RESUMO
Mosquito-transmitted diseases impose a growing burden on human health, and current control strategies have proven insufficient to stem the tide. The bacterium Wolbachia is a novel and promising form of control for mosquito-transmitted disease. It manipulates host biology, restricts infection with dengue and other pathogens, and alters host reproduction to promote rapid spread in the field. In this review, we examine how the intimate and diverse relationships formed between Wolbachia and their mosquito hosts can be exploited for disease control purposes. We consider these relationships in the context of recent developments, including successful field trials with Wolbachia-infected mosquitoes to combat dengue, and new Wolbachia infections in key malaria vectors, which have enhanced the disease control prospects of this unique bacterium.
Assuntos
Culicidae/microbiologia , Insetos Vetores/microbiologia , Malária/prevenção & controle , Controle de Mosquitos/tendências , Wolbachia/fisiologia , AnimaisRESUMO
Here we present the first in a series of articles about the ecology of immature stages of anophelines in the Brazilian Yanomami area. We propose a new larval habitat classification and a new larval sampling methodology. We also report some preliminary results illustrating the applicability of the methodology based on data collected in the Brazilian Amazon rainforest in a longitudinal study of two remote Yanomami communities, Parafuri and Toototobi. In these areas, we mapped and classified 112 natural breeding habitats located in low-order river systems based on their association with river flood pulses, seasonality and exposure to sun. Our classification rendered seven types of larval habitats: lakes associated with the river, which are subdivided into oxbow lakes and nonoxbow lakes, flooded areas associated with the river, flooded areas not associated with the river, rainfall pools, small forest streams, medium forest streams and rivers. The methodology for larval sampling was based on the accurate quantification of the effective breeding area, taking into account the area of the perimeter and subtypes of microenvironments present per larval habitat type using a laser range finder and a small portable inflatable boat. The new classification and new sampling methodology proposed herein may be useful in vector control programs.
Assuntos
Anopheles/fisiologia , Vetores de Doenças , Entomologia/métodos , Indígenas Sul-Americanos , Controle de Mosquitos/tendências , Floresta Úmida , Animais , Brasil , Ecossistema , Humanos , Lagos , Larva , Estudos Longitudinais , Reprodução , Rios , Estações do Ano , Luz SolarRESUMO
Here we present the first in a series of articles about the ecology of immature stages of anophelines in the Brazilian Yanomami area. We propose a new larval habitat classification and a new larval sampling methodology. We also report some preliminary results illustrating the applicability of the methodology based on data collected in the Brazilian Amazon rainforest in a longitudinal study of two remote Yanomami communities, Parafuri and Toototobi. In these areas, we mapped and classified 112 natural breeding habitats located in low-order river systems based on their association with river flood pulses, seasonality and exposure to sun. Our classification rendered seven types of larval habitats: lakes associated with the river, which are subdivided into oxbow lakes and nonoxbow lakes, flooded areas associated with the river, flooded areas not associated with the river, rainfall pools, small forest streams, medium forest streams and rivers. The methodology for larval sampling was based on the accurate quantification of the effective breeding area, taking into account the area of the perimeter and subtypes of microenvironments present per larval habitat type using a laser range finder and a small portable inflatable boat. The new classification and new sampling methodology proposed herein may be useful in vector control programs.
Assuntos
Animais , Humanos , Anopheles/fisiologia , Vetores de Doenças , Entomologia/métodos , Indígenas Sul-Americanos , Controle de Mosquitos/tendências , Floresta Úmida , Brasil , Ecossistema , Lagos , Larva , Estudos Longitudinais , Reprodução , Rios , Estações do Ano , Luz SolarRESUMO
Encouraged by the early success of using dichloro-diphenyl-trichloroethane (DDT) against malaria, the World Health Organization (WHO) embarked on the Global Malaria Eradication Program (GMEP) in 1955. Fourteen years later, the campaign was discontinued when it was recognised that eradication was not achievable with the available means in many areas, although the long-term goal remained unchanged. During the GMEP, malaria was permanently eliminated from many regions. In other areas, however, substantial gains were lost in resurgences, sometimes of epidemic proportions. During the 1970s and 1980s, because of economic and financial crises, international support for malaria control declined rapidly, but in the past decade, following increasing demands from endemic countries and promising results from scaling up of control activities, interest in malaria elimination and the long-term goal of eradication has received international political and financial support. In 2007, there was a renewed call for malaria eradication and a consultative process to define a research and development agenda for malaria eradication (malERA) was established. Lessons learned from the GMEP (1955-1969) highlight the fact that no single strategy can be applicable everywhere and that a long-term commitment with a flexible strategy that includes community involvement, integration with health systems, and the development of agile surveillance systems is needed.
