Constraints faced by parasites during symbiosis – a review

Although parasitic infections remained major obstacles to economic progress and a better life in developing countries due to their ability to damage the host's tissues directly through metabolism, there are many constraints that parasites faced in the course of their interaction with the host. The present review was conducted to document the various challenges faced by the parasites while forming a symbiotic association with their host. Over sixty (60) articles were reviewed to get information on the constraints faced by the parasites of some organs such as skin, blood, gut, and liver. Examples of parasites living on the skin are lice, fleas, mites, ticks, Chilodonella, and Trichodinids, while identified constraints faced by parasites on the skin are: nutrients, life cycle stages, desiccation, water, and temperature; the Blood parasites include Trypanosomes, Schistosomes, and Plasmodium, among others. Some difficulties in the blood habitats faced by the parasites include host immune responses, life cycle stages, and drainage issues. Similarly, the gut parasites include E. histolytica, S. mansoni, A. lumbricoides, etc; and the challenges faced by parasites living in the gut include; pH, peristalsis, enzyme digestion, life cycle stages, and others. The present review highlighted and suggested that the hosts should take other necessary efforts that will prevent becoming exposed to parasites through busting their immunity, personal hygiene, and environmental sanitation, because lack of such preventive and control measures may favor parasites from always wine host using some mechanisms to overcome the mentioned constraints.