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What is the pathogen of smallpox. Smallpox: The Eradicated Virus That Shaped Human History

by alexxlab

What was the origin of smallpox. How did smallpox spread globally. What were the early control efforts for smallpox. How was smallpox eradicated worldwide. What were the last known cases of smallpox.

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The Ancient Origins and Global Spread of Smallpox

Smallpox, a devastating disease that plagued humanity for millennia, has a history as old as civilization itself. While its exact origins remain shrouded in mystery, evidence suggests that smallpox has been a human affliction for at least 3,000 years. Egyptian mummies bearing smallpox-like rashes provide tangible proof of its ancient presence.

The earliest written accounts of a disease resembling smallpox emerged in China during the 4th century CE. Subsequently, similar descriptions appeared in India in the 7th century and Asia Minor in the 10th century. These early records mark the beginning of our documented understanding of this formidable pathogen.

Smallpox’s Journey Across Continents

As human civilizations expanded and exploration flourished, smallpox found new pathways to spread across the globe. Trade routes became conduits for the virus, allowing it to reach far-flung corners of the world. Here’s a timeline of smallpox’s global dissemination:

  • 6th Century: Increased trade with China and Korea introduces smallpox to Japan
  • 7th Century: Arab expansion carries smallpox into northern Africa, Spain, and Portugal
  • 11th Century: The Crusades further propagate smallpox throughout Europe
  • 15th Century: Portuguese occupation of western Africa brings smallpox to the region
  • 16th Century: European settlers and the African slave trade import smallpox to the Caribbean, Central America, and South America
  • 17th Century: North America experiences smallpox through European settlement
  • 18th Century: British explorers introduce smallpox to Australia

This global spread of smallpox had devastating consequences for populations with no prior exposure or immunity to the virus. In many cases, it decimated entire communities and played a significant role in shaping the course of history.

The Deadly Impact of Smallpox on Human Populations

Smallpox was a scourge that instilled fear in populations worldwide. Its impact was both immediate and long-lasting, leaving survivors permanently marked. But just how deadly was smallpox?

On average, 3 out of every 10 people infected with smallpox succumbed to the disease. This 30% mortality rate made smallpox one of the most feared diseases in human history. Those who survived often bore the physical reminders of their ordeal in the form of disfiguring scars, which could be severe and lifelong.

The psychological impact of smallpox epidemics cannot be overstated. Communities lived in constant fear of outbreaks, knowing that once the disease took hold, it could spread rapidly and with deadly efficiency. This fear drove early efforts to control and prevent the disease, leading to some of the first organized public health initiatives in history.

Early Control Efforts: From Variolation to Vaccination

In the face of such a deadly threat, human ingenuity sought ways to combat smallpox. The earliest attempts at control came in the form of variolation, a precursor to modern vaccination. But what exactly was variolation, and how did it work?

Variolation, named after the variola virus that causes smallpox, involved exposing healthy individuals to material from smallpox sores. This was done by either scratching the material into the skin or having the person inhale it through the nose. While variolation often resulted in a mild case of smallpox, it provided immunity against future infections.

Although variolation was certainly risky—some people died from the procedure—it had a significantly lower mortality rate compared to naturally acquired smallpox. This made it an attractive option in many parts of the world where smallpox was endemic.

The Birth of Vaccination: Edward Jenner’s Breakthrough

The true revolution in smallpox prevention came in 1796 with Edward Jenner’s groundbreaking work. Jenner, an English doctor, made a crucial observation: milkmaids who had contracted cowpox seemed to be immune to smallpox. This insight led to a series of experiments that would change the course of medical history.

Jenner’s most famous experiment involved James Phipps, the 8-year-old son of his gardener. Jenner inoculated Phipps with material from a cowpox sore on the hand of Sarah Nelmes, a milkmaid. Months later, Jenner exposed Phipps to smallpox multiple times, but the boy never developed the disease.

