Bovine herpesvirus 1 (BHV-1) is associated with several diseases in cattle: infectious bovine rhinotracheitis (IBR), infectious pustular vulvovaginitis (IPV), balanoposthitis, conjunctivitis, abortion, encephalomyelitis, and mastitis.
2. INTRODUCTION
Bovine herpes virus 1 (BHV-1) is primarily associated with clinical syndromes
Rhinotracheitis,
Pustular vulvovaginitis
Pustular balanoposthitis
Abortion
Infertility
Conjunctivitis
Encephalitis in bovine species.
3. HISTORY
Büchner undTrommsdorf -1st described in Germany- 19th
century the “Bläschenausschlag” (coïtal vesicular exanthema),
a cattle disease probably caused by bovine herpesvirus 1
(BoHV-1).
The viral etiology was demonstrated in 1928 by Reisinger
and Reimann, who transmitted this venereal disease by a
filterable agent.
Büchner undTrommsdorf
4. The manifestations of BoHV-1 infections known as “infectious pustular
vulvovaginitis” (IPV) in cows and “infectious pustular balanoposthitis” (IPB) in bulls
were confined to the genital organs until the early nineteen-fifties
Pustular lesions – penis - cattle
5. Respiratory form arose in North American feedlots.
This more severe disease due to BoHV-1 infection was
called “infectious bovine rhinotracheitis” (IBR).
IBR rapidly spread to Europe when North American
dairy cattle were imported in order to improve the milk
production performance in Europe.
All BoHV-1 strains isolated hitherto
6. ETIOLOGY
Genus -Varicellovirus
Subfamily- Alphaherpesvirinae,
Family -Herpesviridae
Double-stranded DNA
70 proteins, 33 structural and 15 -non-structural proteins (Muylkens et al., 2007).
glycoproteins are located in the envelope on the surface of virion- play an
important role in pathogenesis and immunity.
7. ETIOLOGY
On the basis of restriction enzyme digestion patterns three genotypes of BHV-1 can be distinguished:
subtype 1 is a respiratory subtype; subtype 2 is a genital subtype
BoHV- 1 has three subtypes 1) BoHV -1.1
2) BoHV -1.2a
3) BoHV -1.2b
4) BoHV – 1.3 – renamed as BoHV –5 (encephalitic) (Edwards et al., 1990).
Genital
Respiratory
8. Development of rhinotracheitis or vulvovaginitis/balanoposthitis depends more
on the route of infection than on the subtype of the virus
BHV-1 is also one of the most important pathogens involved in the development
of the respiratory disease syndrome -shipping fever (Yates, 1982;Jones and Chowdhury, 2007).
Isolates of BHV-1.1 are more virulent than are isolates of BHV-1.2b,BHV 5 has
been isolated from calves that died of encephalitis and from aborted fetus (Schudel et
al., 1986).
9. MODE OF TRANSMISSION
The main sources of infection are the nasal exudate and coughed-up droplets,
genital secretions, semen, and fetal fluids and tissues.
Aerosol infection is the method of spread of the respiratory disease.
Inanimate objects
Venereal transmission is the method of spread of the genital diseases.
In the USA, BHV-1 has been isolated from ticks (Ornithodorus) that fed on
animals positive for BHV-1.- Mechanical transmission
The virus may survive for up to 1 year in semen frozen at −196°C
10. DISTRIBUTION - INDIA
The disease is widely distributed around the world.
In India, the disease is endemic
(Mehrotra et al., 1976; Suresh et al., 1999; Chinchkar et al., 2002; Sharma et al.,2004; Kiran et al., 2005; Jain et al.,
2006).
Sero-surveillance studies indicate that about 48% of serum samples were positive
for antibodies to BHV-1 detected by screening with the SNT
and up to 54% by testing the samples by indirect and c-ELISA
(Pharande et al., 2004; Nandi et al.,2004, 2007, 2008a, b).
11. It was observed that cattle were more susceptible to IBR than buffaloes and
crossbred cattle were more susceptible than indigenous cattle.
In buffaloes - mostly mild and non-life threatening.
Animals 3–6 years of age were more prone to infection than were younger
animals (Sarumathi et al., 2002)
Introduction of IBR into a cattle farm can cause severe economic losses due
weight loss, decrease in milk production and restrictions in the international
livestock trade.
12. DISTRIBUTION
The seroprevalence of BHV-1 ranges from 14 to 60% in Africa and from 36 to 48%
in Central and South America
According to OIE data, it has been eradicated from Austria, Denmark, Finland,
Sweden, Italy (Province of Bolzano), Switzerland and Norway
Control programmes are in place in some other countries including Australia,
Belgium, Canada, India, Poland,Turkey and USA
(Edwards et al.,1990, 1991; Noordegraaf et al., 2000; Salwa et al., 2000 Galiero et al., 2001; Madinelli et al., 2001;
Turin and Russo, 2003; Boelaert et al., 2005).
