Viral Hemorrhagic Fevers

• 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

• 38 yo business man returned from West
Africa via London, ill for 3 days
– 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
MMWR 2004;53(38):891-897 Viral Hemorrhagic Fevers

• Fever in a traveler
– Malaria
– Typhoid fever
• Other Differential Diagnoses
– Meningococcemia
– Rickettsial infection
– Leptospirosis
– Acute leukemia
– Idiopathic or thrombotic thrombocytopenic purpura
Viral Hemorrhagic Fevers

• Hospital Day #4
– Despite empiric antibiotics including antimalarials, pt develops acute respiratory distress syndrome (ARDS)
– Required intubation
Viral Hemorrhagic Fevers

• Fever in a traveler
– Malaria
– Typhoid fever
– Yellow fever
– Lassa fever
Viral Hemorrhagic Fevers

• 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

• 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
Filoviridae
Sub-saharan Africa
Ebola
Marburg
AGENT CASE-FATALITY
50-75%
25%
Arenaviridae
West Africa (Lassa)
South America,
California (Whitewater)
Bunyaviridae
Sub-saharan Africa
Egypt, Yemen
SW US (Hantavirus)
Flaviviridae
Sub-saharan Africa
Central Asia
Viral Hemorrhagic Fevers
Old World: Lassa
New World: Junin,
Machupo, Guanarito
Sabia, Whitewater arroyo
Phlebovirus: Rift Valley
Nairovirus: Crimean Congo
Hantavirus: Sin Nombre
Lassa:1-2% (up to 25% in hospitalized pts)
30% for New World
Rift Valley: <1% overall
50% in hemorrhagic
Yellow fever
Dengue
Omsk
Kyasanur
Yellow Fever: 5-7% overall
50% in hemorrhagic www.cidrap.umn.edu/index.html
accessed 2/4/05

• 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

• 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

• Initial:
– High grade fever, headache, myalgias, fatigue, abdominal pain
• Advanced disease:
– Bleeding
– Maculopapular rash
– Exudative Pharyngitis (Lassa)
– Meningoencephalitis
– Jaundice
Viral Hemorrhagic Fevers

Viral Hemorrhagic Fevers

Viral Hemorrhagic Fevers

Viral Hemorrhagic Fevers

Viral Hemorrhagic Fevers

• Direct contact with blood/body fluids/cadavers
• Aerosol spray (droplet v. airborne)
• Sexual transmission
• Percutaneous
• Bite of infected tick or mosquito
Viral Hemorrhagic Fevers

• Lassa Fever in New Jersey Investigation:
– 5 high risk contacts (wife, kids, visitor)
– 183 low risk contacts
• 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

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, living with contact, caretaker, shook hands with contact)
Place under surveillance once index case confirmed
High-Risk Contacts Mucous membrane contact (eg, kissing, or penetrating injury involving contact with index case’s blood such as needlestick)
Place under surveillance as soon as consider diagnosis of VHF in index case

VHF Personal Protective Equipment
• 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

• 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

• Manage severe bleeding complications
– Cryoprecipitate (concentrated clotting factors)
– Platelets
– Fresh Frozen Plasma
– Heparin for DIC
• Ribavirin in vitro activity vs.
– Lassa fever
– New World Hemorrhagic fevers
– Rift Valley Fever
– No evidence to support use in Filovirus or
Flavivirus infections
Viral Hemorrhagic Fevers

• 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

Viral Hemorrhagic Fevers