2018-09-07

Viruses, important viral diseases and how to fight them

Mikael Berg Professor in Veterinary Secon of Virology Department of Biomedical Sciences and Veterinary Public Health Faculty of Veterinary Medicine and Science Swedish University of Agricultural Sciences hps://www.slu.se/cv/mikael-berg/

Outline of the lecture

Short overview of the nature of

Examples of viral diseases of veterinary importance

How to fight them:

1) Vaccines

2) Anvirals

3) Prevenon measures

Summary and conclusions African swine fever viral parcle

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Viruses in the Marine Environment The estimated 1031 viruses in the ocean, if stretched end to end, would span farther than the nearest 60 galaxies.

However, most viruses do not harm us

Are some even good for us?

Enormous multitude of different animal viruses Some are very species specific-others have a few host and some have multiple hosts Every animal species has its own set of viruses and diseases Some are zoonotic Different shapes, complexity of genetic material, and variation between “same ” Divided into families Very few functional vaccines and antiviral drugs

RNA DNA genomes

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THE NATURE OF VIRUSES

Some historical aspects The word virus originates from latin and means poison or irritating substances

Pioneering studies on tobacco mosaic virus

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From Fenner´s Veterinary Virology

How do viruses look like? We need electron microscope to see them; Sizes range from 15-300 nanometer (normally)

Rhabdovirus Human influensa Adenovirus

Ebolavirus

Detailed structure of a virus on the molecular level

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Basic variants of virus structures

Virus relative sizes

Also bacteria can be infected by viruses

So can also plants and all other living organisms..

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Viruses need a living cell to mulply (cannot mulply in meat/dead /food/feed/materials)

How are viruses transmitted in nature

Horisontally: Indirectly: vectors (insects), aerosol (some very effectively FMDV), water, food/feed, transports, tools, clothes, people handling animals etc

Directly: close physical contact

Vertically: From mother to offspring

Differences in stability in the environment

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Extremely stable in various materials Food products Water

Dead animals Feces

Important viral diseases

Foot-and-mouth disease- a of economical importance For example the outbreak in UK 2001 costed corresponding to 65 billion SEK Endemic in many countries

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Dreaded animal viral diseases-high mortality Important historical viral disease of cattle

Eradicated since 2011

African swine fever

Peste des petits ruminants (PPR) Now called Small ruminant (SRMV)

Now in Europe

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Common colds

https://www.youtube.com

”food/feed poisoning”

Lots of important diseases caused by viruses Veterinary importance: Foot-and mouth disease African Swine fever Newcastle disease Peste-des-petits ruminants Avian influenza Bluetongue Rift valley fever Lumpy skin disease

Human inportance: Aids Influenza Measles Hepatitis

Zoonotic viruses: West Nile Nipah/Hendra Avian influenza Ebola

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From OIE (Office Internaonal des Epizooes or World Organisaon for Animal Health )

Another list

From Fenner´s Veterinary Virology

Flaviviridae: The major arboviral families of Genus veterinary significance JE serocomplex (JE, WN, Zika) TBE serocomplex (Kyasanur forest disease)

Reoviridae: Genus : Bluetongue serogroup (1-27) Genus Orthobunyavirus Epizooc hemorrhagic disease serogroup Akabane, Aino, Schmallenberg African horse sickeness serogroup

Palyam serogroup (Kasba, Chuzan) Phasmaviridae: Equine encephalosis serogroup Genus phlebovirus Eubenangee serogroup Ri valley virus

Togaviridae: : Genus Genus Orthonairovirus Eastern equine encephalis virus (EE), WEE, VEE, Getah Nairobi sheep disease

Rhabdoviridae: Genus vesiculovirus VSV

Asfarviridae: Genus Asfivirus-African swine fever virus

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From Fenner´s Veterinary Virology

How can we fight viruses?

What about vaccines?

A number of concepts

More later…

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What about anvirals?

Only a few in use (not in animals) Resistance problems

Can other prevenon meassures minimize the viral spread?

Knowledge on virus nature; how do they spread, how stable in various materials etc

More later…

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In conclusion

1) Viruses are the most abuntant life form 2) They need living cells to mulply 3) Many important diseases are caused by viruses 4) Vaccines are good but very few 5) Anvirals are not in use for animals, and generally very few 6) Prevenon meassures good way to control viruses

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