When we study a disease, one of the main factors we look at is how it is transmitted. Knowing this characteristic is important to create preventive measures and even avoid an outbreak or epidemic. In this context, it is essential to understand the difference between two basic terms: vector and etiological agent.
→ What is the etiologic agent?
The etiological agent is able to trigger the signs and symptoms of a pathology. This means that it is the organism causing the disease. At AIDS, for example, the etiologic agent is the HIV virus. In the case of Chagas disease, the etiological agent is the Trypanosoma cruzi.
The main known etiological agents are usually grouped in the group ofvirus, bacteria, protozoa, fungi, flatworms and roundworms.
→ What is vector?
When we say that a disease is transmitted by a vector, we are saying that, in order for the pathology to be passed from one being to another, a transmission vehicle is needed. Mosquitoes are important vectors, such as the Aedes aegypti, which carries the virus that causes dengue, Zika, yellow fever and chikungunya.
According to the Brazilian Society of Parasitology, there are two types of vectors:
Biological vector: is the one in which the etiologic agent multiplies.
Mechanical vector: it is one that works only as a transport, with no multiplication of the etiological agent.
→ Difference between etiologic agent and vector
The etiologic agent is nothing more than the organism causing the disease, and the vector is the one that transports the etiologic agent.
Citing again the example of Chagas disease, the Trypanosoma cruzi it is responsible for causing the disease, that is, the etiological agent. The vector of the disease are insects known as barbers or hickeys, which release the etiological agent in their feces.
By Ma. Vanessa dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/saude/vetor-agente-etiologico.htm
