General characteristics of the disease
Smallpox is contagious viral infection, which can only infect humans.
This disease is characterized by general intoxication and peculiar rashes on the mucous membranes and skin, after which numerous scars almost always remain. This infection is caused by two types of viruses: the causative agent of smallpox (the mortality rate of those infected is 20-40%, and according to some data - about 90%) and the causative agent of alastrim (the mortality rate is about 1-3%).
The smallpox virus is highly resistant: it can survive on linen and in the dust of rooms for several days; it remains active in the patient’s crusts after desquamation in the dark for more than a year, and in the light for about 2.5 months.
The smallpox virus dies after half an hour when heated to 60 0 C, after 1-5 minutes - to 70-100 0 C and after 6 hours from exposure to ultraviolet irradiation. Alcohol can neutralize the smallpox virus in half an hour, hydrochloric acid, acetone and ether.
Epidemiology
A sick person is a source of infection with last days incubation of the virus until the scabs fall off.
The greatest danger is posed by patients whose symptoms of smallpox are blurred, which makes it difficult to recognize the disease, as a result of which the isolation of patients often occurs late.
However, the danger is not only the patient, but also the things with which he came into contact. The infection can be transmitted both by airborne droplets and airborne dust, through contact and household contact. Mechanical transmission of smallpox by flies is also possible. Susceptibility to infection in people who do not have immunity to it is almost one hundred percent. Children are most susceptible to smallpox infection. A person who has recovered from this infection acquires strong immunity for a long time, but not for life. Vaccination against smallpox provides immunity to the disease for 3-5 years, after which revaccination is necessary.
The smallpox virus was widespread on all continents, but today this disease has been defeated through mass vaccination in the countries of the world community. In 1980, smallpox was officially declared eradicated. Today, the smallpox virus is located in two laboratories belonging to the United States and Russia; the WHO has postponed the issue of its final destruction until 2014.
Symptoms of smallpox
Incubation period In the typical course of the disease, it lasts about 8-12 days.
For initial period Symptoms of smallpox are typical: chills, fever, severe thirst, vomiting severe pain in the sacrum, lower back and limbs, headache, dizziness, vomiting. In some cases, there may be a mild onset of the disease, with erased manifestations of infection.
On days 2-4, the above symptoms of smallpox are joined by an initial skin rash or hemorrhagic rash, localized on both sides of the chest up to armpits, on internal surfaces thighs and in the folds below the navel. A macular rash usually lasts for several hours, while a hemorrhagic rash lasts a little longer.
On day 4 clinical symptoms Smallpox begins to subside, the temperature drops, but pockmarks appear on the skin - a typical manifestation of this disease. Pockmarks begin as spots, then they turn into papules, which in turn become blisters, which later turn into pustules (suppuration). The last stages that pockmarks go through are the formation of crusts, their rejection and the formation of a scar. In addition to the skin, smallpox rashes, which then turn into erosions, also appear on the mucous membrane of the nose, larynx, oropharynx, bronchi, female genital organs, rectum, conjunctiva and other organs.
The 8-9th day of the disease is characterized by the stage of suppuration of the vesicles, which is accompanied by a deterioration in the well-being of patients and the appearance of signs of toxic encephalopathy (excitement, delirium, impaired consciousness).
Smallpox in children at this stage may be characterized by seizures. It takes 1-2 weeks for the pockmarks to dry out and fall off, after which numerous scars remain on the scalp and face. If the disease is particularly severe, those infected may die before the rash appears.
Vaccination against smallpox allows you to transfer the disease easily and without complications in case of infection. Vaccinated patients experience moderate malaise, mild signs of intoxication, a mild smallpox rash, and no pustules form, resulting in no scars on the skin. Milder forms of smallpox are also possible, characterized by short-term fever, the absence of severe disorders and rash. A special feature of vaccinated patients is also the length of the incubation period, which is 15-17 days. Recovery usually occurs within two weeks.
Complications of smallpox can be sepsis, iritis, keratitis, panophthalmitis, pneumonia, meningoencephalitis, encephalitis.
