Infectious diseases are the disorders caused by pathogens or any infectious agents while on the other hand, contagious diseases are those which spread from an infected person to a healthy person. An infectious disease can or cannot be contagious.
Infectious diseases are caused by either some unicellular organisms such as viruses, bacteria, fungi or multi-cellular organisms namely parasites including ectoparasite and endo-parasite. Some of the diseases caused by unicellular pathogens are tuberculosis, urinary tract infection, ringworm, athlete’s foot, and malaria and so on.
There are many modes of transmission of the infections, such as through direct contact with an infected person or animal. For example, if an infected person makes physical contact by shaking hands or when a patient exchanges body fluid with an uninfected person. Rabies is caused when an infected animal bites a healthy person.
The germs get transferred to the body of an uninfected person. The infections can also be transferred from the mother to her unborn child in the womb or through breastfeeding. Indirect means of transmission include when someone catches infection from any object that has germs on it.
For example, if a person who has been suffering from the flu or cold has used a certain object and someone touches it, later on, he or she can get affected too. Those infectious agents that vary germs on them to cause disease are called vectors. This is another mode of getting a disease through insects such as a mosquito.
A mosquito carries malarial germs to be injected into a healthy person. Contaminated food causes food poisoning because the food that was infected with some pathogen when it gets inside someone’s body it causes diarrhea. The most common symptoms of infectious diseases are fever, diarrhea, fatigue, body aches. The people at risk are those who do not follow proper hygiene protocols and who are immune compromised.
Common Infectious Diseases Caused by Viruses
Worldwide, infectious diseases are very frequent, but some are more prevalent than others.
Here is a list of some of the most prevalent infectious diseases, organized by type.
Common infectious diseases caused by viruses:
- Common cold.
- The flu (influenza).
- COVID-19.
- Stomach flu (gastroenteritis).
- Hepatitis.
- Respiratory syncytial virus (RSV).
Common infectious diseases caused by bacteria:
- Strep throat.
- Salmonella.
- Tuberculosis.
- Whooping cough (pertussis).
- Chlamydia, gonorrhea and other sexually transmitted infections (STIs).
- Urinary tract infections (UTIs).
- Clostridioides difficile (C. diff).
Common infectious diseases caused by fungi:
- Ringworm (like athlete’s foot).
- Fungal nail infections.
- Thrush.
Common infectious diseases caused by parasites:
- Giardiasis.
- Toxoplasmosis.
- Hookworms.
- Pinworms.
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Contagious diseases are those infections that are easily spread to another person through any mode of transmission, for example, via air droplets or direct contact. Not all infectious illnesses are contagious. Pathogens require favorable conditions for their survival.
They are in a constant search of its suitable host. As soon as they reside inside its victim, they start to feed and reproduce and complete its life cycle. The diseased time period is basically the period when the parasites are alive in the body of its host. Once the life cycle of the pathogen completes, the disease gets healed.
There are high rates of infection to become contagious when the infectious agent is being active and functional. If a patient does not take proper medications and prevention during the peak time of the disease, it can spread to the general population. Examples of contagious diseases are AIDS, corona and tuberculosis, the never-ending list.
The most effective form of prevention is to get vaccinated timely taking medications and refraining from getting in contact with other healthy persons.