This success led Jenner to publish his findings in 1801 in a treatise titled “On the Origin of the Vaccine Inoculation.” In this work, Jenner expressed his hope for the “annihilation of the smallpox, the most dreadful scourge of the human species.” His method, which he called vaccination (from the Latin ‘vacca’ for cow), gradually replaced variolation as the preferred method of smallpox prevention.

The Evolution of Smallpox Vaccines

While Jenner’s initial vaccine used cowpox, the virus used in smallpox vaccines eventually changed. At some point in the 19th century, vaccinia virus replaced cowpox as the basis for smallpox vaccines. But why did this change occur, and what impact did it have?

The shift to vaccinia virus was likely due to its ability to provide effective immunity against smallpox while causing fewer side effects than cowpox. Vaccinia virus, while closely related to both cowpox and smallpox, had characteristics that made it an ideal vaccine candidate.

This evolution in vaccine production played a crucial role in the eventual eradication of smallpox. The development of freeze-dried vaccines in the 20th century further improved vaccination efforts, as these vaccines remained stable for longer periods and could be transported more easily to remote areas.

Technological Advancements in Vaccine Delivery

As vaccine production improved, so did the methods of delivery. One significant innovation was the development of the bifurcated needle in the 1960s. This simple tool revolutionized mass vaccination campaigns. But what made the bifurcated needle so special?

  • Efficiency: The bifurcated needle could deliver a precise dose of vaccine with minimal waste
  • Ease of use: It required minimal training to use effectively
  • Cost-effectiveness: The needles were inexpensive to produce and could be reused after sterilization
  • Speed: Vaccinators could inoculate more people in less time compared to earlier methods

These advancements in vaccine technology and delivery methods set the stage for the most ambitious public health campaign in history: the global eradication of smallpox.

The Global Smallpox Eradication Program: A Monumental Undertaking

In 1959, the World Health Organization (WHO) embarked on an ambitious plan to rid the world of smallpox. This initiative marked the first time in history that a concerted, global effort was made to eradicate a disease. However, the early years of the program faced significant challenges. What were these obstacles, and how were they overcome?

The initial eradication campaign struggled with several key issues:

  • Lack of funding: Many countries could not allocate sufficient resources to the program
  • Shortage of personnel: Trained healthcare workers were in short supply in many affected regions
  • Limited vaccine supply: There weren’t enough vaccine donations to meet global needs
  • Inconsistent commitment: Some countries didn’t prioritize smallpox eradication efforts

Despite these challenges, the program persevered. By 1966, progress had been made, but smallpox remained widespread in South America, Africa, and Asia. It was clear that a more intensive approach was needed.

The Intensified Eradication Program: A Turning Point

In 1967, the WHO launched the Intensified Eradication Program, marking a new chapter in the fight against smallpox. This reinvigorated effort brought together several key elements that would ultimately lead to success:

  1. Improved vaccine production: Laboratories in endemic countries began producing higher-quality, freeze-dried vaccines
  2. Introduction of the bifurcated needle: This innovation greatly improved vaccination efficiency
  3. Establishment of a case surveillance system: This allowed for rapid identification and containment of outbreaks
  4. Mass vaccination campaigns: These targeted high-risk areas and populations

The Intensified Eradication Program made steady progress. By the time it began in 1967, smallpox had already been eliminated from North America (1952) and Europe (1953). The program then systematically tackled the remaining strongholds of the disease:

  • 1971: Smallpox eradicated from South America
  • 1975: Asia declared free of smallpox
  • 1977: Last case of endemic smallpox reported in Africa

This systematic approach, combining improved technologies with strategic planning and international cooperation, brought humanity to the brink of a historic achievement: the complete eradication of a human disease.

The Final Cases: Smallpox’s Last Stand

As the global eradication effort neared its conclusion, the world watched with bated breath as the last cases of smallpox were identified and contained. These final instances of the disease represent both the culmination of decades of work and poignant reminders of smallpox’s devastating impact. But who were the last individuals to contract this once-ubiquitous disease?

