What does smallpox mean?

variola virus

Smallpox is a serious infectious disease caused by smallpox virus, and it is also the only infectious disease in the world that has been eliminated by human beings so far. The average incubation period after smallpox virus infection is about 12 days (7- 17 days). The initial symptoms after infection include high fever, fatigue, headache, rapid heartbeat and back pain. Typical acne rash will appear after 2-3 days, which is obviously distributed on the face, arms and legs. At the beginning of the rash, there will be a red block area accompanied by a rash. After a few days, the lesion began to fester until the second week. In the next 3-4 weeks, it will develop into scabies and then slowly fall off. Smallpox is caused by pox virus infection, and patients will have pockmarked faces after recovery, hence the name "smallpox".

Virus origin

Smallpox may be a relatively harmless pox virus in domestic animals at first, but it has gradually evolved and adapted before it became a human disease. Later, people gradually discovered the accidental situation similar to vaccinia infection in humans. The fatal adaptation process of smallpox may occur after human beings entered the agricultural era, and people began to domesticate new animals and live with them, often in the same room. Smallpox may also come from human contact with wild animals, just as a few people in Central Africa are infected with monkeypox today.

The common virus is smallpox virus, which is a kind of smallpox and also a kind of orthopoxvirus. In addition to large smallpox, smallpox is also divided into medium smallpox and small smallpox. The symptoms of large smallpox, medium smallpox and small smallpox are exactly the same, and the infection mode is exactly the same. The difference between them is that about 25% of patients infected with large smallpox will die, the mortality rate of medium smallpox is about 12%, and only 1% of patients infected with small smallpox is life-threatening. ?

Symptoms of infection

The average incubation period after smallpox virus infection is about 12 days (7- 17 days). The initial symptoms after infection include high fever, fatigue, headache and back pain. Typical acne rash will appear after 2-3 days, which is obviously distributed on the face, arms and legs. At the beginning of the rash, there will be a red block area accompanied by a rash. After a few days, the lesion began to fester until the second week. Next [2]? It slowly develops into scabies in 3-4 weeks, and then slowly peels off.

Symptoms Benign smallpox symptoms In the first week after infection, the virus only spread quietly in patients. The patient will not have any symptoms, even if he suspects that he may be infected, he is not sure. By the ninth day or so, the first signs of the disease began to appear: headache, fever, nausea, back pain, and sometimes accompanied by some convulsions or insanity.

During this incubation period, some patients have nightmares that last for three or four days. Patients with fair skin often have scattered dark red spots on their faces, sometimes all over the body. At the end of the incubation period, the patient's high fever decreased and he felt that his condition was temporarily improved. It was at this time that smallpox virus began to produce its signature rash on patients to announce its existence. Usually, these flat red spots first appear on the patient's face, then quickly spread to the arms, chest, back and finally to the legs.

Rashes on the face, forearms and legs are denser than those in the center of the body. In the next few days, the flat acne rash began to swell, first a pimple, then a blister, then an pustule, then the pustule cracked and began to turn into a hard shell or scab, and this process also turned the poor patient into an ugly monster with swollen whole body. In the worst case, these pustules are dense. Make the patient's skin sallow. Patients with fair skin will have a faint blush around blisters or early pustules; In the papular stage, the whole skin will turn red. Many patients will die a few days before the rash, some will die soon if they persist for a week at most, and some will even be sent to the grave before the rash breaks out.

Once people are infected, they can only resign themselves to fate. Patients with explosive smallpox symptoms usually die within 3 to 5 days, and the cause of death is usually uncontrollable toxemia or massive bleeding. In the case of massive bleeding, a large amount of blood in the patient's body flows into the skin, throat, lungs, intestines or uterus. This kind of patients will not have typical papules or blisters, but just ordinary red or purple spots, petechiae or measles-like erythema. These symptoms can also occur when the human body is seriously infected and the blood coagulation function is seriously damaged. In the case of other malignant infections, smallpox virus will cause diffuse damage when it is seriously damaged in the tissue layer or deep skin. The patient died within 10 to 14 days after symptoms appeared. At this time, pustules were covered with pustules, and sometimes pustules would fuse. The skin lesions of patients with benign infection are confined to the epidermis and are not easy to cause secondary bacterial infection.

