Smallpox was an infectious disease caused by one of two virus variants, Variola major and Variola minor. The agent of the variola virus (VARV) belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980. The origin of smallpox is unknown; however, the earliest evidence of the disease dates to the 3rd century BCE in Egyptian mummies. The disease historically occurred in outbreaks. In 18th-century Europe, it is estimated that 400,000 people died from the disease per year and that one-third of all cases of blindness was due to smallpox. Although it is believed that smallpox has been eradicated, some cases still are seen in India. Siddha Spirituality of Swami Hardas Life System brings out in-depth about smallpox for well-being.
Definition of Smallpox
There were two forms of the smallpox virus. Variola major was the severe and most common form, with a more extensive rash and higher fever. It could result in confluent smallpox, which had a high death rate of about 30%.
Variola minor was a less common presentation, causing less severe disease, typically discrete smallpox, with historical death rates of 1% or less. Subclinical infections with Variola virus were noted but were not common.
Variola sine eruptione
In addition, a form called variola sine eruptione (smallpox without rash) was seen generally in vaccinated persons. This form was marked by a fever that occurred after the usual incubation period and could be confirmed only by antibody studies or, rarely, by viral culture.
In addition, there were two very rare and fulminating types of smallpox, the malignant and hemorrhagic forms, which were usually fatal.
The initial symptoms were similar to other viral diseases that are still extant, such as influenza and the common cold:
- Fever of at least 38.3 °C (101 °F),
- Muscle pain,
- Vomiting, and
The early prodromal stage usually lasted 2–4 days. By days 12–15, the first visible lesions – small reddish spots called enanthem – appeared on mucous membranes of the mouth, tongue, palate, and throat, and the temperature fell to near-normal. These lesions rapidly enlarged and ruptured, releasing large amounts of virus into the saliva.
Ordinary cases of smallpox
Ninety percent or more of smallpox cases among unvaccinated persons were of the ordinary type. In this form of the disease, by the second day of the rash, the macules had become raised papules. By the third or fourth day, the papules had filled with an opalescent fluid to become vesicles. This fluid became opaque and turbid within 24–48 hours, resulting in pustules.
Sixth or seventh day
By the sixth or seventh day, all the skin lesions had become pustules. Between seven and ten days the pustules had matured and reached their maximum size. Fluid slowly leaked from the pustules, and by the end of the second week, the pustules had deflated and began to dry up, forming crusts or scabs.
Sixteen to twenty days
By day 16–20 scabs had formed over all of the lesions, which had started to flake off, leaving depigmented scars.
Ordinary smallpox generally produced a discrete rash, in which the pustules stood out on the skin separately. The distribution of the rash was most dense on the face, denser on the extremities than on the trunk, and denser on the distal parts of the extremities than on the proximal. Sometimes, the blisters merged into sheets, forming a confluent rash, which began to detach the outer layers of skin from the underlying flesh. Patients with confluent smallpox often remained ill even after scabs had formed over all the lesions.
Modified cases of smallpox
Referring to the character of the eruption and the rapidity of its development, modified smallpox occurred mostly in previously vaccinated people. In this form, the prodromal illness still occurred but may have been less severe than in the ordinary type.
There was usually no fever during the evolution of the rash. The skin lesions tended to be fewer and evolved more quickly, were more superficial, and may not have shown the uniform characteristic of more typical smallpox. Modified smallpox was rarely, if ever, fatal. This form of variola major was more easily confused with chickenpox.
Malignant type cases of smallpox
In malignant-type smallpox, the lesions remained almost flush with the skin at the time when raised vesicles would have formed in the ordinary type. It is unknown why some people developed this type. Historically, it accounted for 5–10 percent of cases, and most (72 percent) were children.
Malignant smallpox was accompanied by a severe prodromal phase that lasted 3–4 days, prolonged high fever, and severe symptoms of viremia.
The prodromal symptoms continued even after the onset of the rash. The rash on the mucous membranes (enanthem) was extensive.
Hemorrhagic type cases of smallpox
Hemorrhagic smallpox is a severe form accompanied by extensive bleeding into the skin, mucous membranes, gastrointestinal tract, and viscera. This form develops in approximately 2 percent of infections and occurs mostly in adults.
Pustules do not typically form in hemorrhagic smallpox. Instead, bleeding occurs under the skin, making it look charred and black, hence this form of the disease is also referred to as variola nigra or “black-pox.”
Smallpox was caused by infection with Variola virus, which belongs to the family Poxviridae, subfamily Chordopoxvirinae, and genus Orthopoxvirus. Other causes include:
The wide range of dates is due to the different records used to calibrate the molecular clock. Examination of a strain that dates from c. 1650 found that this strain was basal to the other presently sequenced strains. The mutation rate of this virus is well modeled by a molecular clock. Diversification of strains only occurred in the 18th and 19th centuries.
