ABSTRACT
Certain diseases are transmitted by particular species of insect, known as vectors. This chapter deals mainly with biological vectors. A biological vector is actually infected by the pathogen, which develops or multiplies inside the body of the vector. Mosquitoes are vectors of malaria, filariasis and arboviral infections. Since humans are effectively the only sufferers from human malaria, it is conceivable that if all malaria sufferers in an area could be cured, then no more mosquitoes could become infected and transmission of the disease would cease. The chapter argues that engineering and environmental measures are effective against a variety of vectors. The mosquito-borne forms of filariasis are caused by nematode worms which develop in the human lymphatic system and release vast numbers of tiny larvae into the blood. Engineering and environmental measures continually reappear as the long-term solution and they are particularly successful in countries where high levels of social control and community involvement are possible.