13. EPIDEMIOLOGY
According to study conducted by ICAR in 2016 Risk Analysis of Occurrence of
Infectious Bovine Rhinotracheitis
Earlier literature indicated that the seroprevalence of IBR in organized dairy farms in
India ranged from 51 to 65%.
Samples from organized farms of Bijapur, Dharwad, Chennai, Cuddalore were taken
In the present study, the seroprevalence of IBR is maintained within the range,
however the seroprevalence showed slight increase from 51.4% during 1996 to 63.2%
in 2015
14.
15. EPIDEMIOLOGY
The relative risk of occurrence of IBR was higher in cattle than buffaloes which
might be due to the resistance nature of indigenous breeds of buffalo than the
cattle (Jersey and Holstein Friesian cross) reared by organized dairy farms.
which might be due to non-availability of IBR vaccine in India.
The high prevalence indicates the importance of the disease in bovines in India.
17. EPIDEMIOLOGY
Introduction of animals into a group often precedes an outbreak of the disease.
Spreads - farm to other adjacent farms when there is an outbreak.
An outbreak usually reaches its peak within 2 or 3 weeks.
Notifiable list B OIE – susceptible animal species disease that includes
transmissible diseases that are considered to be of socio-economic importance
within the countries and that are significant in the international trade of animals
and animal products
(Turin and Russo, 2003).
18. EPIDEMIOLOGY
Disease is endemic in India (1986-2006)
Out of 7313 serum samples tested, 3152 were positive for BHV-1 (Anon,2007) by
indirect and competition ELISA (c-ELISA)/(micro-serum neutralization test (m-
SNT)
2000 - 2008, 26 of 953 semen samples were positive by polymerase chain
reaction (PCR) / isolation in cell culture (Nandi et al., 2004, 2007, 2008a, bDeka et al., 2005)
The Government of India has arranged to screen all the breeding bulls for the
infection before using the semen for IVF/ natural/AI purposes (Anon, 2007).
19. CARRIER STATE
Cattle that recover from an acute IBR infection can prove very harmful to disease-
free herds because they are silent carriers of BHV-1.
Remain carriers- for the rest of their lives until immuno-suppressive treatments
or other conditions reactivate virus replication, leading to the spread of the
infection to the rest of the herd
(Van Oirschot, 1995; Preston and Nicholl, 2008)
20. RISK FACTORS
All ages and breeds are susceptible – mostly over 6
months of age
Higher occurrence in feedlot cattle - winter months
An unvaccinated herd of breeding cattle or a group of
feedlot animals is highly susceptible to epidemics of
respiratory disease and abortion
21. RISK FACTORS
Newborn calves are highly susceptible -systemic form of infection- if level of
specific antibody -in colostrum is inadequate /failure of transfer of passive
immunity. (highly fatal)
Rarely- respiratory and genital form occur together, by routine methodology it is
difficult, to distinguish between isolates obtained from the reproductive and
respiratory mucosa.
22. IMMUNE RESPONSE
Host response to BHV-1 infection can be divided into a specific response
mediated by B- andT-cells and a nonspecific response mediated by
polymorphonuclear neutrophils (PMNs), macrophages, natural killer (NK) cells,
interferon.
(Denis et al., 1993).
Interferon a and b molecules are present within 5 h post-infection, reach peak
levels in the nasal secretions and blood by 36–72 h post-infection, and remain
elevated until virus replication ceases
(van Drunen Littel-van den Hurk et al., 1994).
23. Interferon influences lymphocyte trafficking of CD8+ cells from the blood to the
lung where they may be involved in production of late cytokines that trigger
macrophages to kill BHV-1 infected cells
(Babiuk et al.,1996).
25. RESPIRATORY FORM
Classical IBR is characterized by
Pyrexia
Inappetence
Depression
Bilateral nasal discharge
Dyspnea
Persistent harsh cough
Milk production
26. Fever and accelerated respiration
accompanying nasal discharge
Hyperemia of nostril, purulent nasal
discharge, foamy drooling of saliva,
27. Nasal mucosa - hyperemic and lesions progress from pustular necrosis to large
hemorrhagic and ulcerated areas covered by a cream colored diphtheritic
membrane (Murphy et al., 1999).
If the encrustations are removed, the underlying tissues are hyperemic hence the
name ‘red nose’.
Foul breath, mouth breathing, salivation and a deep bronchial cough are common.
28. On auscultation, tracheitis is evident but lung sounds are normal.
About 10% of the affected animals lose body condition and pneumonia is a
sequelae
(Gibbs and Rweyemamu, 1977)
29. CONJUNCTIVAL FORM
unilateral or bilateral profuse
lacrimation.
