Pulmonary and Critical Care

Infectious Respiratory Diseases

Infectious respiratory diseases are illnesses caused by pathogens that affect the respiratory system, including the nose, throat, bronchi, and lungs. These diseases can range from mild to severe and may be caused by bacteria, viruses, fungi, or parasites. Infectious respiratory diseases encompass a variety of conditions affecting the upper and lower respiratory tracts. Upper respiratory infections (URIs) include the common cold, which is caused by viruses such as rhinoviruses and presents with symptoms like a runny nose, sore throat, cough, and congestion. Sinusitis, an inflammation or infection of the sinuses, often follows a cold or allergic reactions and is characterized by facial pain, nasal congestion, and headache. Pharyngitis involves inflammation of the pharynx, frequently due to viral infections like the common cold or bacterial infections such as streptococci.

Lower respiratory infections (LRIs) include bronchitis, which involves inflammation of the bronchial tubes and can be either acute, often due to viral infections, or chronic, typically caused by smoking or environmental irritants. Pneumonia is a more severe infection of the lungs caused by bacteria (e.g., Streptococcus pneumoniae), viruses (e.g., influenza virus), or fungi, and it presents with symptoms such as cough, fever, shortness of breath, and chest pain. Tuberculosis (TB) is a serious bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs but potentially involving other organs. It is marked by a chronic cough, weight loss, fever, and night sweats.

Specialized infections include COVID-19, caused by the SARS-CoV-2 virus, which ranges from mild respiratory issues to severe pneumonia and multi-organ involvement, and has had a profound global impact. Influenza (flu) is a viral infection known for causing seasonal epidemics, with symptoms like fever, cough, sore throat, body aches, and fatigue. Respiratory Syncytial Virus (RSV), common in infants and young children, can lead to bronchiolitis and pneumonia and also affect older adults.