Assuntos
Malária/prevenção & controle , Organização Mundial da Saúde , África/epidemiologia , Animais , Anopheles/parasitologia , Ásia/epidemiologia , Participação da Comunidade , DDT , Atenção à Saúde/organização & administração , Doenças Endêmicas , Previsões , Saúde Global , Política de Saúde , Humanos , Insetos Vetores/parasitologia , Inseticidas , Comunicação Interdisciplinar , Malária/epidemiologia , Malária/transmissão , Controle de Mosquitos/organização & administração , Controle de Mosquitos/tendências , Plasmodium/fisiologia , Política , Vigilância da População , Avaliação de Programas e Projetos de Saúde , Pesquisa/tendências , América do Sul/epidemiologia , Organização Mundial da Saúde/organização & administraçãoRESUMO
The aim of this study was to determine the coverage of municipal activities in terms of the control of Aedes aegypti and/or Aedes albopictus by routine house-to-house visits and by emergency activity, carried out between 1989 and 1995 in the area of São José do Rio Prêto, São Paulo State, and to evaluate the cross-correlation between them and the Breteau index (BI). For towns with up to 50,000 real estate properties, the joint coverage by routine and emergency activities was mostly appropriate and the routine activities showed a negative cross-correlation with the BI. For the county seat (more than 50,000 real estate properties), the coverage provided by the above activities was not correlated with the BI. In general, the coverage was inversely proportional to town size. Emergency activities did not show a correlation with the BI in any town size range, proving to be ineffective.
Assuntos
Aedes , Dengue/prevenção & controle , Insetos Vetores , Controle de Mosquitos , População Urbana , Animais , Brasil , Dengue/transmissão , Surtos de Doenças/prevenção & controle , Estudos de Avaliação como Assunto , Humanos , Controle de Mosquitos/estatística & dados numéricos , Controle de Mosquitos/tendênciasRESUMO
Throughout Central America, a traditional malaria control strategy (depending on heavy use of organic pesticides) became less effective during the 1970s. In Nicaragua, an alternative strategy, based on frequent local epidemiological assessments and community participation, was developed in the 1980s. Despite war-related social instability, and continuing vector resistance, this approach was highly successful. By the end of the contra war, there finally existed organisational and ecological conditions that favoured improved malaria control. Yet the expected improvements did not occur. In the 1990s, Nicaragua experienced its worst recorded malaria epidemics. This situation was partly caused by the country's macroeconomic structural adjustment programme. Volunteers now take fewer slides and provide less treatment, malaria control workers are less motivated by the spirit of public service, and some malaria control stations charge for diagnosis or treatment. To "roll back malaria", in Nicaragua at least, will require the roll-back of some erroneous aspects of structural adjustment.
PIP: This paper examines the social and political influences on malaria transmission and control activities in Nicaragua. In politically unstable Central America, methods that depend on community participation and planning on the basis of routine surveillance data may be sufficient to control malaria transmission. The Nicaraguan experience in the 1980s and 1990s shows how an integrated approach can prove to be effective where social stability, health education, and strong program administration exists. During the Contra war in the 1980s, implementation of the community-based strategy was limited, resulting in increasing rates of P. vivax transmission in the war zone. The loss of timely epidemiological reporting and the decrease in use of local volunteers for blood slide detection and directly observed therapy resulted in a greater epidemic. More recently, WHO has initiated "Roll Back Malaria" and "Roll Back Structural Adjustment" programs which aim to make more efficient use of limited resources in the health sector to help eradicate malaria. Several components were needed for the strategy: the technical capacity of the national staff needed strengthening, the staff needed to be re-evaluated, additional funds were needed to assure competitive salaries, and malaria control programs needed to be identified for appropriation of funds as essential components to national development planning during structural adjustment. National leadership and the establishment of public service and social solidarity will help mobilize volunteers to work toward the goal of preventing malaria transmission.
