Top 7 most terrifying infectious diseases in human history

Some infectious diseases not only cost people their lives, but also cause people to die painfully. In human history, there have been recorded 7 terrible infectious diseases, claiming countless lives, up to now, they are still the fear of many people.

The world's deadliest infectious diseases

Number 7: Tuberculosis

Tuberculosis has killed more people than any other infectious disease in history; Over a billion people have died in the last 200 years. The origin of the disease is unclear, but it has spread to several other species, including cattle.

Tuberculosis used to be a terror to the world because the death toll reached more than a billion people in 200 years.

Today, about a third of the world's population is thought to be infected with TB, in an inactive form. This is a condition in which bacteria are present in the body but controlled by the immune system. An infected person has no symptoms and cannot infect others.

The bacteria will reactivate in some people, causing them to have symptoms such as fever, sweating, weight loss, fatigue, cough, and coughing up blood.

Tuberculosis occurs in every country. Patients with weakened immune systems due to chemotherapy, HIV, or other underlying medical conditions are at higher risk for TB.

In 2015, there were 10.4 million new TB cases worldwide and 1.8 million deaths. Mostly in developing countries. TB infection and death rates have declined globally since the 1900s.

The emergence of antibiotics has made humanity conquer this disease. Without antibiotics, 70% of people with active TB infections will die. However, TB treatment is often complicated with 4 oral drugs for two months, followed by 2 oral antiretroviral drugs for the next 4 months. These drugs all have side effects, and if used incorrectly, can make TB bacteria resistant to the drugs.

In recent years, drug-resistant TB has been reported worldwide, most commonly in Russia, China and India. Treatment of drug-resistant TB is much more complicated, takes longer, is more likely to fail, and often uses more toxic drugs.

Number 6: Cholera

Cholera is an acute infectious diarrheal disease caused by the bacterium Vibrio cholerae, its main features are rapid transmission, rapid onset and high mortality. The main clinical symptoms are diarrhea and vomiting. The incubation period is usually 1 to 3 days. If not treated promptly, the patient can die from diarrhea and dehydration within hours.

Photo: Vibrio cholerae bacteria

Cholera is mainly caused by bacteria in sewage entering the human body, so water and food hygiene are the main causes of cholera. The feces of a cholera patient will contain Vibrio cholerae bacteria, which when released into the surrounding environment can also cause cholera and infect others.

According to estimates by the researchers involved, there are between 1.3 million and 4 million cases of cholera and 21,000 to 143,000 deaths worldwide each year. Cholera often occurs in areas with poor sanitation, famine, war, and crowded areas.

Number 5: Ebola

Ebola hemorrhagic fever is a highly contagious disease caused by the Ebola virus, first discovered by humans in Africa in the 1970s. Ebola hemorrhagic fever is a type of viral hemorrhagic fever. Withdrawal causes the most death, the patient will eventually die from bleeding throughout the body.

People with the disease often have a sudden high fever, sore throat, headache, muscle aches and weakness, then start diarrhea and vomiting. Usually within two weeks after the onset of illness, the whole body is covered with viral bleeding, the patient can die within 24 hours, the situation when death is very terrible.

Photo: Medical staff handle the body of an Ebola patient.

The incubation period of Ebola virus in the human body is usually from 2 to 21 days, transmission mainly through body fluids, including blood, vomit and feces of Ebola patients is the most contagious. More importantly, there is currently no effective treatment for Ebola, with a very high mortality rate, listed by the World Health Organization (WHO) as one of the most dangerous viruses to humans. People.

Number 4: Spanish Flu

Many people think that the flu is just a common mild illness, but the Spanish flu is no ordinary flu, it has directly caused the death of about 100 million people.

Patients with Spanish flu will have symptoms such as high fever, headache, loss of appetite, blue skin, muscle aches, loss of appetite, coughing up blood. The mortality rate in young people aged 20 to 35 is very high, many patients have no symptoms in the morning and develop the disease at noon, and die that same night.

The Spanish flu was directly responsible for the deaths of about 100 million people.

During World War I, the Spanish flu epidemic raged in the world, killing 25-40 million people within 6 months, Influenza was also the cause of the early end of World War I.

However, the Spanish flu has mysteriously disappeared after 18 months of raging, and the strains that cause it have not been fully identified to date.

Number 3: Plague - Black Death

Plague is also known as the Black Death, and it is usually endemic to rats. The spread of plague is through the bites of rodents and fleas that transmit pathogens from mice to humans, which in turn cause human-to-human disease.

This is a very contagious disease that can also be spread through the respiratory tract. If the plague was left untreated, the mortality rate was as high as 50-70%. Subsequent studies discovered that the pathogen of the plague was a bacterium, known as Yersinia bacillus or Yersinia pestis.

Photo: The body of a plague patient is brought into an isolation area

In human history, there have been many catastrophic plague pandemics, causing a sharp decline in the global population and paralysis of society. In the second half of the 20th century, humanity finally brought the plague under control, which is now very rare.

Number 2: Malaria

Malaria is an infectious disease caused by insects, specifically the female Anopheles mosquito that bites or transmits the blood of a carrier of the malaria parasite, thereby infecting the person with the parasite.

Malaria is one of the biggest killers in human history.

The main symptoms of the disease are sudden high fever and chills, accompanied by fatigue and headache. Malaria is one of the biggest killers in human history, and it seems to have always existed in human society, along with human development.

From about 5,000 years ago, malaria gradually spread from Africa to the world, until a global outbreak in the early 20th century. Over the past 100 years, malaria has caused about 300 million deaths. Worldwide, today more than 1 million people are infected and die from malaria.

Number 1: Smallpox

Smallpox, a serious infectious disease that causes great harm to humans, once infected with smallpox, symptoms of systemic toxicity such as sudden high fever, chills, headache, great fatigue, legs back pain hand. When the disease has progressed to a certain extent, the person will have a rash such as papules, pustules, burning, and herpes.

In the past, because there was no effective treatment, the mortality rate from smallpox was so high, survivors often left scars on their faces.

Photo: Smallpox virus

The smallpox virus is highly infectious and reproducing, and can persist for several months after the patient's death, and even a scab from an infected person can be contagious. It is estimated that around 500 million people worldwide have died from smallpox.

With the advent of vaccines, humans have finally eradicated smallpox. In 1980, the World Health Organization (WHO) announced that smallpox had been completely eliminated. To date, only a few strains of the disease have been kept in advanced laboratories.

However, there will still be new infectious diseases that challenge humanity, for the time being, it is Covid-19. But thanks to the advancement of medicine, humans have the ability to conquer infectious diseases and make great achievements in the control and prevention of infectious diseases.