HERPESVIRIDAE

PETER H. RUSSELL, BVSc, PhD, FRCPath, MRCVS

Department of Pathology and Infectious Diseases, The Royal Veterinary College,

Royal College Street,

London NW1 OTU.

E-mail Web site

ObjectivesStudents should be able to:

• Give 3 reasons why herpesviruses are difficult to control.

• Know the difference between immediate-early, early and late genes and their roles in disease and tumours.

• List the major diseases in each species of animals and the tissue-tropism of the causative virus

Replication

The uncoated double stranded DNA becomes a closed circle in the host nucleus

Three types of genes are involved in replication:

Herpesviruses are bad news for 4 reasons.

Virulence is associated with presence of a thymidine kinase (tk) gene, so this is deleted from genetically engineered vaccines eg to Aujesky’s virus. Tk acclerates new DNA synthesis by

salvaging thymidine from degraded DNA into TTP. It has been widely used to select

cells eg hybridoma's or those which are expressing recombinant vaccines see

Russell and Edington, page 99.

Research. 3 growth areas

The members of the herpesviridae according to host and major

disease patternsHost/virus

HORSE

Abbrevi-ation

Clinicalsyndromes

1. equidherpesvirus

EHV 1 respiratorydisease, abortionand paresis

2. equidherpesvirus

EHV 2 ubiquitous,avirulent

3. equidherpesvirus

EHV 3 pustular lesions onthe genitalia, rare inUK

4. equidherpesvirus

EHV 4 respiratory disease

The members of the herpesviridae according to host and major

disease patternsHost/virus

CATTLE

Abbrevi-ation

Clinicalsyndromes

1. bovid herpesvirus 1 a. infectious bovinetracheitis virus

BHV 1(IBRV) upper respiratory

tractand abortion

b. infectious pustularvulvo vaginitis

BHV 1(IPVV) ustular lesions on

the genitalia, rare inUK, why?

2. bovid mammillitisvirus

BHV 2 (BHMV)

erosive lesions ontheteat and udder

3. malignantcatarrhal fever virus(African)

BHV 3

(MCFV)

proliferation; eyeand respiratorytract

The members of the herpesviridae according to host and major

disease patternsHost/virus

PIG

Abbrevi-ation

Clinicalsyndromes

1. suid herpesvirus1, pseudorabiesvirus;

Aujeszky's disease

PSV respiratory disease,abortion ± CNSinvolvement inin young pigs.(Pruritis in cattle)

2. suid herpesvirus 2,porcinecytomegalovirus;inclusion bodyrhinitis virus

PCMV ubiquitous, generallyavirulent, rhinitis±reproductivedisorders

The members of the herpesviridae according to host and major

disease patternsHost/virus Abbrevi-

ationClinicalsyndromes

DOG1. canid herpesvirus 1 CHV fatalities in puppies

CAT1. felid herpesvirus 1 FHV rhinitis and

bronchitis

The major members of the herpesviridae according to host

and major disease patterns Host/virus

FOWL(1)

Abbrevi- Sub-ation family

Clinicalsyndromes

1. gallidherpesvirus 1

Marek's diseasevirus

AHV 2

MDV

lymphoproliferativetumours invadingperipheral nerves

gonad,eye. Virusreleasedfrom featherfollicles

2. gallidherpesvirus 2turkey herpesvirus

HVT avirulent,protectiveagainst MDV

The major members of the herpesviridae according to host

and major disease patterns Host/virus

FOWL(2)

Abbrevi- Sub-ation family

Clinicalsyndromes

3. gallidherpesvirus 3 infectious laryngo-tracheitis virus

4. duck plaguevirus

AHV 1(ILT)

tracheitis andbronchitis

endothelial andenteric lesions

5. pigeonherpesvirus

respiratory tractdisease

The major members of the herpesviridae according to host

and major disease patterns Host/virus

MAN(1)

