Suspected Viral Hemorrhagic Fever (VHF)

(Ebola, Marburg, Lassa and Crimean-Congo Hemorrhagic Fever)

 

 

Purpose

 

To provide guidelines for managing patients with suspected viral hemorrhagic fever.

 

Description of AgentlSyndrome

 

VHFs are diseases caused by viruses of four distinct families: arenaviruses, foviruses, bunyaviruses, and flaviviruses. Some types can cause relatively mild illnesses, many can cause severe, life-threatening disease.

 

Carriers:

 

1.             Most are zoonotic (viruses naturally reside in an animal reservoir host or arthropod vector). They are totally dependent on their hosts for replication and overall survival.

a)    Animal Reservoir Host: Rodents (multimammate rat, cotton rat, deer mouse, house mouse, field rodents) and

b)    Arthropod Vector: Ticks and mosquitoes

2.           Humans are NOT the natural reservoir for any of these viruses. Humans are infected when they come into contact with infected hosts. Humans CAN transmit the virus to one another.

3.           Hosts of some viruses remain unknown: Ebola and Marburg viruses are well-known examples.

 

Transmission:

 

1.              Naturally acquired

a)    Rodents Reservoirs: When humans have contact with urine, fecal matter, saliva, or other body excretions from infected rodents.

b)    Animals: When humans care for or slaughter animals (livestock) that have been infected by an arthropod vector. In nonhuman primates (i.e., monkeys) there is possible airborne spread among the species.

c)    Arthropod Vectors: When the vector mosquito or tick bites a human, or when a human crushes a tick.

d)    Person-To-Person: Ebola, Marburg, Lassa and Crimean-Congo Hemorrhagic Fever are spread person-to-person. This is a secondary transmission of the virus that can occur directly through close contact with infected people or their body fluids. Airborne transmission may occur. Highest risk for person-to-person transmission is during the latter stages of illness, which are characterized by vomiting, diarrhea, shock, and often hemorrhage.

e)    Indirect Contamination: Through contact with objects contaminated with infected body fluids. (Examples: contaminated syringes/needles, not wearing appropriate barrier precautions)

2.              Inhalation Dissemination

 

Incubation

 

The incubation period ranges from 2 days to 3 weeks, depending on the etiology of the VHF.

 

Signs and Symptoms

 

1.             Specific signs and symptoms vary by the type of VHF, but initial signs and symptoms often include: Marked fever, fatigue, dizziness, muscle aches, loss of strength, and exhaustion.

 

2.             Patients with severe cases of VHF often show signs of bleeding under the skin, in internal organs, or from body orifices like the mouth, eyes, or ears. Although they may bleed from many sites around the body, patients rarely die because of blood loss. Severely ill patient cases may also show shock, nervous system malfunction, coma, delirium and seizures. Some types of VHF are associated with renal (kidney) failure.

 

Diagnosis

 

Definitive diagnosis rests on specific virologic techniques.

 

Prophylasis

 

1.             No post exposure prophylasis is available

2.             With the exception of yellow fever and Argentine hemorrhagic fever, which have vaccines developed, no vaccines exist that can protect against these diseases.

3.             Patients receive supportive therapy

4.             Ribavirin, an anti-viral drug, has been effective in treating some individuals with Lassa fever or HFRS.

5.             Treatment with convalescent-phase plasma has been used with success in some patients with Argentine Hemorrhagic Fever.

 

Control Measures and Decontamination

 

1.             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)    Eye Protection

d)    Gowns and gloves

e)    Hand-washing

f)     Dedicated patient care equipment

g)    Cohort cases if unable to provide private rooms

2.             Nonessential staff and visitors should be restricted from entering the room.

3.             All persons entering the patient’s room should wear gloves and gowns to prevent contact with items or environmental surfaces that may be soiled.

4.             Face shields or surgical masks and eye protection (e.g., goggles or eyeglasses with side shields) should be worn by persons coming within approximately 3 feet of the patient to prevent contact with blood, body fluids, secretions (including respiratory droplets) or excretions.

5.             Need for additional barriers depends on the potential for fluid contact. Note: If copious amounts of blood, other body fluids, vomit or feces are present in the environment, leg and shoe coverings also may be needed. Before entering the hallway, all protective barriers should be removed and shoes that are soiled with body fluids should be cleaned and disinfected as described below.

6.             For patients with suspected VHF who have a prominent cough, vomiting, diarrhea, or hemorrhage, additional precautions are indicated to prevent possible exposure to airborne particles that may contain virus. Patients with these symptoms should be placed in a negative-pressure room. Persons entering the room should wear personal protective respirators as recommended for care of patients with active TB.

7.             Environmental surfaces or inanimate objects contaminated with blood, other body fluids, secretions, or excretions should be cleaned and disinfected using Standard Procedures. Disinfection can be accomplished using a U.S. Environmental Protection Agency (EPA)-registered hospital disinfectant or a 1:100 dilution of household bleach.

8.             If patient dies, handling of the body should be minimal. The state health department and CDC should be consulted regarding appropriate precautions.

 

Notification

 

Internal:   At hospital notify______________________________

 

External: All suspected cases of suspected viral hemorrhagic fever 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.

 

SPECIMENS

 

VIRAL HEMORRHAGIC SYNDROME (Multiple Viral Etiologies)

Blood Cultures: two separate sets from different sites (one set is 2 bottles – 10 ml each bottle)

Green-top (heparin) tube for culture

Red-top or gold-top tubes (for serology)

Stool (not in transport medium)

Nasophary ngeal or throat swab in viral transport medium

Urine

ID consult

Note on requisition

Possible VHS exposure in an asymptomatic patient

No

No

No

No

No

No

No

Not applicable

Viral Hemorrhagic Fever

Yes

Yes

Yes

Yes

Yes

Yes

Yes

R/O Viral Hemorrhagic Fever

 

 

 

References

CDC — MMWR Weekly, June 30, 1995144(25);475-479

 

CDC — Disease Information Viral Hemorrhagic Fevers: Fact Sheet, dated 02/07/2002 —Via internet: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/vhfmanual.htm#content

 

 

Note:    These are guidelines that have been developed with data available as of 5/9/02.

 

 

Initially Prepared by

The Akron Regional Hospital Association

Emergency Preparedness Subcommittee

August 20, 2002