Control of hydatid disease in Wales

BMJ 1996; 312 doi: (Published 16 March 1996) Cite this as: BMJ 1996;312:674
  1. S R Palmer, regional epidemiologista,
  2. A H Biffin, principal scientista,
  3. P S Craig, professorb,
  4. T M Walters, hydatid disease campaign coordinatorc
  1. a Public Health Laboratory Service, Communicable Disease Surveillance Centre (Welsh Unit), Abton House, Roath, Cardiff CF4 3QX
  2. b Department of Biological Sciences, University of Salford, Salford M5 4WT
  3. c Powys Health Promotion, Health Promotion Unit, Mansion House, Bronllys, Brecon, Powys LD3 0LS
  1. Correspondence to: Professor Palmer.
  • Accepted 5 December 1995


Objectives: To evaluate the success of the south Powys hydatid control programme by analysis of trends in cystic disease in humans and sheep and dog infestation.

Design: A review of hospital admissions for human hydatid disease in 1984-90, abattoir prevalence surveys of hydatid cysts in adult sheep, arecoline acetarsol and coproantigen surveys of prevalence of Echinococcus infestation in dogs.

Setting: All hospitals in England and Wales, three abattoirs, and dog populations in mid and south east Wales.

Subjects: Residents of England and Wales admitted to hospital between 1984 and 1990 with a new diagnosis of human hydatid disease (International Classification of Diseases (ICD), ninth revision, code 122) acquired in the United Kingdom.

Results: The average annual incidence of human hydatid disease in Powys, mid-Wales, fell from 3.9 x 10-5 in 1974-83 to 2.3 x 10-5 in 1984-90. Age specific incidence rates in Wales declined over this period only in children, and no cases occurred in children (<15 years) in Powys. Two Welsh children who lived in Gwent and mid-Glamorgan were infected. Prevalence of hydatid cysts in old sheep from south Wales declined during the control period, but in 1993 prevalence of cysts was 13%. Prevalence of E granulosus infestation was zero in the control area in 1993, but it was 2.4% in Powys dogs outside the control area in 1989 and 9.2% in dogs in Gwent in 1991.

Conclusions: Human hydatid disease has been successfully controlled in south Powys but cystic echinococcosis is still endemic in sheep in mid-Wales, and there is a focus of infection in humans, sheep, and dogs in the bordering areas of Gwent and mid-Glamorgan. There is considerable potential for an upsurge in human cases if control measures are relaxed.

Key messages

  • Humans are infected by ingesting eggs of the dog tapeworm, which the dog acquires by eating sheep offal containing hydatid cysts

  • Regular dosing of dogs with praziquantel has eliminated infestation of dogs in the control area and reduced prevalence in sheep

  • No cases in children occurred in Powys, but there were cases outside of the control area in Gwent and mid-Glamorgan

  • Prevalence of hydatid cysts in old sheep in Powys and Gwent is still high and control measures must be continued and the control area extended


  • We thank Dr Tony Swan, PHLS, for statistical advice.

  • Funding Powys Health Authority and Welsh Office.

  • Conflict of interest None.

  • Accepted 5 December 1995
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