The last known natural case of variola major, the more severe form of smallpox, occurred in October 1975. The patient was Rahima Banu, a three-year-old girl from Bangladesh. Her case marked the end of smallpox in Asia and represented a significant milestone in the eradication program. Rahima was isolated at home with 24-hour guards to prevent further spread, and an intensive vaccination campaign was carried out in the surrounding area.

The very last case of endemic smallpox in the world was recorded in Somalia in October 1977. Ali Maow Maalin, a hospital cook in Merca, contracted the milder form of the disease, variola minor. His case prompted a two-year intensive surveillance period to ensure no further cases emerged.

The Tragic Postscript: Janet Parker

While Ali Maow Maalin’s case marked the end of endemic smallpox, there was one final, tragic chapter in the smallpox story. In 1978, Janet Parker, a medical photographer at the University of Birmingham in England, became the last person to die from smallpox. Her case was the result of a laboratory accident, highlighting the ongoing risks of working with the virus even after its eradication in the wild.

Parker’s death led to stricter protocols for handling smallpox samples in laboratories and accelerated efforts to destroy remaining stocks of the virus. It also served as a somber reminder of the disease’s lethal potential, even in its final moments as a threat to human health.

The Legacy of Smallpox Eradication

On May 8, 1980, the 33rd World Health Assembly officially declared smallpox eradicated. This announcement marked the first time in history that humans had completely eliminated a disease. But what does this unprecedented achievement mean for global health, and what lessons can we draw from it?

The eradication of smallpox stands as one of the greatest triumphs in medical history. It demonstrates the power of global cooperation, scientific innovation, and persistent public health efforts. Some key impacts of this achievement include:

  • Lives saved: Millions of people have been spared from death or disfigurement
  • Economic benefits: The world saves an estimated $1 billion annually in smallpox prevention and treatment costs
  • Scientific advances: The strategies developed for smallpox eradication have informed other disease control efforts
  • Inspiration: The success of smallpox eradication has motivated efforts against other diseases like polio and guinea worm

However, the legacy of smallpox is not without complications. The existence of smallpox virus samples in secure laboratories continues to spark debate about the potential risks and benefits of retaining the virus for research purposes.

Lessons for Future Disease Eradication Efforts

The smallpox eradication campaign provides valuable insights for tackling other global health challenges. What key lessons can we draw from this success story?

  1. Global cooperation is crucial: The involvement of all countries was necessary for success
  2. Adapt strategies to local contexts: Tailoring approaches to different regions improved effectiveness
  3. Combine vaccination with surveillance: This dual approach was more effective than vaccination alone
  4. Invest in research and innovation: Developments like the bifurcated needle were game-changers
  5. Maintain political will and funding: Consistent support was essential for seeing the program through to completion

These lessons continue to inform global health initiatives today, from ongoing efforts to eradicate polio to strategies for controlling emerging infectious diseases.

Smallpox in the Modern Era: Ongoing Concerns and Future Challenges

Despite its eradication, smallpox continues to be a topic of discussion in public health and biosecurity circles. What are the ongoing concerns related to smallpox, and what challenges might we face in the future?

One primary concern is the potential for smallpox to be used as a biological weapon. Although the virus officially exists only in two secure laboratories—one in the United States and one in Russia—there are fears that undeclared stocks might exist elsewhere. This possibility has led to ongoing debates about whether to destroy the remaining known samples or retain them for research purposes.

Another challenge is maintaining smallpox expertise in a post-eradication world. As the disease becomes a distant memory, fewer healthcare workers have firsthand experience with it. This lack of familiarity could pose problems if smallpox were to reemerge, either through a laboratory accident or as a bioweapon.

Preparedness in a Post-Smallpox World

Given these concerns, how is the world preparing for potential smallpox-related threats? Several measures are in place:

  • Vaccine stockpiles: Many countries maintain stores of smallpox vaccine for emergency use
  • Research: Ongoing studies aim to develop better treatments and safer vaccines
  • Surveillance: Global systems monitor for any signs of smallpox-like illnesses
  • Training: Some healthcare workers receive education on recognizing and responding to smallpox

These efforts reflect a delicate balance between celebrating the triumph of smallpox eradication and maintaining vigilance against potential future threats.

