Gastrointestinal Viral Diseases Overview

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Questions and Answers

What type of genome does Bovine Viral Diarrhea Virus (BVDV) possess?

Single-stranded DNA

Double-stranded DNA

Single-stranded RNA (correct)

Double-stranded RNA

Which viral family includes the Bovine Viral Diarrhea Virus?

Parvoviridae

Flaviviridae (correct)

Adenoviridae

Reoviridae

Which disease is primarily caused by Rotavirus in animals?

Porcine epidemic diarrhea syndrome

Transmissible gastroenteritis

Rotaviral diarrhea (correct)

Bovine viral diarrhea

What is the approximate genome size of BVDV?

12.5 Kb Signup and view all the answers

What mode of transmission is primarily associated with BVDV?

Direct contact with infected animals Signup and view all the answers

Which characteristic is true for viruses belonging to the Coronaviridae family?

They can cause diseases in both cattle and swine. Signup and view all the answers

Which of the following is a common clinical sign associated with gastrointestinal viral diseases?

Severe gastrointestinal symptoms Signup and view all the answers

What is a key control measure to manage BVDV infections in cattle?

Regular vaccination and biosecurity measures Signup and view all the answers

What is one of the primary economic impacts of BVDV on cattle?

Severe reproductive issues leading to economic losses Signup and view all the answers

Which clinical sign is NOT typically associated with acute infections of BVDV in non-pregnant animals?

Erosive stomatitis Signup and view all the answers

What is the primary method of BVDV transmission from one animal to another?

Direct contact and body fluids Signup and view all the answers

How can vertical transmission of BVDV affect pregnant cows?

It may lead to various fetal outcomes depending on gestational stage. Signup and view all the answers

What distinguishes mucosal disease from typical BVD?

It occurs only in persistently infected animals. Signup and view all the answers

What is a common clinical manifestation in persistently infected calves with BVDV?

Lifelong viral shedding without antibodies. Signup and view all the answers

What is the main cause of persistent infections in calves with Bovine Viral Diarrhea (BVD)?

Non-cytopathic pestivirus Signup and view all the answers

What is a major pathological finding associated with mucosal disease in affected animals?

Hemorrhagic ulcers in the esophagus Signup and view all the answers

Why is timing of infection important in pregnant cows regarding BVDV?

It affects the likelihood of transplacental infection. Signup and view all the answers

Which diagnostic method is NOT commonly used for detecting active BVD infection?

Blood smear analysis Signup and view all the answers

What is the major consequence of a PI (persistently infected) animal being superinfected with a cytopathic virus?

Mucosal disease Signup and view all the answers

What are effective strategies to control the spread of BVDV?

Vaccination and biosecurity measures Signup and view all the answers

What is a common characteristic of rotavirus?

Linear segmented dsRNA genome Signup and view all the answers

What clinical sign indicates that an animal might have developed immune suppression due to BVDV?

Leukopenia Signup and view all the answers

Which type of agent is responsible for the pathogenesis of mucosal disease?

A cytopathic strain emerging postnatally Signup and view all the answers

Which symptom is typically associated with the infection of calves by rotavirus?

Profuse watery diarrhea Signup and view all the answers

What can be a consequence for calves born after infection occurs between 30-120 days of gestation?

Calves may be persistently infected and shed the virus. Signup and view all the answers

What is one of the primary control measures for Bovine Coronavirus (BCoV)?

Vaccination with inactivated viruses Signup and view all the answers

What can acute infections of BVDV lead to in non-pregnant animals?

Transient symptoms and potential for secondary infections Signup and view all the answers

What is the typical duration of virus shedding in calves infected with BCoV?

Days to weeks Signup and view all the answers

Which symptom is characteristic of severe clinical presentation in mucosal disease?

Profuse watery diarrhea Signup and view all the answers

In addition to diarrhea, BCoV infections in calves can present with which other symptom?

Respiratory distress Signup and view all the answers

Which of the following is TRUE about the coronaviruses?

Their crown-like appearance is due to spike proteins. Signup and view all the answers

What diagnostic technique is commonly used for BCoV that is similar to methods used for detecting rotavirus?

Fecal ELISA Signup and view all the answers

What clinical sign is typically seen in adult cattle suffering from winter dysentery due to BCoV?

Hemorrhagic diarrhea Signup and view all the answers

What treatment approach is essential for managing diarrhea in young animals caused by rotavirus?

Supportive care including fluids Signup and view all the answers

Which of the following statements about immunity in herds regarding BVD is accurate?

Major losses can occur in non-immune herds. Signup and view all the answers

How does BCoV primarily affect the gastrointestinal tract?

It causes necrosis of mucosal tissue. Signup and view all the answers

What is the primary route of transmission for Transmissible Gastroenteritis (TGE)?

