Disease relationships of arthropods in Africa with particular reference to mites and ticks

Abstract

Data obtained from the literature on disease relationships of different groups of arthropods (insects, mites and ticks) arc summarized with the aid of tables. The involvement of mosquitoes as insect factors in the transmission of malaria and other diseases has made this group of insects the most studied in Africa. A brief review of ticks as transmitters of pathogens is given. Recent research indicates that mites, a group which has not received adequate attention in Africa, but which has been incriminated in the transmission of disease in other parts of the world, may prove to be of comparable importance in Africa. As Mattingly (1969) aptly put it, 'diseases are not just collections of signs and symptoms calling for treatment by a physician'. They can also be seen as ecological systems involving human populations and their physical and biological environment. This attitude inspires the hope not only of curing diseases when they occur, but also of preventing their occurrence. Disease systems are often quite complicated and arthropod-borne diseases are especially more so because they involve an additional component, the arthropod vector, by which the disease is transmitted from one human host to another. Such a vector is itself subject to environmental hazards which determine whether it will live long enough for the pathogen which it is carrying to mature and become infective. Still more complicated are those diseases, called zoonoses, in which the pathogen is harbored by other animals as well as by man. A measure of the reality of the ecological aspect of disease is its frequent association with habitat