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Surveillance and Reporting Guidelines for
Ebola-Marburg Viral Diseases
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back to
Ebola-Marburg index page |
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Disease
Reporting |
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In Washington |
Described in Africa, these
diseases have never occurred in Washington State. One or more
cases may indicate an act of terrorism and constitute a public
health emergency.Described in Africa, these diseases have never
occurred in Washington State. One or more cases may indicate an
act of terrorism and constitute a public health emergency. |
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Purpose of Reporting and
Surveillance |
- To identify rare diseases associated with travel.
- To identify potentially exposed health care workers or
laboratory personnel and to provide counseling.
- To raise the index of suspicion of a possible bioterrorism
event if no natural exposure source is identified.
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Reporting Requirements |
- Health care providers: immediately notifiable to Local
Health Jurisdiction
- Hospitals: immediately notifiable to Local Health
Jurisdiction
- Laboratories: immediately notifiable to Local Health
Jurisdiction, specimen submission required
- Local health jurisdictions: suspected or confirmed
cases are immediately notifiable to DOH Communicable Disease
Epidemiology: 1-877-539-4344
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Case Definition for Surveillance |
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Clinical Criteria for Diagnosis |
A severe illness
with temperature ≥101oF (38.3oC) of <3
weeks duration, no predisposing factors for hemorrhage, no
established alternative diagnosis with at least two of the
following:
- Petechial or hemorrhagic rash
- Epistaxis
- Hematemesis
- Hemoptysis
- Hematochezia
- Bleeding from other sites
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Laboratory Criteria for Diagnosis |
- Identification of Ebola or Marburg virus from a clinical
specimen.
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Case Definition |
- Probable: A case that meets the clinical case
definition, is not laboratory confirmed, and is not
epidemiologically linked to a confirmed case, but has
appropriate exposure history.
- Confirmed: A case that is laboratory confirmed, or a
case that meets the clinical case definition and is not
laboratory confirmed, but is epidemiologically linked to a
confirmed case.
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A. Description |
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1. Identification |
Severe acute
viral illnesses, usually with sudden onset of fever, malaise,
myalgia and headache, followed by pharyngitis, vomiting,
diarrhea and maculopapular rash. The accompanying hemorrhagic
diathesis is often accompanied by hepatic damage, renal failure,
CNS involvement and terminal shock with multiorgan dysfunction.
Laboratory findings usually show lymphopenia, severe
thrombocytopenia and transaminase elevation (AST greater than
ALT), sometimes with hyperamylasemia. Approximately 25% of
reported primary cases of Marburg virus infection have been
fatal; case-fatality rates of Ebola infections in Africa have
ranged from 50% to nearly 90%.
Diagnosis is
made by ELISA for specific immunoglobulin G (IgG) antibody
(presence of immunoglobulin M (IgM) antibody suggests recent
infection); by ELISA antigen detection in blood, serum or organ
homogenates; by PCR; by detection of the virus antigen in liver
cells by use of monoclonal antibody in an IFA test; or by virus
isolation in cell culture or guinea pigs. Virus may sometimes be
visualized in liver sections by EM. Postmortem diagnosis through
immunohistochemical examination of formalin-fixed skin biopsy
specimens is also possible. IFA tests for antibodies have often
been misleading, particularly in serosurveys for past infection.
Laboratory studies represent an extreme biohazard and should be
carried out only where protection against infection of the staff
and community is available (BSL-4 containment). |
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2. Infectious Agent |
Virions are 80 nm in diameter
and 790 nm (Marburg) or 970 nm (Ebola) in length, and are
members of the Filoviridae. Longer, bizarre virion related
structures may be branched or coiled and reach 10 μm in length.
The Marburg virus is antigenically distinct from Ebola. Ebola
strains from the Democratic Republic of the Congo (formerly
Zaire), Ivory Coast, Gabon and Sudan have been associated with
human disease. A fourth Ebola strain, Reston, causes fatal
hemorrhagic disease in nonhuman primates; few human infections
have been documented and those were clinically asymptomatic. |
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3. Worldwide Occurrence |
Marburg disease
has been recognized on six occasions: in 1967, in Germany and
Yugoslavia, 31 humans (7 fatalities) were infected following
exposure to African green monkeys (Cercopithecus aethiops)
from Uganda; in 1975, the fatal index case of 3 cases diagnosed
in South Africa had originated in Zimbabwe; in 1980, there were
2 confirmed cases in Kenya, 1 fatal; in 1982, 1 case occurred in
Zimbabwe; and in 1987, a fatal case occurred in Kenya. In 1999,
in the Democratic Republic of the Congo, at least 3 fatal cases
of Marburg were confirmed among over 70 suspected cases of viral
hemorrhagic fever.