Treatment of smallpox
Symptoms of smallpox are the basis for specific studies, which will result in a final diagnosis.
Smallpox in children and adults in most cases has a typical clinical picture, therefore the treatment for these age groups is similar.
Due to the fact that effective means There were no treatments for smallpox for a long time; magical and “folk” methods of getting rid of the infection were widely used. Today, to treat smallpox, if necessary, antiviral drugs and anti-smallpox immunoglobulin can be used, which is administered intramuscularly in a dose of 3-6 ml. In order to prevent the addition of a bacterial infection, it is advisable to apply antiseptic drugs to the affected areas. In case of bacterial complications, antibiotics such as cephalosporins, macrolides, and semisynthetic penicillins are suitable for treating smallpox. With this disease, measures are necessary to promote detoxification of the body.
Dr. Hubert V.O. V late XIX century, used smallpox vaccination to treat the disease. Every day, infected people were given a vaccine against this infection, which significantly mitigated the symptoms of smallpox. Today it is impossible to say with certainty why this method treatment is not widespread.
Prevention of smallpox
Disease prevention measures include early diagnosis of infection, isolation of patients, quarantine, disinfection, and prevention of importation from other countries. As medical practice shows and world history, smallpox vaccination is the most important and effective way disease prevention.
Video from YouTube on the topic of the article:
In ancient novels you can often find the following description of appearance: “A face pitted with pockmarks.” Those who survived natural (or, as it is also called, black) smallpox forever had a mark - scars on the skin. They were formed due to the very characteristic feature diseases - pockmarks, which appear on the body of patients.
Today, smallpox no longer exists, although it was once considered one of the most terrible diseases of mankind.
Smallpox epidemics
The first mention of smallpox outbreaks dates back to the 6th century, but historians have suggested that some of the epidemics described by early chroniclers were similar to the same disease. For example, in the 2nd century, during the reign of the philosopher-emperor Marcus Aurelius, a pestilence struck Rome, probably caused by smallpox. As a result, the troops were unable to repel the barbarians due to a lack of soldiers: there was almost no one to recruit into the army - the disease struck a significant part of the empire's population.
The disease hit humanity in full force in the Middle Ages, when, due to non-compliance with hygiene rules, epidemics spread with lightning speed, mowing down cities and villages.
European countries suffered from smallpox until the twentieth century. In the 18th century it was the leading cause of death in European countries— smallpox even killed the Russian Emperor Peter II.
The latest serious outbreak of the disease in Western Europe happened in the 70s years XIX century, then it claimed about half a million lives.
Europeans brought smallpox to other countries, and it destroyed as many Indians as the guns of the palefaces. American colonists even used the disease as a biological weapon. There is a well-known story about how the indigenous people of the New World were given blankets infected with the smallpox virus. The Indians were dying from an unknown disease, and the colonists were seizing their lands.
Only widespread vaccination put an end to regular outbreaks of smallpox in developed countries.
Our victory
However, even after the widespread distribution of the vaccine, smallpox continued to take lives in poor countries in Africa and Asia in the 20th century. Sometimes the disease “visited” places that had long been familiar to it - for example, in Russia, the last outbreak of smallpox was recorded in the late 1950s. The virus was brought by a tourist from India; three people died from the disease.
In 1958, at the XIth session of the World Health Assembly, Deputy Minister of Health of the USSR, Academician Viktor Zhdanov, expressed an incredibly bold idea: smallpox can be completely defeated, this requires mass vaccination on a planet-wide scale.
- Virologist-scientist, epidemiologist, academician of the USSR Academy of Medical Sciences Viktor Mikhailovich Zhdanov
- RIA Novosti
- Vladimir Akimov
The idea of the Soviet scientist was initially met with hostility by the World Health Organization: general manager WHO Marolino Candau simply did not believe that this was possible. Nevertheless Soviet Union on his own initiative, he began donating millions of doses of smallpox vaccine to WHO for distribution in Asia and Africa. It was not until 1966 that the organization adopted a program for the global eradication of smallpox. The leading role in it was played by Soviet epidemiologists who worked in the most remote corners of the world.
