Infectious Diseases

Infectious diseases are illness caused by external organisms known as pathogens as opposed to diseases caused by genetics, aging, or the environment. As the name suggests, you can get an infectious disease when you are infected by pathogens in contrast to non-infectious disease like cancer, Alzheimer’s disease, and diabetes. Depending on the pathogen and disease, you can further pass on the illness to another person. Not all infectious disease spreads from person to person but those that do are known as communicable disease.

The most common infectious agents are made up of pathogenic microorganisms such as viruses, bacteria, fungi, parasites, and rarely, misfolded proteins known as prions. They can spread through droplets when an infected person cough or sneezes, animal or bug bites, contaminated food or water, faecal matter, sexual contact, from mother to foetus, blood transfusion, organ transplants, and other medical procedures. Infectious agents can also survive on inanimate surfaces or objects and the pathogen gains entry to the body when the person touches their mouth, nose, or exposed skin after touching the contaminated surface. Such surfaces or objects are known as fomites and common examples of these are doorknobs, phones, and clothing.

Depending on the pathogen, an infectious disease can spread easily from person to person or be entirely non-communicable. The severity of the illness also depends on the infectious agent and the health of the infected individual. The most significant infectious disease event in recent history is none other than the COVID-19 pandemic, an outbreak of a respiratory disease that was caused by a viral pathogen known as coronavirus.

Diagnostic tests for infectious disease can be as simple as a nasal or mouth swab or obtaining a blood, urine, stool, or saliva sample. Some will require imaging scans like X-rays, MRIs or obtaining a tissue sample through a biopsy. The treatment for infectious diseases also depends heavily on the type of infectious agent. Infectious disease doctors are specially trained in the identification, treatment, and prevention of these illnesses. Infectious disease doctors work closely with other healthcare providers, epidemiologists, and scientists in controlling outbreaks, developing vaccines, and implementing preventive measures.