INFECTIOUS DISEASES AFFECTING THE RESPIRATORY SYSTEM
The respiratory tract comprises the body parts that enable us to breathe. They include the throat/pharynx, larynx, trachea, bronchi, and lungs. Respiratory infections are caused by various viruses and bacteria that are easily passed to people around us through coughing, sneezing, or face-to-face contact. The respiratory system’s infectious diseases are classified according to the respiratory tract part they affect: the upper or the lower regions.
Infectious diseases of the upper respiratory tract
The upper respiratory tract comprises the nose, sinus cavities, pharynx or the throat, and the larynx. Upper respiratory tract infections (URIs) are the most prevalent infectious diseases of the respiratory tract. The most prevalent URI is the common cold, which is also the most frequent human symptomatic respiratory infection. Other infectious diseases of the URI include Sinusitis, Pharyngitis (sore throat), Epiglottis, and Laryngotracheitis. Like Common cold, most URIs are caused by viruses, except in rare but more acute cases caused by Hemophilus influenza type b, Bacterial pharyngitis.
People get infected with URIs when disease-causing organisms gain entry into the upper respiratory tract by inhaling droplets from an infected person. The primary symptoms of a common cold are runny and stuffy nose, sneezing, often without a fever. However, other URIs can be accompanied by a fever. Epiglottis in children causes breathing difficulties, muffled and inaudible speech, excessive drooling, and stridor. Most URIs are treatable using antibacterial and through vaccination.
Infectious diseases of the lower respiratory tract
The lower respiratory tract is composed of the trachea, the bronchi, bronchioles, and the lungs. The most common LRIs include bronchitis, bronchiolitis, and pneumonia. Most LRTIs are caused by a virus, while others like tuberculosis are caused by bacterial infections. LRIs are among the most prevalent infectious diseases comprising 45% of all community-acquired infections and 25% of nosocomial infections
Symptoms of less severe LTRIs may include dry cough, runny nose, sore throat, mild headache, and low-grade fever. However, the mild symptoms often develop into more serious LRTIs such as pneumonia, bronchitis, and other rare but severe LRTIs like swine flu and coronavirus. Serious LRTIs are associated with severe symptoms such as high fever, severe cough, wheezing, breathing difficulties, and chest pains.
Diseases causing microorganisms find their way into the lower respiratory tract through inhalation. They multiply on or inside of the epithelium and cause inflammation and increased mucus secretion. With bronchiolitis, excess inflammation and necrosis can block the tiny airways causing an obstruction and reduced oxygen supply. Antimicrobials are used to treat most LTRIs. Their ability to penetrate pulmonary tissues and cells and kill the disease-causing organisms makes them effective in treating LTRIs.
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