Vector and Fluid-borne Pathogens: Malaria and Ebola

Two different routes of infection

Malaria and Ebola are both communicable diseases, but their pathogens reach new people in different ways. Malaria is caused by a Plasmodium protist carried by an animal vector. Ebola is caused by a virus that spreads through infected body fluids. Understanding the route of transmission helps explain why the two diseases need different prevention measures.

Malaria: a mosquito carries the protist

A female mosquito can pick up malaria protists when it feeds on the blood of an infected person. If that mosquito later bites another person, it can pass the protists into their bloodstream. The mosquito is the vector: it carries the pathogen between people. The protist, not the mosquito, causes malaria. The infection can damage the liver and blood.

Prevention can target either part of this route. Insecticide-treated bed nets, window screens, covering exposed skin and insect repellent reduce the chance of a bite. Removing standing water, where mosquitoes breed, and using insecticides can reduce mosquito numbers. With fewer mosquitoes or fewer bites, there are fewer opportunities for the protist to pass between people.

Ebola: contact with infected body fluids

Ebola virus can pass from a person who is ill with Ebola, or from someone who has died of it, through blood and other body fluids such as vomit or diarrhoea. Infection can occur when these fluids reach another person's broken skin or the moist linings of the eyes, nose or mouth. Objects and surfaces contaminated with the fluids can also spread infection. A person does not transmit Ebola before developing symptoms. Ebola is a severe disease; bleeding can occur, but not every patient has visible bleeding.

Prevention therefore focuses on avoiding contact with infectious fluids. People with suspected Ebola need prompt medical care and separation from others. Health workers use protective equipment and careful hand hygiene when caring for patients; contaminated materials must be handled safely. Tracing and monitoring contacts helps identify new cases, while safe, dignified burial prevents contact with the body fluids of someone who has died.