Viral characteristics

Smallpox is caused by smallpox virus of the same name. The cause of such great damage in history is closely related to the characteristics of smallpox. Smallpox virus spreads rapidly, and its speed of spreading through the air is amazing. Virus carriers are most contagious within 1 week after infection because their saliva contains the largest amount of smallpox virus. But smallpox may still be transmitted to others through the patient until the patient is scarred and desquamated.

There are different varieties of smallpox virus, which will cause different degrees of infection to human beings. Most smallpox patients will recover, and death often occurs within 1 or 2 weeks after onset, with a mortality rate of about 30%.

Spread history

Historians even call it "the greatest genocide in human history" not by guns, but by smallpox. In human history, smallpox, the Black Death, cholera and other plagues have caused an alarming number of deaths.

The earliest recorded smallpox outbreak occurred in ancient Egypt. The mummy of Egyptian Pharaoh Ramses V who died in BC 1 156 showed signs of smallpox rash.

/kloc-At the end of 0/5, when Europeans set foot on the American continent, there were 20-30 million indigenous people living here. After about 100 years, the indigenous population is less than100000. European colonists gave blankets used by smallpox patients to Indians. Subsequently, the plague raged, and mumps, measles, cholera, gonorrhea and yellow fever from Europe followed.

/kloc-in the 1970s, British doctor edward jenner discovered vaccinia, and human beings were finally able to resist smallpox virus. In the following 300 years, the disease made a comeback in Europe many times, and later scholars estimated that as many as 200 million people died of this plague.

1820s, Britain invented the vaccinia vaccine to prevent smallpox. The mortality rate of smallpox patients is still as high as one third. Later, developed countries gradually controlled the disease, but it is still prevalent in rural Africa.

From 1967, the last large-scale campaign to eliminate smallpox was carried out. At present, smallpox virus is only kept in the following two laboratories, namely the Centers for Disease Control and Prevention (CDC) in Atlanta, USA and the National Center for Virology and Biotechnology (VECTOR) in Novosibirsk, Russia, for research purposes.

The last natural patient with mild smallpox appeared in Somalia, Africa, on1October 26th, 1977+65438. Janet Parker, a British medical photographer, was infected with smallpox from the laboratory in 1978, becoming the last patient in the world. (Not long after, Professor Henry Bedson, the head of the laboratory, committed suicide. )

1979101On 26th October, the United Nations World Health Organization announced in Nairobi, Kenya, that smallpox had been eradicated all over the world, and held a celebration ceremony for this purpose. In recent two years, inspectors from the World Health Organization conducted a survey on the last four East African countries that have not yet declared smallpox eradication-Kenya, Ethiopia, Somalia and Djibouti, and found that these four countries have indeed eliminated the disease, so they released this historic news.

1980 in may, the world health organization announced that smallpox had been successfully eradicated. In this way, smallpox became the earliest human infectious disease that was completely eliminated, and at the same time, human beings knew the least about smallpox.

Smallpox killed millions of people before it was completely eliminated by the global vaccination campaign in 1980. These virus samples are only legally kept in two laboratories in the United States and Russia.

Heal history

Vaccines have been used to prevent smallpox for a long time. Sun Simiao, a famous doctor in China, used the pus from smallpox aphtha to prevent smallpox. After the Ming Dynasty, the method of human pox vaccination became popular. 1796, edward jenner, a British rural doctor, discovered a less dangerous inoculation method. He successfully injected an 8-year-old boy with vaccinia. The current smallpox vaccine is not made of smallpox virus, but of vaccinia virus. The antigens of vaccinia virus and smallpox virus are mostly the same and will not cause diseases to human body.

milestone

20 14 July, American scientists were recently sorting out a storage area of the National Institutes of Health (NIH) in Maryland. A scientist from the Food and Drug Administration (FDA) found six forgotten bottles of smallpox virus in a refrigerator. These bottles are all marked with smallpox, and 10 unmarked bottles are put in a carton. It seems that the date of these six bottles of freeze-dried virus is.

