Veterinary sampling guide for anthrax

Page last updated: Friday, 8 June 2018 - 4:37pm

Caution: Anthrax is a serious zoonotic disease. The Department of Primary Industries and Regional Development (DPIRD) recommends that when there is reason to believe that an animal has died from anthrax, veterinarians should not perform a necropsy. Not all animals dying from this disease will show the characteristic signs of blood-stained discharges from external orifices. Death without premonitory signs may be the only clue to the possible cause of death.

Sample selection for DPIRD Diagnostic Laboratory Services (DDLS)

When submitting samples for suspect anthrax cases, veterinarians should follow these guidelines for both the rapid, in-field immunochromatographic test (ICT - for animals that have died within the past 48 hours) and for selective culture:

Personal protective equipment

Personal protective equipment (PPE) that can be discarded or held in biosecure conditions pending test results should be worn. Overalls, glasses, facemask, disposable gloves and impervious boots should be used. PPE should not be used on other properties or for examination of unaffected stock following sampling.

Sample selection

The samples below are appropriate for anthrax testing without unnecessary exposure of personnel to disease risks.

The preferred samples are listed in order below; collection of one (not all) of the samples listed is sufficient for anthrax testing.  
  1. 0.5-1 millilitre blood drawn into a plain tube from a large peripheral, safely accessible vein (e.g. mammary, jugular) or
  2. haemorrhagic exudate pooled in orifices, drawn into a plain tube or
  3. a plain dry swab of haemorrhagic exudate or
  4. soil stained with haemorrhagic exudate.

Note: skin and ear samples are not suitable. 

  • After collection, place a wad of cotton wool soaked with 10 000 parts per million chlorine (e.g. 100 grams of pool chlorine to one litre of water) over the sample site to prevent contamination of the soil below.

Sample packaging

  • Clearly identify swabs and soil samples and separately pack them inside labelled plastic bags.
  • Wipe the outside of all plastic bags and containers with 10 000ppm chlorine before packing.

Sample transport

  • Place a submission form including a detailed clinical and epidemiological history in an envelope and tape it to the outside of the esky.
  • Write the post-mortem interval in the clinical and epidemiological history.
  • Clearly mark the enclosed submission sheet 'SUSPECT ANTHRAX' so that DDLS staff are alerted to the contents of the container.
  • Do not submit material from other cases with suspect anthrax as they will be regarded as contaminated and destroyed.
  • Advise DDLS by telephone when the samples are in transit.

On-farm biosecurity

  • For anthrax, 10 000ppm chlorine is the most effective disinfectant. Pool chlorine is suitable. To make a suitable solution, mix 100g of chlorine in 1L water.
  • Park vehicles well away from the dead animal.
  • Thoroughly clean and disinfect all equipment and footwear before leaving area.
  • Remove any protective clothing and place in a sealed plastic bag for future disinfection.
  • Wash down the tyres and wheel bays before leaving the property.
  • Have all stock removed from the paddock and do not allow the farmer to move the body until anthrax is confirmed or excluded.
  • Ensure that scavengers and other animals do not have access to the body.
  • If the diagnosis is confirmed, DPIRD will discuss disposal and decontamination procedures directly with the farmer.

Laboratory testing

  • The ICT kit test is available for use as a field test or a laboratory test for animals that have died within the past 48 hours. DDLS staff are trained in its use. See above under Sample selection heading.
  • DDLS performs additional diagnostic/confirmatory culture with the results available within 24-48 hours.

Contact information

Livestock Biosecurity

Author

Livestock Biosecurity