Ebola disease
was first recognized in 1976 in the western equatorial province
of the Sudan and 500 miles away in Zaire; more than 600 cases
were identified in rural hospitals and villages; the
case-fatality rate for these nearly simultaneous outbreaks was
about 70%. A second outbreak occurred in the same area in Sudan
in 1979. A distinct strain was recovered from one person and
from chimpanzees in the Ivory Coast in 1994. A major Ebola
outbreak in 1995 was centered around Kitwit, Zaire. In 1996-1997
two outbreaks that were recognized in Gabon resulted in 98
recognized cases and 66 deaths. FA antibodies have been found in
residents of several other areas of sub-Saharan Africa, but
their relation to the highly virulent Ebola virus is unknown.
Ebola related filoviruses have
been isolated from cynomolgus monkeys (Macaca fascicularis)
imported in 1989, 1990 and 1996 to the US and in 1992 to Italy
from the Philippines; many of these monkeys died. Four of five
animal handlers with daily exposure to these monkeys in 1989
developed specific antibodies with no antecedent fevers or other
illness. |
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4. Reservoir |
Unknown despite extensive
studies. |
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5. Modes of Transmission |
Person to person transmission
occurs by direct contact with infected blood, secretions, organs
or semen. Risk is highest during the late stages of illness when
the patient is vomiting, having diarrhea, or hemorrhaging. Risk
during the incubation period is low. Under natural conditions,
airborne transmission among humans has not been documented.
Nosocomial infections have been frequent; virtually all Ebola
(Zaire) patients who acquired infection from contaminated
syringes and needles died. Transmission through semen has
occurred 7 weeks after clinical recovery. |
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6. Incubation Period |
Three to 9 days with Marburg and
2-21 days in Ebola virus disease. |
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7. Period of Communicability |
As long as blood and secretions
contain virus. Up to 30% of primary caregivers in Sudan were
infected, while most other household contacts remained
uninfected. Ebola virus was isolated from the seminal fluid on
the 61st, but not on the 76th, day after onset of illness in a
laboratory acquired case. |
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8. Susceptibility and Resistance |
All ages are susceptible. |
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B. Methods of Control |
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1. Preventive Measures |
- Report to local health authority.
- Isolation: Institute immediate strict barrier isolation
in a private hospital room away from traffic patterns. Entry
of nonessential staff and visitors should be restricted.
Because of the low incidence of nosocomial infections
reported from African hospitals, transfer to special
isolation units is not considered necessary; however,
nosocomial transmission has occurred, and strict procedures
for isolation of body fluids and excreta should be
maintained. A negative pressure room and respiratory
protection is desirable. Male patients should refrain from
sexual activity until the semen has been shown to be free of
virus or for 3 months. To reduce exposure to infectious
materials, laboratory tests should be kept to the minimum
necessary for proper diagnosis and patient care. Technicians
should be alerted to the nature of the specimens and
supervised to ensure that appropriate specimen
inactivation/isolation procedures are followed. Dead bodies
should not be embalmed but rather sealed in leak proof
material and cremated or buried promptly in a sealed casket.
- Concurrent disinfection: Patient's excreta, sputum,
blood and all objects with which the patient has had
contact, including laboratory equipment used to carry out
tests on blood, should be disinfected with 0.5% sodium
hypochlorite solution or 0.5% phenol with detergent, and, as
far as possible, appropriate heating methods, such as
autoclaving, incineration or boiling. Laboratory tests
should be carried out in special high containment
facilities; if there is no such facility, tests should be
kept to a minimum and specimens handled by experienced
technicians using all available precautions such as gloves
and biological safety cabinets. When appropriate, serum may
be heat inactivated at 60ºC (140ºF) for 1 hour. Thorough
terminal disinfection with 0.5% sodium hypochlorite solution
or a phenolic compound is adequate; formaldehyde fumigation
can be considered.
- Quarantine: Only surveillance is recommended for close
contacts (see B2f, below).
- Immunization of contacts: None.
- Investigation of contacts and source of infection:
Identify all close contacts (people living with, caring for,
testing laboratory specimens from or having noncasual
contact with the patient) in the 3 weeks after the onset of
illness. Establish close surveillance of contacts as
follows: body temperature checks at least 2 times daily for
at least 3 weeks after last exposure. In case of temperature
greater than 38.3ºC (101ºF), hospitalize immediately in
strict isolation facilities. Determine patient's place of
residence during 3 weeks prior to onset, and search for
unreported or undiagnosed cases.
- Specific treatment: Ribavirin (Virazole), most effective
within the first 6 days of illness, should be given IV, 30
mg/kg initially, followed by 15 mg/kg every 6 hours for 4
days and 8 mg/kg every 8 hours for 6 additional days. See
also: Borio L, Inglesby TV, Peters, CJ, et al. Hemorrhagic
fever viruses as biological weapons: medical and public
health management. JAMA 2002; 287:2391-2405 (in
Additional Resources).
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2. Control of Patient, Contacts
and the Immediate Environment |
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3. Epidemic Measures |
Not determined. |
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4. International Measures |
Notification of source country
and to receiving countries of possible exposures by infected
travelers. |
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