The story of smallpox—from its ancient origins to its eventual eradication and its place in modern biosecurity discussions—serves as a powerful reminder of both human vulnerability to disease and our capacity to overcome even the most formidable health challenges through science, cooperation, and determination.

History of Smallpox | Smallpox

Origin of Smallpox

The origin of smallpox is unknown. The finding of smallpox-like rashes on Egyptian mummies suggests that smallpox has existed for at least 3,000 years. The earliest written description of a disease like smallpox appeared in China in the 4th century CE (Common Era). Early written descriptions also appeared in India in the 7th century and in Asia Minor in the 10th century.

Spread of Smallpox

Historians trace the global spread of smallpox to the growth of civilizations and exploration. Expanding trade routes over the centuries also led to the spread of the disease.

Highlights from History:

  • 6th Century—Increased trade with China and Korea brings smallpox to Japan.
  • 7th Century—Arab expansion spreads smallpox into northern Africa, Spain, and Portugal.
  • 11th Century—Crusades further spread smallpox in Europe.
  • 15th Century—Portugal occupies part of western Africa, bringing smallpox.
  • 16th Century—European settlers and the African slave trade import smallpox into:
    • The Caribbean
    • Central and South America
  • 17th Century—European settlers bring smallpox to North America.
  • 18th Century—Explorers from Great Britain bring smallpox to Australia.

Early Control Efforts

Smallpox was a terrible disease. On average, 3 out of every 10 people who got it died. People who survived usually had scars, which were sometimes severe.

One of the first methods for controlling smallpox was variolation, a process named after the virus that causes smallpox (variola virus). During variolation, people who had never had smallpox were exposed to material from smallpox sores (pustules) by scratching the material into their arm or inhaling it through the nose. After variolation, people usually developed the symptoms associated with smallpox, such as fever and a rash. However, fewer people died from variolation than if they had acquired smallpox naturally.

The basis for vaccination began in 1796 when the English doctor Edward Jenner noticed that milkmaids who had gotten cowpox were protected from smallpox. Jenner also knew about variolation and guessed that exposure to cowpox could be used to protect against smallpox. To test his theory, Dr. Jenner took material from a cowpox sore on milkmaid Sarah Nelmes’ hand and inoculated it into the arm of James Phipps, the 9-year-old son of Jenner’s gardener. Months later, Jenner exposed Phipps several times to variola virus, but Phipps never developed smallpox. More experiments followed, and, in 1801, Jenner published his treatise “On the Origin of the Vaccine Inoculation.” In this work, he summarized his discoveries and expressed hope that “the annihilation of the smallpox, the most dreadful scourge of the human species, must be the final result of this practice.”

Vaccination became widely accepted and gradually replaced the practice of variolation. At some point in the 1800s, the virus used to make the smallpox vaccine changed from cowpox to vaccinia virus.

Traces of smallpox pustules found on the head of the 3000-year-old mummy of the Pharaoh Ramses V. Photo courtesy of World Health Organization (WHO)

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Edward Jenner (1749–1823). Photo courtesy of the National Library of Medicine.

Global Smallpox Eradication Program

In 1959, the World Health Organization (WHO) started a plan to rid the world of smallpox. Unfortunately, this global eradication campaign suffered from a lack of funds, personnel, and commitment from countries, and a shortage of vaccine donations. Despite their best efforts, smallpox was still widespread in 1966, causing regular outbreaks across South America, Africa, and Asia.

The Intensified Eradication Program began in 1967 with a promise of renewed efforts. Laboratories in many countries where smallpox occurred regularly were able to produce more, higher-quality freeze-dried vaccine. Other factors that played an important role in the success of the intensified efforts included the development of the bifurcated needle, the establishment of a case surveillance system, and mass vaccination campaigns.

By the time the Intensified Eradication Program began in 1967, smallpox was already eliminated in North America (1952) and Europe (1953). Cases were still occurring in South America, Asia, and Africa (smallpox was never widespread in Australia). The Program made steady progress toward ridding the world of this disease, and by 1971 smallpox was eradicated from South America, followed by Asia (1975), and finally Africa (1977).

