes con malaria, variando de 70 a 586 pacientes en el estudio. La recaída fue estimada en 0,47%, con intervalo de confianza de 95% e i cuadrado de 99,04%. En los estudios incluidos, la prevalencia de recaída varió de 17,00% a 92,85%. Se considera el resultado de la metaanálisis relevante, a pesar de la heterogeneidad. Conclusión: la recaída es un fenómeno que puede contribuir para el mantenimiento de la endemicidad de la malaria en el mundo, además de poder introducirla en áreas no afectadas. Además de eso, es necesario de calificar los métodos de investigación sobre prevalencia para el avance en la producción de conocimiento referente a esa enfermedad.

Vigilancia molecular de la malaria en potenciales reservorios silvestres que viven en una región históricamente endémica de Paraguay / Molecular surveillance of malaria in potential wild reservoirs that live in a historically endemic region of Paraguay

En Paraguay, no se han registrado casos autóctonos de malaria desde el 2011. Se realizó un estudio descriptivo observacional transversal en 6 monos y 23 aves que vivían en una región históricamente endémica de Paraguay para buscar presencia de reservorios silvestres de parásitos plasmodios causantes de la malaria. El ADN se extrajo por el método de Chelex a partir de una gota de sangre en un papel de filtro, y la detección del parásito se realizó mediante la PCR múltiple semianidada. Por este método, no se detectaron parásitos en ninguna de las 29 muestras. Se evaluó el riesgo potencial de circulación selvática de los parásitos que causan la malaria. Teniendo en cuenta la presencia de mosquitos anofelinos vectores en la zona, el hecho de que no se hayan observado casos positivos es un buen indicador teniendo en cuenta que nuestro país fue declarado recientemente como país libre de malaria por la OMS(AU)

In Paraguay, autochthonous cases of malaria have not been recorded since 2011. A cross-sectional observational descriptive study was conducted in 6 monkeys and 23 birds living in a historically endemic region of Paraguay to identify wild reservoirs of plasmodium parasites that cause malaria. DNA was extracted by the Chelex method from a blood drop in a filter paper, and parasite detection was performed by the seminested multiplex PCR. By this method, parasites were not detected in any of the 29 samples. The risk of potential sylvatic circulation of the parasites causing malaria was evaluated. Considering the presence of anopheline mosquitoes in the area, the fact that we did not find any positive cases is a good indicator as our country was recently certified as a malaria-free country by the WHO(AU)

Vigilancia de paludismo en Argentina: 2005-2018 / Malaria surveillance in Argentina: 2005-2018

El paludismo o malaria es una enfermedad potencialmente mortal causada por la infección de una o más de cinco especies de parásitos protozoarios intracelulares: Plasmodium vivax, Plasmodium falciparum, Plasmodium ovale, Plasmodium malariae, y Plasmodium knowlesi, que se transmiten al ser humano por la picadura de mosquitos hembra infectados del género Anopheles. Se describen antecedentes, situación actual, casos notificados en Argentina, estratificación de riesgo de reintroducción de paludismo en el país, definición de casos sospechosos y confirmados, y acciones epidemiológicas realizadas

Impacto de diferentes esquemas terapéuticos sobre la malaria en la costa y amazonia peruana, en el marco de una política de medicamentos antimaláricos, 1994-2017 / Impact on the transmission of malaria with different treatment schemes in the peruvian coast and amazon region within the framework of a policy on antimalarial medications, 1994-2017

RESUMEN Al final de los 90 en el Perú, después de determinar la resistencia a antimaláricos, se decidió el cambio de los esquemas terapéuticos antimaláricos, que incluía la terapia combinada para P. falciparum, mefloquina/artesunato en la amazonia y sulfadoxina pirimetamina/artesunato en la costa norte. Luego de dos décadas, con el objetivo de evaluar el impacto en la endemia de malaria de estos esquemas, se revisaron los reportes de malaria en tres departamentos que juntos agrupan más del 70% de los casos reportados en el país. Fue evidente el mayor impacto del esquema sulfadoxinapirimetamina/artesunato en costa norte reduciendo a casi cero los casos de P. falciparum luego de cuatro años de implementar terapia combinada. La monodosis y la capacidad de limitar el desarrollo de esporozoitos fueron importantes para conseguir este objetivo. El esquema mefloquina/artesunato tuvo impacto limitado por la imposibilidad de asegurar tratamiento supervisado en los servicios de salud y la necesidad de tres dosis. Seleccionar un esquema eficaz y de fácil administración es importante al elegir la primera línea de tratamiento para malaria. Esta experiencia es significativa para los objetivos de eliminación de la malaria en el Perú.

