VHF Flashcards
What are the 3 main VHFs?
Crimean Congo Haemorrhagic Fever
Lassa Fever
Ebola
Where does CCHF occur?
Turkey
Iran
Iraq
Russia
Pakistain
Afghanistan
But really, it occurs more or less anywhere
How does CCHF spread?
Tick bite (unique to other VHFs)
Nosocomial spread (esp. Needlestick, splash to Nosocomial)
Animal Slaughter (esp. alongside religious festivals)
How does CCHF present?
Non - specific
Fever, myalgia, headache + bleeding
** People are usually bleeding early, when the’re still pretty well physiologically –> typically not thought of early
What kind of Virus is CCHF? DNA or RNA?
RNA (all VHFs are RNA)
What are the complications of CCHF?
Sepsis
Multiorgan failure
Death
How do you manage CCHF?
Good supportive care
Ribavirin trial (usually only good at the beginning of disease treatment)
±Favapiravir (effective against most RNA viruses)
What is the epidemiology of Lassa Fever
West Africa
- Nigeria (most cases of all other countries, 1000 cases per year)
- Sierra Leone
- Liberia
- Guinea
Rural settings only
How is Lassa Spread?
Spread by a rat, which sheds it in its faeces/urine
People become sick when they ingest the virus
Nosocomial spread in hospitals
How can you prevent Lassa?
Reduce rat populations in the area
How does Lassa present?
FAR
Bleeding
Sensorineural deafness
Renal Failure (often the cause of death)
How do you manage Lassa Fever?
Ribavirin
Supportive Care
VHF presents the same as myriad illnesses….
What might suggest to you that a VHF is occurring.
HEALTH CARE WORKERS ARE DYING
Where does Lassa Fever Occur?
Sub-saharan WEST AFRIC
Where does Lassa Fever Occur?
Sub-saharan WEST AFRICA
Endemic in areas, occurs all year round due to the chronic presence of rat and rat faeces
How does Lassa spread?
Rat Faeces
How does Lassa Present?
Majority: ASYMPTOMATIC
Fever, myalgia, headache, generalised flu like symptoms
Deafness!!! Common
Bleeding
What is the CFR of Lassa Fever?
Generally pretty low, but up to 90% in pregnancy
How do you manage Lassa Fever
Supportive Care
IV Ribavirin
±Faipravir
±Monoclonal Antibodies
How do you prevent Lassa Fever?
Improve hygiene
Better housing
Better food management to prevent rats from getting into food stores
What kind of Virus is Ebola?
Single Strand RNA Virus
Filviridae Family
How does Ebola infect humans
Bats –> primates/antelopes –> Bushmeat ingested by humans
Bats –> Humans
How many strains of Ebola are there/
4
Zaire
Sudanese
Bundibugyo
Tai Forest
How does Ebola Present?
Initially +++ non specific - fever, malaise, mylagia anorexia, hiccups, conjunctivitivis
–> GI Symptoms, profound weakness, dehydration, renal failure, electrolyte disturbances and seizures
–> Heamorrhage and death
-
Give 5 differentials for Ebola Haemorrhagic Fever
Dengue and other arthropods
Malaria
Rickettsial illnesses
Leptospirosis
Typhoid
Lassa
CCHF
What is the mainc ause of death in Ebola?
Multi organ failure/dehydration rather than haemorrhage
How do you diagnose Ebola?
POCT
PCR Testing!!!
±ELISA IgM IgG
±Electrolyte monitoring
±FBC/UEs/LFTs/Glucose
How is CCHF spread?
CCHF is transmitted by a tick from infected domestic or wild animals (such as deer, cattle, goats and sheep), but it can also be transmitted by contact with blood or body fluids from infected animals or humans
How can you prevent further ebola spread?
PPE
Safe burials
Safe dead body transport
Ring vaccination of contacts
What is the incubation period of Ebola and other haemorrhagic fevers?
21 days
What PPE should you use in confirmed cases of VHFs
-Strict isolation in a reserved area separate from other patient areas, with a defined circuit for entrance/exit and changing room at the entrance/exit
- dedicated staff and equipment/supplies
- use of disposable material if possible
PLUS
Droplet precautions AND contact precautions including personal protective equipment (PPE)
The PPE is to be worn systematically prior to entry into isolation area, regardless the tasks to be performed and to be removed before leaving the isolation area
two pairs of gloves,
double gown or coverall suit, surgical cap or hood, mask, protective glasses, impermeable apron, rubber boots.
Disinfection of surfaces, objects, clothing and bedding with chlorine solution;
safe handling and on site disposal of waste and excreta, etc.
In the event of a death, do not wash the body.
Prompt and safe burial of the dead as quickly as possible, using a body bag.
What vectors are assocaited with Ebola, Lassa and CCHF?
Lassa: Rats
Ebola: Bats –> mammals –> bushmeat
CCHF: Ticks
How is Lassa Fever diagnosed?
RT PCR
ELISA
You are in the middle of a ??? VH Fever outbreak. Create a Case Definition to catch suspected VHF cases
Fever <3 weeks
+
Absence of local inflamation
+
No response to antimalarial treatments after 48h
What are the clinical indications for Ribavirin?
Lassa and CCHF
**not technically for Ebola or Marburg, but i think pragmatically people give
How should you manage a women in late pregnancy who survives ebola?
ebola can persist in breast milk for some time
Give Cabergoline to prevent breast milk production
Give breast pump and advice on how to eliminate breast milk safely
Which tick is responsible for CCHF?
Hyalloma tick
How does CCHF present differently compared to the other viral haemorrhagic fevers?
Profuse bleeding while a person is still relatively well
In other VHFs bleeding is a sign of complete organ failure and full end organ disease/disease severity
What tests can give you an early pronostic picture of your patients outcome in VHFs?
Platelet count (<50 = high risk of bleeding)
Viral Load with quantitative PCR
How should you treat people who have been exposed to a CCHF?
PEP - Ribavirin
Where does CCHF present? (epidemioogy)
Turkey (they have a low CFR and do a good job of controlling due to good PH campaigns to present early for ribavirin if fever + tick bite
Russia
Congo
Pakistan
Iran
What are the three diseases stages of Ebola?
- Early or mild Viral Illness
- Gastrointestinal Illness (some people say it presents more like cholera than a VHF!)
- Multi organ failure and severe disease
What happens to CK in VHF?
Rises - concerns that high CK might be contriubting to the massive renal failure that patients with severe Ebola experience
For health workers who have had an exposure to ebola, what should the PEP be?
Favipiravir
How should you treat Ebola?
Supportive care ++++++++
–> this inlcudes blood products as required
Favipiravir
Monoclonal antibodies
WHO guidelines state no ribavirin, but some people do give it
