Scientists believe that hot weather may speed up both the breeding cycle of mosquitoes and replication of the virus in insects’ guts.

Drugs that treat chronic conditions and lifestyle ailments are more profitable. Modern medicine needs new kinds of antibiotics to treat drug-resistant infections, but antibiotic research and development are expensive, risky, and time-consuming.

The clearing and settlement of tropical rainforests has exposed woodcutters, farmers, and ecotourists to new vector-borne diseases.

White blood cells are not a type of infectious agent. Part of the immune system, white blood cells fight infection rather than cause it. 

White blood cells are not a type of infectious agent. Part of the immune system, white blood cells fight infection rather than cause it. 

White blood cells are not a type of infectious agent. Part of the immune system, white blood cells fight infection rather than cause it. 

Not all microbes are harmful to humans. In fact, many of them protect us, helping our bodies function properly and competing with harmful organisms in an eternal contest for habitable space in or on our bodies. Although the microorganisms that cause disease often receive more attention, most microorganisms do not cause illness.

Trichinosis is not a viral disease. It is caused by a helminth (parasitic worm) found in undercooked meat, not by a virus. 

Trichinosis is not a viral disease. It is caused by a helminth (parasitic worm) found in undercooked meat, not by a virus.   

Bacteria are 10 to 100 times larger than viruses.

Most infectious diseases are impacted by changes in the environment. Malaria, dengue, and viral encephalitis infections, for example, are highly sensitive to environmental changes.

Infection occurs when viruses, bacteria, or other microbes enter your body and begin to multiply. Disease follows when the cells in your body are damaged as a result of infection, and signs and symptoms of an illness appear.