11 years after the start of the global vaccination program, October 26, 1977, in Somalia last time history was diagnosed with smallpox.
The disease was finally declared defeated at the XXXIII WHO conference in 1980.
What if he comes back?
Is it possible that this deadly disease will return, the head of the laboratory of vaccine prevention and immunotherapy of allergic diseases at the I.I. Research Institute of Vaccines and Serums told RT. Mechnikov RAMS, professor Mikhail Kostin.
“Viruses can return, because virus strains are still preserved in special laboratories in Russia and the USA. This is being done just in case, in order to quickly create a new vaccine if necessary,” Kostin said. — The development of new vaccines against smallpox is still underway. So if, God forbid, such a need arises, then vaccination can be carried out.”
Since the 70s of the twentieth century, people have not been vaccinated against smallpox, Kostin noted, since the disease is considered eliminated, and “now a generation is being born that does not have immunity from smallpox.”
According to the professor, all infections are controllable; they are controlled by vaccination. If it is not carried out, then the infection that has not been completely defeated threatens to become uncontrollable, and this can lead to severe consequences, especially against the background of calls heard here and there to refuse vaccinations.
- Vaccination against smallpox
- Reuters
- Jim Bourg
To date, humanity has defeated not only smallpox - the list of deadly diseases that have become a thing of the past is gradually expanding. Such sad companions of humanity as mumps, whooping cough or rubella are close to extinction in developed countries. Until recently, the vaccine against the polio virus had three serotypes (varieties). It has already been proven that one of them has been eliminated. And today the vaccine against this disease contains not three varieties of the strain, but two.
But if people refuse vaccines, then “disappearing” diseases may return.
“An example of the return of diseases is diphtheria,” Kostin commented on the situation. — In the nineties, people massively refused vaccination, and the press also welcomed this initiative. And in 1994-1996 there was no diphtheria anywhere on the planet, and only former Soviet republics faced with its epidemic. Experts came from other countries to see what diphtheria looks like!”
Smallpox is an extremely dangerous disease, the victims of which at one time were tens and even hundreds of thousands of people around the globe. Fortunately, today this disease has been completely eliminated. Nevertheless, information about what the disease is, how dangerous it is and what complications it is associated with will be of interest to many readers.
Smallpox: pathogen and its main characteristics
Of course, many people are interested in questions about what causes such a dangerous disease. The causative agent of smallpox is the DNA virus Orthopoxvirus variola, which belongs to the family Poxviridae. This virion has small sizes and relatively complex structure. The basis of the outer membrane is lipoproteins with glycoprotein inclusions. The inner shell contains a non-cleoprotein complex, which consists of specific proteins and a linear double-stranded DNA molecule.
It is worth noting that the variola virus is unusually resistant to environmental influences. At room temperature, virions persist in sputum and mucus for about three months, and in smallpox crusts even longer - up to one year. The pathogen tolerates the effects of high and low temperatures. For example, with strong cooling (-20 o C), the infection remains virulent for decades. The virus dies when exposed to a temperature of 100 degrees, but only after 10-15 minutes.
Variola virus: history of discovery
In fact this infection known to mankind for a long time. Today, no one can say exactly when the virus evolved. Previously, it was believed that the first outbreaks of this disease were recorded several thousand years ago - in the fourth millennium BC in the territory of Ancient Egypt. However, today scientists are inclined to believe that it was the so-called camel pox.
The first outbreaks of black smallpox were reported in China in the 4th century AD. Already in the sixth century, the disease struck Korea and then Japan. Interestingly, in India there was even a goddess of Smallpox, who was called Mariatale. This deity was depicted as young, beautiful woman in red clothes - they tried to appease this lady with a bad character (as evidenced by ancient myths).
Today it is not known exactly when smallpox appeared in Europe. However, some scientists believe that the infection was brought to this part of the continent by Arab troops. The first cases of this disease were recorded in the sixth century.
And already in the 15th century, smallpox epidemics in Europe became commonplace. Some doctors of that time even argued that every person should suffer such a disease at least once in their life. From the Old World, the infection spread to the American continent - in 1527, an outbreak of the disease took the lives of millions of inhabitants of the New World, including some indigenous tribes. In order to describe the scale of the defeat, it is worth noting that in the 17th century in France, when the police were looking for a person, they indicated as a special sign that he had no traces of smallpox.
