Fill in the Blanks КРОК 1- текстOnline version fill in by Елена Awramenko 1 infectiousness adults weeks eradicated discontinued People Organization 1980 evolution high prodromal Because body bedridden days children headache Assembly civilian 24 In , the World Health declared that smallpox ( variola virus ) had been successfully worldwide . The United States routine childhood immunization against smallpox in 1972 and routine immunization of health care professionals in 1976 . Following eradication , 2 World Health reference laboratories were authorized to maintain stocks of variola virus . In 2003 , the United States initiated a smallpox immunization program for first responders to facilitate preparedness and response to a possible smallpox bioterrorism event . infected with variola develop a severe prodromal illness characterized by fever , malaise , severe , backache , abdominal pain . Infected children can suffer from vomiting and seizures during this period . Most patients with smallpox are severely ill and during the febrile prodrome . The prodromal period is followed by development of lesions on mucosa of the mouth or pharynx . This stage occurs less than hours before onset of rash , which is usually the first recognized manifestation of . With onset of oral lesions , the patient becomes infectious and remains so until all skin crust lesions have separated . The rash typically begins on the face and rapidly progresses to involve the forearms , trunk , and legs . Lesions increase in size for approximately 8 to 10 after which they begin to crust . Once all the crusts have separated , 3 to 4 after the onset of rash , the patient is no longer infectious . Varicella ( chickenpox ) is the condition most likely to be mistaken for smallpox . Generally , with varicella do not have a febrile prodrome , but can have a brief , mild prodrome . Although the 2 diseases are confused easily in the first few days of the rash , smallpox lesions develop into pustules that are firm and deeply embedded in the dermis , whereas varicella lesions develop into superficial vesicles . varicella erupts in crops of lesions that evolve quickly , lesions on any one part of the will be in different stages of ( papules , vesicles , and crusts ) , whereas all smallpox lesions on any one part of the body are in the same stage of development .