dsDNA Herpesviridae Flashcards by Bec Crawford

Viruses of family _____ are enveloped (with glycoprotein complexes embedded in the lipid envelope) and spherical to pleomorphic in shape. 150-200 nm in diameter with an icosahedral capsid (T = __). The capsid contains 162 capsomeres and is surrounded by a layer of globular material known as the _____.

herpesviridae; 16; tegument

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The viral genome of herpesviridae is a _____ (non-segmented), linear, double stranded DNA genome of 120-200 kb; containing terminal and internal _____/repeated sequences.

monopartite; reiterated;

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Herpes virus genes fall into one of three categories:

1) those encoding proteins concerned with regulatory functions and virus replication (immediate early and early genes)
2) those encoding structural proteins (late genes)
3) a heterologous set of optional genes, in the sense that they are not found in all herpesviruses and are not essential for replication in cultured cells

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DNA replication and encapsidation occur in the _____.

nucleus

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The viral envelope is acquired by _____ through the inner layer of the nuclear envelope.

budding

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Mature virions accumulate within vacuoles in the cytoplasm and are released by _____ or _____.

exocytosis or cytolysis

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Herpesviruses do not survive well outside of the host. True or False

True

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Transmission usually requires close contact, especially mucosal contact (coitus, licking, etc) but _____ infection is also common.

droplet

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Moist, cool environmental conditions promote extended survival of herpesviruses, and windy conditions can promote aerosol transmission over longer distances. _____ infected animals can serve as a reservoir for transmission.

latently

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_____ infection with periodic or continuous shedding occurs in all herpesvirus infections.

persistent

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Some herpesviruses are oncogenic. True or False

True

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Shedding of virus in nasal, oral or _____ secretions provides the source of infection for other animals, including transfer from dam to offspring.

genital

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_____ of latent herpesvirus infection is usually associated with stress caused by intercurrent infections, shipping, cold, crowding, or by the administration of _____ drugs.

Reactivation; glucocorticoid

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Eosinophilic intranuclear inclusion bodies composed of nucleic acid and protein (known as _____ _ _____ _____) are characteristic of herpesvirus infections, both in animals and in cell cultures.

type A Cowdry bodies

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Virus specific proteins are also found in the host cell plasma membrane, where they are involved in cell fusion, resulting in formation of _____ or multinucleated giant cells. Cell to cell fusion facilitates spread of infection and the virus is not exposed to the immune system.

syncytium

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Family Herpesviridae: Subfamily _____herpesvirinae: Genus (4) Iltovirus, Mardivirus, Simplexvirus, Varicellovirus

Alpha

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Family Herpesviridae: Subfamily _____herpesvirinae: Genus (4) Cytomegalovirus, Muromegalovirus, Proboscivirus, Roseolovirus

Beta

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Family Herpesviridae: Subfamily _____herpesvirinae: Genus (4) Lymphocryptovirus, Macavirus, Percavirus, Rhadinovirus

Gamma

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Subfamily Alphaherpesvirinae have a relatively short replication cycle and are generally highly cytopathic in cell culture, lysing infected cells. Multiple colonies of viral DNA are demonstrable, either as _____, or more rarely, integrated into the chromosomal DNA of latently infected neurons.

episomes

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Some Alphaherpesviruses, such as Pseudorabies virus (suid herpesvirus 1), have a broad host range; whereas most are _____ _____ in their natural host range.

highly restricted

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Many alphaherpesviruses produce _____ lesions, particularly on the skin or on the mucosae of the _____ and _____ tracts.

localized; respiratory and genital tracts

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Generalized alphaherpesvirus infections are characterized by foci of _____ in almost any organ or tissue. Typically infect very young and/or immunocompromised animals. In pregnant animals, a mononuclear cell associated _____ may result in the transfer of virus across the placenta, leading to abortion, characteristically with multifocal areas of necrosis in several fetal organs.

