Introduction about vector-borne diseases — lesson. Science State Board, Class 9.

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Vector:

What do you think is the deadliest animal for humans? You may think it is either lion or a shark. But mosquito is the deadliest organism for the human. Mosquito is killing human by spreading diseases such as Malaria, Dengue, Chikungunya. These diseases are called as vector borne diseases. In this topic we are going to explore about the vector borne diseases.

Vectors are living organisms which act as intermediate carriers of infectious agents. They transfer the infectious agents from one human to another human or from an animal.

Vectors can be an insect or an animal. Diseases such as malaria, filaria, chikungunya, dengue are transmitted through insects, and the diseases transmitted by animals are bird flu and swine flu.

Important!

Pathogens stick to flies bodies as they sit on garbage, and these pathogens are then transferred to food when the flies sit on it again.

Examples of insect vectors:

Example:

Mosquitoes, lice, ticks and fleas.

Top left to right : Mosquito and lice; Bottom left to right - Ticks and fleas

Examples of animal vectors:

Example:

Monkeys, bats, pigs and birds

Top left to right: chimpanzee and bird; Bottom left to right - pig and bat

How it spreads the disease:

Vector such as mosquitoes, do not carry the pathogen from its birth. During a blood meal from an infected person, mosquito gets ingested with the pathogen, and when it bites an animal or healthy person, the pathogen will transmit into them. Thus, disease-producing microorganisms are transmitted through vectors.

A mosquito bite carrying an infectious agent

Vector-borne diseases:

Diseases transmitted from one human to another through vectors are called vector-borne diseases.

Comparison of airborne, waterborne and vector-borne diseases

Topics	Airborne	Waterborne	Vector-borne
Mode of transmission	Contaminated Air	Contaminated food and water	Insects and animals
Reservoir of infection	Mostly within the host	water, food and host	Vector and host
Infectious agents	Bacteria and Virus	Bacteria, virus	Protozoa, worms, virus
Host	Humans and animals	Humans and animals	Humans, animals
Diseases	Tuberculosis, whooping cough, diptheria, common cold, mumps, measles, chicken pox, influenza	Cholera, typhoid, polio myelitis, acute diarrohea, Hepatitis A	Malaria, dengue, chikungunya, filaria