(with praziquantel (PZQ) from 1979) and the application of strict importation regulations (Beard et al., 2001). Iceland has been considered free of E. granulosus since the 1970s, after previously (1880s) having the highest national prevalence ever recorded worldwide. The Iceland hydatid campaign was the first in the world, and succeeded, in large part through health education, to eliminate parasite transmission and human CE from the country. Though elimination took more than 100 years, human CE incidence fell dramatically within 30 years of the distribution in 1864 of Krabbe’s booklet on E. granulosus and hydatid disease. Educational programmes, however, without a vertical control effort directed against dogs, have not been successful in reducing CE transmission in other regions of the world (Craig and Larrieu, 2006). Echinococcosis control in Australasia (from 1959) E. granulosus and human CE remain endemic in mainland Australia, especially in eastern regions (Gemmell, 1990; Jenkins, 2005). Human CE, however, was also formerly an important public health problem in New Zealand and Tasmania, but both island territories declared that hydatid disease was eliminated from their islands by 2002. This was the result of wide-scale well-organized government-backed hydatid control programmes implemented between 1959 and 1997 (New Zealand) and 1964 and 1996 (Tasmania) (Craig and Larrieu, 2006). Human CE in New Zealand was recognized as a public health problem towards the latter part of the 19th century and was made a notifiable disease in 1873; emphasis was also placed on health education (as was done in Iceland). Intensified health education from 1938 to 1958 also provided free arecoline for owners to dose their dogs every 3 months, and the 1940 Meat Act made it illegal to feed raw offal to dogs. However, despite this health education approach, in the late 1950s nearly 50% of sheep remained infected, including >80% of sheep ranches surveyed, and human CE incidence in rural areas was 11.8 surgical cases per 100,000 (Gemmell, 1990). As a result, a National Hydatid Eradication Council (Hydatid Act 1959) was formed, with local authorities applying the day-to-day control measures; this was funded through a local dog tax added to the normal dog licence fee. Overall this ‘attack’ phase lasted about 32 years (1959–1991) and initially involved supervision of dog registration and the application of arecoline hydrobromide by technicians to detect dogs infected with E. granulosus (or Taenia hydatigena), and to penalize owners. Dosing was applied up to four times yearly over 13 years (1959–72), and later under the more effective direction by the Ministry of Agriculture through 6-weekly dosing (niclosamide initially then PZQ after 1978). During this period in New Zealand, transmission of E. granulosus from dogs to humans virtually ceased (Meslin et al., 2000) and the national ovine CE prevalence by 1980 was only 0.43%. In 1990 movement control of livestock and slaughterhouse surveillance (including diagnostic histology for very small lesions) with trace-back was introduced as key elements of a ‘consolidation’ phase of control after dog dosing had ceased. A ‘maintenance of eradication’ phase was reached in New Zealand in about 1998 and consisted of permanent surveillance of livestock at meat inspection, together with restrictions to re-entry of the parasite in livestock (Gemmell and Lawson, 1986; Gemmell, 1990). The Australian island State of Tasmania adopted a very effective hydatid control programme (1964–1996) at a time when human CE incidence was >25 per 100,000 in the rural population. The Tasmanian programme differed in four important aspects from the New Zealand hydatid control scheme, which resulted in a shorter ‘attack’ phase (11 years in Tasmania versus 32 years for New Zealand) (Craig and Larrieu, 2006). These were: (i) funding and management was by the Department of Agriculture from the outset; (ii) mobile dog testing/purgation (with arecoline) units were used to visit farms annually (with added value for educational aspects), rather than purge samples being sent to a central testing laboratory (as was done in New Zealand); (iii) dog testing was confined to rural dogs only; and (iv) farms with positive dogs were quarantined under strict State