People often get confused with the words epidemic and pandemic. The epidemic is an outbreak of a disease that spreads at a jet speed and impacts many lives. There will be a massive rise in the cases in the people who are prone to the epidemic disease. The increase in the number of cases is never predicted. The outbreak can be geographically or in the community.
The epidemic is the term used to describe a disease that has grown in huge numbers and is out of control. When the disease is called an epidemic means it is spread like wildfire. The epidemic that shook the world is swine flu in 1918, measles in 1981 to 1991, and recently in 2014 whopping cough.
The infection would spread to a huge population in a short time. The epidemic would spread in the community or a region than its normal expectancy. It is easy to specify the community or region that would be affected due to the epidemic.
The epidemic disease need not require being contagious. It is an unusual occurrence of disease or a health-related behavior in the community or a region.
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What are the causes of epidemic disease?
There are many factors for the cause of infectious diseases, and few of them include:
- There is a sudden change in the host population due to the increase of stress on the vector species.
- Change in the pathogen genetically, or there is a new pathogen that got into the host population.
- The epidemic increases with the reduction in the immunity of the new or existing pathogen below its equilibrium.
- The outbreak of the epidemic is due to the contaminated water and poor sanitation in different areas. These are the places where the population and animals would migrate to another place and carry the disease.
- There could be seasonal epidemics. The best example is the whopping cough that occurs in the spring season, and the measles would outbreak in the winter or in March. The influenza is a flu that would badly affect the respiratory tract, and the patients will have a sore throat. This type of disease is caused in winter.
- The disease would spread through infection from person to person, or it can happen even when an animal or a person gets in contact or from the environment.
- An outbreak can also occur when people are exposed to radioactive chemicals and harmful pollutants. The best example of this is Minamata disease, which takes a toll on the lives of many people who are exposed to mercury.
- The epidemic can also occur due to disasters such as floods, storms, droughts, and so on.
Different types of epidemics
Common source epidemic disease
The common source epidemics occur when exposed to infectious things. It can be due to the contamination of air, water, food, and soil due to harmful pollutants and toxic chemicals.
The best example of this type of epidemic is Minamata disease, which has occurred due to the outbreak of Bhopal gas in India. The disease attacked the humans when they ate the fish that has high levels of methyl mercury.
There are two types of common source epidemics. These include:
Point source epidemic
It is also known as a single-source epidemic. It occurs when you are exposed to the epidemic disease agent, and the cases would increase in just an incubation period. The best example of this type of epidemic is food poisoning.
There are an increase and decrease in cases due to this epidemic. It can be explosive, and the clusters would increase in a short time.
Continuous epidemic
If the epidemic is persisting after one incubation period, then it is termed a continuous epidemic. The disease would spread at a rapid pace. The exposure would be from the same source and for a long time. However, it can be continuous or intermittent.
The best example of this is the prostitute, who is the main reason for the gonorrhea outbreak. The person can infect other people in a certain period. Another example of a continuous epidemic is Legionnaire’s disease, which attacked in Illinois.
It is a respiratory disease that was a continuous outbreak. It continued after one incubation period, but there are no infected cases found in the people who came in contact with the person who was ill.
Propagated epidemic
It is an infectious disease where the infectious agent will spread from a person to another person. The best examples are polio and hepatitis A. There is a steep rise or fall in the epidemic over a while.
The transmission of disease would spread until the people who are vulnerable to it are reduced. The speed at which this type of epidemic would spread relies on the immunity power of the individual or the times at which they come in contact with the infected.
Mixed epidemic
It is the epidemic that has the traits of both the propagated and common source epidemics. The epidemic will begin at a common source and would follow the propagated spread. The most common mixed type of epidemics would be due to foodborne infections.
Best examples of epidemic diseases
The third cholera
The period in which this disease has claimed the lives of many is from 1852 to 1860. It is a waterborne disease that is spread through bacteria. It is the third-largest outbreak globally and was started in India and spread in different parts of India.
Asian flu
This epidemic disease was attacked in 1957 and claimed the lives of many people in China.
SARS (Severe Acute Respiratory Syndrome)
SARS attacked in 2003 and is a respiratory tract infection that is caused due to the coronavirus. It is found to be transferred from animals to humans. It took a toll on the lives of many people.
Ebola
Many people are vulnerable to this disease in 2014. It is a horrifying virus that would result in fever, diarrhea, and fever. This disease is spread from wild animals and is fatal to the human population.
HIV
HIV is the disease that is claiming the lives of many people until today. It was started in 1960. It is spread to humans from chimpanzees. The virus would take a toll on the immune power of the human body. There are around 25 million people who are lost to this disease.
Lassa fever
Though the death rate of this disease is 1%, 1 out of 5 people is infected with this disease. It is caused due to a virus that takes a toll on the organs. There are 80% of people who are infected with this disease showed no symptoms of it.
Nipah virus
It claimed the lives of humans and animals and identified in 1998. However, there is no treatment available to diagnose patients who are vulnerable to this virus.
Rift valley virus
Though it affects animals, the symptoms of this virus seen in humans. The virus would reside in the body for seven days. There are only a few people who are severely affected by this virus.
