Transmission and pathogenesis Flashcards
(20 cards)
CPV-2 infection occurs due to fecal–oral transmission, and clinical signs occur within?
4-10 days
Myocarditis may develop in neonates infected within?
first 2 weeks postpartum
CPV-2 infection is commonly associated with acute-onset lethargy, anorexia, vomiting, abdominal pain, and pyrexia, followed 12 to 48 hours later by?
small intestinal diarrhea
In severely affected animals, clinical findings consistent with?
sepsis, systemic inflammatory response syndrome, coagulopathy, and multiple organ dysfunction
Lymphopenia occurs initially as a result of direct?
lymphocytolysis.
The lymphopenia is typically followed by neutropenia because of ?
peripheral consumption and destruction of white blood cell precursors in the bone marrow.
Anemia, which may be poorly regenerative, can develop due to?
repeated blood sampling, gastrointestinal hemorrhage, and an inflammation-related reduction in red blood cell lifespan and suppression of erythropoiesis.
One study reported that a lymphocyte count over 1.0 × 103/μl in CPV-2 infected dogs on admission and at 24 and 48 hours postadmission had a positive predictive value of?
100%
Nonsurvivors in the same study failed to develop a ?
degenerative left shift and continued to have significant leukopenia, lymphopenia, eosinopenia, and monocytopenia at 24 and 48 hours after admission. Interestingly, severe neutropenia was not a useful prognostic indictor.7
Biochemical changes in affected dogs may include?
hypoproteinemia, hyperbilirubinemia, elevated alkaline phosphatase and alanine aminotransferase, hyponatremia, hypochloremia, hypokalemia, hypoglycemia, and a prerenal azotemia. One study reported that dogs with CPV-2 had evidence of acute kidney injury, which was revealed by assessing urine protein:creatinine and novel urinary biomarkers, but was not evident when assessing serum creatinine, urea, or urine specific gravity.8
An IDEXX CPV SNAP parvo test is positive. What is the sensitivity and specificity of this test compared to PCR testing?
Depending on the method of validation, fecal antigen ELISA testing has a sensitivity between 18% and 82% and a specificity of up to 100%
What circumstances might cause a false negative point of care ELISA test? 4 reasons
False-negative ELISA fecal antigen results occur due to test failure to detect low levels of fecal antigen early in the course of disease, insufficient sample size, antibody binding of CPV-2 antigen within the gastrointestinal tract, and/or the dilutional effect of diarrhea
gold standard for diagnosing CPV-2?
conventional and real-time laboratory techniques are available PCR
Further diagnostic testing should be pursued in dogs with a negative in-house fecal CPV-2 antigen ELISA test result if a high clinical index of suspicion for parvoviral enteritis is present. which are they?
Ideally samples should be submitted for RT-PCR and the fecal ELISA antigen repeated within 36-48 hours while the results are pending.
false-positive result secondary to vaccination can happen?
Given the high specificity of ELISA fecal antigen testing and the improbability of a false-positive result secondary to vaccination, a positive result likely indicates true infection.
Abdominal ultrasonographic findings that are consistent with CPV-2 may include?
ileus, thinning of the duodenal and jejunal mucosa with altered wall layering, hyperechoic mucosal speckling, and undulation of the luminal-mucosal interface.
The use of synthetic colloids as a resuscitation fluid is controversial why?
as they are associated with acute kidney injury, coagulopathy, and pathological tissue uptake
Type I interferons enhance what?
the ability of the immune system to recognize microbes and establish a connection between the innate and acquired immune system. Furthermore, type I interferons have antiviral properties and are capable of blocking viral replication and inducing apoptosis of infected cells
what is neuraminidase inhibitor?
Neuraminidase inhibitors are used for treating human influenza because the neuraminidase enzyme is required for viral penetration of respiratory mucin barriers. It has been suggested that oseltamivir administration to dogs with CPV-2 enteritis could reduce bacterial translocation by preventing viral degradation of the intestinal mucin barrier. Thus far, a clear outcome benefit associated with oseltamivir treatment in dogs with CPV-2 has not been demonstrated, although treatment has been associated with decreased weight loss during hospitalization and higher mean white blood cell count
Tammy’s owners have also heard about a new treatment for parvovirus involving monoclonal antibody administration. What peer-reviewed evidence exists for this treatment?
Canine granulocyte colony-stimulating factor has been shown to increase mean white blood cell count and decrease hospitalization times in dogs with CPV-2.38 However, the same study also reported significantly decreased 7-day survival in the treated group compared with the untreated group, raising safety concerns.38
Passive immunotherapy using CPV-2-immune plasma has been reported. One clinical trial did not document any significant difference in leukocyte count, duration of hospitalization, treatment cost, and magnitude of viremia between the treatment and placebo groups.39 The lack of treatment efficacy may have been influenced by the frequency and timing of administration in addition to the fact that the same dose was administered regardless of body weight. Improvement in markers of shock within the first 24 hours of hospitalization is reported in dogs with naturally occurring CPV-2 infection treated with canine hyperimmune CPV-2 plasma when compared with a placebo group. There was no significance difference in the duration of hospitalization or mortality between the treatment and placebo groups; however, the study was underpowered to detect this effect.40 The efficacy of feline antiparvovirus antibodies in the treatment of CPV was also evaluated, and excellent in vitro viral neutralisation was reported. Unfortunately, this failed to translate into a clinical benefit in vivo.41
Fecal microbiota transplantation has been assessed in puppies with CPV-2 and was associated with significantly faster resolution of diarrhea and shorter duration of hospitalization.
