Infectious Disease

Learn more about some common respiratory infections.



Bronchitis means inflammation of the bronchi, or airways. Bronchitis can be “acute” meaning of relatively sudden onset and short lived, or “chronic”, meaning lasting weeks, or longer. Acute bronchitis can be caused by pollution, or inhaling dusts or chemicals. Most of the time, though, acute bronchitis is caused by an infection of the airways. Usually the infection is viral, caused by many of the same “bugs” that produce URIs. But bacteria are not an uncommon cause of bronchitis. The main symptom is a cough productive of sputum that is usually not clear. Sputum color can be from cream color, to yellow, green, tan or grey. Patients often have low grade fever. For most patients, treatment is, again, supportive. Rest, liquids and cough medicine are the mainstays. For patients with severe symptoms, especially those with significant underlying lung disease, such as COPD, antibiotics are usually called for. Sometimes, a patient’s sputum is collected and “cultured” to determine if and what kind of infection is causing the bronchitis. But a standard sputum culture takes two to three days to be reported. There are evolving technologies, to include blood tests, to help doctors more rapidly determine if a patient will benefit from antibiotics, besides clinical criteria.

For more information see The Mayo Clinic web site.

Nontuberculous Mycobacterium


Mycobacteria are a large group of bacteria which can cause disease in humans. Non tuberculous mycobacterium (NTM) is a group within the Mycobacterium family which includes all the other mycobacteria which can cause pulmonary disease, skin disease, lymphadenitis or disseminated disease.

Read More About Nontuberculous mycobacterium



Pneumonia is an infection of the lung tissue. It can be caused by viruses, fungi, or even parasites. But in adults it is usually caused by bacteria. Symptoms include cough, usually productive like in bronchitis, fever, chills, and sometimes difficulty breathing or chest pain. Diagnosis, unlike for a URI or bronchitis, usually requires a chest X ray in addition to examination by the doctor. Treatment, virtually always involves antibiotics, in addition to supportive care similar to that for URI and bronchitis.

For more information see The Mayo Clinic web site.

Upper Respiratory Tract Infection


An Upper Respiratory Tract Infection or “rhinopharyngitis”, is commonly known as the “common cold”. Symptoms are drainage from the nose, congested or “stuffy nose”, sore or irritated throat, a mild cough, and mild systemic symptoms such as low grade fevers, and malaise or a lack of energy. URIs are almost always caused by viruses. In fact, two hundred different types of viruses can cause a cold, but most are caused by common rhinoviruses. Treatment is usually supportive, and includes rest, drinking plenty of fluids, decongestants (nasal sprays rather than pills are recommended for older adults), and cough medicine, as needed. Antibiotics, are generally avoided, unless the URI is from an Influenza virus.

Symptoms of “the flu” are similar to upper respiratory tract infections but more severe and additionally include a high fever (greater than 100 degrees F), headache, and aching muscles. The symptoms (reflecting progressively severe infection of the respiratory system) may progress to include symptoms of bronchitis or even pneumonia. For most patients, antibiotics are not necessary for treating the flu, supportive care is enough. However, there are patients, such as those with severe underlying lung disease, who will not tolerate the virus. For such patients, we like to start antibiotics within 48 hours of symptom onset. There is rapid office based testing that helps us to sort out patients with this potentially severe viral infection.

For more information see The Mayo Clinic web site:


For information on other infectious diseases we recommend the American Lung Association website.