Treatment, Prevention and Control - Variola (Smallpox) Virus Infections

Treatment

No specific antiviral agents are available against variola virus. Methisazone is of some value against some poxviruses. It is rec-ommended only for chemoprophylaxis but not for treatment. Vaccinia immune globulin is recommended for treatment of all complications except postvaccinated encephalitis. Although smallpox has been eradicated worldwide, concern still exists about the possible occurrence of smallpox through bioterrorism.

Prevention and Control

Smallpox was the first disease to be eradicated by success-ful immunization program. Empirical preventive measures against smallpox had been used in India and China even before the first millennium. The practice of variolation carried out by intentional inoculation with some virulent strains of variola to prevent against variola infection spread from India to the Old World and subsequently East Europe in the eighteenth century. This procedure of variolation became very popular in Europe till it was replaced by vaccination introduced by Jenner 1796.

      The variolation conferred lifelong immunity in vaccinated individuals. It was a risky procedure and was associated with a mortality rate of approximately one-tenth of that seen in indi-viduals with naturally occurring disease. Moreover, inoculated individuals were capable of transmitting smallpox to suscep-tible individuals for sometime after variolation.

      In 1960s, the WHO formulated a concept program for global eradication of smallpox. The disease was then present in 44 countries with a global incidence of around 10 million cases annually. By use of highly potent and stable vaccine, rapid iden-tification of outbreaks, and carrying out ring vaccination in all contacts of a person who are infected, the disease was finally eradicated in 1977 when the last case of endemic smallpox was detected in Somalia.