IMMUNOLOGY

Detailed explanation-1: -Infectious diseases can be viral, bacterial, parasitic or fungal infections. There’s also a rare group of infectious diseases known as transmissible spongiform encephalopathies (TSEs).

Detailed explanation-2: -Cellulitis is a deep infection of the skin caused by bacteria. It usually affects the arms and legs. It can also develop around the eyes, mouth, and anus, or on the belly. Normal skin can be affected by cellulitis, but it usually happens after some type of injury causes a skin break, including trauma or surgery.

Detailed explanation-3: -Primary infections have characteristic morphologies and courses, are initiated by single organisms, and usually occur in normal skin. They are most frequently caused by Staphylococcus aureus, Streptococcus pyogenes, and coryneform bacteria. Impetigo, folliculitis, boils, and erythrasma are common examples.

Detailed explanation-4: -COVID-19 is a viral disease, just one of the four main types of infectious diseases. The others include bacterial, fungal, and parasitic-each different in how they spread and how they affect the body. Let’s break these down individually to understand the types of infectious diseases.

Detailed explanation-5: -While a primary infection can practically be viewed as the root cause of an individual’s current health problem, a secondary infection is a sequela or complication of that root cause. For example, an infection due to a burn or penetrating trauma (the root cause) is a secondary infection.

Detailed explanation-6: -Two examples of a secondary infection are: A vaginal yeast infection after taking antibiotics to treat an infection caused by bacteria. Pneumonia caused by bacteria or fungi after having an upper respiratory infection (like a cold) that was caused by a virus.