ABSTRACT
The malaria situation in the WHO South-East Asia Region is reviewed in terms of its epidemiological diversity, problems encountered and implications for control. Varying host-parasite-vector interrelationships are shown to be influenced significantly by prevailing environmental conditions (eg topographic, climatic) as well as behavioral and socio-economic determinants. Drug-resistant falciparum malaria and vector resistance to insecticides are the main biological deterrents to the success of control programs. Thus, the potential for malaria transmission remains high in many places. The malaria control strategy includes Primary Health Care and integration with basic health services. However, operational research is needed in many of the countries in the Region.
Subject(s)
Asia, Southeastern/epidemiology , Drug Resistance , Environment , Female , Health Behavior , Humans , Malaria/epidemiology , Male , Morbidity , Mosquito Control , Operations Research , Population Surveillance , Primary Health Care , Socioeconomic Factors , World Health OrganizationABSTRACT
Demographic Subsystem (DSS) comprising structure, distribution, along with its dynamic process has been identified to influence Malaria as Anthropo-Ecosystem (MAES) broadly in two ways. Innate characters of some essential elements of DSS viz. growth, age and sex composition, infants, children, young and old adults, non-pregnant and pregnant and lactating mothers exert direct influence while other elements, viz. spatial distribution, density, configuration of settlements and migration are influenced by environmental factors and affect MAES indirectly. Attempt has been made to discuss each of these factors in the light of present knowledge and available data.
Subject(s)
Adolescent , Adult , Asia, Southeastern/epidemiology , Child , Child, Preschool , Demography , Female , Geography , Humans , Infant , Infant, Newborn , Malaria/epidemiology , Malaria, Falciparum/epidemiology , Male , Population Density , Population Growth , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Transients and MigrantsABSTRACT
In biological ecosystems, population tends to fluctuate above or below asymptotic level or the 'carrying capacity'. Self-regulation is achieved by extrinsic, that is, environmental limiting factors and intrinsic, that is, physiological and genetic factors. In Malaria Anthropo-Ecosystem (MAES) which is much more intricate and complex system, Plasmodium being endoparasite is required not only to interact with intrinsic factors of its vertebrate and invertebrate host but also to regulate itself to environmental factors to which its both the hosts are subjected. Attempt has been made to provide, on the basis of present knowledge, the probable explanation of self-regulatory mechanisms from molecular, cell, organ/organism, population/community levels of vertebrate and invertebrate hosts which give stability to MAES as a whole system.
Subject(s)
Animals , Host-Parasite Interactions , Humans , Malaria/parasitology , Plasmodium/physiologyABSTRACT
Adaptations have been recognized as an essential facets of evolution. These broadly cover two types exemplified by change (adjustments) and that leads to creation of new species. The former is generally in response to environmental factors, while the others are genetic and heritable and enable the population to continue its existence. These are also accompanied by biological and behavioural changes. In the study of MAES, adaptations appear to be main mechanism which facilitate the dynamics of the malaria system in time and space. Schematically, three broad groups of resultant factors of adaptations within MAES. viz. genetical, biological and environmental have been identified and briefly discussed with regard to their diversity in all the three elements of MAES.
Subject(s)
Adaptation, Biological/genetics , Animals , Anopheles/parasitology , Host-Parasite Interactions , Humans , Insect Vectors/parasitology , Malaria/parasitology , Plasmodium/physiology , Polymorphism, GeneticABSTRACT
Diversity being one of the main characteristics of Malaria Anthropo-Ecosystem (MAES) is reflected in time and space. Temporal diversity of MAES generally may be divided into two types--long time periods usually on a global scale, and various local fluctuations expressed as malaria periodicity. Geographical confinement of MAES is determined by interactions of various elements of the latter with biotic and abiotic components of the environment. The diversity of the MAES within climatic zones of South and South-East Asia is shown to be of many types of sub-systems depending, apart from climatic conditions, on types of human activity in those ecosystems.