Hi!
The answer is breathing.
Protozoans are organisms that can multiply themselves in humans, and serious infections can develop from one organism. The most frequently transmission methods are contaminated food or fecal contact. Dog bites inoculate bacteria into deep tissue, and they also serve as a transmission method.
Breathing is not considered to be likely to transmit protozoan infection because protozoans rarely develop in the respiratory tract.
Parthenolide is a sesquiterpene lactone which occurs naturally in the plant feverfew--highly concentrated in the flowers and fruit.
