ABSTRACT
Deforestation and high human mobility due to mining activities have been key to the increase in malaria cases in the Americas. Here, we review the epidemiological and control aspects of malaria in the Amazon mining areas. Epidemiological evidence shows: 1) a positive correlation between illegal mining activity and malaria incidence, mostly in the Amazon region; 2) most Brazilian miners are males aged 15-29 years who move between states and even countries; 3) miners do not fear the disease and rely on medical care, diagnosis, and medication when they become ill; 4) illegal mining has emerged as the most reported anthropogenic activity within indigenous lands and is identified as a major cause of malaria outbreaks among indigenous people in the Amazon; and 5) because mining is largely illegal, most areas are not covered by any healthcare facilities or activities, leading to little assistance in the diagnosis and treatment of malaria. Our review identified five strategies for reducing the malaria incidence in areas with mining activities: 1) reviewing legislation to control deforestation and mining expansion, particularly in indigenous lands; 2) strengthening malaria surveillance by expanding the network of community health agents to support rapid diagnosis and treatment; 3) reinforcing vector control strategies, such as the use of insecticide-treated nets; 4) integrating deforestation alerts into the national malaria control program; and 5) implementing multi-sectoral activities and providing prompt assistance to indigenous populations. With this roadmap, we can expect a decrease in malaria incidence in the Amazonian mining areas in the future.
Subject(s)
Malaria , Mining , Humans , Brazil/epidemiology , Malaria/epidemiology , Malaria/transmission , Malaria/prevention & control , Incidence , Male , Conservation of Natural Resources , AnimalsABSTRACT
ABSTRACT Deforestation and high human mobility due to mining activities have been key to the increase in malaria cases in the Americas. Here, we review the epidemiological and control aspects of malaria in the Amazon mining areas. Epidemiological evidence shows: 1) a positive correlation between illegal mining activity and malaria incidence, mostly in the Amazon region; 2) most Brazilian miners are males aged 15-29 years who move between states and even countries; 3) miners do not fear the disease and rely on medical care, diagnosis, and medication when they become ill; 4) illegal mining has emerged as the most reported anthropogenic activity within indigenous lands and is identified as a major cause of malaria outbreaks among indigenous people in the Amazon; and 5) because mining is largely illegal, most areas are not covered by any healthcare facilities or activities, leading to little assistance in the diagnosis and treatment of malaria. Our review identified five strategies for reducing the malaria incidence in areas with mining activities: 1) reviewing legislation to control deforestation and mining expansion, particularly in indigenous lands; 2) strengthening malaria surveillance by expanding the network of community health agents to support rapid diagnosis and treatment; 3) reinforcing vector control strategies, such as the use of insecticide-treated nets; 4) integrating deforestation alerts into the national malaria control program; and 5) implementing multi-sectoral activities and providing prompt assistance to indigenous populations. With this roadmap, we can expect a decrease in malaria incidence in the Amazonian mining areas in the future.
ABSTRACT
Intraspecific competition between mosquito larvae can affect several adult traits, particularly size. This study tested the hypothesis that intraspecific competition during the larval stage affects wing length in Ae. aegypti and Ae. albopictus adults, in turn influencing locomotor activity. L1 larvae of both species were reared in trays under conditions of low and high competition. After adults had emerged, the locomotor activity of virgin females of Ae. aegypti and Ae. albopictus was evaluated under light-dark cycles of 12:12 h at 25 °C and 70% relative humidity. At the end of the locomotor activity experiment, the left wings of the mosquitoes were removed to be measured, and wing length was used as an indicator of adult female size. Although the results showed that the wing lengths of Ae. aegypti and Ae. albopictus females reared under low larval competition were significantly greater than those of females reared under high larval competition, this difference did not affect locomotor activity in females of either species, demonstrating that locomotor activity in small Ae. aegypti and Ae. albopictus females is not lower than in larger females. Our findings reinforce the idea that intraspecific competition alters the wing length of Ae. aegypti and Ae. albopictus females and provide new evidence about this effect on the locomotor activity of these species.
