Viruses are microscopic organisms that consist of genetic material, RNA or DNA, surrounded by a coat of protein, lipid (fat), or glycoprotein. They can infect animals, plants, fungi.

Although there is no known cure for virus, vaccination can prevent them from spreading.

Let's take a look at some of the viral diseases that has plagued mankind.

1. Novel Coronavirus
Discovered in China late 2019, this virus nicknamed COVID-19 has spread rapidly across countries with China and Italy suffering the highest outbreak.

According to W.H.O, The most common symptoms of COVID-19 are fever, tiredness, and dry cough. Some patients may have aches and pains, nasal congestion, runny nose, sore throat or diarrhea.

COVID-19 can spread from person to person through small droplets from the nose or mouth which are spread when a person with carrier coughs or exhales. These droplets land on objects and surfaces around the person. Other people then catch COVID-19 by touching these objects or surfaces, then touching their eyes, nose or mouth. People can also catch COVID-19 if they breathe in droplets from a person with COVID-19 who coughs out or exhales droplets.

2. H.I.V (Human Immunodeficiency Virus
This virus makes a person more vulnerable to other infections and diseases by attacking the cells that helps the human body fight off infections.

It is spread by contact with bodily fluid of infected persons during unprotected sex or through sharing injection drug equipment.

HIV can lead to the disease AIDS (acquired immunodeficiency syndrome) if not treated.

3. Measles
Measles aso known as rubeola or morbilli is a viral disease that spread rapidly.

Symptoms include fever, running nose, dry hacking cough, watery eyes and a reddish brown rash.

Well the good news about this virus is person gains immunity for the rest of their life. They are very unlikely to contract measles a second time.

4. Hepatitis
This is an inflammation and damage to the liver cells. There are different types and causes, but the symptoms can be similar

Hepatitis are categorised into three main types known as hepatitis A, B, and C. Each is caused by a different virus. All three types can be acute, lasting for 6 months or less, and types B and C can be chronic, lasting for longer.

Symptoms of the early stage of hepatitis which is called acute hepatitis include diarrhoea, fatigue, loss of appetite, fever, nausea, slight abdominal pain.

5. Polio
Polio, also known as poliomyelitis and infantile paralysis, is a highly contagious viral infection that can lead to paralysis, breathing problems, or even death.

Polio, in its most severe forms, can cause paralysis and death. However, most people with polio do not display any symptoms or become noticeably sick. When symptoms do appear, they differ depending on the type of polio.

Symptomatic polio can be broken down further into a mild form, called non-paralytic or abortive polio, and a severe form called paralytic polio that occurs in around 1 percent of cases.
Many people with non-paralytic polio make a full recovery. Unfortunately, those with paralytic polio generally develop permanent paralysis.