Bovine Virus Diarrhoea - Revision history

Bara: Redirected page to Bovine Viral Diarrhoea Virus

2010-05-25T15:59:48Z

Redirected page to Bovine Viral Diarrhoea Virus

Bara: moved Bovine Virus Diarrhoea Virus to Bovine Virus Diarrhoea

2010-05-25T15:49:19Z

moved Bovine Virus Diarrhoea Virus to Bovine Virus Diarrhoea

Bara at 14:00, 24 May 2010

2010-05-24T14:00:06Z

Bara at 10:07, 22 May 2010

2010-05-22T10:07:32Z

Bepocock: /* Epidemiology */

2008-11-14T12:02:04Z

Epidemiology

Bepocock: /* Control */

2008-10-29T19:24:03Z

Control

Bepocock at 19:23, 29 October 2008

2008-10-29T19:23:30Z

Bepocock: /* Pathogenesis */

2008-10-21T21:33:04Z

Pathogenesis

Bepocock: New page: {{unfinished}} {{toplink |linkpage =Viruses |linktext =VIRUSES |sublink1=Flaviviridae |subtext1=FLAVIVIRIDAE |pagetype =Bugs }}
====Antigenicity==== *RNA virus closely related to [[...

2008-10-21T21:30:33Z

New page: {{unfinished}} {{toplink |linkpage =Viruses |linktext =VIRUSES |sublink1=Flaviviridae |subtext1=FLAVIVIRIDAE |pagetype =Bugs }} <br> ====Antigenicity==== *RNA virus closely related to [[...

New page

{{unfinished}}

{{toplink
|linkpage =Viruses
|linktext =VIRUSES
|sublink1=Flaviviridae
|subtext1=FLAVIVIRIDAE
|pagetype =Bugs
}}
<br>

====Antigenicity====
*RNA virus closely related to [[Classical Swine Fever]] and [[Border Disease Virus]]
*2 Serological Types
**BVDV-1 is traditional, existing as two biotypes
***BVDV-1nc: noncytopathogenic
***BVDV-1c: cytopathogenic
**BVDV-2 is an emerging hemorrhagic virus

====Hosts====
*Cattle

====Pathogenesis====
'''BVDV-1c'''
*Infects cattle regardless of age
*Usually mild: diarrhoea with recovery in 10 dyas
*Immunosuppression can lead to secondary infection
'''BVDV-2nc'''
*Transient '''thrombocytopenia''' and '''leukopenia''' over 2 weeks
*Hemorrhages
*Secondary infection
*Death
'''BVDV-1nc'''
*'''Transplacental''' infection of naive heifers
*Outcome depends on age of fetus at contraction
**0-110 days: '''abortion''' or '''persistently infected (PI)''' calves born
**110-220 days: congenital damage with noticeable '''CNS''' and '''musculoskeletal''' lesions
**220 days to term: '''active immunity''' developed
'''Mucosal Disease'''
*Mucosal disease is caused by a '''superinfection''' of PI animals with a second homologous cytopathic biotype (eg BVDV-1nc followed by BVDV-1c)
*Infection typically occurs between '''6-18 months of age''' but is variable
*Superinfection will quickly '''spread horizontally''' among PI animals
*Invariable '''fatal'''
*Characterized by '''oral and enteric erosions''', particularly overlying Peyer's patches, and ulceration of the feet
*Animals can show anorexia, depression and/or diarrhoea for 2-5 days before death
*Vaccination can lead to '''iatrogenic''' infection in undiagnosed PI calves

====Epidemiology====
*Virus is widespread: 60-70% exposure by 4 years of age
*PI cows:
**100% vertical transmission to offspring
**Are infected with BVDV-1nc and NEVER BVDV-1c
**Are often antibody-negative (though they can show low levels of Ab to ''heterologous'' virus)
**Show a wide range of clinical signs:
***Severe congenital damage (ataxia)
***Poor body condition
***Increased susceptibility to enteric and respiratory disease
**Act as the herd '''reservoir''' of BVDV
**Can ONLY be identified by blood testing
*Transfer via '''semen''', '''direct contact''' with acutely infected animals, or vertical from dam to offspring
*Transfer can be iatrogenic: repeated use of needles and gloves, etc.

