2. What is Viral
Hemorrhagic Fever?
Severe multisystem syndrome
Vascular instability and
decreased vascular integrity
Damage to microvascular system
leads to increased permeability
and hemorrhage
Hemorrhage occur infrequently
•Rarely life-threatening in itself,
reflection of widespread vascular
damage
•Includes conjunctivitis hemorrhage,
petechiae, ecchymosis
3. Characteristics of VHF
■ RNA viruses
■ Enveloped in lipoprotein
■ Exist in host population and restricted
geographically
■ Spread to humans when in contact with host
population and occasionally human to human
4. Viral Hemorrhagic fever
■ History of travel to an endemic region within
IP
■ Abrupt onset of fever and myalgia
■ Followed by abdominal or chest pain,
anorexia, dizziness, severe headache,
photophobia, nausea and vomiting
■ Periorbital swelling, shock, multifocal bleeding
6. Overview of management
■ Limited effective drug treatment or vaccine
■ Early recognition and prompt treatment
■ Supportive care-Fluid, vasopressors, antibiotics for secondary
bacterial infection
■ Strict barrier nursing and precautionary measures
■ Outbreaks could be seasonal, sporadic and irregular
■ Infection control and prevention is crucial to minimize spread
7. Viral Hemorrhagic Fever
■ Viruses of four distinct families
− Arenaviruses
− Filoviruses
− Bunyaviruses
− Flaviviruses
■ RNA viruses
− Enveloped in lipid coating
■ Survival dependent on an animal or insect host, for the natural
reservoir
10. • Arena virus are pleomorphic round or oval virus
• Diameter ranging from 50 to 300mm
• Virus surface has club shaped projections
11. Arenaviridae History
■ 1958: Junin virus - Argentina
– First to cause hemorrhagic fever
– Argentine hemorrhagic fever
■ 1963: Machupo virus – Bolivia
– Bolivian hemorrhagic fever
■ 1969: Lassa virus – Nigeria
– Lassa fever
12. Arenaviridae Transmission
■ Virus transmission and amplification occurs in
rodents
■ Shed virus through urine, feces, and other excreta
■ Human infection
− Contact with excreta
− Contaminated materials
− Aerosol transmission
■ Person-to-person transmission
13. Arenaviridae Epidemiology
■ Africa
– Lassa
■ South America
– Junin, Machupo, Guanarito, and Sabia
■ Contact with rodent excreta
■ Case fatality: 5 – 35%
■ Explosive nosocomial outbreaks with Lassa and
Machupo
14. Arenaviridae in Humans
■ Incubation period
– 10–14 days
■ Fever and malaise
– 2–4 days
■ Hemorrhagic stage
– Hemorrhage, leukopenia, thrombocytopenia
– Proteinuria
– Neurologic signs
15. Lassa Fever
First documented in
lassa, Nigeria is 1969
Widely spread in
west Africa
especially Nigeria,
Liberia, Sierra
Leone, and Guinea
Reservoir in
multimammate rats
(mastomys
natalensis)
Contract disease by
ingesting foods
contaminated by rat
urine or saliva
Person to person
spread by body
fluids do occur
(only 10 to 30% of
infections are
symptomatic)
-Virus present in
urine during
convalescence and
seminal fluid early in
recovery
17. CONT. HISTORY OF LASSA
■ The mystery disease spread to two SIM nurses who helped
care for Laura. Charlotte Shaw died of the disease.
Penny Pinneo, who also contracted the fever, was flown
to New York along with samples of tissue and fluids from
the previous victims, and survived after receiving care at
Columbia-Presbyterian Medical Center for more than nine
weeks
■ Took about 5 years after this before Lassa virus was
identified.
18.
19. Continuation Lassa Fever
Incubation period 7 – 18days
Incidence is highest in the dry season but transmission is
year-round
Characterised fever, myalgia, severe headache, malaise
of headache
A transient maculopapular rash
Half of the patients have sorethroat, pharyngitis and LNE
Severe cases epistaxis and GI bleeding
20. Maternal lethality is high especially in
the last trimester
CFR 15 to 20% usually from
irreversible hypovolemic shock
Reverse transcriptase polymerase
chain reaction of throat swab, serum
or urine
21. CASE DEFINITION
1. Temperature >/= 38 o Celsius for 2/7 -fever is saddle pattern, high
grade, ass with chills and rigor, transiently relieved with antipyretics
•Exclude typhoid and malaria
•Some or one of chest pain, headache, sore throat- uncommon, non exudative,
vomiting, diarrhea( rare)
2. Fever + bleeding or facial oedema ( pregnant woman with fever and
abortion, breast engorgement)
3. Fever and history of contact with lassa fever patient.
4. Fever not responsive to antimalarial and antibiotics.
22. INVESTIGATION ■ Diagnostic- RT PCR for Lassa virus
Cycle time is inversely
proportional to viral load and
infectivity
■ Supportive
E,U,CR- commonest complication-
AKI
LFT- high AST- poor prognosis
FBC- high of low WBC, Low PLT
PT/PTTK/INR
RBG- high incidence of
hypoglycemia in dialyzed patients
MP
, Blood culture
23. Treatment
■ IV Ribavirin- mechanism not well understood
■ Favipiravir – in clinical trial
■ Supportive care- strict I/O monitoring
■ Avoid NSAIDS, IM injections
■ Give 50% of Heparin to patients needing dialysis
■ Ideal dialysis- CRRT for 12-24 hrs
25. POOR
PROGNOSTI
C FACTORS
■ AKI
■ Shock
■ Encephalopathy/ altered
sensorium
■ Late commencement of ribavirin
■ Age <5 and > 50
■ Elevated serum AST
■ Leucopenia/cytosis
■ Seizures
■ pregnancy
26. DISCHARGE CRITERIA
The decision to discharge a patient should be taken based
on:
■ clinical grounds
■ supported by laboratory results
■ A negative PCR means that the virus can no longer be
detected in the blood and the patient is unlikely to be
infectious with casual contact.