Subject(s)
Aedes , Animals , Body Size , Female , Larva , LocomotionABSTRACT
Doenças como a dengue, chikungunya, Zika e febre amarela urbana são causadas por patógenos transmitidos pela picada de fêmeas infectadas de Ae. aegypti e Ae. albopictus. Fatores bióticos, como a competição na fase larval, e abióticos, como a variação da temperatura, provocam alterações no ciclo de desenvolvimento dessas espécies. O presente estudo avaliou os efeitos da competição intraespecífica e da temperatura na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus. Os objetivos do trabalho foram: comparar o tamanho das fêmeas de Ae. aegypti e Ae. albopictus oriundas de criadouros com baixa e alta competição intraespecífica; avaliar o efeito da competição intraespecífica na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, à 25ºC e analisar o padrão da atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, sob diferentes temperaturas (20ºC, 25ºC e 30ºC). As colônias dos mosquitos utilizados nos experimentos são provenientes da FIOCRUZ-RJ. Para o experimento de competição, larvas de ambas as espécies foram criadas sob condições de alta (100 larvas) e baixa (20 larvas) densidades. Para isso, foram utilizadas 14 bacias preenchidas com 500 ml de água e 0,2 g de ração para peixes. Após a competição, as fêmeas oriundas de cada densidade foram transferidas para incubadoras para a realização da análise da atividade locomotora. Após a atividade, verificou-se o tamanho dos adultos oriundos de cada densidade larvária, por meio da medição das asas de cada fêmea. Para a análise da atividade locomotora sob diferentes temperaturas, as fêmeas utilizadas foram desenvolvidas em ambiente com quantidade de ovos similares. Foi utilizado o mesmo procedimento para análise da atividade do experimento anterior, porém, cada experimento ocorreu sob diferentes temperaturas: 20°C, 25°C e 30°C. Para a análise dos dados obtidos foram utilizados os testes T e ANOVA multifatorial. Para o experimento de competição, fêmeas de ambas as espécies oriundas de competição de baixa densidade foram maiores do que as oriundas de desenvolvimento sob alta densidade larvária. A atividade das fêmeas de Ae. aegypti e Ae. albopictus de ambas as densidades foi muito semelhante, sugerindo que fêmeas menores tem atividade equivalente à de fêmeas maiores. Já no experimento que avaliou a atividade das fêmeas sob faixas térmicas distintas, notou-se que, em Ae. aegypti, houve diferença significativa na atividade total sob 20°C quando comparadas a 25°C e 30°C, demonstrando que a temperatura mais baixa foi limitante para a atividade desta espécie. Houve diferenças em algumas médias avaliadas na atividade de Ae. albopictus, porém, esta espécie pareceu ter sido menos influenciada com a variação da temperatura. Análises estatísticas confirmaram que as fêmeas de Ae. aegypti respondem de forma distinta das fêmeas de Ae. albopictus quando as temperaturas foram modificadas. O presente estudo ajuda a esclarecer alguns aspectos relacionados ao comportamento dos mosquitos Ae. aegypti e Ae. albopictus, que são considerados de grande importância para a saúde pública
Diseases such as dengue, chikungunya, Zika and urban yellow fever are caused by pathogens transmitted by the bites of infected females of Ae. aegypti and Ae. albopictus. Biotics factors essentially competition on larval stages, and abiotics factors, for instance, temperature variation, occasion adjustments on development cycle of these species. The present study evaluated the effects of intraspecific competition and temperature on locomotor activity of Ae. aegypti and Ae. albopictus. The aims of this study were: to compare the size of females Ae. aegypti and Ae. albopictus from breeding sites with low and high intraspecific competition; to evaluate the effect of intraspecific competition on locomotor activity of virgin females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark at 25°C and to analyze the pattern of the locomotor activity of virgins females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark, under different temperatures (20ºC, 25ºC e 30ºC). The mosquitoes colonies used on experiment are from FIOCRUZ-RJ. For the competition experiment, larvae from both species were raised under conditions of high (100 larvae) and low (20 larvae) densities. For this 14 containers filled with 500 ml of water and 0,2 g of fish food were used. After the competition, the females from each density were transferred to incubators to perform locomotor activity analysis. After the activity, the size of adult from each larval density, were verified by wings measurement of each female. For the analysis of the locomotor activity under different temperatures, the females used were developed in an environment with similar amount of eggs. The same procedure was used to the analyze the activity of the previous experiment, however, each experiment happened under different temperatures: 20°C, 25°C e 30°C. For the analysis of the obtained data were applied T tests and ANOVA multivariate. For the competition experiment, females of both species from low density of competition were longer than females from competition under high larval density. The activity of females of Ae. aegypti and Ae. albopictus from both densities was very similar, suggesting that smaller females have equivalent activity to that of larger females. In the experiment that evaluated the activity of females under different thermal bands, it was noticed that in Ae. aegypti there was significant difference in total activity under 20°C when compared with 25°C and 30°C degrees, demonstrating the lower temperature was limiting to activity for this species. There were differences in some averages evaluated in Ae. albopictus activity, however, this species seemed to have been less influenced with the temperature variation. Statistical analysis confirmed that females of Ae. aegypti respond differently than females of Ae. albopictus when the temperatures were modified. The present study helps to clarify some aspects about the behavior of mosquitoes Ae. aegypti and Ae. albopictus which are considered of great concern for public health