Respiratory infections may reflect deficiencies in host defense mechanisms.

@article{Reynolds1985RespiratoryIM,
  title={Respiratory infections may reflect deficiencies in host defense mechanisms.},
  author={Herbert Y. Reynolds},
  journal={Disease-a-month : DM},
  year={1985},
  volume={31 2},
  pages={1-98}
}
Serious respiratory tract infections are rare in the healthy individual and most of the nuisance morbidity that occurs results from nasopharyngeal viral infections that many people get once or twice a year. The economic impact from these upper respiratory tract infections is appreciable, however, in terms of absenteeism from school or work, but unfortunately there is little that can be done to ward them off in a practical way. Pneumonia is an infrequent lifetime experience for most non-smoking… CONTINUE READING