The first attempt to protect against infection was variolation - this procedure consisted of infecting a healthy person with pus from the pustule of an infected patient. Most often, smallpox vaccinated in this way was much easier, and some people even developed lasting immunity. By the way, it's interesting that this technique was brought to Europe from Turkey and Arab countries, where variolation was considered the only way to combat smallpox. Unfortunately, such a “vaccination” often itself became the source of a subsequent outbreak of the disease.
First ever vaccination
Not everyone knows that it was smallpox that became the impetus for the invention of the first vaccine in the history of medicine. Due to constant epidemics of this disease, interest in it has increased. In 1765, doctors Fewster and Sutton, speaking about a specific form of smallpox that affected cows, said that infecting a person with this infection helps him develop resistance to smallpox. However, the London Medical Society considered these observations to be an accident.
There is evidence that in 1774, farmer Jestley successfully inoculated his family with the cowpox virus. However, the honor of the discoverer and inventor of the vaccine belongs to the naturalist and physician Jenner, who in 1796 decided to vaccinate publicly, in the presence of doctors and observers. His study involved milkmaid Sarah Nelmes, who accidentally contracted cowpox. It was from her hand that the doctor removed samples of the virus, which he then injected into an eight-year-old boy, D. Phipps. In this case, the little patient’s rash appeared only at the injection site. A few weeks later, Jenner injected the boy with samples of smallpox - the disease did not manifest itself in any way, which proved the effectiveness of such vaccination. Vaccination laws began to be passed in 1800.
Routes of transmission
Of course, one of the important questions is how exactly smallpox is transmitted. The source of infection is a sick person. Isolation of viral particles in external environment occurs throughout the entire period of the rash. According to research, the disease is most contagious in the first ten days after symptoms appear. It is worth noting that the facts of latent carriage of infection and the transition of the disease to a chronic form are unknown to science.
Since the pathogen is localized mainly on the mucous membranes of the mouth and upper respiratory tract, viral particles are released in environment mainly during coughing, laughing, sneezing or even talking. In addition, crusts on the skin can also be a source of virions. How is smallpox spread? The transmission routes in this case are aerosol. It is worth noting that the virus is very contagious. The infection spreads to people who are in the same room with the patient, and often travels over fairly long distances along with the air current. For example, there has been a tendency for the virus to quickly spread in multi-storey buildings.
A person is very susceptible to this disease. The probability of infection upon contact with the virus is approximately 93-95%. After an illness, the body forms a strong immune system.
Pathogenesis of the disease
During aerosol transmission of infection, the variola virus primarily affects the cells of the mucous membrane of the nasopharynx, gradually spreading to the tissues of the trachea, bronchi and alveoli. During the first 2-3 days, viral particles accumulate in the lungs, after which they penetrate the lymph nodes - this is where their active replication begins. Together with lymph and blood, the virus spreads to the tissues of the liver and spleen.
After 10 days, the so-called secondary viremia begins - damage to the cells of the kidneys, skin, central nervous system. It is at this time that the first external signs of the disease begin to appear (in particular, characteristic skin rashes).
Incubation period of the disease and first signs
What are the features of the clinical picture? What does smallpox look like? The incubation period for such a disease usually lasts from 9 to 14 days. Occasionally this time can increase to three weeks. In modern medicine, there are four main stages of the disease:
- prodromal period;
- rash stage;
- period of suppuration;
- convalescence stage.
The prodromal stage of smallpox is the so-called period of precursors of the disease, which lasts on average from two to four days. At this time, there is a significant increase in body temperature. In addition, all the main signs of intoxication are present - patients complain of muscle pain, body aches, as well as severe chills, weakness, fatigue, and headache.
Around the same time, a rash appears on the skin of the chest and thighs, which resembles the exanthema of measles. As a rule, by the end of the fourth day the fever subsides.