Fecal-oral route Signup and view all the answers

What characterizes the genome of the TGE virus?

Approximately 28.5Kb Signup and view all the answers

Which of the following has the highest mortality rate due to TGE?

Young pigs under 7 days old Signup and view all the answers

What is a common clinical sign of TGE in pigs?

Watery diarrhea Signup and view all the answers

What is the impact of environmental temperature on the prevalence of TGE?

Lower temperatures increase environmental persistence Signup and view all the answers

How is Porcine Epidemic Diarrhea Syndrome (PEDS) diagnosed?

Through PCR and ELISA testing Signup and view all the answers

What type of coronavirus causes Porcine Epidemic Diarrhea Syndrome?

Alphacoronavirus Signup and view all the answers

What long-term strategy is recommended to control TGE outbreaks?

Strict biosecurity and vaccination strategies Signup and view all the answers

Which of the following coronaviruses is considered milder compared to TGE and PEDS?

Porcine Delta Coronavirus (PDCoV) Signup and view all the answers

What method is effective for eradicating TGE from infected herds?

Depopulation, sanitation, and repopulation with negative swine Signup and view all the answers

What role do maternal antibodies play in the susceptibility of young pigs to coronaviruses?

They provide protection until weaning Signup and view all the answers

What is a critical component of supportive care for pigs infected with TGE?

Providing fluids and electrolytes Signup and view all the answers

When were highly virulent strains of PEDS first observed in the US?

2013 Signup and view all the answers

What is the approximate genome size of Porcine Delta Coronavirus?

26Kb Signup and view all the answers

What are the two main syndromes caused by Bovine Viral Diarrhea Virus (BVDV)?

Bovine Viral Diarrhea and Mucosal Disease Signup and view all the answers

How does Bovine Coronavirus primarily affect the gastrointestinal tract?

By necrosis and fluid secretion in epithelial cells Signup and view all the answers

Why is immunotolerance significant in persistently infected calves with BVDV?

They do not produce antibodies, allowing for lifelong viral shedding. Signup and view all the answers

What role does environmental persistence of Bovine Coronavirus play in its transmission?

It enables transmission via air and feces and necessitates stringent biosecurity. Signup and view all the answers

What is a significant impact of Rotavirus on young farm animals?

It leads to severe diarrhea and can cause high mortality rates due to dehydration. Signup and view all the answers

What is the main benefit of vaccinating cows against Bovine Viral Diarrhea?

It boosts antibodies in colostrum, protecting calves and enhancing herd immunity. Signup and view all the answers

Which of the following statements is true regarding the incubation period for Porcine epidemic diarrhea syndrome (PEDS)?

It spans 3-4 weeks. Signup and view all the answers

What is the primary mode of action of Rotavirus on the gastrointestinal tract?

Targets mature villus tip enterocytes and leads to villous atrophy Signup and view all the answers

Which of the following accurately describes the characteristics of Bovine coronavirus?

It can lead to diarrhea, winter dysentery, and respiratory disease. Signup and view all the answers

What distinguishes Mucosal Disease from Bovine Viral Diarrhea in terms of infection nature?

Mucosal Disease has more severe clinical manifestations and is associated with chronic infections. Signup and view all the answers

Study Notes

Gastrointestinal Viral Diseases Overview

Gastrointestinal viruses are classified into various families, each affecting different species and causing specific diseases.
Understanding the viral structure and replication process is essential for developing effective vaccines and treatments.
The presence of neutralizing antibodies is critical for controlling BVDV infections.

Bovine Viral Diarrhea and Mucosal Disease

Bovine viral diarrhea virus (BVDV) is a +ssRNA virus, enveloped, and belongs to the Flaviviridae family.
BVDV is economically significant due to its widespread impact on cattle health and productivity.
BVDV can infect a range of hooved animals, including goats, sheep, and pigs.
Two distinct syndromes: Bovine viral diarrhea (acute) and mucosal disease (chronic).
Effective vaccination and biosecurity measures are essential to control the spread of BVDV.

Pathogenesis and Transmission of BVD

BVDV transmission occurs horizontally through exposure to body fluids of persistently infected animals, including direct contact and aerosol transmission.
Vertical transmission can occur transplacentally, affecting the fetus during pregnancy.
Acute infections typically result in transient symptoms, while chronic infections can lead to persistent viral shedding and immunotolerance in calves.
The pathogenesis involves replication in the nasal mucosa and tonsils, spreading to lymph nodes and the bloodstream, affecting lymphoid tissues and intestines.
Clinical signs in non-pregnant animals include fever, leukopenia, diarrhea, and potential secondary infections due to immune suppression.

