Equine influenza

Description

Equine influenza (EI) is an acute, highly contagious, viral disease that can cause rapidly-spreading outbreaks of respiratory disease in susceptible populations of horses.  EI is endemic in Europe (except Iceland) and in North and South America.  In these countries most outbreaks are minor and sporadic, because of the high level of vaccination.  In the past 20 years serious outbreaks have occurred in a number of countries (including Australia in 2007), associated with importations of subclinically infected horses and inadequate post-arrival quarantine procedures.

The primary clinical signs include pyrexia, nasal discharge (initially serous and later mucous or mucopurulent), and a deep, dry, hacking cough.  Most horses recover within a couple of weeks given good care and rest. Rarely, it causes deaths in young foals and debilitated or old horses.  Death in adult horses is usually a consequence of secondary bacterial infection. In the 2007 Australian outbreak, coughing was inconsistently reported.

The features of rapid spread and high morbidity assist the differentiation of EI from other infectious and non-infectious respiratory diseases.  The following diseases should be considered in the differential diagnosis:

  • Bacterial bronchopneumonia / pleuropneumonia
  • Viral bronchopneumonia due to equine herpesvirus 1 and 4, and equine rhinitis A and B viruses
  • Inflammatory airway disease due to exposure to environment irritants and aeroallergens
  • Equine viral arteritis
  • Parasitic infections, including ascarids and lungworms
  • The pulmonary form of African horse sickness
  • Strangles
  • Hendra virus infection

Virus titres are highest during the initial 24-48 hours of fever, which is the best time to sample for detection of the virus. Animals seroconvert about 2-3 weeks after infection.  Serology must be interpreted in the context of vaccination history.

Diagnosis and tests available

Diagnosis

The principal diagnostic test for early detection of EI is a real-time PCR which detects all type A influenza viruses.

Serology is useful for retrospective confirmation of infection. In vaccinated horses serology may be complicated by the presence of vaccine-induced antibody, unless vaccines that allow differentiation of infected and vaccinated horses have been used.

Tests available

Test

Sample(s) required

Days of the week test is conducted

Turnaround time1

Equine influenza antibody ELISA

Whole blood (red top tube)

According to demand

Up to 7D2

Equine influenza HI

Whole blood (red top tube)

According to demand

Up to 7D

Influenza type A real time PCR

Swab

According to demand

Same day to 48 hours3

Please Note: D= Working days, W= Weeks. This excludes Public Holidays.

1 Turnaround times are provided as a guide only. For specific information about your submission please contact Customer Service.
2 Confirmation testing of positives may affect turnaround time.
3 Turnaround time is dependent on urgency.

Additional Information

Specimen requirements

Blood (without anti-coagulant)
  • 10 mL of blood collected into a plain evacuated tube
    • Do not use serum separator tubes.
    • Submit chilled
Swab
  • Nasal swabs - Mucosal surface of each nostril, collected separately into viral transport media (PBGS)
    • Submitted chilled.
    • Do not use commercially prepared swabs with plastic sleeves that contain transport medium. Tubes containing PBGS can be ordered via the online media request form. If PBGS is not available, swabs should be placed in 2 mL sterile saline.

Further information

Customer Service

Contact Customer Service for enquiries relating to testing and results, quotations and pricing, couriers, sample submission and invoicing.

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CONTACT DETAILS

Phone1800 675 623
Email

laboratory.services@dpi.nsw.gov.au

Operating Hours

8:30am-4:30pm Monday-Friday (excluding public holidays)

8:30am-12:00pm Saturday (for deliveries only)

Postal Address

Private Bag 4008, Narellan NSW 2567

Quotations

For Animal export, Plant health or Veterinary quotations, please complete the online quotation request

For Edible oil & oilseed or Feed quality quotations and pricing enquiries, please contact DPI AgEnviro Labs at Wagga Wagga on (02) 6938 1957

For Plant nutrition, Soil health or Water quality quotations and pricing enquiries, please contact DPI AgEnviro Labs at Wollongbar on (02) 6626 1103

Courier services and specimen delivery

For NSW submissions, please contact the relevant Customer Service team for courier account details and to order consignment notes.

For submitters outside of NSW, Couriers can be contacted directly to make bookings and arrange collection of packages at the submitters own cost.

Commercial couriers may use either road or air transport and specimens should therefore be packed in accordance with International Air Transport Association (IATA) requirements. Most submission sent by veterinarians to the SVDL for testing are defined as “Biological Substance Category B” and must be packed according to the IATA packing instructions 650 (Biological Substance Category B). As requirements for transport can change, customers should consult with their transport agent to obtain current requirements.

Samples may also be hand delivered to the site during normal business hours (8.30am - 4.30pm).

Sample Type

Laboratory

Street Address

Animal (including aquatic animals)

NSW Animal and Plant Health Laboratories (APHL)

EMAI, Woodbridge Road, Menangle NSW 2568