Causes of smallpox

Smallpox is a disease caused by the Variola virus. The disease has a high mortality rate with severe systemic symptoms and a characteristic pustular rash. Treatment is possible with support and the use of antiviral drugs. However, vaccination is recommended to prevent this disease.

Smallpox is caused by an acute infection of the Variola virus. The disease is characterized by symptoms such as fever, rash, and a fairly high mortality rate. Since 1979, the disease has been declared to have wiped out the world and marked a great achievement of the era's medicine.
Smallpox has 2 main types:
The severe form of the Variola virus has a mortality rate of about 30 to 50% in people who have never been vaccinated. The disease is milder with 1% mortality. These two diseases are caused by different strains of the Variola virus.
In the past, smallpox was known to be endemic. In temperate climates, the disease could circulate in winter - spring, mainly in children and young adults.

One of the causes of smallpox is caused by Variola virus of the orthopoxvirus family, Poxviridae family. This virus belongs to a large DNA virus that lacks two-sided symmetry, unlike other DNA viruses. The Variola virus has a rather complex structure with an outer membrane, two lateral bodies and a heavy body containing a double-stranded DNA mononuclear molecule.
In the 1800s, another form of smallpox appeared, but with a milder severity, and the definitive cause was also the Variola virus. Viral genome sequencing revealed changes in genotype expression and explained differences in viral dynamics.

Smallpox has 2 diseases. However, the 2 infections were clinically indistinguishable in individual patients. New modern molecular diagnostic techniques are capable of distinguishing these two strains of Variola.
Clinically smallpox is divided into 5 subtypes related to severity. Severe smallpox mainly occurs in infants, the elderly, and people with immunocompromised conditions, but symptoms are milder in those who have been vaccinated.
The common form of smallpox:
The duration of the illness is from 10 to 14 days or it can range from 7 to 19 days. In the early stages, the disease can last from 2 to 4 days with signs of high fever, severe headache, vomiting, diarrhea, back pain and fatigue. In the full-blown phase, smallpox is characterized by lesions appearing on the mucous membranes, followed by a rash on the skin about 24 hours later. Lesions in the mouth will first appear as nodules and blisters under the tongue and nasopharynx. The spread of mucus can be centrifugally from the face to the tendons, trunk, and finally the distal extremities. The rash progresses to papules, vesicles, and pustules, and the febrile process may be due to recurrence during the pustular phase. With this form, more than 70% of people with smallpox are divided into 3 types of rash. Variant of smallpox:
Symptoms may be similar to common. Elimination of the progressive stages of the variant will be faster than that of the rest. Smallpox usually causes fairly small pustular lesions. Variant smallpox is more common in people who have been vaccinated. Flat form with early disease:
Is characterized by white, flat pustules. Smallpox is common in children and is fatal to children. Hemorrhagic smallpox:
Usually quite rare, there are lesions on the skin as well as mucous membranes and formation of hemorrhages. The pathogenic symptoms of this form can be quite severe, including heart failure, disseminated bleeding, and bone marrow suppression leading to death within 3 to 4 days of illness. However, with this form of the disease, it is quite difficult to recognize the infected person and come into contact with the patient without knowing it. Furthermore, secondary bacterial infections may contribute to the development of hemorrhagic encephalopathy. Atypical form:
Occurs in people who have been vaccinated or have partial immunity due to previous infection. Patients with this form of smallpox usually have a fever but no rash. An increase in antibody titres after fever may indicate that the patient has been infected with Variola virus but has not developed a rash.

The patient can be examined, including clinical diagnosis and laboratory tests if necessary.
For clinical diagnosis, most physicians generally adopt the primary and secondary criteria for varicella-infected smallpox. However, to confirm the correct diagnosis, the doctor may order tests. These cases are usually presymptomatic with fever, fixed smallpox lesions, and stage of disease progression.
Diagnostic methods for smallpox include:
Isolate the virus from the oropharynx, conjunctiva and urine, in addition, the doctor may perform additional tests in areas of skin damage before scabs form. The polymerase chain reaction assay is intended to determine the polymerase chain reaction of the Variola viral DNA to make a definitive diagnosis. In addition, the doctor also ordered to perform smallpox virus culture from the patient by PCR. Serology was performed to indicate orthopoxvirus infections, but was not diagnostic of smallpox. Serum antibodies appear on days 6 to 8 of infection. Antibody titres may increase after 2 - 3 weeks to demonstrate the patient's viral status. Differential diagnosis with Varicella, monkeypox and vaccinia.

Smallpox can cause complications for patients such as secondary bacterial infections of the skin, keratitis, corneal ulcers leading to blindness, bacterial pneumonia, viral arthritis and myelitis bone, orchitis, encephalitis...

Prevention of smallpox virus infection can first be applied by infection control. For patients presenting with a rash accompanied by vesicles or acute generalized pustulosis, appropriate standard airborne and contact precautions should be taken. Next, use N95 respirator mask, gloves and gown. If it is necessary to move the sick person, use a mask to cover the rash, use a mask to cover the patient's mouth and nose
Smallpox vaccination is recommended to help eradicate the disease worldwide. Although routine vaccination is not required for the general population, it is recommended that routine vaccination be performed for laboratory or medical personnel.
In short, smallpox is caused by the Variola virus. Treatment is possible with support and antiretroviral drugs, but vaccination is the best way to prevent the disease.