Manuel Carvalho de Almeida. Michelle Pereira. Kety Viana. Wilhan Jose Gomes. Richard Woolite. Anthenagoras Da Silva Leal. Samuel Zefanias. Claudinei Souza. Riviane Lucena. Leandro Romeiro De Souza Santos. Epi Sida. Mais de paulo silva. Cary Ribeiro.
Populares em Belief. Rodolfo Cabral. Literature Literatura. Trends Ecol. The worldwide AIDS epidemic is clearly new. The first cases occurred in Africa and the United States and the epidemic gained serious proportions during the eighties.
However, the question of its origin still remains a mystery. Assuming as correct that the precursor AIDS virus spread from monkeys to humans, complete explanations as to how it could have happened are still not available.
It is a puzzle why, after thousands of years in which man and the primates have lived together in Africa, the human infection should have made its epidemiologic appearance so recently. As background, it is convenient to consider the nidality theory of infectious agents and the varied ways by which they interact with their hosts. In the resulting communities, each of the species which participate in them plays its own peculiar role in the sharing of the available resources called the ecological niche of the species Forattini, When this is represented by an infectious agent, the infection which it brings about may eventually disappear, either in terms of place or time, if it shows itself to be an inefficient transmitter, i.
This may happen due to several factors, both natural and artificial. Among the former the development of immunity or the disappearance of the host populations, while the latter occurs when the transmission is interrupted by public health measures. Although the earliest know AIDS-related human death-is recognized as having occurred in the s, it is believed that the infection arose in Central and East Africa, because that was where cases first began to appear frequently and where the related simian viruses occur naturally.
As a result of this there is a tendency to assume that the AIDS viruses spread from monkeys to the human population. In other words, it must be accepted that these viruses were able to occupy an available ecological niche, interacting with the human population. It is not clear what mechanism was involved in this. Several aspects needs explanation. Leitura complementar: Por que o HIV demora tanto para causar sintomas?
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Como o nome William virou Guilherme? As 42 regras de Jordan B. Seguir Seguindo.
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