Last Cases of Smallpox

In late 1975, three-year-old Rahima Banu from Bangladesh was the last person in the world to have naturally acquired variola major. She was also the last person in Asia to have active smallpox. She was isolated at home with house guards posted 24 hours a day until she was no longer infectious. A house-to-house vaccination campaign within a 1.5-mile radius of her home began immediately. A member of the Smallpox Eradication Program team visited every house, public meeting area, school, and healer within 5 miles to ensure the illness did not spread. They also offered a reward to anyone who reported a smallpox case.

Ali Maow Maalin was the last person to have naturally acquired smallpox caused by variola minor. Maalin was a hospital cook in Merca, Somalia. On October 12, 1977, he rode with two smallpox patients in a vehicle from the hospital to the local smallpox office. On October 22, he developed a fever. At first healthcare workers diagnosed him with malaria, and then chickenpox. The smallpox eradication staff then correctly diagnosed him with smallpox on October 30. Maalin was isolated and made a full recovery. Maalin died of malaria on July 22, 2013, while working in the polio eradication campaign.

Janet Parker was the last person to die of smallpox. In 1978, Parker was a medical photographer at England’s Birmingham University Medical School. She worked one floor above the Medical Microbiology Department where staff and students conducted smallpox research. She became ill on August 11 and developed a rash on August 15 but was not diagnosed with smallpox until 9 days later. She died on September 11, 1978. Her mother, who was providing care for her, developed smallpox on September 7, despite having been vaccinated two weeks earlier. An investigation suggested that Janet Parker had been infected either via an airborne route through the medical school building’s duct system or by direct contact while visiting the microbiology corridor.

World Free of Smallpox

Almost two centuries after Jenner hoped that vaccination could annihilate smallpox, the 33rd World Health Assembly declared the world free of this disease on May 8, 1980. Many people consider smallpox eradication to be the biggest achievement in international public health.

Stocks of Variola Virus

Following the eradication of smallpox, scientists and public health officials determined there was still a need to perform research using the variola virus. They agreed to reduce the number of laboratories holding stocks of variola virus to only four locations. In 1981, the four countries that either served as a WHO collaborating center or were actively working with variola virus were the United States, England, Russia, and South Africa. By 1984, England and South Africa had either destroyed their stocks or transferred them to other approved labs. There are now only two locations that officially store and handle variola virus under WHO supervision: the Centers for Disease Control and Prevention in Atlanta, Georgia, and the State Research Center of Virology and Biotechnology (VECTOR Institute) in Koltsovo, Russia.

Three-year-old Rahima Banu with her mother in Bangladesh. Rahima was the last known person to have had naturally acquired smallpox in the world. An 8-year-old girl named Bilkisunnessa reported the case to the local Smallpox Eradication Program team and received a 250 Taka reward. Source: CDC/World Health Organization; Stanley O. Foster M.D., M.P.H.

WHO poster commemorating the eradication of smallpox in October 1979, which was officially endorsed by the 33rd World Health Assembly on May 8, 1980. Courtesy of WHO.

The Spread and Eradication of Smallpox | Smallpox

Smallpox began causing illness and death more than a thousand years ago.

Follow its spread and eventual eradication in the timeline below.

Smallpox is present in the Egyptian Empire

Traces of smallpox pustules found on the head of a 3,000-year-old mummy of the Pharaoh Ramses V. By G. Elliot Smith, Public Domain.

A written description of a disease that clearly resembles smallpox appears in China

In China, people appealed to the god Yo Hoa Long for protection from smallpox. Image taken from Recherche sur les Superstitions en Chine (Research on Chinese Superstitions) by Henri Dore, Shanghai, 1911-1920. Bibliotheque nationale de France.

Increased trade with China and Korea introduces smallpox into Japan.