necrosis; viremia

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Alphaherpesviruses frequently cause latent infections in _____ _____. The virus can be reactivated from latency by stress or immunosuppression. Both primary and disseminated infections can lead to deadly CNS infections.

sensory ganglia

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Disease caused by Human herpesvirus 1:

cold sores

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Disease caused by Human herpesvirus 2:

genital infections

Disease caused by Human herpesvirus 3:

chickenpox and shingles (Varicella Zoster virus)

Disease caused by Bovine herpesvirus 1:

infectious bovine rhinotracheitis, infectious pustular vulvovaginitis, infectious balanoposthitis, abortion

Disease caused by Bovine herpesvirus 2:

bovine mammilitis, pseudo-lumpy skin disease

Disease caused by Bovine herpesvirus 3:

encephalitis

Disease caused by Equine herpesvirus 1:

abortion, respiratory disease, encephalitis, perinatal foal mortality

Disease caused by Equine herpesvirus 3:

coital exanthema

Disease caused by Equine herpesvirus 4:

rhinopneumonia

Disease caused by Porcine herpesvirus 1:

pseudorabies, Aujeszky's disease

Disease caused by Feline herpesvirus 1:

feline viral rhinotracheitis

Disease caused by Canine herpesvirus 1:

hemorrhagic disease in puppies

Disease caused by Caprine herpesvirus 1:

conjunctivitis, respiratory and enteric disease

Disease caused by Gallid herpesvirus 1:

infectious laryngotracheitis of chickens

Disease caused by Gallid herpesvirus 2:

Marek's disease of chickens (serotype 1)

Disease caused by Gallid herpesvirus 3:

Nonpathogenic Marek's disease (serotype 2)

Disease caused by Meleagrid herpesvirus 1:

Nonpathogenic turkey herpesvirus

Bovine herpesvirus 1: five disease presentations (Bovine herpesvirus 1 has been associated with rhinotracheitis, vulvovaginitis, balanoposthitis, conjunctivitis, abortion, enteritis, and a generalized disease of newborn calves.)

1) Infectious bovine rhinotracheitis (IBR), 2) Infectious pustular vulvovaginitis, 3) Ocular form of IBR, 4) Abortion, 5) Systemic disease of newborn calves

One serotype of Bovine herpesvirus 1 is recognized. True or False

True

Three subtypes of Bovine herpesvirus 1 have been described. True or False

True

BHV 1.1 is the _____ subtype.

respiratory

BHV 1.2 is the _____ subtype.

genital

BHV 1.3 is the _____ subtype.

encephalitic

The encephalitis subtype known as BHV-1.3 has been renamed as Bovine herpesvirus _.

Bovine herpesvirus is distributed worldwide. True or False

True

Respiratory disease and _____ result from droplet transmission.

conjunctivitis

Genital disease may result from coitus or _____ _____ with infective semen.

artificial insemination

Within the animal, Bovine herpesvirus 1 disseminates from the initial focus of infection and probably occurs via cell-associated _____. In both the genital and respiratory forms of the disease, the lesions are focal areas of epithelial cell _____ in which there is ballooning of epithelial cells. Typical herpesvirus inclusions may be present in the _____ at the periphery of necrotic foci. Intense _____ response within the necrotic mucosa occurs, frequently with formation of a _____ (overlying accumulation of fibrin and cell debris).

viremia; necrosis; nuclei; inflammatory; pseudomembrane

A life-long latent infection with periodic virus shedding occurs after bovine herpesvirus infection; these animals are a potential source of new outbreaks and all seropositive animals are considered potential carriers. True or False

True

Bovine herpesvirus 1 can be reactivated from latency by _____ or _____.

corticosteroids or stress

Respiratory BHV-1 remains latent in the _____ nerve.

trigeminal

Genital BHV-1 remains latent in the ____ nerve.

