Hydatids – when a dog is not man's best friend
Box 2 | Hydatids vaccine
A vaccine to prevent hydatid disease has been developed at the University of Melbourne. The vaccine uses a protein that is normally contained within the parasite's eggs. The protein was cloned using recombinant DNA methods into bacteria, which can be grown on an industrial scale, so that the Echinococcus. granulosus protein can be obtained in amounts suitable for a practical vaccine.
Initially, the vaccine will be used to prevent infection in livestock species such as sheep, which are commonly involved in transmitting the parasite. However, the project leader, Associate Professor Marshall Lightowlers, believes that the protein is likely to be effective as a human vaccine and plans are under way to carry out human clinical trials. Up to now the vaccine has undergone successful trials in Australia, New Zealand, Argentina and China. Commercial manufacture of the vaccine will be undertaken in a purpose-built factory in China.
However, the use of the vaccine does not mean that hydatid disease will be eradicated – vaccinating livestock will not reduce transmission of hydatid disease through wildlife.
The vaccine will have its biggest impact in those parts of the world where hydatid disease is most prevalent, such as South America, Africa, China and the Mediterranean region. In Australia, it is unlikely that the intensity of hydatid infection in livestock or humans would warrant the use of a vaccine. So for our purposes the other control measures such as control of the availability of hydatid-infected offal, regular 'worming' of dogs and personal hygiene will remain important for prevention of hydatid disease.
Box
Box 1. The life-cycle of E. granulosus
Related site
Molecular
cloning of a vaccine antigen against infection with the larval stage
of Echinococcus multilocularis by Charles Gauci et al (July
2002, Infection and Immunity)
Page updated October 2004.