Carnivore Virology Flashcards
(2 cards)
Describe the efficacy of deliving rabies vaccine to duodenal mucosa in Gray foxes (Urocyon cinereoargenteus).
Discuss the advantages of preserving rabies vaccine by vaporization.
Preserved, non-preserved, and alginate encapsulated vaccine was delivered to duodenal mucosa via endoscopy
- Alginate encapsulated vaccine failed to stimulate immune responses
- Live attenuated RABV Preserved by Vaporization & RABV without vaporizaiton preservation both produced sufficient immune responses
- No viral shedding in saliva or blood was documented
- No nerve tissue or CSF virus was isolated at necropsy either
Vaporization
- foam-drying technique PBV effectively stabilizes RABV at ambient temperatures for 15 months
- can induce RABV-neutralizing antibodies when delivered IM
- advantage - ability to micronize biologics, which allows for needle-free and traditional pharmaceutical delivery (intradermal microneedle patches, intranasal inhaler, dissolvable oral gels, or gastric capsules)
Reference: AJVR 2017 78(6) 752-756. Assessment of the immunogenicity of rabies vaccine preserved by vaporization and delivered to the duodenal mucosa of gray foxes (Urocyon cinereoargenteus)
Describe the infection of SARS-CoV-2 in wild animals.
What hosts have been documented?
How is it transmitted?
How is it diagnosed?
What treatments are available?
How is it prevented?
What disinfectants are effective?
Range of hosts
* NHP and carnivores main spillover hosts in first year
* Farmed mink
* Feral boars, red foxes, jackals had seroconversion
* WTD seroconverted and had DNA in LN
Transmission routes and clinical signs in animals
* Aerosol main route, fomite contamination role low
* Animals generally expressing milder signs than humans
* URT (sinusitis, tracheitis), LRT (pneumonia), and SI tract (diarrhea)
* Virus can be found in many organs, including brain
* Mortality rate very low, even zero in most species
* Except African monkey
Diagnostic
Direct
- Sample nasal, tracheal, rectal, fecal swabs
- PCR
– rtPCR is gold standard
– some kits may lose efficacy with variants
– rtPCR targeting nucleocapsid, envelop should be used as those are most stable sequences
– Genomic analysis paramount (online databases exist)
- Antigenic analysis
– Commercial tests can be used on nasal, trachea, rectal, fecal swabs to detect SARS-Cov02 antigen
– 98% specific, but sensitivity may be low (30-88%) depending on viral load
– Low predictive value in zoo setting
Indirect
- Serology
– Triggers both cellular and humoral immunity
– First Ig (usually IgM) in first week post-infection, then IgG, IgA rise and last for several months
– In rhesus, reinfection at 28 and 35 days was protective enough to greatly decrease signs
– ELISA or LIPS assays looking for antibody targeting N or S subunits
Treatment
- Supportive care
– NSAID, mucolytic and fluid/vitamin (D)
– Glucocorticoids can be used
- Antimicrobials
– Avoid secondary infections
– Some have in vitro properties vs SARS-Cov-2: azithromycin, hydroxychloroquine, ivermectin, itraconazole
- Monoclonal antibody
– It has been proven than human monoclonal antibodies can protect animals
– mAbs has been used in a gorilla
– Innocuity was good, efficiency in viral load decrease could not be determined
– Should be given early in infection to be most effective
Prevention
- Viral circulation
– Level of viral circulation in zoo
– Human screening, vaccination, biosafety, temp monitors, auto-tests
– Environmental monitoring – sewers
- Best practice and PPE
– Reducing indoor time with animals, increasing distance, increasing air flow
– Surgical masks or N95/N99
– Wear gloves with food
– Adjust medical training behaviors
Disinfection methods
- Very resistant as it is enveloped
Inactivated by heat after 10min above 56C or 5 min at 70C
- Barely impaired by freezing
- UV light can inactivate virus on surfaces or aerosols (sunlight over 5 min)
- All anthropogenic items should be disinfected or kept for a week before used as enrichment
- Effective compounds: alcohol >70% (30 sec), sodium hypochlorite >0.1% (1min), hydrogen peroxide >0.5% (1min)
- Other disinfectants can be used, but exposure time 5-10min
Vaccination
- Staff vaccines reduce risk of passage to animal
- Human RNA vaccines successfully used in NHP
- Vet vaccines: based on recombinant antigen (S) with adjuvants to elicit antibody response in carnivores
- Serology: carnivores show high titers, NHPS reach weak titers after booster
- Use killed or recombinant in wild species to avoid risk of recombination events