sciatic

Respiratory BHV-1 is commonly called _____ _____, necrotic rhinitis or dust pneumonia. Presents with rhinitis, laryngitis, tracheitis, anorexia, fever, depression, serious discharge from the eyes and nose, +/- conjunctivitis. It is common to observed infected cattle breathing through the mouth and salivating excessively.

red nose

Morbidity and mortality with Respiratory BHV-1 are higher in feedlot cattle than in dairy herds. True or False

True

Respiratory BHV-1 presented with inflamed nares giving the appearance of a red nose due to _____. Nasal lesions consist of numerous clusters of grayish necrotic foci on the mucous membrane of the septal mucosa and nasal discharge becomes more profuse and mucopurulent.

hyperemia

_____ _____ with hemorrhage and congestion of the muzzle, erosions in the buccal mucosa and gums, exudates in the turbinates, and necrotic lesions in the epiglottis may occur with Respiratory BHV-1.

fibrinonecrotic rhinits

Both _____ _____ and _____ _____ both may occur in the respiratory form of BHV-1.

fibrinopurulent bronchopneumonia and thrombotic pneumonia

Uncomplicated cases of respiratory BHV-1 recover in 10-14 days. True or False

True

Ocular forms of Infectious Bovine Rhinotracheitis may present with _____: the conjunctiva is inflamed, reddened and edematous unilaterally or bilaterally with profuse ocular discharge.

conjunctivitis

Infectious Bovine Keratoconjunctivitis, or pink eye, is caused by a Gram negative diplobacilli called _____ _____. Do not confuse pink eye with Infectious Bovine Rhinotracheitis.

Moraxella bovis

Infectious Bovine Rhinotracheitis lesions are confined to the conjunctiva and no lesions on the cornea occur with the exception of diffuse edema. True or False

True

Abortion occurs as a common sequel to natural infection, which can occur 100 days after infection with _____ _____ _.

Bovine herpesvirus 1

Abortion may result following vaccination with some modified live virus (MLV) vaccines for BHV1 given to pregnant animals. True or False

True

Abortion can also result in animals that have had contact with IBR-susceptible pregnant animals. True or False

True

Fetuses in the second half of gestation have a _____ incidence of abortion, but early embryonic death is also possible. Incidence of abortion does not correlate with the severity of disease in the dam, but is often preceded by _____ _____.

higher; pustular vulvovaginitis

_____ ______ ___ _____ _____ is a severe often fatal disease caused by in utero or post-birth BHV1 infection in calves less than 10 days of age.

Systemic Disease of Newborn Calves

Calves with Systemic Disease of Newborn Calves develop a generalized disease with pyrexia, diarrhea, respiratory distress, ocular discharge, incoordination, convulsions and death. Small _____ of the lining of the forestomachs as well as peritonitis are common post-mortem findings.

ulcers

The two genital forms of BHV1 are: _____ _____ _____ (female) and _____ (male)

Infectious Pustular Vaginitis (IPV) in females and Balanoposthitis in males

Infectious Pustular Vaginitis in females infected with the genital form of BHV1 may occur within _____ days following coitus. It presents with frequent urination, elevated tail and excessive tail switching, red and swollen vaginal mucosa, mild vaginal discharge, and swollen, red spotted, discrete pustules noted on the vulva.

1-3 days

_____ in males infected with the genital form of BHV1 presents with inflammation and pustules in the mucosa of the penis and prepuce.

Balanoposthitis

BHV1 can be controlled with five types of vaccines:

live, subunit or inactivated vaccines available

BHV1 subunit vaccines contain the major surface _____ (gB, fC, gD) that elicit anitbody response.

glycoproteins

_____ or _____ vaccines containing other respiratory pathogens (BSRV, BVDV) are also available.

combination or multivalent vaccines

Parenteral and intranasal vaccines are available for BHV1, which both stimulate the production of humoral antibodies. True or False

True

The parenteral vaccine may cause abortion in pregnant cows, whereas the intranasal vaccine is safe for use in pregnant cows. True or False

True

Bovine Herpes Virus 2 presents as _____ _____ _____ or _____-_____ _____ _____.