Clinical Manifestations of BVDV

Acute transient infections often present with mild symptoms, particularly in young animals after maternal antibodies wane.
Symptoms include fever, leukopenia, mild to explosive diarrhea, and decreased milk production.
Immune suppression can lead to increased susceptibility to secondary infections, particularly respiratory and gastrointestinal.
Transplacental infection can lead to severe outcomes depending on the gestational stage at which the infection occurs.
Persistently infected calves are immunotolerant to the virus and shed virus without developing antibodies.

Mucosal Disease in BVDV

Mucosal disease occurs only in persistently infected animals and presents with more severe clinical features than typical bovine viral diarrhea.
Symptoms include fever, anorexia, profuse watery diarrhea, and severe erosive or ulcerative stomatitis, leading to dehydration and emaciation.
The rapid progression of the disease often leads to death within two weeks.

Pathogenesis of Mucosal Disease

Mucosal disease results from a noncytopathic strain persisting in utero and a cytopathic strain that emerges postnatally due to mutation or infection.
The cytopathic BVDV damages the gastrointestinal epithelium, leading to fluid leakage, diarrhea, and dehydration.
The damaged epithelial barrier increases susceptibility to secondary infections and septicemia.

Bovine Viral Diarrhea (BVD)

BVD is caused by a pestivirus, leading to persistent infections in calves that are born antibody negative.
Persistently infected (PI) animals shed large amounts of virus throughout their lives.
If the non-cytopathic (ncp) virus mutates into a cytopathic (cp) biotype or if a PI animal is superinfected with a related cp virus, it can lead to lethal mucosal disease.

Diagnosis and Immunity of BVD

Diagnosis methods include antigen ELISA for active infection detection, PCR, and virus isolation.
Antibody ELISA is used to determine if animals have been exposed or vaccinated.
Immunity can develop in herds, with sporadic losses in immune herds and major losses in non-immune herds upon exposure.

Control and Treatment of BVD

Key control measures include testing and removing persistently infected animals to reduce virus reservoirs.
Vaccination with attenuated virus vaccines is recommended to prevent reinfection.
Implementing farm biosecurity measures and quarantine protocols is essential for controlling BVD.

Rotavirus

Rotavirus is a major cause of diarrhea in young animals, particularly in intensively reared species like calves, piglets, and foals.
It belongs to the Reoviridae family, characterized by a linear segmented dsRNA genome.

Pathogenesis of Rotavirus

Direct mechanisms include infection of mature villus tip enterocytes, leading to villi blunting and reduced digestive enzyme activity.
Indirect mechanisms involve osmotic dysregulation and malabsorption due to villus atrophy.
Neonates are particularly susceptible due to slower epithelial cell turnover and immature immune responses.

Clinical Signs and Diagnosis of Rotavirus

Clinical signs in calves include soft to liquid feces with mucus, risk of dehydration, and secondary bacterial infections.
Diagnosis can be made through fecal ELISA, PCR, and electron microscopy, although isolating the virus in cell culture is challenging.

Bovine Coronavirus (BCoV)

BCoV is a member of the Coronaviridae family, causing three clinical syndromes: calf diarrhea, winter dysentery in adults, and respiratory disease across all ages.
The virus is enveloped, with a positive-sense single-stranded RNA genome.

Transmission and Control of BCoV

Calves can shed the virus for days to weeks, while adult carriers may shed without showing clinical signs.
Transmission occurs via aerosol or direct contact with feces and respiratory secretions.
Control measures include proper feed and manure management to reduce risk factors for transmission.

Clinical Signs of BCoV

Calf diarrhea typically occurs in calves less than 3 weeks old, presenting as profuse watery diarrhea for 4-5 days.
Winter dysentery affects adults, characterized by hemorrhagic diarrhea and concurrent mild respiratory disease.
Respiratory disease can manifest as pneumonia and fibrino-mucopurulent tracheitis.

Overview of Coronaviruses

Coronaviruses are a family of viruses known for their crown-like appearance due to spike proteins on their surface.
They are RNA viruses that can rapidly evolve, leading to new strains and variants.

Bovine Coronaviruses (BCoV)

BCoV is involved in the bovine respiratory disease complex, commonly known as shipping fever.
Clinical signs of BCoV infection can range from mild to severe pneumonia.

Pathogenesis of Bovine Coronavirus

BCoV primarily targets epithelial cells of the gastrointestinal tract, leading to necrosis and reduced enzyme secretion.
The infection results in stunted and fused villi, compensatory crypt hyperplasia, and increased fluid secretion.

Diagnosis and Clinical Signs of BCoV

Diagnosis of BCoV can be achieved through virus isolation, PCR, and ELISA tests.
Clinical signs include diarrhea, respiratory distress, and dehydration.

Treatment and Prevention of Bovine Coronavirus

Supportive care includes administering fluids and electrolytes to combat dehydration.
Antibiotics may be used to prevent or treat secondary bacterial infections.
Vaccination strategies involve using modified live and inactivated vaccines to boost immunity in adult cows.

