Module 7 of 10 ~30 minutes

Viral Hemorrhagic Fevers

Ebola, Marburg, Lassa, CCHF - High-Consequence Infectious Diseases

Filoviruses Enhanced PPE Trained Observer

Learning Objectives

1

Identify the four viral families that cause hemorrhagic fevers

2

Recognize clinical presentation and phases of VHF disease

3

Explain transmission routes and why VHFs are NOT airborne

4

Implement enhanced PPE requirements for VHF patients

5

Demonstrate proper donning and doffing sequences with trained observer

6

Provide supportive nursing care for VHF patients

Viral Hemorrhagic Fever Overview

What are VHFs?

Viral hemorrhagic fevers are caused by RNA viruses from four distinct families. They share the ability to damage the vascular system and impair blood clotting, leading to hemorrhage, shock, and multi-organ failure.

Filoviridae

Ebola, Marburg

Arenaviridae

Lassa, Junin, Machupo

Bunyaviridae

CCHF, Rift Valley, Hantavirus

Flaviviridae

Yellow fever, Dengue

Bioterrorism Potential

The Soviet Union weaponized both Ebola and Marburg viruses. VHFs are considered high-priority bioterrorism threats due to their high mortality, potential for person-to-person spread, and ability to cause widespread panic.

Filoviruses: Ebola & Marburg

Ebola Virus Disease

Mortality: 50-90%

Depends on strain and available care

Incubation: 2-21 days

Average 8-10 days

Endemic Regions:

Central/West Africa: DRC, Guinea, Liberia, Sierra Leone, Uganda

Vaccine Available:

Ervebo (rVSV-ZEBOV) - FDA approved for Zaire ebolavirus

Marburg Virus Disease

Mortality: 24-88%

Similar presentation to Ebola

Incubation: 2-14 days

Average 5-7 days

Endemic Regions:

Africa: Angola, DRC, Kenya, Uganda

Reservoir:

Egyptian fruit bats; caves and mines are high-risk

Other VHFs: Arenaviruses & Bunyaviruses

Virus Family Endemic Region Reservoir Mortality Treatment
Lassa Fever Arenaviridae West Africa Mastomys rodents ~1% overall; 15-20% hospitalized Ribavirin effective
CCHF Bunyaviridae Africa, Balkans, Middle East, Asia Hyalomma ticks 20-50% Ribavirin may help
Rift Valley Fever Bunyaviridae Africa, Middle East Mosquitoes; livestock ~1%; higher with hemorrhagic form Supportive care
Hantavirus (HFRS) Bunyaviridae Asia, Europe, Americas Rodents (deer mice) 5-15% (HFRS); ~40% (HPS) Supportive care

Lassa Fever: The "Quiet" VHF

Lassa fever causes 300,000-500,000 infections annually in West Africa. Most cases are mild, but severe cases have high mortality. Deafness is a common sequela - up to 30% of survivors experience hearing loss. Ribavirin is effective if given early.

Clinical Presentation & Phases

1

EARLY/PRODROMAL PHASE (Days 1-3)

Non-specific symptoms: High fever, severe headache, myalgia, fatigue, sore throat

Indistinguishable from influenza, malaria, or other febrile illnesses

2

GI PHASE (Days 3-5)

GI symptoms predominate: Severe nausea, vomiting, diarrhea, abdominal pain

Massive fluid losses lead to dehydration and electrolyte imbalances

3

HEMORRHAGIC PHASE (Days 5-7+)

Bleeding manifestations: Petechiae, ecchymoses, mucosal bleeding (gums, nose), GI bleeding, hematuria

Not all patients develop overt bleeding - absence doesn't rule out VHF

4

TERMINAL/RECOVERY PHASE (Days 7-12+)

Death: Multi-organ failure, shock, DIC, cardiac arrhythmias

Recovery: Prolonged convalescence, weakness, arthralgia; survivors may shed virus for weeks

Laboratory Findings

  • • Thrombocytopenia (low platelets)
  • • Leukopenia early, then leukocytosis
  • • Elevated transaminases (AST, ALT)
  • • Elevated BUN/creatinine
  • • DIC parameters: prolonged PT/PTT, elevated D-dimer
  • • Low albumin, metabolic acidosis

Transmission

CRITICAL: Ebola is NOT Airborne

Despite common misconceptions, Ebola and most VHFs are NOT transmitted through the air. They spread through direct contact with body fluids.

This is why contact precautions - not airborne precautions - are the primary protection. However, negative pressure rooms are recommended when available.

HOW VHFs ARE Transmitted

  • •Direct contact with blood
  • •Contact with body fluids (vomit, diarrhea, urine, sweat, semen)
  • •Mucous membrane exposure (eyes, nose, mouth)
  • •Needlestick injuries
  • •Contact with contaminated surfaces
  • •Handling deceased bodies

HOW VHFs are NOT Transmitted

  • •Airborne droplet nuclei
  • •Casual contact (unless body fluids involved)
  • •Food or water (except in endemic areas)
  • •Mosquito bites (Ebola/Marburg)
  • •Asymptomatic individuals

Key Point: Patients are NOT infectious until symptomatic. Contact tracing focuses on the period after symptom onset.

Highest-Risk Period

Viral load increases as disease progresses. Patients are most infectious during the hemorrhagic phase when viral titers are highest and bodily fluid production (vomiting, diarrhea, bleeding) is greatest.

Enhanced PPE for VHFs

WARNING: Standard Contact Precautions are INSUFFICIENT

VHF patients have high viral loads in all body fluids. Standard hospital gowns and gloves do NOT provide adequate protection. Enhanced PPE is mandatory.

