21.   Infected mucus then drips into the lower respiratory tract, where it can cause bronchitis and asthma.

22.   Infected mucus that drips from sinus cavities into the lower respiratory tract can cause or aggravate bronchitis, chronic cough and asthma.

23.   Infection occurs when the virus invades the respiratory tract and then the immune system.

24.   It has also been developing drugs for hepatitis C and RSV, a respiratory tract virus common in infants.

25.   It can also damage the skin and upper respiratory tract.

26.   Natural therapies are helpful because they strengthen both the body and the tissues of the respiratory tract, reducing the impact of asthma triggers.

27.   Mustard gas is a chemical agent that blisters the skin and lungs, burns the eyes and can cause cancers in the mouth, throat and respiratory tract.

28.   Other strains of the same bacterium cause disease in poultry and other birds, and some strains can infect the respiratory tracts of chickens and reduce egg production.

29.   Preventable diseases like malaria, respiratory tract infections and diarrhea are major killers.

30.   Rebetol is currently sold by ICN in a different version under the brand name Virazole as a treatment for respiratory tract infections.