ABSTRACT At the end of the 90s in Peru, after determining the resistance to antimalarial drugs, a change in antimalarial treatment schemes was decided; this change included the combined therapy for P. falciparum, mefloquine/artesunate in the Amazon region, and sulfadoxine pyrimethamine/artesunate in the North coast. After two decades, and aimed at assessing the impact of these schemes on the malaria endemic, a review was conducted of malaria reports in three departments accounting for more than 70% of cases reported in the country. The major impact of the sulfadoxine-pyrimethamine/ artesunate scheme in the North coast was evident since it reduced the number of cases of P. falciparum to virtually zero four years after implementation of the combined therapy. The single dose and the ability to limit the development of sporozoites were crucial in order to achieve this goal. The mefloquine/artesunate scheme had a limited impact because it was not possible to ensure supervised treatment in the health service facilities and the need for three doses. It is important to select an effective and easy-to-administer scheme when choosing the first line of treatment for malaria. This experience is significant for the malaria eradication goals in Peru.

Anophelines species and the receptivity and vulnerability to malaria transmission in the Pantanal wetlands, Central Brazil

BACKGROUND Studies on malaria vectors in the Pantanal biome, Central Brazil, were conducted more than half a century ago. OBJECTIVES To update anopheline records and assess receptivity and vulnerability to malaria transmission. METHODS Five-day anopheline collections were conducted bimonthly in Salobra, Mato Grosso do Sul state, for one year. Indoors, mosquitoes were collected from their resting places, while in open fields, they were captured using protected human-baited and horse-baited traps near the house and at the Miranda River margin, respectively. Hourly biting activity outdoors was also assessed. Secondary data were collected on the arrival of tourists, economic projects, and malaria cases. FINDINGS A total of 24,894 anophelines belonging to 13 species were caught. The main Brazilian malaria vector Anopheles darlingi was the predominant species, followed by An. triannulatus s.l. Hourly variation in anopheline biting showed three main peaks occurring at sunset, around midnight, and at sunrise, the first and last being the most prominent. The highest density of all species was recorded near the river margin and during the transition period between the rainy and early dry seasons. This coincides with the time of main influx of outsider workers and tourists, whose activities mostly occur in the open fields and frequently start before sunrise and last until sunset. Some of these individuals originate from neighbouring malaria-endemic countries and states, and are likely responsible for the recorded imported and introduced malaria cases. MAIN CONCLUSION Pantanal is a malaria-prone area in Brazil. Surveillance and anopheline control measures must be applied to avoid malaria re-emergence in the region.

Ecological characterisation and infection of Anophelines (Diptera: Culicidae) of the Atlantic Forest in the southeast of Brazil over a 10 year period: has the behaviour of the autochthonous malaria vector changed?

BACKGROUND In southeastern Brazil, autochthonous cases of malaria can be found near Atlantic Forest fragments. Because the transmission cycle has not been completely clarified, the behaviour of the possible vectors in those regions must be observed. A study concerning the entomological aspects and natural infection of anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state was performed in 2004 and 2005. Similarly, between 2014 and 2015, 12 monthly collections were performed at the same area of the study mentioned above. METHODS Center for Disease Control (CDC) light traps with CO2 were set in open areas, at the edge and inside of the forest (canopy and ground), whereas Shannon traps were set on the edge. FINDINGS A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most frequently captured species in the CDC traps set in the forest canopy, as well as being the vector with the highest prevalence of Plasmodium vivax/simium infection, according to molecular polymerase chain reaction techniques. CONCLUSIONS P. vivax/simium was found only in abdomens of the mosquitoes of the subgenus Nyssorhynchus, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.