Hendra virus. a guide for veterinary professionals

Transcription

1 Hendra virus a guide for veterinary professionals

2 Understanding Hendra Virus Hendra virus: reported cases 1 3 * Hendra is a deadly disease that can affect horses, domestic animals and humans. Townsville Rockhampton Ingham Mackay 2012 Trinity Beach 1999 Peachester Murwillumbah Townsville Gordonvale Redlands Proserpine Clifton Beach Peachester Tewantin Bowen Cawarral 2011 Boonah Beaudesert Boondall Macksville Logan Reserve Wollongbar Chinchilla Mullumbimby Hervey Bay Kuranda Lismore Park Ridge North Ballina South Ballina Ballina Gold Cost Hinterland Beachmere 1994 Mackay Hendra Hendra virus (HeV) was first detected in southern Queensland in More recently, HeV has been reported further south in NSW and west of the Great Dividing Range. 1-3 The unprecedented inter-species and geographical spread of HeV underpins the need for the development and widespread administration of a safe and effective vaccine. Development of the HeV vaccine was achieved through collaboration between Pfizer Animal Health, CSIRO and the Henry Jackson Foundation. *Information correct as of July 20th Uniformed Services University of the Health Sciences and the not for profit Henry M. Jackson Foundation for the Advancement of Military Medicine.

3 How to minimise the risk of Hendra Virus disease transmission Follow Hendra vaccination protocols Protect water and food sources from contamination by flying foxes Isolate sick horses from other horses, animals and humans HeV Virology HeV is a negative sense single stranded RNA virus belonging to the family Paramyxoviridae genus Henipavirus 4 Hendra Virus Ensure strict hygiene and cleaning practices are used when handling horses Personal protective equipment (PPE) should be used when Hendra virus is suspected 1 Genus Family Order Species Host/Vector Henipavirus Paramyxoviridae Mononegavirales Hendra virus Pteropid fruit bats (flying foxes) Pteropus alecto (Black flying fox) For comprehensive advice on how to minimise the risk of virus transmission we recommend reading: Guidelines for veterinarians handling potential Hendra virus infection in Horses. 1 Pteropid fruit bats do not exhibit clinical signs of HeV disease 4 Pteropus conspicillatus (Spectacled flying fox) Pteropus scapulatus (Little red flying fox) Pteropus poliocephalus (Grey headed flying fox) Hendra virus: Presumed transmission pathway 5 Host to Horse Horse ingests feed or water contaminated with fruit bat urine, faeces or bodily fluids Horse to Horse Close contact with bodily secretions and/or blood of infected horse Horse to Human Close contact with bodily secretions and/or blood of infected horse Sharing feed/water trough or other equipment Not adhering to strict hand washing or cleaning procedures Incubation period 5-16 days. Possible viral shedding 2 days prior to onset of symptoms 1 Incubation period 5-21 days. 1

4 Heading Understanding Hendra Virus Clinical signs of HeV in horses 1 Common Signs in Horses: Acute onset of illness Increased body temperature Increased heart rate Discomfort/weight shifting between legs Rapid deterioration with respiratory and/or neurological signs Depression positional Other Observations: Respiratory signs Pulmonary oedema Respiratory distress Terminal nasal discharge Pulmonary involvement leading to terminal weakness, ataxia and collapse Neurological signs Wobbly gait Altered consciousness Head tilting Muscle twitching Urinary incontinence Other clinical observations may be noted: Previous unexplained horse deaths Facial oedema, facial paralysis and/or locked jaw Spasms of the jaw, involuntary chomping Muscle trembling Altered gait, high stepping Anorexia Colic like symptoms Straining with difficulty passing manure Stranguria (difficult urination) Hot hooves Bad breath/halitosis Delayed blood clotting times Congestion of oral mucous membranes

5 Heading Field investigation 1 Hendra virus infection control procedures, including appropriate PPE, should be implemented when investigating and sampling any case where Hendra virus is a differential diagnosis. Does the horse display unexplained elevated heart rate and temperature? Does the horse display other signs characteristic of Hendra virus? Has the horse been exposed to Hendra virus OR is there a property history of Hendra virus OR is there other evidence indicative of Hendra virus? YES Sample to exclude or confirm Hendra virus infection Common signs of HeV in humans 6 Common Signs in Humans: Influenza-like illness Pyrexia Cough If it appears that human illness may also be associated with the case, seek medical attention immediately (this information should also be reported to the notifying authorities as listed overleaf). 1 Sore throat Headache Neurological symptoms High fever Encephalitis with headache Drowsiness

6 Equivac HeV Protect with Equivac HeV vaccine Equivac HeV vaccine is for use in healthy horses from 4 months of age as an aid in the prevention of clinical disease caused by Hendra virus (and for the reduction of shedding). 7 Trials have shown no clinical signs and neither virus nor evidence of virus replication in any tissue in vaccinated horses 21 days following the administration of the second IM dose. 7 Booster doses will be required to maintain protective levels of antibodies. Equivac HeV safety and efficacy profile Trials in healthy horses have demonstrated prevention of HeV and virus replication when vaccinated with Equivac HeV 7 Site reactions, including swelling (2 cm x 2 cm) were observed at the site of vaccination in approximately 30% of horses following booster vaccination in clinical trials. These reactions resolved quickly, usually within a few days and with no treatment 7 Precautions for use Equivac HeV vaccine is for use as a preventative and NOT as a treatment for Hendra virus disease in horses Although vaccinated horses in trials did not become infected, show clinical signs or shed virus, there is no guarantee of protection. Personal Protective Equipment (PPE) should be worn whenever a Hendra virus case is suspected. 7 No data exists regarding the safety and efficacy of Equivac HeV vaccine in pregnant mares or animals intended for breeding; use in these animals must be weighed against the risk of serious illness or death from disease caused by Hendra virus Any adverse events should be reported by the veterinarian to Pfizer Animal Health Technical Services Helpline:

