A Model For The Ecology Of Avian Malaria*
A Model For The Ecology Of Avian Malaria*
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禽疟疾生态学模型*
DOI：
10.7589/0090-3558-7.1.5
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发表时间：
1971
期刊：
影响因子：
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通讯作者：
R. Mclean
中科院分区：
文献类型：
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作者：
R. Beaudoin;J. E. Applegate;D. E. Davis;R. Mclean
虽然有关野鸟疟原虫感染的研究已在文献中频繁报道，但我们对这些寄生虫的生态学知识仍然不完整。综合这些实地研究的数据和想法，以及最近的实验工作，构建了以下关于禽疟生态学的假设模型：在春末、夏季和初秋，易感鸟类（当年的幼鸟或以前未感染的成年鸟）在繁殖地被受感染的蚊子叮咬而感染。鸟类迁徙或留在该地区，感染在冬季变得潜伏。春季，候鸟返回繁殖区，所有鸟类开始繁殖活动。随着迁徙和繁殖活动的开始，鸟类中的寄生虫数量增加。疟疾感染的复发与病媒的出现相吻合。蚊子获得了寄生虫，将其传递给种群中的易感者（由于繁殖的结果，其数量同时增加），并且循环继续。在有利条件下，传播率等于或超过取代受感染鸟类死亡率所需的水平。在不利的条件下，寄生虫由鸟类宿主维持，易感群体增加，传播被推迟，直到有利的条件恢复并且向扩大的易感群体的传播补充了受感染成年人的供应。在这样一个循环中，寄生虫、媒介和易感宿主的种群以一种明显有利的顺序达到最大值，并为偶尔的传播失败做好准备，这一循环具有明显的生存价值。通过对该模型中定义的特定问题区域的调查，将更全面地了解禽疟的生态学。该模型可能会被证明是额外的价值，建议一个生态的方法，我们了解人类疟疾的流行病学。它也可能适用于其他疾病系统，其中鸟类-蚊子的关系是类似的，如某些虫媒病毒。
Although studies on Plasmodium infections of wild birds have been reported frequently in the literature, our knowledge of the ecology of these parasites remains incomplete. A synthesis of data and ideas from these field studies, and recent experimental work led to the construction of the following hypothetical model for the ecology of avian malaria: During the late spring, summer, and early fall susceptible birds (young of the year or previously uninfected adults) contract the infection from the bite of an infected mosquito on the breeding ground. The birds migrate or remain in the area and infections become latent over the winter. In the spring, migratory birds return to the breeding area and all birds commence reproductive activity. With the onset of migration and breeding activity, parasite populations become elevated in the birds. This relapse of malarial infections coincides with emergence of vectors. The mosquitoes obtain the parasite, passing it on to susceptibles in the population (whose numbers are simultaneously increasing as the result of reproduction), and the cycle continues. Under favorable conditions, transmission rates equal or exceed a level needed to replace mortality of infected birds. Under unfavorable conditions the parasite is maintained by the bird reservoir, the population of susceptibles increases, and transmission is postponed until favorable conditions return and transmission to the expanded population of susceptibles replenishes the supply of infected adults. Such a cycle, in which the parasite, vector, and susceptible host populations reach a maximum in an apparently favorable sequence, with provision for occasional failure of transmission, has obvious survival value. A more complete understanding of the ecology of avian malaria will be achieved with the investigation of specific problem areas defined in this model. The model may prove of additional value in suggesting an ecological approach to our understanding of the epidemiology of human malarias. It may also have applicability in other disease systems where bird-mosquito relationships are similar, such as certain of the arboviruses.