Infection with Echinococcus granulosus

Article 8.5.1.

General provisions

Echinococcus granulosus(E. granulosus) is a widely distributed cestode (tapeworm). The adult worms occur in the small intestine of canids (definitive host). Larval stages (hydatid) occur in tissues of liver, lung and other organs of other mammals (intermediate host), including humans. Infection with the larval stage of the parasite in the intermediate host, referred to as 'cystic echinococcosis' or 'hydatidosis', is associated with significant economic losses in livestock production and causes a major disease burden in humans.

For the purposes of the Terrestrial Code, infection with E. granulosus is defined as a zoonotic parasitic infection of canids, ungulates and macropod marsupials with E. granulosus (ovine, bovine, cervid, camelid and porcine strains).

For the purposes of this chapter, offal is defined as internal organs of ungulates and macropod marsupials.

Transmission of E. granulosus to canids occurs through ingestion of hydatid-infected offal.

Infection in intermediate hosts, as well as in humans, occurs by ingestion of E. granulosus eggs from contaminated environments. In humans, infection may also occur following contact with infected canids or by consumption of food or water contaminated with E. granulosus eggs from canine faeces.

Infection in humans can be prevented by good food hygiene and personal hygiene, community health education and preventing infection of canids. Collaboration between the Competent Authority and the public health authority is an essential component in preventing and controlling E. granulosus transmission.

This chapter provides recommendations for prevention of, control of, and surveillance for infection with E. granulosus in dogs and livestock.

When authorising the import or transit of the commodities covered in this chapter, with the exception of those listed in Article 8.5.2., Veterinary Authorities should apply the recommendations in this chapter.

Standards for diagnostic tests are described in the Terrestrial Manual.

Article 8.5.2.

Safe commodities

When authorising import or transit of the following commodities of livestock, Veterinary Authorities should not require any E. granulosus-related conditions regardless of the status of the animal population of the exporting country or zone:

1. skeletal muscle meat and skeletal muscle meat products;

2. processed fat;

3. casings;

4. milk and milk products;

5. hides and skins;

6. semen, oocytes and embryos.

Article 8.5.3.

Programmes for the prevention and control of infection with E. granulosus

In order to prevent and control infection with E. granulosus, the Veterinary Authority or other Competent Authority should carry out community awareness programmes about the risk factors associated with transmission of E. granulosus, the role of dogs (including stray dogs) and the importance of responsible dog ownership. The Veterinary Authority or other Competent Authority should also implement the following prevention and control measures.

1. Prevention of infection in dogs (owned and stray)

   1. Dogs should not be fed offal unless it has been treated in accordance with Article 8.5.6.

   2. Dogs should be prevented from scavenging on dead ungulates and macropod marsupials. Dead animals should be disposed of in accordance with Article 4.12.6.

   3. The Veterinary Authority or other Competent Authority should ensure that slaughterhouses/abattoirs have implemented measures that prevent access of dogs to the premises, and to animal carcasses and waste containing offal.

   4. When livestock cannot be slaughtered in a slaughterhouse/abattoir and are slaughtered on-farm, dogs should be prevented from having access to raw offal, and not be fed offal unless it has been treated in accordance with Article 8.5.6.

2. Control of infection in dogs (owned and stray)

   1. For control of stray dog populations, the Veterinary Authority or other Competent Authority should implement relevant aspects of Chapter 7.7.

   2. Dogs known to be infected or suspected of having access to raw offal or in contact with livestock should be dewormed at least every 4-6 weeks with praziquantel (5 mg/kg) or another cestocidal product with comparable efficacy. Where possible, faeces excreted up to 72 hours post treatment should be disposed of by incineration or burial.

   3. In areas of persistent transmission, the Veterinary Authority and other Competent Authority should collaborate to identify the possible origins of the infection, and review and amend the control programme, as appropriate.

3. Control of infection in livestock

   1. The Veterinary Authority should ensure that all slaughtered livestock are subjected to post-mortem meat inspection in accordance with Chapter 6.2., including inspection of offal for hydatids.

   2. When hydatids are detected during post-mortem meat inspection:

      1. offal containing hydatids should be disposed of in accordance with Article 4.12.6., or treated in accordance with Article 8.5.6.;

      2. an investigation should be carried out by the Veterinary Authority and other Competent Authority to identify the possible origin of the infection, and review and amend, as appropriate, the control programme.

Article 8.5.4.

Surveillance and monitoring for infection with E. granulosus

An animal identification and animal traceability system should be implemented in accordance with Chapters 4.1. and 4.2.

1. Monitoring in dogs

   1. Monitoring for infection with E. granulosus in dogs should be undertaken at regular intervals as it is an essential activity for assessing the risk of transmission to dog populations and for evaluating the success of control programmes. This can be achieved through testing of faeces from dogs, and canine faecal samples from the environment.

   2. Monitoring strategies should be appropriate to local conditions, in particular where large populations of stray dogs and wild canids exist. Under these circumstances testing of environmental samples (faeces, soil) may provide a useful indicator of infection pressure.

2. Surveillance in slaughterhouses/abattoirs

   1. The Veterinary Services should carry out systematic surveillance for hydatids in livestock in slaughterhouses/abattoirs.

   2. Data collected should be used for the design or amendment of control programmes.

Veterinary Authorities should use information from public health authorities on cases of human hydatidosis in initial design and any subsequent modification of surveillance and monitoring programmes.

Article 8.5.5.

Recommendations for the importation of dogs and wild canids from an infected country

Veterinary Authorities of importing countries should require the presentation of an international veterinary certificate attesting that:

1. the animal has been treated between 24 and 72 hours prior to embarkation with praziquantel (5 mg/kg), or another cestocidal product with comparable efficacy against intestinal forms of E. granulosus;

2. adequate precautions have been taken to avoid reinfection of the animal between treatment and embarkation.

Article 8.5.6.

Procedures for the inactivation of E. granulosus hydatids in offal

For the inactivation of E. granulosus hydatids present in offal, one of the following procedures should be used:

1. heat treatment to a core temperature of at least 80°C for ten minutes or an equivalent time and temperature;

2. freezing to minus 20°C or below for at least two days.

nb: first adopted in 1982.