Drawing of a woman defeating the “smallpox demon” by wearing red. A myth commonly believed around the world advocated that red light would cure smallpox. In Japan, families who fell sick with smallpox set up shrines to the “smallpox demon” in their homes with the hope they would appease the demon and be cured. By Sensai Eitaku (鮮斎永濯, Japanese, *1843, †1890) – scanned from ISBN 978-4-309-76096-4., Public Domain]

Smallpox is widespread in India. Arab expansion spreads smallpox into northern Africa, Spain, and Portugal.

Figurine of Indian smallpox goddess Shitala Mata worshipped in northern India. She was considered both the cause and cure of smallpox disease. Symbolically, she represents the importance of good hygiene in people’s health and motivates worshipers to keep their surroundings clean. Photo courtesy of the National Library of Medicine.

Smallpox spreads to Asia Minor, the area of present-day Turkey.

The map shows the Ottoman Empire in 1801, which then extended from Turkey (Anatolia) to Greece, Hungary, Bulgaria, Romania, as well as northern Africa and parts of Middle East. Smallpox is thought to arrive to the area from Asia through major trade routes, like the Silk Road.

Entrance into Europe

Crusades further contribute to the spread of smallpox in Europe with the European Christians moving to and from the Middle East during the next two centuries.

Smallpox moves north

Population expansion and more frequent travel renders smallpox endemic in previously unaffected Central and North Europe, with severe epidemics occurring as far as Iceland.

Smallpox is widespread in many European countries, and Portuguese expeditions to African west coast and new trade routes with eastern parts of Africa introduce the disease into West Africa.

Statue of Shapona, the West African god of smallpox. Smallpox was thought to be a disease forced upon humans due to Shapona’s “divine displeasure,” and formal worship of the god of smallpox was highly controlled by specific priests in charge of shrines to the god. People believed that the priests themselves were capable of causing smallpox outbreaks. Even though the British colonial rulers banned the worship of Shapona in 1907, worship of the deity continued. Source: CDC, photo credit James Gathany.

European colonization and the African slave trade import smallpox into the Caribbean and Central and South America.

Illustration by the Franciscan missionary Bernardino de Sahagun who wrote detailed accounts of the Aztec history during his life there from 1545 until his death in 1590 into 12 books entitled “General History of the Things of New Spain.” Introduction of smallpox into Mexico by the Spanish around 1520 was one of the factors that led to the demise of Aztec Empire. Scanned from (2009) Viruses, Plagues, and History: Past, Present and Future, Oxford University Press, USA, p. 60. Public Domain.

Variolation—a process of grinding up dried smallpox scabs from a smallpox patient and inhaling them or scratching them into an arm of an uninfected person—is being used in China (inhalation technique) and India (cutaneous technique) to control smallpox.

A container from Ethiopia used to store the powdery variolation material, which was produced by grinding up dried smallpox scabs taken from a smallpox patient. Source: CDC, photo credit Brian Holloway.

Increased use of variolation

Variolation (cutaneous technique) is a widespread method for preventing smallpox in the Ottoman Empire (former Asia Minor, present-day Turkey) and North Africa.

Smallpox spreads into North America

European colonization imports smallpox into North America.

Variolation is introduced into England by Lady Mary Wortley Montagu, the wife of the British ambassador to Turkey.

Lady Mary Wortley Montagu, the wife of the British ambassador, learned about variolation during their appointment in Turkey. A survivor of smallpox herself, she had both of her children variolated and was the foremost person responsible for the introduction of the technique to England.

In 1796, Edward Jenner, an English doctor, shows the effectiveness of previous cowpox infection in protecting people from smallpox, forming the basis for vaccination.

Edward Jenner (1749–1823). Photo courtesy of the National Library of Medicine.

Smallpox is widespread in Africa, Asia, and South America in the early 1900s, while Europe and North America have smallpox largely under control through the use of mass vaccination.

The map shows the worldwide distribution of smallpox and the countries in which it was endemic in 1945. Source: CDC, photo credit Dr. Michael Schwartz.

After a global eradication campaign that lasted more than 20 years, the 33rd World Health Assembly declares the world free of smallpox in 1980.