Porcine Enteric Coronaviruses

Key porcine coronaviruses include Transmissible Gastroenteritis (TGE), Porcine Epidemic Diarrhea Syndrome (PEDS), and Porcine Delta Coronavirus (PDCoV).
Each virus is antigenically distinct, meaning there is no cross-protection between them.
All porcine coronaviruses cause severe intestinal diseases, leading to watery diarrhea and high mortality rates in infected piglets.

Transmissible Gastroenteritis (TGE) Overview

TGE virus (TGEV) belongs to the genus Alphacoronavirus, characterized by a 28.5Kb genome.
Transmission occurs primarily through the fecal-oral route.
The virus is enveloped.

Clinical Impact of TGE

All age groups of pigs can be affected, but mortality rates are highest in piglets under 7 days old.
Clinical signs include fever, decreased lactation, vomiting, inappetence, and diarrhea.

Pathogenesis of TGE

TGEV primarily targets the jejunum and ileum, leading to destruction of apical enterocytes.
The resulting villous atrophy decreases the absorptive area and digestive enzyme production.

Diagnosis and Treatment of TGE

Diagnosis is typically confirmed through PCR, ELISA, or virus isolation.
Supportive care includes administering fluids and electrolytes to affected animals, along with maintaining warmth to aid recovery.

Transmission and Control of TGE

Outbreaks generally last 3-4 weeks, with virus shedding continuing for approximately 2 months.
The introduction of νέα animals can lead to renewed susceptibility.
TGE is more prevalent in winter months.
Effective prevention strategies include maintaining a closed herd, implementing all-in all-out production systems, and ensuring thorough sanitation practices.

Managing Active Outbreaks of TGE

Deliberate exposure of pregnant sows can help minimize the impact on the herd.
Vaccination strategies are essential.
Successful eradication involves depopulating infected herds, sanitizing facilities, and repopulating with TGEV-negative swine.

Porcine Epidemic Diarrhea Syndrome (PEDS)

PEDS is caused by the porcine epidemic diarrhea virus (PEDV).
The disease was first observed in the UK in 1971.
The introduction of PEDS resulted in a 10% mortality rate in the US herd.

Clinical Signs and Pathogenesis of PEDS

In naïve herds, PEDS affects animals of all ages, but the severity of the disease is inversely proportional to age.
Clinical signs include osmotic and malabsorptive diarrhea, similar to TGE.

Diagnosis and Treatment of PEDS

Diagnosis is confirmed through PCR, ELISA, and virus isolation.
Supportive care focuses on fluids and electrolytes.
There is currently no vaccine available for PEDS.

Other Porcine Coronaviruses: Porcine Delta Coronavirus (PDCoV)

PDCoV, classified under the genus Deltacoronavirus, was first identified in China in 2012.
It is considered milder compared to TGE and PEDS.
The genome of PDCoV is approximately 26Kb.

Swine Acute Diarrhea Syndrome (SADS)

First detected in China in 2017
Suspected origin: Bat to pig transmission
Outbreaks in multiple Chinese provinces
Characterized by diarrhea, weight loss, and high mortality rates
Mortality rate up to 90% in piglets under 6 days old
Classified under Alphacoronavirus genus

Bovine Viral Diarrhea Virus (BVDV)

Causes two distinct syndromes: Bovine Viral Diarrhea and Mucosal Disease
Bovine Viral Diarrhea: Characterized by mild symptoms in susceptible animals, transient infection
Mucosal Disease: Occurs in persistently infected cattle, severe condition, rapid mortality
Persistently infected calves do not develop antibodies against the virus, leading to lifelong viral shedding

Rotavirus

Targets mature villus tip enterocytes
Causes villous atrophy and malabsorption
Results in secretory diarrhea

Bovine Coronavirus

Affects epithelial cells throughout the gastrointestinal tract
Causes necrosis and fluid secretion
Leads to malabsorptive diarrhea and extensive damage to the intestinal lining
Can survive for several days at room temperature, facilitating transmission through aerosol and direct contact with feces

Rotavirus Impact on Farm Animals

Significantly impacts young farm animals, particularly those under two months old
Causes severe diarrhea and high mortality rates due to dehydration

Bovine Viral Diarrhea Control

Vaccination is crucial for control
Vaccination helps establish herd immunity and reduce the incidence of both acute and persistent infections
Vaccinating cows boosts antibodies in colostrum, protecting calves from infection

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Description

This quiz covers essential information about gastrointestinal viral diseases, focusing on Bovine Viral Diarrhea Virus (BVDV). Participants will learn about the viral structure, transmission, and impact on cattle health. Understanding these factors is crucial for effective disease management and vaccine development.