====Diagnosis====
*Traditional test: virus isolation followed by serology on infected cells
*'''ELISA''' for virus '''antigen''' in animals with persistent viremia
*PI calves often appear virus negative as a result of receiving neutralizing Ab in colostrum: can be countered by RT-PCR
*'''Paired serum samples''' from cows with acute BVDV
*'''Herd sampling''' by ELISA for antibody on bulk milk

====Control====
*No known treatment to reverse persistent infection or to cure mucosal disease
*BUT, without exposure to BVDV, the whole herd is at risk as there is no developed immunity
*Vaccination of dams before pregnancy will prevent PI calves being born
**'''Beta-propiolactone inactivated''' vaccine
**Combine with screening for antigen and removal of PI animals

← Older revision		Revision as of 15:59, 25 May 2010
Line 1:		Line 1:
−	~~{{unfinished}}~~	+	#REDIRECT[[Bovine Viral Diarrhoea Virus]]
−
−	~~====Antigenicity====~~
−	*RNA virus closely related to [[Classical Swine Fever]] and [[Border Disease Virus]]
−	*2 Serological Types
−	**BVDV-1 is traditional, existing as two biotypes
−	***BVDV-1nc: noncytopathogenic
−	***BVDV-1c: cytopathogenic
−	**BVDV-2 is an emerging hemorrhagic virus
−
−	~~====Hosts====~~
−	*Cattle
−
−	~~====Pathogenesis====~~
−	~~[[Image:BVD-MD.gif\|right\|thumb\|125px\|<small><center>Small erosions of MDV/BVDV - vesicles are microscopic (Courtesy of Alun Williams (RVC))</center></small>]]~~
−	~~[[Image:Bvd2.gif\|right\|thumb\|125px\|<small><center>Coalescing lesions of BVDV (Courtesy of Alun Williams (RVC))</center></small>]]~~
−	~~'''BVDV-1c'''~~
−	*Infects cattle regardless of age
−	*Usually mild: diarrhoea with recovery in 10 dyas
−	*Immunosuppression can lead to secondary infection
−	~~'''BVDV-2nc'''~~
−	*Transient '''thrombocytopenia''' and '''leukopenia''' over 2 weeks
−	*Hemorrhages
−	*Secondary infection
−	*Death
−	~~'''BVDV-1nc'''~~
−	*'''Transplacental''' infection of naive heifers
−	*Outcome depends on age of fetus at contraction
−	**0-110 days: '''abortion''' or '''persistently infected (PI)''' calves born
−	**110-220 days: congenital damage with noticeable '''CNS''' and '''musculoskeletal''' lesions
−	**220 days to term: '''active immunity''' developed
−	~~'''Mucosal Disease'''~~
−	*Mucosal disease is caused by a '''superinfection''' of PI animals with a second homologous cytopathic biotype (eg BVDV-1nc followed by BVDV-1c)
−	*Infection typically occurs between '''6-18 months of age''' but is variable
−	*Superinfection will quickly '''spread horizontally''' among PI animals
−	*Invariable '''fatal'''
−	*Characterized by [[~~Cavity & Gingiva - Pathology#~~Bovine Viral Diarrhoea ~~/ Mucosal Disease\|'''oral]] and enteric erosions''', particularly overlying Peyer's patches, and ulceration of the feet~~
−	*Animals can show anorexia, depression and/or diarrhoea for 2-5 days before death
−	*Vaccination can lead to '''iatrogenic''' infection in undiagnosed PI calves
−
−	~~====Pathology====~~
−
−	*'''Mucosal Disease''': erosive condition produces small multiple, cleanly punched out lesion in mouth
−	*[[Neutrophils - WikiBlood\|Neutrophils]] invade the ulcer and if bacterial colonisation occurs, further excavation follows. Either:
−	~~::#This lesion develops a granular base and becomes diphtheritic.~~
−	~~::#If bacterial colonisation does not take place, healing occurs within fourteen days.~~
−	*Seen in most parts of mouth (or maybe on muzzle) e.g. dental pad, [[Cheeks - Anatomy & Physiology\|cheeks]], sides of [[Oral Cavity - Tongue - Anatomy & Physiology\|tongue]]
−	*Lesions extend throughout gut with particularly big ulcers in small intestine over [[Peyer's Patches - Anatomy & Physiology\|Peyers patches]]. Necrosis occurs in lymph nodes and [[Spleen - Anatomy & Physiology\|spleen]]
−
−	~~====<span id="BVDHistology">Histology</span>====~~
−	*No vesicular stage, prickle cells die off from surface resulting in layer of necrotic debris over epithelial layer
−	*Infection penetrates inward through stratum germinativum.
−	*Epithelium does not recover as animal does not recover
−	~~====Epidemiology====~~
−	*A major concern is that it can be confused with [[Foot and Mouth Disease (FMDV)\|FMD]] (especially as it often occurs with clinical signs of salivation and depression)
−	*Virus ~~is widespread: 60-70% exposure by 4 years of age~~
−	**Often may sweep through a whole colony of young stock causing profuse diarrhoea (perhaps febrile) for a few days and then recover
−	**Due to primary exposure to cytopathic strain of virus
−	*PI cows:
−	**100% vertical transmission to offspring
−	**Are infected with BVDV-1nc and NEVER BVDV-1c
−	**Are often antibody-negative (though they can show low levels of Ab to ''heterologous'' virus)
−	**Show a wide range of clinical signs:
−	***Severe congenital damage (ataxia)
−	***Poor body condition
−	***Increased susceptibility to enteric and respiratory disease
−	**Act as the herd '''reservoir''' of BVDV
−	**Can ONLY be identified by blood testing
−	*Transfer via '''semen''', '''direct contact''' with acutely infected animals, or vertical from dam to offspring
−	*Transfer can be iatrogenic: repeated use of needles and gloves, etc.
−
−	~~====Diagnosis====~~
−	*Traditional test: virus isolation followed by serology on infected cells
−	*'''ELISA''' for virus '''antigen''' in animals with persistent viremia (will show up 3-8 days post-infection)
−	*PI calves often appear virus negative as a result of receiving neutralizing Ab in colostrum: can be countered by RT-PCR
−	*'''Paired serum samples''' from cows with acute BVDV
−	*'''Herd sampling''' by ELISA for antibody on bulk milk
−
−	~~====Control====~~
−	*No known treatment to reverse persistent infection or to cure mucosal disease
−	*BUT, without exposure to BVDV, the whole herd is at risk as there is no developed immunity
−	*'''Vaccination of dams''' before pregnancy will prevent PI calves being born
−	**'''Beta-propiolactone inactivated''' vaccine
−	**Combine with screening for antigen and removal of PI animals
−	~~[[Category:Pestiviruses]][[Category:Cattle]]~~
−	~~[[Category:Oral_Cavity_-_Erosive_&_Ulcerative_Pathology~~]]

