Transcript Viral Hemorrhagic Fevers

Viral
Hemorrhagic
Fevers
Viral Hemorrhagic Fevers
Objectives
• Describe the natural geographic distribution
of VHF and scenarios suggestive of
bioterrorism
• Describe the clinical manifestations of VHF in
general
• List exposure classification of contact for
cases of VHF
• Describe infection control precautions for
personnel caring for patients with VHF
• List therapeutic options for patients with VHF
Viral Hemorrhagic Fevers
Case Presentation
• 38 yo business man returned from West
Africa via London, ill for 3 days
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new onset fever
chills
severe sore throat
diarrhea
back pain
• PE: T103.6 BP 90/60, alert
– Skin with diffuse ecchymosis and a maculopapular
rash on the extremities
Viral Hemorrhagic Fevers
MMWR 2004;53(38):891-897
Differential Diagnosis
• Fever in a traveler
– Malaria
– Typhoid fever
• Other Differential Diagnoses
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Meningococcemia
Rickettsial infection
Leptospirosis
Acute leukemia
Idiopathic or thrombotic thrombocytopenic purpura
Viral Hemorrhagic Fevers
Hospital Course
• Hospital Day #4
– Despite empiric antibiotics including
antimalarials, pt develops acute respiratory
distress syndrome (ARDS)
– Required intubation
Viral Hemorrhagic Fevers
Differential Diagnosis
• Fever in a traveler
– Malaria
– Typhoid fever
– Yellow fever
– Lassa fever
Viral Hemorrhagic Fevers
Hospital Course
• Hospital Day #4
– Despite empiric antibiotics including antimalarials,
pt develops ARDS
– Required intubation
• Hospital Day #5
– Local and state health departments notified
– Investigational new drug (IND) protocol to
administer IV ribavirin
– Patient died before administration of any drug
Viral Hemorrhagic Fevers
Diagnosis
• Clinical and post-mortem specimens
sent to CDC
• Lassa virus confirmed
– Serum antigen detection
– Immunohistochemical staining liver tissue
– Virus isolation in cell culture
– RT-PCR sequencing of virus
Viral Hemorrhagic Fevers
FAMILY/GEOGRAPHY
AGENT
CASE-FATALITY
Filoviridae
Sub-saharan Africa
Ebola
Marburg
Arenaviridae
West Africa (Lassa)
South America,
California (Whitewater)
Old World: Lassa
New World: Junin,
Machupo, Guanarito
Sabia, Whitewater arroyo
Lassa:1-2% (up to 25%
in hospitalized pts)
Bunyaviridae
Sub-saharan Africa
Egypt, Yemen
SW US (Hantavirus)
Phlebovirus: Rift Valley
Nairovirus: Crimean Congo
Hantavirus: Sin Nombre
Rift Valley: <1% overall
50% in hemorrhagic
Flaviviridae
Sub-saharan Africa
Central Asia
Yellow fever
Dengue
Omsk
Kyasanur
Viral Hemorrhagic Fevers
50-75%
25%
30% for New World
Yellow Fever: 5-7%
overall
50% in hemorrhagic
www.cidrap.umn.edu/index.html accessed 2/4/05
Epidemiology
• Incubation period
– 2 days to 3 weeks for most VHF
– Lassa fever: 21 days
• Endemic regions
– Sub-saharan Africa
• Lassa fever causes 100-300,000 infections and 5,000
deaths each year
• 20 imported cases reported worldwide
• Human to human transmission has occured
– South America
Viral Hemorrhagic Fevers
Why do VHFs make good Bioweapons?
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Disseminate through aerosols
Low infectious dose
High morbidity and mortality
Cause fear and panic in the public
No effective vaccine
Available and can be produced in large quantity
Research on weaponization has been conducted
Viral Hemorrhagic Fevers
Clinical Presentation
• Initial:
– High grade fever, headache, myalgias, fatigue,
abdominal pain
• Advanced disease:
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Bleeding
Maculopapular rash
Exudative Pharyngitis (Lassa)
Meningoencephalitis
Jaundice
Viral Hemorrhagic Fevers
Viral Hemorrhagic Fevers
Viral Hemorrhagic Fevers
Viral Hemorrhagic Fevers
Viral Hemorrhagic Fevers
Transmission
• Direct contact with blood/body
fluids/cadavers
• Aerosol spray (droplet v. airborne)
• Sexual transmission
• Percutaneous
• Bite of infected tick or mosquito
Viral Hemorrhagic Fevers
Infection Control
• Lassa Fever in New Jersey Investigation:
– 5 high risk contacts (wife, kids, visitor)
– 183 low risk contacts
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9 other family members
139 HCW at hospital: 42 labworkers, 32 RN, 11 MD
16 labworkers in Virginia and California
19 passengers on flight from London to Newark
• No additional cases occurred
Viral Hemorrhagic Fevers
Infection Control
Risk Category
Description
Surveillance
Casual Contacts
Remote contact with
index case (eg, stayed
in same hotel)
VHF not spread by
casual contact, no
special surveillance
Close Contacts
More than casual (eg, Place under surveillance
living with contact,
once index case
caretaker, shook
confirmed
hands with contact)
High-Risk Contacts
Mucous membrane
Place under surveillance
contact (eg, kissing, or
as soon as consider
penetrating injury
diagnosis of VHF in
involving contact with
index case
index case’s blood
such as needlestick)
CDC Update:
Viral Hemorrhagic
management Fevers
of patients with suspected VHF-United States MMWR 1995;44:475-79
VHF Personal Protective Equipment
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Airborne and Contact isolation for patients with respiratory symptoms
– N-95 or PAPR mask
– Negative pressure isolation
– Gloves
– Gown
– Fitted eye protection and shoe covers if going to be exposed to
splash body fluids
Droplet and Contact isolation for patients without respiratory symptoms
– Surgical mask
– Gloves
– Gown
– Fitted eye protection and shoe covers if going to be exposed to
splash body fluids
Environmental surfaces
– Cleaned with hospital approved disinfectant
– Linen incinerated, autoclaved, double-bagged for wash
Viral Hemorrhagic Fevers
Treatment
• Supportive care:
– Fluid and electrolyte management
– Hemodynamic monitoring
– Ventilation and/or dialysis support
– Steroids for adrenal crisis
– Anticoagulants, IM injections, ASA,
NSAIDS are contraindicated
– Treat secondary bacterial infections
Viral Hemorrhagic Fevers
Treatment
• Manage severe bleeding complications
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Cryoprecipitate (concentrated clotting factors)
Platelets
Fresh Frozen Plasma
Heparin for DIC
• Ribavirin in vitro activity vs.
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Lassa fever
New World Hemorrhagic fevers
Rift Valley Fever
No evidence to support use in Filovirus or
Flavivirus infections
Viral Hemorrhagic Fevers
Vaccination
• Argentine and Bolivian HF
– PASSIVE IMMUNIZATION
• Treat with convalescent serum containing
neutralizing antibody or immune globulin
• Yellow Fever
– ACTIVE IMMUNIZATION
• Travelers to Africa and South America
P. Jahrling,
29, Medical
Aspects of Clinical and Biological Warfare; p591-602
ViralChapter
Hemorrhagic
Fevers
This completes the current
presentation.
Viral Hemorrhagic Fevers