airborne
Adjective

transported by air currents.

chickenpox
Noun

disease common in children; caused by the varicella-zoster virus and characterized by itchy blisters on the skin

direct transmission
Noun

when disease-causing germs pass from an infected person to a healthy person via direct physical contact with blood or body fluids. 

disease
Noun

harmful condition of a body part or organ.

droplet
Noun

tiny drop (as of a liquid).

E. coli
Noun

(Escherichia coli) common bacteria found in the digestive system of many animals. Some strains of E. coli are dangerous to people.

HIV
Noun

(human immunodeficiency virus) virus that is a cause of AIDS (anti-immune deficiency syndrome).

indirect transmission
Noun

when disease-causing germs pass from an infected person to a healthy person via sneezes or coughs, sending infectious droplets into the air or onto objects.

infect
Verb

to contaminate with a disease or disease-causing organism.

influenza
Noun

contagious disease, characterized by fever, exhaustion, and difficulty breathing. Also called the flu.

Lyme disease
Noun

inflammatory, bacteial disease that is transmitted by ticks.

malaria
Noun

infectious disease caused by a parasite carried by mosquitoes.

microscopic
Adjective

very small.

mosquito
Noun

insect capable of piercing the skin and sucking the blood of animals.

parasite
Noun

organism that lives and feeds on another organism.

Noun

infectious, sometimes deadly, disease of the lungs.

vector
Noun

animal that transmits a disease from one organism to another.