Transmission of agent by vectors is facilitate by the following ways except one-
**Core Concept**
The transmission of infectious agents by vectors is a significant public health concern. Vectors, such as mosquitoes and ticks, play a crucial role in the spread of diseases like malaria, dengue fever, and Lyme disease. Understanding the mechanisms of vector-borne transmission is essential for developing effective control measures.
**Why the Correct Answer is Right**
Vector-borne transmission is facilitated by several factors, including the vector's feeding behavior, the agent's ability to multiply within the vector, and the vector's ability to transmit the agent to a human host. The correct answer is likely to involve one of these factors. For example, the agent's ability to multiply within the vector is crucial for maintaining a high infectious titer, which increases the likelihood of successful transmission.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because vector attraction to a host is an important factor in transmission, but it is not the primary mechanism facilitating transmission.
**Option B:** Incorrect because the agent's ability to penetrate the vector's saliva is a critical step in transmission, but it is not the only factor involved.
**Option C:** Incorrect because the vector's feeding behavior, such as probing and feeding, is essential for transmission, but it is not the correct answer.
**Clinical Pearl / High-Yield Fact**
One important aspect of vector-borne transmission is the concept of "vector competence," which refers to the vector's ability to transmit a particular agent. Understanding vector competence is crucial for developing targeted control measures.
**Correct Answer:** C.