Epiphora is the most characteristic
Hair beneath the eye- soiled
Eversion of the eyelids
Purulent lacrimal discharge
photophobia
30. Swelling of eye-lids and hyperemia of
conjunctiva
Swelling (edema) of eye-lids and lacrimation.
31. GENITAL FORM - (IPV AND IPB)
Acute IPV usually develops 1–3 days after mating and frequent micturition and
tail swishing are characteristic signs noticed initially.
Affected animals develop fever, depression and anorexia; they seek to avoid
contact of the tail with the vulva.
The vulva - swollen and hyperemic with small pustules (1–2 mm in diameter).
32. The pustules usually coalesce to form
yellowish white fibrinous membranes that
gradually detach to form ulcers.
Secondary bacterial infection is common and
varying amounts of pus are discharged.
The lesions usually heal 10–14 days post
infection
33. IPB
Incubation period of 1–3 days.
Lesions similar to those of IPV develop on the mucosa of the penis and prepuce.
Secondary bacterial infection is common.
If mating is continued, scar tissue may form.
The sequelae of this condition include extensive adhesions, annular constrictions
and penile distortions.
Healing occurs within 10–14 days but some animals may lose libido, have painful
erection and ejaculation and require several weeks to resume regular mating.
35. Semen contaminated with BHV-1 can cause IPV, cervicitis with copious
mucopurulent discharge and endometritis in cows
Abortions due to BHV-1 have been reported in the USA, India, Argentina, Italy,
Japan, Belgium, China and Canada
(Edwards et al.,1990, 1991; Galiero et al., 2001; Nandi et al., 2008a, b;Yanet al., 2008).
Abortions – 4-7 months of gestation after natural infection or vaccination.Often
associated with RFM
36. ENCEPHALITIC FORM
Incoordination ataxia.
Initial depression followed by excitement characterized by
incoordinate running, tremor, cycling and terminating in
stumbling and falling.
In the fallen position they develop clonic spasms of the legs,
neck and lumbar muscles and show opisthotonus.
Coma and death usually occur within 4 days from the onset
of the neurological disorders.
Some animals recover but are blind (Gibbs and Rweyemamu, 1977;
Schudel et al., 1986).
Opisthotonus
37. PATHOGENESIS
Viral entry into cells is a multi-step process involving several glycoproteins and at
least two cellular receptors(Mettenleiter, 1994).
Glycoprotein gC of alphaherpesviruses initiates these steps by binding to heparan
sulfate proteoglycans on the cell surface.These receptor molecules are present on
many cells, thus allowing adsorption of herpesviruses to a variety of different cell
types
Binding of gD is necessary for initiation of viral entry (Karger et al., 1995) and for
steps between virus binding and membrane fusion by interacting with other
cellular or viral components.
38. Viral entry into the cell is finally mediated by fusion of the viral envelope with the
cell membrane, due to interactions of gB, gH and gL (Liang et al., 1995).
Life long latent infection with periodic virus shedding occurs after BHV1 infection;
the sciatic and trigeminal ganglia are the main sites of latency following genital
and respiratory diseases.
Administration of corticosetroids results in reactivation of the and has been used
as the means of detecting and eliminating carrier bull in AI centre
39.
40. Intra nasal
Multiply in
respiratory tract
Rhinitis,
Laryngitis,
Tracheitis
Destruction of
tracheal
microvili
Lesions may extend
to eyes, through
nasolacrimal duct
Conjunctivitis and
nasal discharge
From nasal mucosa
Reach brain via
trigeminal nerve
encephalitis
41. HISTOPATHOLOGY
Rhinitis with hyperemia and edema of the mucosa.
The nasal catarrh is copious and the nasolabium becomes excoriated
Hyperemia of the vulval and vaginal mucosa with focal hemorrhages
Small (2–3 mm) yellow colored pock-like lesions replace the focal hemorrhages
The epithelium over the lesions is lost and an ulcer is revealed
43. HISTOPATHOLOGY
Microscopically, there is a ballooning & degeneration of the epithelium and
Cowdry type A intranuclear inclusion bodies are seen (Engels and Ackermann, 1996).
The epithelial disruption and ulceration are due to infiltration of neutrophils.The
lamina propria is acutely inflamed and infiltrated with numerous plasma cells.
Histologically, intranuclear inclusion bodies in the astrocytes and neurons and
perivascular cuffing in the cerebrum are found throughout the brain.
Diffuse areas of degeneration of the cerebral cortex with vacuolation around the
neurons are also evident.