Variola is a large brick-shaped virus measuring approximately 302 to 350 nanometers by 244 to 270 nm, with a single linear double-stranded DNA genome 186 kilobase pairs (kbp) in size and containing a hairpin loop at each end. The two classic varieties of smallpox are variola major and variola minor.
Four orthopoxviruses cause infection in humans:
- Cowpox, and
Variola infects only humans in nature. Vaccinia, cowpox, and monkeypox viruses can infect both humans and other animals in nature.
Transmission occurred through inhalation of airborne Variola virus, usually, droplets expressed from the oral, nasal, or pharyngeal mucosa of an infected person.
One person to another
It was transmitted from one person to another primarily through prolonged face-to-face contact with an infected person, usually, within a distance of 1.8 m (6 feet), but could also be spread through direct contact with infected bodily fluids or contaminated objects (fomites) such as bedding or clothing.
Smallpox was highly contagious, but generally spread more slowly and less widely than some other viral diseases, perhaps because transmission required close contact and occurred after the onset of the rash.
In temperate areas, the number of smallpox infections was highest during the winter and spring. In tropical areas, seasonal variation was less evident and the disease was present throughout the year. Age distribution of smallpox infections depended on acquired immunity. Vaccination immunity declined over time and was probably lost within thirty years.
Smallpox was not known to be transmitted by insects or animals and there was no asymptomatic carrier state.
Certain laboratory tests were in practice, which includes:
Microscopically, poxviruses produce characteristic cytoplasmic inclusion bodies, the most important of which are known as Guarnieri bodies, and are the sites of viral replication.
Electron microscopic examination
The diagnosis of an orthopoxvirus infection can also be made rapidly by electron microscopic examination of pustular fluid or scabs. All orthopoxviruses exhibit identical brick-shaped virions by electron microscopy. If particles with the characteristic morphology of herpesviruses are seen this will eliminate smallpox and other orthopoxvirus infections.
RFLP and ELISA Test
Definitive laboratory identification of Variola virus involved growing the virus on chorioallantoic membrane (part of a chicken embryo) and examining the resulting pock lesions under defined temperature conditions. Strains were characterized by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis.
Serologic tests and enzyme-linked immunosorbent assays (ELISA), which measured Variola virus-specific immunoglobulin and antigen were also developed to assist in the diagnosis of infection.
Other methods of smallpox diagnosis
Chickenpox was commonly confused with smallpox in the immediate post-eradication era. Chickenpox and smallpox could be distinguished by several methods. Unlike smallpox, chickenpox does not usually affect the palms and soles. Additionally, chickenpox pustules are of varying size due to variations in the timing of pustule eruption. Smallpox pustules are all very nearly the same size since the viral effect progresses more uniformly.
A variety of laboratory methods were available for detecting chickenpox in the evaluation of suspected smallpox cases.
Complications of smallpox arise most commonly in the respiratory system and range from uncomplicated bronchitis to fatal pneumonia. Respiratory complications tend to develop on about the eighth day of the illness and can be either viral or bacterial in origin. Secondary bacterial infection of the skin is a relatively uncommon complication of smallpox. When this occurs, the fever usually remains elevated.
Other complications include:
- Encephalitis (1 in 500 patients), which is more common in adults and may cause temporary disability;
- Permanent pitted scars, most notably on the face; and
- Complications involving the eyes (2% of all cases).
Conjunctiva, and cornea
Blindness results in approximately 35-40% of eyes affected with keratitis and corneal ulcer. Hemorrhagic smallpox can cause subconjunctival and retinal hemorrhages. In 2-5% of young children with smallpox, virions reach the joints and bone, causing osteomyelitis variolosa.
Bony lesions are symmetrical, most common in the elbows, legs, and characteristically cause separation of the epiphysis and marked periosteal reactions. Swollen joints limit movement and arthritis may lead to limb deformities, ankylosis, malformed bones, flail joints, and stubby fingers.
Smallpox vaccination within three days of exposure will prevent or significantly lessen the severity of smallpox symptoms in the vast majority of people. Vaccination four to seven days after exposure can offer some protection from disease or may modify the severity of the disease.
Wound care and infection control
Other than vaccination, treatment of smallpox is primarily supportive, such as wound care and infection control, fluid therapy, and possible ventilator assistance. Flat and hemorrhagic types of smallpox are treated with the same therapies used to treat shock, such as fluid resuscitation. People with semi-confluent and confluent types of smallpox may have therapeutic issues similar to patients with extensive skin burns.
In July 2018, the Food and Drug Administration approved tecovirimat, the first drug approved for the treatment of smallpox. Antiviral treatments have improved since the last large smallpox epidemics, and studies suggest that the antiviral drug cidofovir might be useful as a therapeutic agent. The drug must be administered intravenously and may cause serious kidney toxicity.