WHO poster commemorating the eradication of smallpox in October 1979, which was later officially endorsed by the 33rd World Health Assembly on May 8, 1980. Courtesy of WHO.

transmission, pathogen, causes, symptoms, signs, diagnosis, treatment, prevention

Smallpox is an infectious disease caused by the Variola virus (VARV) belonging to the genus Orthopoxvirus. The disease is characterized by fever, symptoms of intoxication, the appearance of a rash on the skin and mucous membranes.

The official start of vaccination against smallpox infection in Russia is October 23, 1768. The vaccine was first administered to Empress Catherine II and her heirs. The material for vaccination was obtained from a smallpox boy of peasant origin. Subsequently, not only children were vaccinated, but also the grandchildren of the Empress.

By the beginning of the 19th century (1804-1810), about 8 million people had already been infected with smallpox in Russia. As a result, for 827 thousand patients, the outcome of the disease was fatal. In our country, mass vaccination and revaccination began in 1919 and became mandatory after the Great October Revolution. Serious success in the prevention of smallpox was achieved only in the USSR. By 1936, the disease had been eradicated.

By the early 1960s, smallpox had been completely eradicated in Europe and North America. In the first half of the 1970s, WHO set the task of completely coping with the causative agent of the disease. This required preventing variolation and closely monitoring smallpox outbreaks.

The last case of viral infection was reported at the end of October 1977. In 1980, global eradication of smallpox was certified by WHO.

How smallpox is transmitted

The causative agent of the disease is the Variola virus (VARV), which can infect humans and animals. The pathogen has excellent resistance to various environmental factors, easily tolerates both low temperatures and drying. In the frozen state, the causative agent of smallpox is able to maintain viability for several years. After drying at an increase in temperature to 100°C, the death of the pathogen occurs within 5-10 minutes.

The source of infection is a person with smallpox. High infectivity is observed during the first ten days, however, the release of viral particles into the environment occurs during the entire period of the appearance of rashes. The asymptomatic course of the disease, as well as the carriage of the pathogen in this pathology, is uncharacteristic, as is the transition to the chronic form.

Places of localization of variola in the human body are the mucous membranes of the respiratory organs, as well as the oral cavity. The causative agent is excreted with coughing, sneezing and breathing. The infection can be transmitted from the patient by airborne droplets and airborne dust. An aerosol with pathogenic microflora is able to travel long distances, infecting people who are in the same room with a sick person.

Human susceptibility to infection is very high. People who are not immunized are most often infected. After the illness, the formation of stable long-term immunity (more than 10 years) is noted.

Of the available candidates for the “relatives” of the Variola virus, monkeypox and cowpox are of the greatest interest.

The first of these is a rare infectious disease that can affect both animals and humans. The main signs of monkeypox are general intoxication of the body, a high rise in temperature, and the formation of exanthema on the skin.

The causative agent is genetically close to the human smallpox virus. To date, there has been an increase in monkeypox. So, in May 2021, an infected patient was identified in the UK, on ​​June 2 and 24, two more cases of the disease were registered. In the US, on July 16, 2021, an American was diagnosed with monkeypox. All of them have been to Nigeria.

Varicella is a highly contagious viral disease caused by the Varicella Zoster virus, which belongs to the herpes family of viruses. The pathogen, with a decrease in immunity, causes a severe disease – herpes zoster. Chickenpox predominantly affects children. Most often, their disease is milder than in adults.

Clinical manifestations of human smallpox

The duration of the incubation period of the disease ranges from 9 days to two weeks. In some cases, an increase of up to three weeks is possible. Symptoms of smallpox will depend on the severity of the disease.

The following stages are distinguished in the clinical course of the disease:

  • prodromal period;
  • rash stage;
  • suppuration of contents of eruptions;
  • recovery period.

