Small Pox Disease
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Small Pox Disease
Introduction
Smallpox is a deadly infection that is caused by the Variola major virus. It is a contagious infection transmitted through droplets and aerosols from infected, symptomatic individuals. Activities such as sneezing, coughing, talking, spitting, at close face-to-face contact will cause the virus to spread from the symptomatic individual to the healthy one causing infection. The disease adopted its name from the symptoms of small pus-filled blisters called pocks that formed on the skin during infection (Foege 3).
History
Smallpox dated back to the 300 CE when it is thought to first occur in Europe. Since then, it continued to be an epidemic for thousands of years among the human population. In 1157 BCE, the Egyptian pharaoh Ramses V’s mummy succumbed to the disease since scars resembling those of smallpox were observed on the remains. In the 20th century, the estimated mortality cases from the disease were about 300 million globally. However, there have not been recent cases of smallpox worldwide since the last case was reported in 1977 where it occurred in Somalia. About 30% mortality cases were reported two weeks after infection, and the survivors sustained severe scars, which were permanent and extensive on the skin. The survivors also suffered other deformities including loss of ears, nose and lips. In cases of corneal scarring, blindness was a common occurrence. The disease was normally spread through close contact with lesions or infected respiratory fluids. Getting into contact with infected bedding and linen also caused infections since a patient remained infectious until the last scab disappeared from the skin (Foege 17).
Epidemiology
Many years before the successful eradication of the disease, smallpox remained a global endemic infection and almost everybody contracted the disease at one point in time. The disease prevailed all year round since it mostly occurred among the large susceptible populations. Epidemics occurred in isolated areas where the disease was introduced and triggered permanent immunity to the population. Hence, transmission rates reduced when the number of symptomatic individuals reduced. Smallpox infection was seasonal with high incidences being during spring and winter. The high incidences were triggered by social behavior since most people convened at marriage parties and festivals during these seasons, and nomads moved their livestock during this period, as well. Major epidemics at 4-7 year intervals were also common due to accumulation of susceptible individuals and events such as civil war and famine. The virus also spread rapidly due to the movement of refugees (Henderson and Bernard Web).
The spread of smallpox was not as rapid and widespread as other contagious infections such as chicken pox and measles. This is because the virus was not transmitted until a rash occurred, and most of the symptomatic individuals were confined in bed because of the discomfort of malaise and high fever. Thus, few people were exposed to the infected; curbing the spread of the infection was successful except in a few cases, in family and friends who took care of them at home or in hospitals. As a result, cases of smallpox were clustered in isolated areas, in the province or country. This made it easy to control the few outbreaks that occurred through vaccinations of individuals living in areas with infected patients. Smallpox cases depended on the age distribution in the population where acquired immunity was by either infection or vaccination. Some cases were reported in adults in India between 1974 and 1975, in areas where smallpox was endemic. 23,546 cases were recorded where 21% of the patients were older than 20 years, and 2% were older than 50 years. Most of the cases in western Africa were reported in the rural areas among all age groups between 1967 and 1969. Both countries recorded cases of both male and female patients.
Pathology
Variola major is the most virulent strain that causes classic smallpox while Variola minor is the less virulent strain that causes alastrim. The virus is the largest animal virus belonging to the orthopoxvirus genus. Smallpox viruses are slightly bigger than bacteria, and they can replicate outside a host cell, unlike most viruses. They are visible with a light microscope, and measure about 302 to 350 nm by 244 to 270 nm with smooth and round edges. The incubation period of the virus is about 2 weeks after getting into the host through inhalation where it invades the respiratory system and multiplies in the lymph nodes. The virus then migrates to the blood stream for further multiplication in the bone marrow, spleen and lymph nodes. When the virus invades the white blood cells, it initiates toxemia and fever before spreading to the skin, kidneys, lungs, intestines and brain. The disease manifests in the form of headache, lethargy, vomiting, sore throat, and fever in a span of two weeks after contact with the virus. A few days along, a raised rash occurs on the patient’s body and face. In addition, lesions form in the mouth, nose, and throat, which later develop to infective papules and vesicles. These are released into the environment as respiratory droplets causing infection. Pus-filled pustules later form expanding and spreading to cover large areas on the skin. Scabs also form and detach from the skin about three weeks after infection with the virus (Foege 26).
Response and Treatment
Smallpox has no known cure yet, but preventive measures in the form of vaccination have been successful in eradicating the disease. Innate acquired immunity has also been used to eradicate the epidemic through the introduction of smallpox virus into the body. They, in turn, elicit antibodies against the disease such that the individual gains immunity. In addition, World Health Organization launched the successful campaign in 1967 to eradicate smallpox. The disease was completely eradicated in 1980, and it no longer occurs naturally since nobody has contracted the disease recently. There is no treatment for the disease itself, but painkillers and antibiotics can be administered to treat symptoms and secondary infections. The disease was the first to be eradicated via vaccination using the live smallpox vaccine known as vaccinia virus (Henderson Web).
Socio-Politico-Economic Effects
Various international health organizations have been working to devise a plan on how to deal with a possible outbreak of smallpox in the future. The organizations, which include WHO and Centers for Disease Control and Prevention, are majorly concerned with the fact that the virus could be used as a biological weapon by terrorists. In turn, they have developed the plan issuing directives to both local and state health professionals and caregivers on measures to take in case of an emergency. Currently, with no treatment for smallpox, prevention via vaccination is what nations implement to fight the disease. The government and health organizations should also assure the public that measures to handle the problem are available in case of an emergency (Scheibner Web).
Conclusion
Smallpox can be described as disease of the past since its successful eradication in 1980 through vaccination. There are no recent cases of the disease since the last case was in 1949 in the United States and 1977 in Somalia. Thus, people need to receive immunization against the disease to prevent future occurrences since it has no known cure and 90% of the cases are fatal. Prevention is the only way of dealing with the deadly and virulent smallpox.
Works Cited
Foege, William. House on Fire: The Fight to Eradicate Smallpox. University of California Press, 2011. Web. 22 Nov. 2013.
Henderson, Daniel and Bernard Moss. Epidemiology. National Center for Biotechnology Information, U.S. National Library of Medicine, 1999. Web. 22 Nov. 2013.
Henderson, Daniel. “Epidemiology in the Global Eradication of Smallpox.” International Journal of Epidemiology 1.1 (1972): 25-30. Web. 22 Nov. 2013.
Scheibner, Viera. Smallpox was declared eradicated, yet still infects humans today. International Medical Council on Vaccination, 2 April 2012. Web. 22 Nov. 2013.