ACAM2000 smallpox vaccine
It contains live vaccinia virus, cloned from the same strain used in an earlier vaccine, Dryvax. The vaccine is not routinely available to the US public; it is, however, used in the military and maintained in the Strategic National Stockpile.
In June 2021, brincidofovir was approved for medical use in the United States for the treatment of human smallpox disease caused by the variola virus.
Home remedies for Smallpox
The person carrying the virus is highly contagious and spread it to others easily.
Many countries have restored live cultures of the smallpox virus for making biological weapons or vaccines to protect lives from biological weapons. This condition has maintained smallpox as a threat for humans even today.
Neem leaves have been used since ancient times as a natural treatment for smallpox. These work well not only to control infection in a patient but also to spread to others.
However, some methods of using neem leaves include:
- Apply a paste of Neem leaves over blisters.
- The smoke of Neem leaves or hanging fronds of Neem leaves around patients helps in curtailing the movement of the virus in the air to protect others.
Keeping Neem fronds close to the bed is also an old practice to prevent infection from spreading. Neem leaves are trusted home remedies for smallpox.
Parh leaves are an effective and trusted natural treatment for smallpox. For a few minutes, boil 5-7 leaves with a glass of water. Give it to the patient when warm after straining.
These leaves are wonderful for speeding up the healing process of blisters and also relieving symptoms. The properties of these leaves supplement antibodies that fight back the variola virus efficiently and suppress its activities. Regular use of parh leaves is one of the trusted home remedies.
Weakness and fatigue are major concerns of patients. Milk works as one of the efficient home remedies for smallpox as it speeds up recovery and maintains energy.
To use milk as a remedy take one liter of it and bring it to a boil. Add two teaspoons of lemon juice which will make milk curdle.
Allow it to become warm and give it to the patient first-up in the morning. It is easily digestible and maintains energy to fight back infection.
Poppy seeds are other home remedies for smallpox that help in suppressing the virus and its activities and relieving symptoms. The blisters of smallpox can cause severe burning and itching.
The paste of poppy seeds, when applied over blisters, provides cooling effects. It relieves itching and burning and helps in healing blisters faster.
The poppy seeds can also be used as internal remedies these when consumed treat abdominal pain and maintain energy levels which helps in faster recovery.
A paste of Red sandalwood powder with water is one of the most popular home remedies for smallpox. Paste provides instant relief from itching and burning and heals blisters faster.
Diet for patients of Smallpox
Fruits juice and milk
Initially, the patient may not feel at all like eating. It is better to just focus on fluid intake rather than providing or forcing things to eat.
At the onset of infection, fever may rise up to 102 degrees which prevents one from eating. Water and diluted fruit juices are the best diets for the patient to eat for an initial one or two days. Later when fever, headaches, and abdominal pain get relieved a baked potato is the best diet for smallpox.
This veggie contains starch and carbs which will energize weak muscles and stay in the stomach longer. Milk toast, lighter milk preparations, and eggs can also form a diet for smallpox after the fever subsides.
Lemon and orange
Lemon and orange are excellent fruits that shall be part of a regular diet for smallpox. These are vitamin C-rich foods that help the body in fighting back viruses and also improve metabolism.
During convalescence well-cooked cereals, rice puddings, rice preparation, custard, etc. along with lemon and orange juice shall be the diet for smallpox. These foods will bring back energy and also improve digestion and immunity.
One should strictly avoid heavy meals. It is necessary to give something to eat or drink every couple of hours even at night. Avoid foods like meat, course vegetables, brown bread, and rich sauces. These can aggravate symptoms and also deteriorate the body’s disease-fighting abilities.
Frequently asked questions
Before posting your query, kindly go through them:
|What is the definition of Smallpox?
It is an acute contagious febrile disease of humans that is caused by a poxvirus (species Variola virus of the genus Orthopoxvirus), is characterized by a skin eruption with pustules, sloughing, and scar formation, and is believed to have been eradicated globally by widespread vaccination —called alsovariola.
| What are the complications of Smallpox?
Complications of smallpox arise most commonly in the respiratory system and range from uncomplicated bronchitis to fatal pneumonia. Respiratory complications tend to develop on about the eighth day of the illness and can be either viral or bacterial in origin. Secondary bacterial infection of the skin is a relatively uncommon complication of smallpox. When this occurs, the fever usually remains elevated. Other complications include encephalitis, which is more common in adults and may cause temporary disability; permanent pitted scars, most notably on the face; and complications involving the eyes.
|Which is the good news about Smallpox?
The last known natural case was in Somalia in 1977. In 1980 WHO declared smallpox eradicated – the only infectious disease to achieve this distinction.