The duration of the prodromal stage is from two to four days. During this period, there are symptoms of intoxication of the body, which are accompanied by a rise in body temperature, the presence of a headache, a feeling of chills, weakness, the appearance of pain in the muscles, the lumbar region. The skin of the thighs and chest is covered with eruptions similar to the exanthema characteristic of scarlet fever or measles. By the end of the prodrome stage, the temperature index is normalized. By the fifth day, rashes appear, which are initially represented by small roseolas, turning into papules and vesicles with many chambers. They are surrounded by hyperemic skin and have an umbilical depression in the central part. Vesicles are localized in the face, torso, upper and lower limbs. With the progression of the rash, the symptoms of intoxication increase again.

After 5-7 days from the onset of the disease, the stage of suppuration begins. During this period, there is a sharp rise in temperature, the condition worsens. The pockmarks form a purulent pustule and become painful. After about a week, they open up, leaving blackened necrotic crusts. Also at this stage there is a strong skin itch.

By the twentieth day of illness, the recovery period begins. Body temperature gradually decreases, pockmarks begin to heal, peeling of the skin is noted in their place, and scars remain in the future.

The clinic of the disease is characterized by several degrees of severity:

  1. Severe – papular-hemorrhagic, confluent, smallpox purpura.
  2. Moderately severe – disseminated smallpox.
  3. Light. The disease proceeds without obvious signs of intoxication, there are no rashes.

Most often, a mild form of the disease occurs in people vaccinated against smallpox. A severe pathology with a hemorrhagic component has a tendency to complication with a fatal outcome.

Clinical manifestations of monkeypox

The duration of the incubation period is from one to three weeks. The onset of the disease is acute, accompanied by complaints of severe headache, there is a rise in temperature to high numbers. The patient feels weakness, chills. Lymph nodes located near the site of infection increase in size, become inflamed, and become painful on palpation. The patient complains of nausea, vomiting, loss or lack of appetite, which is associated with intoxication of the body.

By the fourth day, the temperature begins to drop to 38.5 °C or lower. Rashes appear on the body, which go through several stages:

  1. Formation of a small spot up to 1 cm in diameter with transformation into a tubercle.
  2. Appearance of a vesicle, initially filled with clear contents, which gradually become cloudy.
  3. Scab formation with scar formation.

At each stage, the temperature again rises to high values. In each of these periods, the patient notes a deterioration in well-being. An increase in lymph nodes is already noted over the entire surface of the body.

Due to the appearance of rashes on the mucous membrane of the pharynx, the disease is accompanied by the appearance of cough, dryness in the pharynx. In the presence of a rash in the mouth, increased salivation and a feeling of discomfort during chewing are noted. If the eyelids and genitals are affected, then painful sensations appear in these areas.

In the case of a purulent infection, the temperature rises, blood pressure decreases, the pulse becomes frequent, consciousness is disturbed. These signs indicate the development of infectious-toxic shock.

Smallpox diagnostics

Diagnosis of the disease is aimed at detecting the pathogen. To identify the smallpox virus, the contents of the rash and crusts are examined. The following methods are used, which allow not only to detect pathogenic microflora, but also antibodies to the virus:

  • viroscopy;
  • serological tests: ELISA, agar microprecipitation;
  • blood test for antibodies: ELISA, RTGA, RSK, RN – are possible already from the 5-8th day of illness.

Treatment of smallpox

Therapy of the disease is carried out with the appointment of:

  • drugs with antiviral action;
  • immunoglobulins;
  • antibacterial drugs of the penicillin group, cephalosporins and macrolides;
  • means for intravenous drip administration, relieving intoxication;
  • glucocorticoids.

Smallpox is also treated externally: rashes are treated with antiseptics.

Smallpox prophylaxis

In order to prevent infection with the pathogen, specific preventive measures are taken to exclude the importation of a dangerous infection from regions that are unfavorable in terms of the epidemic.

Successful eradication of the disease has been achieved through decades of immunization of the population. At the moment, the mass introduction of the smallpox vaccine is impractical.

If a sick person is identified, they are isolated, including those who were in contact. Disinfection of the focus of infection. Everyone who has been in contact with an infected person, if no more than 72 hours have passed, must be vaccinated.

The author of the article:

Ivanova Natalya Vladimirovna

therapist

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