Bovine Ulcerative Mammillitis or Pseudo-Lumpy Skin Disease

Bovine Ulcerative Mammillitis is commonly caused by BHV2 and rarely by BHV_, with worldwide distribution.

BHV4

Cattle/heifers are infected with Bovine Ulcerative Mammillitis within __ weeks of calving, and large herds may have persistent disease.

Bovine Ulcerative Mammillitis caused by BHV2 is transmitted by direct contact and fomite-mediated contact through trauma to the _____, as well as mechanical transmission via _____ flies and other arthropods.

skin; stable

In severe cases of Bovine Ulcerative Mammillitis, the teat is swollen and painful with raw _____, and the skin becomes bluish, exuding serum. Vesicles may occur but are not commonly seen.

ulcers

Significant mild yield reduction and high incidence of _____ occur with Bovine Ulcerative Mammillitis.

mastitis

Pseudo-lumpy skin disease infects cattle most commonly in Southern Africa via _____ transmission of BHV2 by arthropods.

mechanical

Pseudo-lumpy skin disease presents with mild pyrexia, followed by the sudden appearance of skin nodules, a few or many, on the _____, _____, _____ and _____. The nodules have a flat surface with a slightly depressed center and involve only the superficial layers of the epidermis, which undergo _____.

face, neck, back and perineum; necrosis

Pseudo-lumpy skin disease has a longer course of disease than Lumpy-skin disease. True or False

False; disease course: Lumpy > Pseudo-lumpy skin disease

Porcine Herpesvirus 1 or Suid Herpesvirus 1 of Subfamily Alphaherpesvirinae is the cause of _____, also known as Aujeszky Disease or Mad Itch, is primarily a disease of swine.

Pseudorabies

Although Pseudorabies is primarily a disease of swine, there is a diverse range of _____ hosts, including bovines, canines, caprines, equines, felines, ovines, and many feral species.

secondary

Humans are refractory/resistant to infection with PHV1 or Pseudorabies. True or False

True

Primary Host Transmission of Pseudorabies: Recovered pigs acts as primary reservoirs and are _____ carriers of the virus for life. _____ can also act as reservoirs and transmit the disease from farm to farm.

latent; rodents *rats

Pseudorabies is shed in saliva, nasal discharges and _____ of infected pigs, but it is not shed in the urine or feces. Transmission can therefore occur via licking, biting, aerosol, ingestion of contaminated carcass, water and feed.

milk

Secondary Host Transmission of Pseudorabies: _____ and _____ become infected via ingestion of infected pig carcasses, meats, or rodents, whereas _____ become infected via direct contact with infected pigs by oral or nasal route.

cats and dogs; cattle

Following natural infection, the primary site of Pseudorabies viral replication is the _____ _____ _____ (tonsils and nasopharynx), from which it spreads via the _____ to regional lymph nodes where replication continues.

upper respiratory tract; lymphatics

A brief _____ is associated with virulent strains of Pseudorabies, with localization of the virus in different organs.

viremia

Pseudorabies spread to the CNS occurs via axons of the cranial nerves, with preference for neurons of the _____ and _____ as it progresses.

pons and medulla

Pseudorabies CNS Lesions: (3)

Ganglioneuritis, Nonsuppurative Meningoencephalitis, Perivascular Cuffing

Clinical Signs of Pseudorabies in swine are age dependent. True or False

True

Pseudorabies in nonimmune piglets presents with ___% mortality rate.

100

Pseudorabies in nonimmune pregnant sows presents with ___% abortion rate.

Pseudorabies in older piglets, growers and adult pigs presents with mild disease and ___% mortality rate.

dsDNA Herpesviridae Flashcards

(101 cards)