If you suspect a case of smallpox, isolate the person immediately using airborne-contact precautions. Airborne and contact precautions will be employed that includes the use of gowns, gloves, N95 masks or equivalent or greater protection and a negative pressure room with the door closed at all times. Cohorting of patients may be necessary. If the patient needs to be transported, a surgical mask should be placed on the patient to minimize disbursement of the droplets. Contact the local health department immediately. They are responsible for notifying the state health officials, as well as the FBI and the local law enforcement officials. State health officials will notify the Centers for Disease Control (CDC).

Suspected Smallpox Exposure

Purpose

The purpose of these policy guidelines is to recommend procedures for handling potential biological threats of smallpox exposure.

Description of AgentlSyndrome

Smallpox is an infection caused by the variola virus, a member of the chordopoxvirus family. Naturally occurring smallpox has been eradicated from the globe since 1977. Repositories of the virus are known to exist in only two laboratories worldwide. Monkeypox, cowpox and vaccinia are closely related viruses that might lend themselves to genetic manipulation and subsequent development of a smallpox-like disease.

Transmission

Smallpox may be transmitted from person-to-person by infected saliva droplets that expose the person having face-to-face contact with the ill person. Virus is also present in the skin lesions and may be spread by direct contact. The frequency of infection is highest after face-to-face contact with a patient once fever has begun and during the first week of rash, when the virus is released via the respiratory tract.

Incubation

The incubation period of smallpox is about 12 days (range 7-17 days).

Signs and Symptoms

Clinical manifestations begin acutely with a prodromal period involving malaise, fever, rigor, vomiting, headache and backache. After 2 to 4 days, skin lesions appear and progress uniformly from macules to papules to vesicles to pustules. Lesions progress centrifigally (starts peripherally and moves centrally) and scab in 1-2 weeks. The progression of the lesions centrifigally should be differentiated from varicella (chickenpox) lesions that progress centripetally (starts centrally and moves peripherally). Variola Major, the classic form of the disease, has a 30% mortality rate.

Diagnosis

In its full-blown form, smallpox is readily diagnosed on clinical grounds. However, in its minor form or in individuals who have been previously vaccinated, smallpox may be difficult to differentiate from other vesicular exanthems such as varicella and erythema multiforme. The Ohio Department of Health should be contacted regarding testing procedures.

Treatment

Supportive care is the mainstay of treatment. This may include intravenous fluids, medications to control fever and pain and antibiotics to treat any secondary bacterial infections. No specific antiviral therapy is currently recommended.

Prophylaxis

Routine immunization stopped in 1972. Individuals who received the vaccine may or may not be protected from disease. The effectiveness of the vaccine past ten years is not known. Lifetime immunity is present for individuals who survived the disease.

The only prophylaxis is the smallpox vaccine. However, the vaccine is not currently available. It is anticipated that there will be a vaccine available by 2004.

A licensed, live vaccinia virus vaccine is available. However, this is available only through the Centers for Disease Control. The vaccine is effective in post exposure prophylaxis, but should be administered within 4 days of the exposure. Vaccination may decrease the severity of the illness or eliminate it altogether. There may also be a role for Vaccinia Immune Globulin (VIG), but the CDC will recommend its use.

Control Measures and Decontamination

People with smallpox are most infectious once fever has begun and during the first week of rash, when the virus is released via the respiratory tract. Although patients remain infectious until the last scabs falloff, the large amounts of virus shed from the skin are not highly infectious. Exposure to patients in the late stages of the disease is much less likely to produce infection in susceptible contacts. As a precaution, WHO isolation policy during the eradication campaign required that patients remain in isolation, in hospital or at home, until the last scab has separated.

1. Isolation

Isolation (airborne precautions, contact precautions) should be utilized to contain the disease in addition to standard precautions

a) Negative pressure room

b) N95 mask should be worn

c) Cohort cases if unable to provide private rooms

d) Gowns and gloves

e) Hand-washing

f) Dedicated patient care equipment

2. Quarantine of Exposed Individuals

If it is not feasible to vaccinate contacts, they should be placed on daily fever watch, which should continue up to 18 days from the last day of contact with the case. If these contacts have 2 consecutive readings of 38 deg C or above, they should be isolated. Contacts do not need to be admitted but can be quarantined at home.

3. Environmental Surfaces

a) All material used in the care of a suspected case of smallpox should be handled as infectious waste and incinerated or autoclaved.

b) Contaminated bed linens and patient clothing should be bagged at the point of use while using personal protective equipment. These items should be laundered in bleach and hot water.

c) Disinfectants such as bleach and quaternary ammonium compounds may be used to disinfect and clean horizontal surfaces and for other environmental cleaning.

In the event that a building is felt to be the source of an aerosol release of smallpox virus, there is no routine recommendation to decontaminate the building. By the time the first cases are recognized in 12-14 days, the virus in the building will be gone. Smallpox virus is fragile and will be inactivated or dissipated within 1-2 days of its release.

Notification

Internal: At hospital notify_______________________________

External: All suspected cases of suspected smallpox exposure are Class Al Reportable and should be reported immediately to the Local Health Department who will then contact the State Health Department and/or CDC.

Lab

Due to potential risks associated with handling infectious materials, laboratory testing should be the minimum necessary for diagnostic evaluation and patient care. Laboratory specimens should be placed in plastic bags that are sealed, and then transported in clearly labeled, durable, leak-proof containers directly to the specimen handling area of the laboratory. Care should be taken not to contaminate the external surfaces of the container. Lab personnel should be notified of what they are handling. Bio-Safety Level 2 should be used for handling specimens.

SPECIMENS

SMALLPOX

(Smallpox/Variola Virus)

Skin scrapings of lesions:

· Use blunt edge of a scalpel to open previously unopened vesicular lesion

· Harvest fluid with cotton swab

· Scabs can be removed by forceps

ID Consult

Note on requisition

Possible Smallpox Virus exposure in an asymptomatic patient

Not applicable

Smallpox

Yes

· Swabs and scabs should be placed in a sterile tube, sealed with tape.

· Double-bag in Biohazard bag.

· Hand carry to the microbiology lab

o DO NOT send via pneumatic tube

Yes

R/O Smallpox

References:

http://www.who.int/docstore/wer/pdf/2001/wer7644.pdf

CDC Website

http://www.bt.cdc.gov/agent/smallpox/index.asp

Note: These are guidelines that have been developed with data available as of 1/21/02.

Initially Prepared by

The Akron Regional Hospital Association

Emergency Preparedness Subcommittee

August 20, 2002