Overview of other “FAST diseases” in the European neighbourhood -Rift Valley Fever and Bovine Ephemeral Fever

Kiril KRSTEVSKI, Short Term Professional, EuFMD

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RIFT VALLEY FEVER

Rift Valley fever (RVF) is a peracute or acute arthropod-borne, zoonotic disease of domestic ruminants.

Rift Valley fever virus (REFV)• Bunyaviridae family • Single serotype, but strains of variable

virulence exist• Transmitted by various arthropods,

Aedes and Culex mosquitoes are the most important

• Many competent vectors

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Death Rate 100%

Severe Illness Abortion Death

Severe Illness Virus in Blood

Abortion

Infection

Virus in Blood

Lambs Sheep Monkeys Horses

Calves Cattle Camels Cats

Kids Goats Rats Dogs

Humans Squirrels Monkeys

Pathogenicity of RVF in animals and humans

ANIMALS

• Hepatitis• Abortions• Death

HUMANS

• Febrile illness• Neurological disorders• Hemorrhagic fever

Egypt –

During 1977-78, the first epidemic of RVF reported in Egypt and the largest recorded thus far - associated with approximately 18,000 human cases and 598 deaths in humans (CDC, https://www.cdc.gov/mmwr/preview/mmwrhtml/00032619.htm)

Citation: Sayed-Ahmed M, Nomier Y, Shoeib S. Epidemic situation of

rift valley fever in Egypt and Saudi Arabia. J Dairy Vet Anim Res.

2015;2(3):77‒79. DOI: 10.15406/jdvar.2015.02.00034

Geographical distribution of Rift Valley fever virus

Source: AI Rolin et al 2013, The risk of Rift Valley fever virus introduction and establishment in USA and EU

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Results from recent study on Landscape suitability to RVF epidemics The risk is derived from the ecological niche of RVF outbreaks

(Walsh et al, 2017)

CONCLUSIONS:• Landscapes suitable to RVFV beyond

the range of previous occurrence (N.African and Middle East countries);

• Transmission possible if the virus is introduced

HUMAN SAMPLES from 2014

Results suggest active circulation of RVFV and evidence for human exposure

IgG antibodies (past infection) in non-febrile slaughtering workers

IgM antibodies (recent infection) in febrile patients (travel was excluded)

However, NO SEROLOGICAL EVIDENCE for RVFV presence was found in previous study - 2006!!

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The regions with seropositive people in 2014,were included in the 2006 serosurvey

2006 2014

Sporadicintroduction(s) ?

Seroconversions in Algeria also reported

Lybia… ?

CONCLUSIONS:

Risk for RVFV introductions in N.African and Middle East countries remains high and continuous, and introductions most probably do occur sporadically (animal trades; aircraft spread of infected vectors)

Sustained virus transmission and epidemics outside the endemic regions are possible if these introduction event(s) coincide with optimal conditions (ideal temperature and water conditions for vector and virus survival, e.g. Arabian peninsula epidemic)

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THE RVF THREAT TO EUROPE IS REALISTIC

The disease is close to Europe and many ecological and epidemiological processes relevant for epidemic event are still uncertain/unknown …

ARE WE PREPARED TO EARLY DETECT/CONFIRM AND TO EFFECTIVELY REACT TO A POTENTIAL RVF INCURSION?

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Concerns:• Capacities of the NRLs in Europe are most probably very variable

• No appointed EU-RL to ensure high-quality, uniform testing in Europe and support Commission risk assessment activities, in the area of laboratory analysis

NRLs in Europe – do we have:• Implemented valid testing procedures for different purposes

(case-confirmation, sero-surveys ? )

• Adequate knowledge and expertise to interpret the test results and support the decision making at national level??

• Access to sufficient quantities of specific reagents ?

BOVINE EPHEMERAL FEVER

Bovine Ephemeral fever (BEF) is economically important arthropod-borne disease that affects cattle and water buffalo

Bovine ephemeral fever virus (BEFV)\Rhabdoviridae family • Single serotype • Transmitted by arthropods: various mosquitos

and number of midges (Culicoides)• no evidence on direct transmission

Morbidity - can be very high (approaching 100%)Mortality - typically low (<1%)

- recent years several countries reported alarmingly high case-fatality rates, sometimes exceeding 20%

Source: http://www.lbn.org.au/2018/03/bovine-ephemeral-fever-three-day-sickness/

FMD? FMD? RVF?

Known geographical occurrence of BEF

Source: https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-015-0262-4

• BEFV distribution may include neighboring countries from which there are no known formal reports of disease.

• The distribution may also vary seasonally and from year to year.

Likely general directions of seasonal spread of BEFV for S.Africa and Middle East

Pathways in the Middle East are less clear and may be complex with potential for epizootics to originate in either East Africa or West Asia. Dashed arrows indicate possible pathways in this region.

Source: https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-015-0262-4

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THE BEF THREAT TO EUROPE IS REALISTIC

• Big epidemic recorded in Turkey 2012, with outbreaks in many regions (unlike previous Turkey epidemics)…

• Frequency of new epidemics increased over the year

• Should be differentially diagnosed with FMD and RVF

Same concerns about the rapid detection/confirmation if introduced in Europe, as for the RVF

Disease-specific expertise gained through different project exists ...

Common project objectives:Link innovative diagnostics,Risk identification and implementation surveillance strategies

MediLabSecure

EDENextVmerge

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To face the threats prepared, we need disease-specific expertise and collaboration and networking within and outside Europe

(increase and share knowledge on risk of introduction, epidemiology, diagnosis, best control practices, etc)

Roster of EUFMD –MS disease experts

(examples)• CIRAD and ANSES (France)• FLI (Germany)• CISA-INIA (Spain)• IZS G.Caporale (Italy)• TPI (UK)• Wageningen (The Netherlands)• Other relevant• Kimron Institute (Israel)• Etlik Institute (Turkey)

• Others: Morocco, Tunisia,..

Network of national experts

in the neighboring countries

(high risk countries)

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Closer and more active

collaboration with national

labs in the neighboring

countries, focused on

identified “hot-spots”

THANK YOU FOR YOUR ATTENTION !