legislation (Beard et al., 2001). No human CE cases occurred in the under-20 years age group in Tasmania after 1976; ovine CE prevalence reduced from 52% to 3.4% in older sheep by 1978, and dog prevalence dropped from >12% to 0.06% by 1981–85 (Beard et al., 2001). Two small outbreaks of CE in local livestock have occurred in Tasmania since 1990, in 1997 and in 2009. Both may be associated with import of infected dog(s) from the mainland (D. Jenkins, pers. comm.). Echinococcosis control in the Falkland Islands (from 1965) and Cyprus (from 1971) CE was first recorded in the Falklands in a sheep in 1941 (probably introduced), but by 1969 slaughter records showed a prevalence of 59% (Whitely, 1983). The first local human CE cases were recorded in 1963 with an equivalent annual incidence of 55 cases per 100,000 for the period 1965–75 (Bleany, 1984). Hydatid disease control was introduced in the Falklands in 1965 (Tapeworm Eradication Dogs Order). This order made provision for: (i) the appointment of dog inspectors; (ii) the purging of dogs with arecoline acetarsol (Tenoban); and (iii) prohibiting the feeding of raw offal to dogs. From 1970, under a second Tapeworm Eradication Order, dog-dosing was undertaken every 12 weeks with bunamidine hydrochloride and from 1977 was replaced with PZQ every 6 weeks. Drugs were paid for by owners initially, then PZQ was provided free; dosing continued at least until 2011. Strong reliance was also placed on offal disposal and confinement of dogs unless being worked. Legislation was updated by the Hydatid Eradication (Dogs) Order 1981. By 1981 ovine CE prevalence was 1.8% and further reduced to 0.16% in 1993 (Reichel et al., 1996). Unfortunately no pre-control dog data exist. The only dog prevalence data refer to coproantigen ELISA testing done in 1992–3 when 1.7% of 464 dogs were positive (Reichel et al., 1996). The last human CE case (old case) was reported in 1992 (S. Ponting, pers. comm). In the Falklands, several permanent measures remain in place, which have kept echinococcosis at very low transmission or district level elimination. These include: (i) a national dog registration scheme with notifications of transfer to new owners, births, and deaths to the Department of Agriculture; (ii) coproantigen tests applied periodically to dog populations; (iii) retention of 6-weekly supervised dog treatment with PZQ; and (iv) retention of safe offal disposal and surveillance through meat inspection and restrictions to parasite re-entry (Gemmell and Roberts, 1998; S. Pointing, pers. comm.). In 2010 a suspect hydatid cyst in a 7-year-old sheep was confirmed by DNA analysis to be E. granulosus (sheep G1 genotype), and only 2/563 (0.004%) of dog faecal samples were coproantigen positive, including one dog positive for E. granulosus copro-DNA (S. Ponting, B. Boufana, P.S. Craig, unpublished). In the 1960s, the annual surgical CE incidence on the island of Cyprus was 12.9 per 100,000; ovine CE prevalences ranged from 25% to >80% in aged ewes, while 14% of farm dogs were infected (Economides et al., 1998). A national hydatid control programme was introduced into the Republic of Cyprus in 1971 under the Ministry of Agriculture. The intervention emphasis (i.e. attack phase) was primarily focused on the reduction/elimination of stray dogs (85,000 killed between 1971 and 1985), and obligatory field-testing with arecoline every 3 months for registered owned dogs, with euthanasia of all E. granulosus purge-positive dogs (Polydoru, 1993). A public health education programme was also instigated, together with strict slaughter controls and meat inspection (Economides et al., 1998). Total dog prevalence reduced from 7.4% to 0.75% by 1977 and by 1984–5 zero (0/36,000) dogs were infected after arecoline testing; in addition, no human CE cases under 20 years of age were diagnosed. It should be noted that after 1974 the campaign was continued only in the area controlled by the Government of the Republic of Cyprus. Eradication was claimed in 1985, with cessation of activities in the Government Controlled Area (GCA) (Polydorou, 1993). Following a reappraisal in 1993–1996, however, it was found that the parasite was still present sporadically in livestock in 21% of villages and in 0.6% of dogs purged in the GCA.
Open Next Page To See More