Plasmodium vivax
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring (Benign tertian) malaria, "P. vivax" is one of the five species of malaria parasites that commonly infect humans. Although it is less virulent than "Plasmodium falciparum", the deadliest of the five human malaria parasites, "P. vivax" malaria infections can lead to severe disease and death, often due to splenomegaly (a pathologically enlarged spleen). "P. vivax" is carried by the female "Anopheles" mosquito; the males do not bite.
John Augustus Abayomi-Cole
At the turn of the century, malaria was the greatest scourge of West Africa, and was taking a deadly toll particularly of Europeans living in West Africa. Dr. Abayomi-Cole was called upon by the Colonial Government to help combat the disease. He made an effective preparation of herbs, containing as its main ingredients "broomstone" leaves and "agiri". But he found that his cured patients returned within a few weeks with the same symptoms. Through intensive research, he was able to establish that poor environmental sanitation was the root cause of the relapse — mosquitoes were breeding in stagnant pools of water around houses. He organised groups of voluntary workers known as "mosquito missionaries" who went from compound to compound advising people on the necessity of keeping their living areas clean. The scheme worked so well that the Colonial Government later paid the volunteers monthly.