Required PPE Components

1
Fluid-Impermeable Coverall or Gown

Tyvek suit or fluid-resistant isolation gown

2
PAPR or N95 + Face Shield

PAPR preferred; N95 must be fit-tested

3
Double Gloves

Outer gloves extended over gown cuffs, taped

4
Impermeable Boot Covers

Or dedicated boots that stay in isolation area

5
Impermeable Apron

If significant fluid exposure anticipated

6
Hood or Head Cover

If not using PAPR with integrated hood

Isolation Room Requirements

  • • Private room with adjoining anteroom for donning/doffing
  • • Negative pressure with 6-12 air changes/hour (ideal)
  • • Dedicated equipment - stethoscope, BP cuff stay in room
  • • Waste management - autoclave or chemical treatment before disposal
  • • Environmental decontamination - 0.5% hypochlorite (bleach) solution

Donning & Doffing Protocols

THE TRAINED OBSERVER IS MANDATORY

A trained observer MUST supervise every donning and especially every doffing procedure. Most healthcare worker infections occur during improper PPE removal.

The Dallas Lesson (2014): Two nurses were infected while caring for an Ebola patient. Both infections likely occurred during doffing. After the CDC mandated trained observers, no healthcare workers in designated treatment centers were subsequently infected.

DONNING SEQUENCE

Putting on PPE - performed in anteroom with observer

  1. 1Perform hand hygiene
  2. 2Put on inner gloves
  3. 3Put on coverall/gown (tie/zip securely)
  4. 4Put on boot covers
  5. 5Put on N95/PAPR
  6. 6Put on hood (if not using PAPR)
  7. 7Put on face shield/goggles
  8. 8Put on apron (if needed)
  9. 9Put on outer gloves (tape to sleeves)
  10. 10Observer verifies all components

DOFFING SEQUENCE

HIGHEST RISK! Removing contaminated PPE with observer

  1. 1Disinfect outer gloves
  2. 2Remove apron (if worn)
  3. 3Disinfect outer gloves again
  4. 4Remove outer gloves (inside-out)
  5. 5Disinfect inner gloves
  6. 6Remove face shield (by strap only!)
  7. 7Remove hood/PAPR
  8. 8Remove coverall (inside-out, rolling down)
  9. 9Remove boot covers with coverall
  10. 10Remove N95 (by straps only!)
  11. 11Remove inner gloves (inside-out)
  12. 12FINAL hand hygiene

Trained Observer Responsibilities

  • • Read each step aloud from written checklist
  • • Watch for ANY contact with contaminated surfaces
  • • STOP the process immediately if error occurs
  • • Guide remediation if contamination occurs
  • • Document completion of each step
  • • NEVER allow rushing - fatigue causes errors

Nursing Care for VHF Patients

Fluid Management

  • • Aggressive fluid resuscitation - patients lose massive volumes through GI tract
  • • Monitor urine output (goal >0.5 mL/kg/hr)
  • • Replace electrolytes (especially K+, Mg++)
  • • May need 5-10 L/day in severe cases
  • • Colloids if severe hypoalbuminemia

Hemorrhage Management

  • • Monitor for signs of bleeding
  • • Blood products: PRBCs, platelets, FFP as needed
  • • Avoid IM injections (causes hematoma)
  • • Minimize venipuncture - use saline locks
  • • Apply pressure to all puncture sites

Hemodynamic Support

  • • Continuous cardiac monitoring
  • • Vasopressors for refractory shock
  • • Watch for arrhythmias (electrolyte imbalances)
  • • Central line if needed (but infection risk)

Supportive Measures

  • • Antiemetics for nausea/vomiting
  • • Antidiarrheals with caution
  • • Pain management - avoid NSAIDs (bleeding risk)
  • • Nutritional support (enteral if tolerated)

Psychological Support

VHF patients are terrified and isolated. They cannot have normal human contact. Provide emotional support through communication, explain procedures, and arrange video calls with family if possible. Staff psychological support is equally important - caring for VHF patients is traumatic.

Treatment Options

Virus Specific Treatment Status
Ebola (Zaire) Inmazeb (atoltivimab/maftivimab/odesivimab)
Ebanga (ansuvimab)		 FDA Approved
Ebola (Zaire) Ervebo vaccine (rVSV-ZEBOV) FDA Approved (prevention)
Lassa Fever Ribavirin - most effective if given early Off-label / IND
CCHF Ribavirin - may reduce mortality Off-label / IND
Marburg Supportive care only; monoclonal antibodies investigational No specific treatment
Hantavirus Supportive care; ribavirin investigational No specific treatment

The 2018-2020 DRC Outbreak Breakthrough

During the DRC Ebola outbreak, clinical trials showed that monoclonal antibody treatments (Inmazeb and Ebanga) significantly improved survival - reducing mortality from ~70% to ~34% when given early. These became the first FDA-approved treatments for Ebola in 2020.

Key Takeaways

VHFs are caused by 4 viral families: Filoviridae, Arenaviridae, Bunyaviridae, Flaviviridae

Ebola is transmitted by DIRECT CONTACT with body fluids - NOT airborne

Patients are NOT infectious until symptomatic

Standard contact precautions are INSUFFICIENT - enhanced PPE required

A TRAINED OBSERVER is MANDATORY for all donning and doffing

Most HCW infections occur during DOFFING - never rush

Ribavirin is effective for Lassa fever if given early

FDA-approved Ebola treatments (Inmazeb, Ebanga) significantly improve survival

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