44. DIAGNOSIS
Virus specific PCR
Electron microscopic evaluation of vesicular fluid or scraping
Immunofluorescence staining of mucosal smears or tissues
Virus isolation - primary or secondary bovine kidney, lungs, testis, turbinate, or
trachea and established cell lines such as Madin–Darby Bovine Kidney (MDBK) cells
Primary culture is more sensitive
The virus can be isolated from nasal swabs, conjunctival swabs, vaginal swabs,
preputial washing, placental cotyledons of aborted fetus, fetal liver, lung, spleen,
kidney, lymph node, mucous membrane of respiratory tract, tonsils and lungs
45. Normal MDBK cell MDBK cell infected with BHV-1 infected cell line
The CPE of BHV-1 is characteristic and usually appears within 3 days after inoculation.
There are grape-like clusters of rounded cells present around a microplaque in cell culture.
Giant cells or syncytia are also observed.
46. variety of ELISAs namely indirect ELISA, c-ELISA and avidin–biotin ELISA have
been employed to screen serum samples of cattle and buffaloes in India
(Nandi et al., 2004, 2007).
VNT and ELISA have been used for the detection of antibodies.
ELISA is a specific, sensitive and practical test for the detection of antibody and has
advantages over theVNT (Kaashoek et al., 1995;Van Oirschot et al., 1997;Nandi et al., 2008a, b).
The IgM ELISA is useful for diagnosis of recently infected calves
For aborted fetus- histopathologic evaluation with immunohistochemical staining futher
confirmed with PCR
47. PHYSIOCHEMICAL PROPERTIES
OF THE VIRUS
The virus BHV-1 is resistant to environmental influences
Inactivation of the virus in the environment depends on factors such
temperature, pH, light, humidity and kind of medium harboring the
virus
(Gibbs and Rweyemamu,1977).
As the virus is enveloped, it is sensitive to organic solvents such as
chloroform, ether and acetone.
48. The virus is stable for at least 1 month at 4°C, 50 days at 22°C , 10 days at 37°C and
21 minutes at 56°C
The virus is sensitive to many disinfectants
INACTIVATED BY (Straub, 1990)
0.5% NaOH
0.01 % HgCl2
1% chlorinated lime
1% phenolic derivatives
1% quaternary ammonium bases
10% Lugol’s iodine
Formalin (5%) inactivates BHV-1 within 1 min
50. COMPOSITION : Bovine herpesvirus type 1 (BHV‐-1)
inactivated
TARGET SPECIES : Cattle from the age of 3 months.
DOSAGE : 2 ml, intramuscularly.
BASIC VACCINATION: two applications in the 3-week
interval.
REVACCINATION: one application every 6 months.
51.
52.
53. ACTIVE INGREDIENTS :Bovine Rhinotracheitis-Virus
Diarrhea-Parainfluenza3-Respiratory SyncytialVirus
Vaccine
Modified LiveVirus and KilledVirus
Pregnant cows can be vaccinated intramuscularly 5ml
PRIMARYVACCINATION: 2 doses administered 2-4
weeks apart
REVACCINATION : annually
54. vaccines - reduce the incidence and severity of disease.
Breeding animals in enzootic countries should be vaccinated before coitus, to
prevent the virus inducing abortion.
vaccination to maintain population immunity is best done prior to stressful
situations such as weaning or transport.
Currently available vaccines, which are made with 1.1 subtype vaccines, cannot be
given to pregnant cattle because they are abortifacient.
55. CONTROL
Hygienic measures
Maintaining 2-3 weeks of quarantine period before
introducing new stock
Whole herd may be vaccinated- if there is a outbreak of
BoHV-1 in the close vicinity.
infected animal must be identified and removed- reactivation
of latent virus
56. ERADICATION
Eradication is recommended in areas where the
prevalence of the infection is not high.
Eradication programs are difficult as animals in infected
herd tend to become unapparent carriers.
Eradication programs is possible by systemic testing and
culling reactors and a second herd test is carried out 3-12
month later and repeating till clear test is achieved.
57. In enzootic areas, the most control efforts are based on hygiene,
management, isolation procedures, broad-spectrum antibiotics
treatment to avoid the challenge of other infections and the use of
vaccine.
Vaccination has been effective in preventing the respiratory
disease and abortions if given prior to natural exposure.
Available vaccines are modified live MLV (Intramuscular "IM" –
Intranasal) or inactivated virus vaccines.
58. MLVs have the risk of virus persistence and its potential reactivation and used in
healthy animals only.
The IM type of MLV is easer to use and often used in feedlots as it may cause
abortions in breeding herds while, the intranasal type are highly attenuated and
safe for pregnant cows.
Inactivated vaccine are safe to use in cattle but it sometimes produces
hypersensitivity reaction, it requires two doses initially and an annual booster for
adequate protection.
59. Bulk tank milk testing for BHV-1 antibodies may be useful in eradication and
monitoring programs (Yan et al., 2008).
If BHV-1 is detected in the bulk milk there is a high probability that more than one
animal in a herd is infected and that the infection has spread.