@@ Line 39: / Line 39: @@
 *Vaccination can lead to '''iatrogenic''' infection in undiagnosed PI calves
 ====Epidemiology====
 *A major concern is that it can be confused with [[Foot and Mouth Disease (FMDV)|FMD]] (especially as it often occurs with clinical signs of salivation and depression)
@@ Line 71: / Line 84: @@
 **Combine with screening for antigen and removal of PI animals
 [[Category:Pestiviruses]][[Category:Cattle]]

@@ Line 51: / Line 51: @@
 ====Epidemiology====
-*A major concern is that it can be confused with [[Foot and Mouth Disease|FMD]] (especially as it often occurs with clinical signs of salivation and depression)
+*A major concern is that it can be confused with [[Foot and Mouth Disease (FMDV)|FMD]] (especially as it often occurs with clinical signs of salivation and depression)
 *Virus is widespread: 60-70% exposure by 4 years of age
 **Often may sweep through a whole colony of young stock causing profuse diarrhoea (perhaps febrile) for a few days and then recover

← Older revision	Revision as of 15:49, 25 May 2010
(No difference)

@@ Line 1: / Line 1: @@
 {{unfinished}}
 ====Antigenicity====
@@ Line 81: / Line 70: @@
 **'''Beta-propiolactone inactivated''' vaccine
 **Combine with screening for antigen and removal of PI animals

@@ Line 78: / Line 78: @@
 *No known treatment to reverse persistent infection or to cure mucosal disease
 *BUT, without exposure to BVDV, the whole herd is at risk as there is no developed immunity
-*Vaccination of dams before pregnancy will prevent PI calves being born
+*'''Vaccination of dams''' before pregnancy will prevent PI calves being born
 **'''Beta-propiolactone inactivated''' vaccine
 **Combine with screening for antigen and removal of PI animals

@@ Line 9: / Line 9: @@
 }}
 <br>
 ====Antigenicity====
@@ Line 22: / Line 24: @@
 ====Pathogenesis====
 '''BVDV-1c'''
 *Infects cattle regardless of age
@@ Line 47: / Line 51: @@
 ====Epidemiology====
 *Virus is widespread: 60-70% exposure by 4 years of age
 *PI cows:
 **100% vertical transmission to offspring
@@ Line 63: / Line 70: @@
 ====Diagnosis====
 *Traditional test: virus isolation followed by serology on infected cells
-*'''ELISA''' for virus '''antigen''' in animals with persistent viremia
+*'''ELISA''' for virus '''antigen''' in animals with persistent viremia (will show up 3-8 days post-infection)
 *PI calves often appear virus negative as a result of receiving neutralizing Ab in colostrum: can be countered by RT-PCR
 *'''Paired serum samples''' from cows with acute BVDV

@@ Line 42: / Line 42: @@
 *Superinfection will quickly '''spread horizontally''' among PI animals
 *Invariable '''fatal'''
-*Characterized by '''oral and enteric erosions''', particularly overlying Peyer's patches, and ulceration of the feet
+*Characterized by [[Cavity & Gingiva - Pathology#Bovine Viral Diarrhoea / Mucosal Disease|'''oral]] and enteric erosions''', particularly overlying Peyer's patches, and ulceration of the feet
 *Animals can show anorexia, depression and/or diarrhoea for 2-5 days before death
 *Vaccination can lead to '''iatrogenic''' infection in undiagnosed PI calves