Respiratory Infection

A respiratory tract infection (RTI) refers to any of a number of infectious diseases involving the respiratory tract. An infection of this type is normally further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI or LRTI). Lower respiratory infections, such as pneumonia, tend to be far more serious conditions than upper respiratory infections, such as the common cold. Unfortunately, clinical features and current laboratory methods do not readily identify the etiologic agent of RTIs. These laboratory methods have traditionally involved culture and antibody-based approaches, but in recent years, nucleic acid (DNA-based) methods have gained acceptance and even preference over traditional methods for pathogen identification due to their higher sensitivities and specificities, decreasing cost, and multiplexing capabilities.

Acute Upper Respiratory Infection
An acute upper respiratory infection is a contagious infection of your upper respiratory tract. Your upper respiratory tract includes the nose, throat, pharynx, larynx, and bronchi. The common cold is the most well known URI, while other types include sinusitis, pharyngitis, epiglottitis, and bronchitis. Influenza is not a URI because it is a systemic illness.

• Sinusitis – inflammation of the sinuses.
• Epiglottitis – inflammation of the epiglottis, the upper part of your trachea. It protects the airway from foreign particles that could get into the lungs. Swelling of the epiglottis is dangerous because it can block the flow of air into the trachea.
• Laryngitis – inflammation of the larynx or voice box.
• Bronchitis – Inflammation of the bronchial tubes. The right and left bronchial tubes branch off from the trachea and go to the right and left lungs.

Acute Lower Respiratory Infection

Acute lower respiratory infections include pneumonia, bronchitis, bronchiolitis, influenza, and whooping cough. General symptoms include shortness of breath, weakness, fever, coughing, and fatigue. They are a leading cause of illness and death in children and adults across the world. Acute lower respiratory infections are not uniformly defined, but usually include bronchitis and bronchiolitis, influenza, and pneumonia.

• Bronchitis describes the swelling or inflammation of the bronchial tubes. Additionally, bronchitis can be either acute or chronic depending on its presentation and is also further described by the causative agent. Acute bronchitis can be a bacterial or viral infection of the larger airways in healthy patients with no history of recurrent disease, which typically resolves on its own with time.
• Bronchiolitis is a common lung infection in young children and infants. It causes inflammation and congestion in the small airways (bronchioles) of the lung. Bronchiolitis is almost always caused by a virus.
• Influenza is a viral infection that attacks the respiratory system – your nose, throat, and lungs. Influenza, commonly called the flu, is not the same as stomach “flu” viruses that cause diarrhea and vomiting. For most people, influenza resolves on its own and is not treated with medication.
• Pneumonia is an infection of the air sacs in one or both lungs. The air sacs may fill with fluid or pus, causing cough with phlegm, fever, chills, and difficulty breathing. A variety of pathogens, including bacteria, viruses and fungi, can cause pneumonia. Pneumonia can range in seriousness from mild to life-threatening. It is most serious for infants and young children, people older than age 65, and people with health problems or weakened immune systems. Antibiotics are the first line treatment for bacterial pneumonia; however, they are not effective for viral infections.