may vary from 1 to 7 days. Patients are communicable during the acute stage until Shigella is no longer found in the stool, about 4 weeks after the disease. In a few cases, a carrier condition may last for several months. Asymptomatic carriers may also transmit shigellosis. Shigellosis is more severe in young children.
Preventive medicine personnel should be prepared to evaluate each outbreak and provide recommendations to prevent the spread of disease for each local situation. Preventive measures include (1) sanitary disposal of patient feces; (2) scrupulous handwashing by patients after defecation and by health care persons attending the patient; (3) proper food sanitation measures for preparation, handling, and refrigeration; (4) in rural areas, proper fly control and refuse (food, etc.) disposal.
Management of patients, contacts, and the nearby environment includes (1) use of enteric precautions for the patient during the acute illness; (2) excluding all contacts of shigellosis patients from foodhandling and child or patient care until two negative stool cultures are obtained; and (3) in the investigation of contacts, stool cultures should be restricted to foodhandlers, child care worker, children, and others where disease transmission is likely.
Epidemic measures require that preventive medicine personnel should investigate milk, food, water supplies, and general sanitation.
There is a potential problem of major epidemics in situations where people are crowded together with deficient environmental sanitation, e.g., institutions and refugee camps.
Smallpox as a naturally occurring disease was certified eradicated from the world by the World Health Organization in May 1980. The occurrence of even a single case, acquired from a laboratory or naturally, would be a grave emergency and require immediate effective control measures.
Smallpox is a systemic viral disease with a sudden onset characterized by fever, headache, backache, abdominal pain, malaise, and prostration. After 2 to 4 days, the temperature falls and a rash develops. The rash progresses through macules to vesicles/pustules and scabs. After about a month, the lesions heal and the scabs drop off. Lesions appear first on the face and then on the trunk and extremities. More lesions develop on the face and extremities than on the trunk. The rash may be mild or absent, or with only a few lesions in previously vaccinated patients.
Two types of smallpox were historically recognized, variola minor (alastrim) and variola major (classical smallpox). The fatality rate for unvaccinated cases of classical smallpox ranged from 15 to 40 percent, with death usually occurring during the second week. The fatality rate for variola minor was about 1 percent.
The infectious agent is the variola virus, which is maintained in cultures for research in a few restricted laboratories.
Smallpox transmission was occasionally airborne but usually occurred by contact with body discharges, e.g., respiratory, skin lesions, and contact with articles and material contaminated by patients. Sometimes unrecognized cases were the source of large secondary outbreaks. The average incubation period is for 10 to 12 days. The disease is communicable during the period of lesions, usually about 3 weeks. Supportive treatment is as directed by a medical officer.
Regarding preventive measures, roqtine vaccination is no longer recommended or required for international travel. However, research personnel in the few laboratories handling the smallpox virus are vaccinated. Some countries, including the United States, continue to vaccinate military forces. Vaccinations are administered to the U.S. military only when members can be isolated from the general public for about 2 weeks, that is, during basic training.
Many staphylococcal infections result in lesions of the skin such as infected lacerations, abscesses, carbuncles, and boils. Most frequently these skin lesions are localized and discrete. When lesions are widespread, constitutional symptoms such as loss of appetite, headache, malaise, and fever may accompany. Normally lesions are uncomplicated, but sometimes the organisms may be carried by the blood stream and result in abscesses of the lung, bone, and brain, as well as meningitis. These complications may also occur from the parenteral use of illicit drugs with contaminated needles. Staphylococcal infections occur worldwide, but most frequently in areas where people are crowded and personal hygiene is not adequate.
The infectious agents are various strains of Staphylococcus aureus. The organisms may be identified by several laboratory methods.