Assuntos
Países em Desenvolvimento , Malária/prevenção & controle , Política , Fatores Socioeconômicos , Humanos , Malária/mortalidade , Malária/transmissão , Malária Falciparum/mortalidade , Malária Falciparum/prevenção & controle , Malária Falciparum/transmissão , Malária Vivax/mortalidade , Malária Vivax/prevenção & controle , Malária Vivax/transmissão , Controle de Mosquitos/tendências , Nicarágua , Vigilância da PopulaçãoAssuntos
Controle de Mosquitos/tendências , Sociedades Médicas , Animais , Educação , Previsões , Humanos , Liderança , Política Organizacional , Saúde Pública , Estados UnidosRESUMO
Malaria-control policies enforced at US military bases set up in Brazil during World War II serve as an example in this analysis of the associations between disease and war. Case studies of the three main US bases (located in Belém, Recife and Natal) show how malaria can be transformed into a matter of political-military security. An examination of the Natal case allows the reader to perceive the prejudices, political mistrust, and nationalistic tensions marking relations between the Brazilians and Americans.
Assuntos
Malária , Controle de Mosquitos , II Guerra Mundial , Brasil , História do Século XX , Internacionalidade/história , Malária/história , Malária/prevenção & controle , Controle de Mosquitos/ética , Controle de Mosquitos/história , Controle de Mosquitos/métodos , Controle de Mosquitos/tendências , Medidas de Segurança/história , Medidas de Segurança/tendências , Estados UnidosRESUMO
Since the 1970s, when malaria had seemed at the threshold of eradication, its incidence has increased in several countries of the world. This situation posed a series of questions, and for some time malariologists and public health authorities scarcely understood what was happening. In order to better comprehend the process, the author of this article studied the frequency of malaria cases in São Paulo, Brazil, from 1930 to 1990, attempting to examine the following factors in each of the periods studied: the importance of malaria in the society, the conditions under which the disease occurred, the epidemiologic knowledge of the time, the available technical instruments, and the control strategies that were used. Through the construction of technological models based on these factors, it became clear that the occurrence of the disease, knowledge about it, and, consequently, the ways it was dealt with changed over time. In light of this research, the paper discusses current options for the control of malaria.
Assuntos
Malária/prevenção & controle , Controle de Mosquitos/tendências , Animais , Anopheles/parasitologia , Anopheles/fisiologia , Brasil/epidemiologia , Reservatórios de Doenças , Humanos , Incidência , Insetos Vetores/parasitologia , Malária/epidemiologia , Modelos Teóricos , Mudança Social , Fatores Socioeconômicos , Saúde da População UrbanaRESUMO
A eficacia de dois inseticidas biologicos a base de Bacillus sphaericus e Bacillus thuringiensis foi comparada a do inseticida quimico Abate, um organofosforado a base de Temefos, utilizado sistematicamente no controle de mosquitos na area urbana de Brasilia. O trabalho foi realizado pelo Nucleo de Controle de Vetores do Instituto de Saude do Distrito Federal em cooperacao com o Centro Nacional de Pesquisa de Recursos Geneticos e Biotecnologia (CENARGEN). Os tres produtos apresentaram resultados satisfatorios, reduzindo a densidade de larvas nos criadouros. Entretanto, no decimo quinto dia de avaliacao do experimento, os criadouros tratados com B. sphaericus continuavam apresentando baixo numero de larvas, indicando persistir mais tempo que os outros dois produtos (Au);
Assuntos
Bacillus thuringiensis , Controle de Mosquitos , Controle de Mosquitos/instrumentação , Controle de Mosquitos/tendências , Controle Biológico de Vetores/métodos , Controle Biológico de Vetores/tendênciasRESUMO
The potential of residual insecticides with their direct action against the sporogonic cycle of plasmodia prompted the idea of possible eradication of malaria. In the early fifties health administrators supported by technicians favoured the control of endemic diseases through "mass campaigns". In such an atmosphere, at the 8th World Health Assembly held in Mexico in 1955 a resolution was adopted urging member states to initiate health programmes aimed at eradicating malaria. Initial spectacular results continued for ten years, but the progress slowed down considerably in the late sixties due to a number of technical, operational and administrative problems encountered in many countries. Nevertheless, malaria was eradicated in 37 countries and territories, thus freeing the population of some 500 million from the risk of infection. During the period 1972-1977 serious resurgence of malaria affected a number of countries in South East Asia, Central America and Turkey. Energetic counter measures have brought down malaria to a level which is far from being under control. At the same time in Africa, south of the Sahara, practically no organised control of malaria is being carried out. While malaria morbidity is rising, the policy of national health administrations is to carry out malaria control applying the strategy of Primary Health Care. However, in view of the multiple difficulties countries are facing much more flexibility and an epidemiological approach are required at this stage. Possible modalities for action are discussed in the paper in more detail.