The cold room was originally part of NIH laboratory. In 1970s, the laboratory moved to the headquarters of FDA, and the cold room was also moved to FDA.

2065438+In July 2004, NIH immediately put the virus into a highly secure laboratory and informed the CDC of this discovery. The CDC research team transported the samples to Atlanta by government plane and sent them to the biosafety level 4 laboratory. Researchers will analyze these viruses overnight, and more research will reveal whether these viruses can grow in Petri dishes.

If they contain live viruses, these vials will be destroyed and the World Health Organization (WHO) will be invited to supervise the destruction. A department of the CDC is currently working with the FBI to investigate the source of these virus samples.

Although smallpox was eliminated in 1980, smallpox virus still exists. At present, smallpox virus specimens are kept in two places, one is the Center for Disease Control and Prevention in Atlanta, USA, and the other is the National Center for Virus and Biotechnology Research in Novosibirsk, Russia. Recently, it is difficult for scientists to decide whether the residual samples of smallpox virus should be eliminated. Dissenting scientists say that the key questions about smallpox virus have not been answered and the specimens should not be destroyed.

Security officials said that the virus discovered this time has not been leaked and will not pose a health threat to the employees who found it. The sample was later sent to Atlanta, Georgia for inspection, and the researchers confirmed that the sample contained smallpox virus DNA. Now they are trying to confirm whether the smallpox virus in the specimen is still biologically active.

Devil's smallpox forgotten in a bottle

On July, 2065438, scientists from the National Institutes of Health (NIH) accidentally discovered six bottles of smallpox virus that had been forgotten for decades.

According to international agreements, smallpox virus samples from all over the world can only be kept in two laboratories: the Centers for Disease Control and Prevention (CDC) in Atlanta, USA and the National Center for Virology and Biotechnology (VECTOR) in Novosibirsk, Russia, which is supervised by the World Health Organization (WHO).

There will be such a warning sign outside the laboratory where smallpox is preserved.

According to the CDC statement, there is no evidence that anyone has ever taken or used these viruses. Because these viruses have been freeze-dried, and smallpox virus will die after freeze-drying, NIH biosafety staff think these small bottles are not contagious.

1975.

In an interview on Tuesday, CDC officials said that he thought the bottle was kept at room temperature. But later that same day, FDA officials said that these virus samples had been kept in the refrigerator for decades.

The CDC thinks these vials are from the 1950s. At that time, many laboratories kept smallpox virus. But they are still investigating who kept these samples and why they appeared in this abandoned laboratory in Maryland.

According to ABC news, these small bottles were labeled as "smallpox", which is the scientific name of smallpox. At the same time, some unlabeled vials were also found. On July 1 day, after they were discovered, they were immediately protected and informed the CDC. The CDC sent three experts to collect the virus in the bottle.

The CDC statement said that on July 7, these bottles were safely transferred to the CDC's highly sealed facility in Atlanta for overnight polymerase chain reaction (PCR) testing. After testing, it was confirmed that smallpox virus DNA did exist in these six labeled bottles, but not in other bottles. Next, they will spend two weeks to test whether they can survive (that is, grow in tissue culture). After that, it will be destroyed under the full supervision of WHO.

1979, smallpox was basically eliminated by human beings due to the extensive vaccination of vaccinia. To this end, the United Nations World Health Organization also held a celebration ceremony. In the same year, laboratories around the world agreed to destroy smallpox samples or send them to either of the above two laboratories (CDC in the United States or VECTOR in Russia). According to the official statement at that time, by the early 1980s, all smallpox viruses except CDC and VECTOR had been eliminated.

Members of the global smallpox eradication certification Committee signed the certification in Geneva on February 9, 1979.

Newborns are not vaccinated now. Only scientists who study smallpox, specific medical personnel and others who may be exposed to the virus are vaccinated, because vaccination with vaccinia may have serious side effects (although few). The government can keep vaccines, because these vaccines do not contain smallpox virus, so they do not violate international agreements.