Main symptoms of the disease
Of course, other changes follow that accompany smallpox. Symptoms begin to appear on the fourth or fifth day. At this time, the period of appearance of characteristic smallpox rashes begins. At first, the rash appears as small roseola, which then develop into papules. After another 2-3 days, characteristic multi-chamber vesicles can already be seen on the skin - these are smallpox vesicles.
The rash can cover almost any area of the skin - it appears on the face, torso, limbs and even the soles of the feet. Around the beginning of the second week of the disease, a period of suppuration begins. At this time, the patient's condition worsens significantly. The pockmarks begin to merge at the edges, forming large pustules filled with pus. At the same time, the body temperature rises again, and the symptoms of intoxication of the body worsen.
After another 6-7 days, the abscesses begin to open, forming necrotic black crusts. In this case, patients complain of unbearable skin itching.
At 20-30 minutes after the onset of the disease, the period of convalescence begins. The patient's body temperature gradually normalizes, the condition improves significantly, and the skin tissue heals. Quite deep scars often form in place of pockmarks.
What complications are associated with the disease?
Smallpox is an extremely dangerous disease. The occurrence of certain complications with such a disease can hardly be considered rare. Most often, patients experience infectious-toxic shock. In addition, certain inflammatory diseases of the nervous system are possible, in particular neuritis, myelitis, and encephalitis.
On the other hand, there is always the possibility of a secondary bacterial infection. The situation of patients with smallpox was often complicated by the formation of phlegmons, abscesses, as well as the development of otitis, lymphadenitis, pneumonia, osteomyelitis and pleurisy. One more possible complication is sepsis.
Basic methods for diagnosing the disease
How is smallpox determined? The causative agent of the disease is discovered during special studies. First of all, the doctor will place a patient suspected of having this disease in quarantine. After this, it is necessary to take tissue samples - these are smears of mucus from the mouth and nose, as well as the contents of vesicles and pustules.
Subsequently, the pathogen is sown on a nutrient medium and examined using electron microscope using immunofluorescent methods. In addition, the patient's blood is taken for analysis, which is then examined for the presence of specific antibodies produced by the body in case of a similar disease.
Is there an effective treatment?
Once again it is worth noting that in modern world There is no disease called smallpox. Treatment, however, exists. The patient must be hospitalized, placed in quarantine, provided with rest, bed rest, and high-calorie food.
The basis of therapy is antiviral drugs. In particular, the drug “Metisazon” is considered quite effective. In some cases, immunoglobulins are additionally administered. It is very important to reduce the symptoms of intoxication and speed up the process of removing toxic substances from the body. For this purpose, patients are given intravenous infusions of glucose and hemodez solutions.
Affected skin also requires special care. In particular, areas of the rash are regularly treated with antiseptic agents. Quite often, a viral disease is accompanied by bacterial infection, as evidenced by severe suppuration of the pustules. In order to prevent complications, in particular sepsis, patients are prescribed antibacterial agents. Antibiotics from the group of macrolides, semisynthetic penicillins, and cephalosporins are considered quite effective in this case. Sometimes anti-inflammatory drugs, in particular glucocorticoid drugs, are also included in the course of therapy.
For lesions of the cardiovascular system, appropriate symptomatic treatment is carried out. Severe pain is an indication for the use of analgesics and sleeping pills. Sometimes patients are additionally prescribed multivitamin complexes, which stimulates the functioning of the immune system.
By the way, people with whom the patient came into contact must also be isolated and vaccinated no later than the first three days.
Basic preventive measures
As mentioned earlier, smallpox has now been completely eradicated - this was officially announced on May 8, 1980 by the UN General Assembly. By the way, the last case of the disease was recorded in 1977 in Somalia.
The victory over smallpox was achieved through mass vaccination of the population over several generations. The smallpox vaccine contained a virus that was similar to the pathogen, but could not cause harm to the body. Such drugs were really effective - the body developed lasting immunity to the disease. Currently, no vaccinations are required. The only exceptions are scientists who work with virus samples.
If there is an infection, the patient is indicated for complete quarantine. Moreover, people who have been in contact with an infected person must also be isolated for 14 days - this is what smallpox prevention looks like in the modern world.
