Falklands : Hydatids Disease - The Way Forward
Submitted by Falkland Islands News Network (Juanita Brock) 18.09.2009 (Article Archived on 02.10.2009)
Proposal to carry out faeces sampling of all farm dogs in the Falkland Islands and subject them to the copro – ELISA and copro – PCR tests for hydatid infection.
HYDATIDS DISEASE – THE WAY FORWARD
By Steve Pointing
Proposal to carry out faeces sampling of all farm dogs in the Falkland Islands and subject them to the copro – ELISA and copro – PCR tests for hydatid infection.
Much information has been gathered about the prevalence of hydatid cysts in the intermediate host (mainly sheep and lambs) over recent years but very little information has been gathered about the level of infection in the definitive host of the tapeworm – namely the dog. The last time a serological survey of farm dogs was carried out was between 1991 and 1993 by Michael Reichel, the veterinary officer at that time. The testing system used by him looked at blood serum samples and gave an indication of past infestation with the tapeworm as well as current infestation – this led to some disagreements with certain dog owners. In this proposal it is intended to use new testing methods which look for tapeworm antigens in fresh dog faeces – and, if found positive, this would be indicative of current infestation with the hydatid tapeworm.
It is hoped that by using this dual approach (PM inspection of sheep offals at the abattoir to look for hydatid cysts and active monitoring of farm dog faeces for the presence of the adult tapeworm) it may be possible to determine whether there is still a “reservoir” of infection somewhere within the Islands.
Recommendations as to future hydatid control will depend on the outcome of this monitoring exercise.
Recommendation
To take fresh faeces samples from all the farm dogs in the Falkland Islands (current number approx. 494 – figures available from the annual farm statistics) and subject them to the copro-ELISA test at a designated laboratory in the University of Salford in the UK. The samples would need to be received and processed in the DoA lab. in Stanley prior to being sent off for final testing in the UK. Any samples which proved to be positive to the copro-ELISA test would then be subjected to a second test – the copro-PCR test on a duplicate faecal sample from the same dog. Only if both tests were positive would the dog be deemed to be positive for the presence of E. granulosus and further investigations would need to be undertaken on the farm of origin.
Background
Control of hydatid disease in dogs has been carried out in the Falkland Islands since the mid 1970’s. This takes the form of worming the dogs every 6 weeks with an anthelmintic that is effective against the tapeworm that causes hydatid disease in sheep (and other ruminants and occasionally man) – namely Echinococcus granulosus (E.granulosus) and preventing dogs from having access to raw ruminant offals which might contain an infectious hydatid cyst.
The national prevalence levels of hydatid disease have been monitored at the abattoir for several years by a meat inspector and official veterinarian when carrying out post mortem meat inspection of sheep and lambs submitted for slaughter.
Approximately 55 farms submitted sheep to the abattoir in the past export season – this represents just over 60% of all Falkland Island farms. During the most recent export season only one hydatid cyst was found out of a total of 33,000 sheep and lambs killed. This represents a national prevalence of about 0.003%. The prevalence has been at this very low level for many years now but complete eradication appears to be difficult to achieve.
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