5 types of epidemics across the century

Here are five of the most terrifying diseases that have claimed many lives worldwide in the history of human development.

>>>Why does the disease often become heavy at night?

Flu

Influenza viruses are constantly changing and can spread from pets to humans. Influenza virus strains have caused the most dangerous epidemics in recent times and have claimed millions of deaths worldwide.

An emergency hospital during the 1918 influenza pandemic at Funsston, Kansas.

Historically, a flu pandemic occurred in 1918 killing about 50 million to 100 million people. In 2009 a pandemic of swine flu also killed thousands of lives. In addition, there was a flu in Asia in 1957, a flu in Hong Kong in 1968.

In seasonal flu, about 15% of the population is infected by the virus. According to the World Health Organization (WHO), this disease occurs every year, leading to a situation of between 3 million and 5 million people with severe flu and about 250,000 to 500 thousand deaths each year in the world.

SARS

SARS stands for Severe Acute Respiratory Syndrome , caused by SARS coronavirus . For the first time this virus infects the human body at the end of 2002 in China. Within a few weeks, it spread to 37 countries through air travel. SARS has infected about 8,000 people worldwide, of whom about 800 die.

Most patients infected with SARS coronavirus develop pneumonia. The virus is spread by contact between an infected person and a person who is not sick. The infection is thought to be through a patient's fluid (sputum, nasal discharge, saliva .) from an infected person coughing or sneezing. It can also be spread by touching objects that are attached to the fluid. SARS can also spread more widely in the air.

HIV AIDS

HIV stands for the virus that causes the acquired immunodeficiency syndrome in humans. When entered into the human body, this virus attacks and disrupts the immune system, leading to a condition called AIDS (acquired immunodeficiency syndrome). Without a well-functioning immune system, people with AIDS are more likely to suffer from other injuries, often causing infections, leading to death.

The virus spreads through blood, semen and other body fluids. Most people infected with HIV are sexually active or sharing injections with infected people.

Since its inception in the 1980s, HIV has infected 60 million people and has caused about 30 million deaths.

According to the Centers for Disease Control and Prevention (CDC), in the United States, about 50,000 people are infected with HIV each year. At the end of 2009, 1.1 million people lived with HIV. It is estimated that about 18% of people with this disease do not know they are infected. Around the world, in 2010, there were about 1.8 million deaths; In 2011, there were about 2.5 million more HIV infections.

Malaria

Plasmodium malaria parasites enter human blood through mosquito bites and they travel to the liver. Eventually they escape the liver to invade the bloodstream, infecting red blood cells, and disrupting blood supply to other organs.

Mosquito-borne malaria since ancient times has continued to become a global problem. According to WHO, in many parts of the world, the parasite of this disease is resistant to some anti-malarial drugs.

In 2010, an estimated 219 million people worldwide were infected and 660,000 people died of malaria. The disease is common in tropical regions like Africa, Asia and the Americas, of which about 90% of the disease occurs in Africa.

Tuberculosis

Tuberculosis caused by Mycobacterium tuberculosis . This disease is considered 'killer' second only to HIV / AIDS.

Over the past two decades, the death rate of TB infection has decreased by almost half. In 2012, 8.6 million people were infected with tuberculosis, of which 1.3 million died. More than 95% of deaths occur in low- and middle-income countries.

According to WHO, although tuberculosis can be cured, the concern of the disease is that its pathogen is resistant to most specific drugs that are widely released in all countries.