Abbrevi- Sub-ation family

Clinicalsyndromes

1. herpes simplex HSV 1

HSV2

oral cold sores; encephalitis;

genital ulceration

2. varicella-zostervirus

VZ-V chicken pox inchildren, shinglesin adults

The major members of the herpesviridae according to host

and major disease patterns Host/virus

MAN(2)

Abbrevi- Sub-ation family

Clinicalsyndromes

3. humancytomegalovirus

HCMV ubiquitous and notpathogenic usually,but may causecongenital defects.AIDS related

4. Epstein-Barrvirus

EBVglandular fever,Burkitt's lymphomaand nasopharyngealcarcinoma

The major members of the herpesviridae according to host

and major disease patterns Host/virus

MAN(3)

Abbrevi- Sub-ation family

Clinicalsyndromes

5. humanherpesvirus 6

HHV 6?HHV 7?HHV 8

Kaposi sarcoma,AIDS related

AIDS related

The major members of the herpesviridae according to host

and major disease patterns Host/virus

MONKEY

Abbrevi- Sub-ation family

Clinicalsyndromes

1. B virus oral ulcers inmonkeys,fatal encephalitisin man

2. herpes saimiri not pathogenic forsome species,lymphomas inothers

Equid herpesvirus 1(1)

This is the most common cause of abortion in mares in the U.K. It also causes respiratory disease and, more rarely, paresis

Equid herpesvirus 1(2)

This is the most common cause of abortion in mares in the U.K. It also causes respiratory disease and, more rarely, paresis

Equid herpesvirus 4

This virus cannot be distinguished from EHV 1 by polyclonal sera - but can be distinguished by mAbs, PCR probes and by RE profile. It is more prevalent than EHV 1 (by a factor of 2) in the U.K., but in the majority of cases it only causes respiratory disease.

Bovid herpesvirus 1

Pathogenesis

Rhinotrachietis with lacrimation then lymphocyte-associated viraemia and then latency in cranial ganglia. Can cause 75%

mortality of feed lot cattle with bronchpneumonia. Viraemia can spread to cause meningo-encephalitis, especially in

calves, infectious pustular vulvovaginits and abortion.

Bovid herpesvirus 2 (Bovine mammillitis virus)

Moist, raised erosions/plaques on teats with spread to udder

A zoonosis of milkers.

Infection can be a perennial problem in winter

Bovid herpesvirus 3

(Malignant catarrhal fever virus)

Suid herpesvirus 1

*Notifiable.

Also known as Aujeszky's disease, pseudorabies, "mad itch".

While this has been eradicated from mainland Britain by a pig levy and area eradication

scheme it is still present in much of Europe and Ireland.

Canid herpesvirus 1

Felid herpesvirus 1

The virus is widespread within the feline population. It affects the upper respiratory tract

but erosions affect the bronchii and interstital pneumonia can result. Latent infections can be

reactivated during boarding.. Infections are often concurrent with calicivirus and chlamydial

infections.

Herpes B Virus

Monkeys. Asiatic (old world) monkeys (eg macaques and rhesus) are the natural hosts. In the

wild only 10% of the population carry latent virus in ganglia/have antibodies; but in captive colonies,

where monkeys are kept at high density, the prevalence is frequently 60%.

The lesions in monkeys are oral focal erosions, very similar to cold sores of man. New world monkeys, like man, die with encephalitis and do not excrete

salivary virus.

Summary EHV1 is a disease not only of the resp tract but also causes abortion storms

and paresis. Vaccines are not good and so the Jockey club has regs re isolation and transport after abortions

IBR causes a spectrum of disease and live vaccines can reduce disease. Porcine herpevirus 1 is a notifiable disease which cause abortion in sows

and some fatalies after encephalitis in piglets and fatal pseudorabies in carnovores and ruminants. It has been eradicated from GB, but not N.Ireland.

Feline herpes can be reactivated during boarding to cause erosive lesions Herpesvirus B only causes oral lesions in monkeys, but causes a fatal

encephalitis in man.