What Are the 4 Most Common Infectious Illnesses?

Infectious illnesses are common. Although there are four that are the most common, there are so many disorders caused by viruses, bacteria, and fungus that affect us as human beings.
What Are the 4 Most Common Infectious Illnesses?

Last update: 21 June, 2021

Infectious illnesses are those that develop from harmful microorganisms, like viruses, bacteria, fungus, or parasites. These illnesses can be transmitted directly or indirectly, from another person. Among the most common infectious illnesses, we can name, for example, pneumonia and tuberculosis. Keep reading to discover the 4 most common infectious illnesses!

These types of illnesses are similar in that they share the same stages: incubation period. development, and convalescence. These three stages range from contracting the disease to the recovery from the infection.

Throughout this article, we’ll explain some of the most common infectious illnesses that develop all over the world. Remember that in order to prevent them, it’s best to practice good hygiene and not share personal objects with anyone.

1. Pneumonia

This is a bacterial infection caused mainly by Streptococcus pneumonia. Initially, pneumonia affects the pulmonary parenchyma. However, when the illness advances to its more serious stages, it can spread from the lungs to the blood.

To treat this illness, a doctor will usually suggest antibiotics. The guidelines they suggest will be directly related to the characteristics of the patient and the illness. Not all pneumonia develops in the same way.

2. Tuberculosis

This is another one of the most common infectious illnesses on a global scale. Specifically, it’s one of the top ten causes of death in the world, affecting 10 million people in 2018. Of the 10 million affected, 1.5 million people died, according to the data proposed by the World Health Organization (WHO).

The bacteria that causes this illness – Mycobacterium tuberculosishas become very resistant to conventional treatment, and this has caused a public health crisis and a threat to health security. Despite this negative data, it’s true that each year we’re achieving approximately a 2% reduction in the contagion rate.

Tuberculosis transmits through the air, and the infected person may or may not develop symptoms. Of all the infected people, only 10% show symptoms. Among the most common symptoms, we can find the following:

  • General unease
  • Feverish state
  • Coughing and spitting
  • Excessive sweat
artists interpretation of infected lungs on a man

You may also be interested in: World Tuberculosis Day: It’s Time to End TB

3. Hepatitis A

In addition to pneumonia and tuberculosis, hepatitis A is another of the most common infectious illnesses that we should mention. In contrast to the previous two, hepatitis A isn’t caused by bacteria; a virus is responsible for this infection. This microorganism gets its name from the virus hepatitis A or VAH.

This illness is transmitted through water or through food in a bad condition that’s contaminated by the feces of someone infected by the virus. The infection is closely associated with poor sanitation, poor personal hygiene, and also anal sex. For that reason, it’s more common in countries that have deficient hygiene measures.

This illness affects the liver, as it suggests. The symptoms are:

  • Jaundice: Yellowing of the skin and mucous
  • Choluria: Darkening of the urine
  • Abdominal pain
yellowing of the skin and eyes due to jaundice hep A test
Hepatitis A can cause the skin and mucus to turn yellow.

4. HIV

The human immunodeficiency virus (HIV) continues to be one of the most common infectious illnesses, making it one of the biggest health problems on a global scale. In fact, it has ended the lives of more than 32 million people. At the end of 2018, there were approximately 37.9 million people diagnosed with HIV.

However, thanks to advancements in treatment, like the efficiency of preventive measures, the disease has become manageable. In this way, people infected with the virus can live without it affecting their day-to-day lives nor their quality of life.

Prevention of infectious illnesses

Although we’ve mentioned four of the most infectious illnesses on a global scale, that doesn’t mean they’re the only ones or the most dangerous. In fact, there are others like malaria, dengue, and meningitis that have killed millions of people.

As we mentioned at the beginning, good hygiene is fundamental for the prevention of this kind of illness. It’s also essential to get a quick and timely consultation in order to deal with what can easily be resolved. Medical advances are fantastic. However, infections also advance through resistance to medication. Prevention is always better.

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