Rare and imported pathogens Flashcards
What is the family and genus of hendra virus?
Henipavirus genus in Paramyxoviridae
What is the reservoir host of hendra virus?
What is the risk factor for human infection?
Where does hendra circulate?
Flying foxes (Pteropid fruit bats)
Close contact with infected horses (not bats)
Only in Australia
What is the main clinical presentation of hendra?
Neurological disease - can be biphasic, encephalitis can occur up to 1 year after acute infection
Is there a vaccine available for hendra?
What treatment has been used?
No human vaccine, only vaccine for horses
Ribavirin has been used for treatment and PEP
mAbs are in development for PEP
What is the family and genus of nipah virus?
Henipavirus genus in Paramyxoviridae
What is the reservoir host of nipah virus?
What is the risk factor for human infection?
Where does nipah circulate?
Flying foxes (Pteropid fruit bats)
Close contact with infected pigs, undercooked horse meat, drinking raw date palm sap
South East Asia (Philippines, Malaysia, Bangladesh, India)
Why is nipah an HCID and hendra not?
No evidence of human to human transmission of hendra
What are the transmission routes of nipah?
Likely respiratory spread
Direct contact with infected secretions and excretions of pigs, bats, humans ?horses
Possible sexual transmission
What are the clinical symptoms of nipah?
What is the fatality rate?
Can be asymptomatic or mild
Sudden onset ILI followed by encephalitis (also meningitis and pneumonia)
Late onset encephalitis (up to 11 years!)
Severe sequalae in survivors
40-70% mortality
What treatment has been used for nipah?
… Ribavirin! (little evidence)
What is the family and genus of EEEV/WEEV/VEEV?
Togaviridae family, alphavirus genus
What does EEEV cause in horses?
Febrile disease leading to encephalitis!
How are humans infected with E/W/VEEV?
When bitten by ‘bridging mosquitos’ which are infected from birds
Mostly Aedes sp.
Which is most severe - EEEV, WEEV, VEEV?
EEEV
What are the reservoir hosts for:
EEEV?
WEEV?
VEEV?
Passerine birds
Passerine birds
Rodents
What is the most severe mosquito borne encephalitides?
EEEV
Where are the following found it the world:
EEEV?
WEEV?
VEEV?
EEEV = Eastern and North USA and Eastern Canada
WEEV = Western USA and Canada, and some of South America
VEEV = South America (both epidemic and enzootic viruses)
Are horses amplifying hosts in EEV/WEEV or VEEV?
VEEV only
Small mammals and rodents are amplifying hosts in EEEV and hares in WEEV
Treatment for EEEV/WEEV/VEEV?
Supportive only
How is the UK blood supply protected from EEEV?
Default deferral of American returners for 28 d due to risk of WNV
What are the mosquito vectors for:
EEEV?
WEEV?
VEEV?
EEEV = Culiseta melanura
WEEV = Culex tarsalis
VEEV = Aedes taeniorhynchus and Culex
Fatality rate of:
EEEV
WEEV
VEEV
EEEV - 30%
WEEV 3-4%
VEEV <1%
What is Sindbis virus?
A virus in the WEEV complex
Causes rash, fever and arthritis
In Eastern hemisphere - mainly Northern Europe
What are Everglades, Mucambo, Tonate and Cabassou viruses?
Viruses of the Venezualean equine encephalitis virus complex
(Alphaviruses)
In which patients is WEEV and VEEV most severe?
Children
What disease do the equine encephalitis viruses cause?
Acute ILI followed by neurological disease
EEEV is biphasic with neurological signs 1-2 weeks after infection, often severe encephalitis
What is the family and genus of chikungunya virus?
Togaviridae family, alphavirus genus
Vector of chikungunya
Aedes aegypti (A. albopictus has been associated with infection in Italy)
Is chikungunya present in Europe?
No, however sustained outbreaks in France and Italy have occurred due to imported travel case
In which countries are UK travellers most at risk of chikungunya?
India, SE Asia, Caribbean
What are the reservoir hosts of chikungunya?
Monkeys and humans
What are the risks of chikungunya in pregnancy?
No congenital infection but CHIKV infection perinatally can cause neonatal meningoencephalitis
Is there a vaccine available for chikungunya in UK?
No, however there is a live attenuated vaccine available in the US
Clinical symptoms of chikungunya
Mild or asymptomatic
Sudden onset fever and joint pain - joint pain is debilitating and arthritis can persist for several months or years
Death is rare
Other than joint pain and ILI what are additional symptoms of chikungunya?
75% of patients have dermatological compications including:
Pigmented rash
Ulcers in groin or oral mucosa
Haemorrhagic lesions
Desquamation
Joint pain and arthritis can last for several months or years
Severe eye, neurological and heart complaints have also been reported
How is the UK blood supply protected from CHIKV?
Blood donors are deferred for 28 d post travel to an at risk country
If infected with CHIKV they are deferred for donation for 6 months