■ If patient is still RT-PCR positive at day 10 and still
symptomatic, treatment can be extended for 5-10 days.
29. Bunyaviridae History
1910
Rift Valley Fever – Kenya
• Epizootic in sheep and cattle
1940s
CCHF - Crimean peninsula in 1944
and Congo in 1969
• Hemorrhagic fever in agricultural workers
1951
Hantavirus – Korea
• Hantavirus pulmonary syndrome
• Hemorrhagic fever with renal syndrome
(Korean HF, Epidemic hemorrhagic fever,
nephropathica epidemica)
30. Bunyaviridae Transmission
■ Arthropod vector
– Exception – Hantaviruses
■ RVF – Aedes mosquito
■ CCHF – Ixodid tick. (reservoir and vector)
Tick or animal blood or Infected human blood.
■ Hantavirus – Rodents
Contaminated air with virus ( airborne)
■ Less common
– Aerosolized urine, droppings or saliva
– Exposure to infected animal tissue
31. Bunyaviridae Epidemiology
• 1% case fatality rate
RVF - Africa and Arabian Peninsula
• 30% case fatality rate ( ranges from 9% to 50%)
CCHF - Africa, Eastern Europe, Asia
• 5 -15% case fatality rate
Hantavirus - North and South America,
Eastern Europe, and Eastern Asia
32. Bunyaviridae. Clinical features
RVF
• Incubation period – 2-5
days
• 0.5% - Hemorrhagic
Fever
CCHF- sudden onset of
headache, high fever,
back pain, joint pain,
and vomiting
• Incubation period – 3-7
days
Hantavirus
• Incubation period – 1–8
weeks
• Hanta Pulmonary
Syndrome-fatigue,
fever and myalgia.
Latter Cough,
breathlessness and
chest tightness
• Hemorrhagic Fever
with Renal Syndrome-
Headaches, fever and
conjunctivitis. Latter
AKI, hypotension
36. Filoviridae History
■ 1967: Marburg virus
− European laboratory workers
■ 1976: Ebola virus
− Ebola Zaire
− Ebola Sudan
■ 1989 and 1992: Ebola Reston
− USA and Italy
− Imported macaques from Philippines
■ 1994: Ebola Côte d'Ivoire
37. ■Severe haemorrhagic, febrile illness
■Named after Marburg and the Ebola River Region in
the Sudan & Zaire
■Mortality ranged from 25 to 90% with slow recovery
in those who survive.
■Characterised by acute onset of severe headache,
severe myalgia and high fever followed by prostration.
38. ■Non-pruritic maculopapular rash on face of and rest of
the body
■Profuse diarrhoea and associated abdominal cramps &
vomiting
■Hematemesis, melaena or haemoptysis
■Hepatosplenomegaly & facial oedema
■Chest pain & dry cough
39. Filoviridae Transmission
■ Reservoir is UNKNOWN
− Bats implicated with Marburg
■ Intimate contact
■ Nosocomial transmission
− Reuse of needles and syringes
− Exposure to infectious tissues, excretions, and hospital
wastes
■ Aerosol transmission
− Primates
40. Filoviridae Epidemiology
■ Marburg – Africa
– Case fatality – 23-33%
■ Ebola - Sudan, Zaire and Côte d'Ivoire – Africa
– Case fatality – 53-88%
■ Ebola – Reston – Philippines
■ Pattern of disease is UNKNOWN
41. Filoviridae Humans
■ Most severe hemorrhagic fever
■ Incubation period: 4–10 days
■ Abrupt onset
– Fever, chills, malaise, and myalgia
■ Hemorrhage and DIC
■ Death around day 7–11
■ Painful recovery from arthralgia, uveitis and orchitis
49. Clinical Symptoms
■ More severe
− Bleeding under skin
Petechiae, ecchymoses, conjunctivitis
− Bleeding in internal organs
− Bleeding from orifices
− Blood loss rarely cause of death
51. Treatment
■ Supportive treatment
■ Ribavirin
− Not approved by FDA
− Effective in some individuals
− Arenaviridae and Bunyaviridae only
■ Convalescent-phase plasma
− Argentine HF, Bolivian HF and Ebola
■ Strict isolation of affected patients is required
■ Report to health authorities
52. Prevention and Control
■ Avoid contact with host species
− Rodents
Control rodent populations
Discourage rodents from entering or living in human populations
Safe clean up of rodent nests and droppings
− Insects
Use insect repellents
Proper clothing and bed nets
Window screens and other barriers to insects
53. Prevention
and
Control
Vaccine available for
Yellow fever
• Argentine HF, Rift Valley
Fever, Hantavirus and
Dengue HF
Experimental vaccines
under study
• Decrease person-to-person
transmission
• Isolation of infected
individuals
If human case occurs
54. Prevention and
Control
■ Protective clothing
– Disposable gowns, gloves, masks
and shoe covers, protective
eyewear when splashing might
occur, or if patient is disoriented
or uncooperative
55. Prevention and Control
■ Anyone suspected of having a VHF must use a
chemical toilet
■ Disinfect and dispose of instruments
− Use a 0.5% solution of sodium hypochlorite
(1:10 dilution of bleach)
56. Protective equipment worn by a nurse
during Ebola outbreak in Zaire, 1995
Protective equipment worn by a nurse
during Ebola outbreak in Zaire, 1995