7 Administration Prior to administration, the proposed site of injection may be swabbed with cotton wool soaked in a suitable antiseptic solution, e.g. methylated spirits. Administer via IM injection to the centre of the side of the horse s neck. Permits and accreditation Under the conditions of the Minor Use Permit, Equivac HeV vaccine can only be obtained and administered by accredited veterinarians. See next page for instructions about the accreditation and approval process. Storage Store Equivac HeV vaccine between 2 C and 8 C Equivac HeV Refrigerate, do not freeze Protect from light

8 understanding your role Notifying the authorities 1 Actions in the event of a suspected HeV case: 1. Hendra virus infection is a notifiable disease in all jurisdictions and there is a legal obligation to immediately notify biosecurity staff whenever Hendra virus infection is suspected Suspected Hendra virus infection may be reported by calling the Emergency Animal Disease Watch Hotline on State biosecurity staff will consult with the reporting veterinarian to determine an appropriate course of action: 1 - this usually involves further investigation and sampling by the private veterinarian. 1 Notification can be made by contacting one of the following: Biosecurity Queensland on (business hours) There are no known specific treatments for HeV disease for any species. Current treatment for HeV infection in humans is supportive only. 4 Emergency Animal Disease Watch Hotline on (24 hours) - all states When a veterinarian makes contact they should identify themselves and clearly state they are ringing to notify a possible case of HeV.

9 Heading Veterinary approval process to administer Equivac HeV vaccine Vets Australia members must follow these steps before administering Equivac HeV vaccine: 1. Login to and click on the veterinary training tab. 2. Complete the elearning Module (expected completion time is around 20 minutes). 3. Once the elearning module has been completed and you have agreed to uphold the conditions of the APVMA permit, an automated will be sent to your nominated wholesaler, after which you will be eligible to order and administer the Equivac HeV vaccine. 4. Order Equivac HeV vaccine using your unique Hendra Vaccination Code from: Your selected wholesaler Not a Vets Australia member? Join today at Under the APVMA permit conditions, each vaccinated horse must be permanently identified by a microchip carrying a unique identification number. In addition, the following information must be recorded in the Equivac HeV registry at your role Details of all vaccinated horses: age, and unique identification details (where a horse is scanned and two microchips have been identified- the details of both microchips must be added to the vaccination registry) Details of ownership including management and location of all vaccinated horses For accurate vaccination record keeping in the field, download the Manual Vaccination Record Kit in the Tools and Resources section at

10 Heading ADDITIONAL NOTES

11 References 1. State of Queensland, Department of Employment, Economic Development and Innovation. Guidelines for veterinarians handling potential Hendra virus infection in horses: Version 4.2, December, Queensland Horse Council Inc. Fact Sheet: Hendra Virus. January Queensland Government. Department of Agriculture, Fisheries and Forestry, Biosecurity Queensland Alert: Hendra virus - Veterinarian communique 28th June Australian Wildlife Health Network. Hendra Virus (HeV) and Australian Wildlife Draft Fact Sheet October Hess IMR, Massey PD, Walker B, Middleton DJ, Wright TM. Hendra Virus: What do we know? NSW Public Health Bulletin, 2011;22(5-6): : Hendra Virus Infection, A Queensland Health Fact Sheet: Version: 23, 16th September, Australian Pesticides and Veterinary Medicines Authority. Permit to allow supply and minor use of an AVGET chemical product. Permit number PER13510, version 1. August ADDITIONAL NOTES

12 Summary Equivac HeV vaccine: Equivac HeV vaccine is for use in healthy horses from 4 months of age as an aid in the prevention of clinical disease caused by Hendra virus (and for the reduction of viral shedding) 7 Equivac HeV vaccine is administered as two 1 ml doses by intramuscular (IM) injection 21 days apart 7 Trials have shown that protection is provided 21 days following the administration of the second IM dose 7 Further booster doses will be required to maintain protective levels of antibodies What is the Equine Vaccination Registry? A secure online location to collect and store accurate vaccination details for all horses in Australia. It is a requirement to input details in the registry for all horses that have been vaccinated with Equivac HeV. 5 steps to vaccinate horses against Hendra virus: 1. Gain accreditation to purchase and administer Equivac HeV vaccine through 2. Administer the 1st dose against Hendra virus with Equivac HeV 3. Enter the horse vaccination (1st dose) details to the Hendra vaccination registry at (this must be entered within 48 hours of individual vaccinations) 4. Administer the 2nd dose 21 days after the first/primary dose 5. Enter the horse vaccination (2nd dose) details in the Hendra vaccination registry at (this must be entered within 48 hours of individual vaccinations 21 day (second/booster dose) and further booster vaccination reminders will be sent via for each horse you vaccinate with Equivac HeV Two primary doses of Equivac HeV are required for the protection of horses under your care. Development of the HeV vaccine was achieved through collaboration between Pfizer Animal Health, CSIRO and the Henry Jackson Foundation Pfizer Animal Health Australia Pty Ltd Wharf Road, West Ryde NSW Registered Trademark of Pfizer. Pfizer PFISR /12 AM 02294