|
|
|
2007-9-3 13:50:00 |
|
Britain on Saturday confirmed its first outbreak of highly virulent bird flu strain H5N1 in domestic turkeys at a farm run by Europe's biggest turkey producer. The confirmation tests, performed by the Veterinary Laboratories Agency (VLA), also showed that the virus, similar to the one found in Hungary in January, is the highly pathogenic Asian strain. Preliminary tests Friday already indicated that an avian flu H5 strain was present in samples from poultry found dead on the infected farm. But it¡¯s unknown whether it is a H5N1 strain until Saturday. There are many types of bird flu viruses, ranging from H1 to H16 among which H5 and H7 are known to be highly pathogenic or virulent and birds are most vulnerable to these two types. The outbreak, first reported on Thursday February 1, has so far killed about 2,500 turkeys at the Bernard Matthews farm near Lowestoft in eastern England. But no human case was reported. A similar outbreak occurred at a farm in eastern France a year ago, killing hundreds of turkeys. The outbreak was contained and no cases of H5N1 were reported in European poultry until last month when the virus killed thousands of geese on a farm in Hungary. In May, another outbreak of bird flu H7N3 led to culling of 50,000 chickens at three farms in Norfolk. In response to the current outbreak, the Department for the Environment, Food and Rural Affairs (Defra) said that all 159,000 turkeys kept alive on the farm would have to be slaughtered to prevent spreading of the virus. Protective measures were already taken on Thursday night after the outbreak was discovered and the appropriate contingency plan has been in place since. The State Veterinary Service has been enforcing a Protection Zone of 3 kilometers radius and a Surveillance Zone of 10 kilometers around the affected farm, according to Defra. Upon confirmation of the H5N1 virus, ¡°a wider Restricted Zone has also been imposed; covering east Suffolk and South East Norfolk bounded to the west and the north by the A140 and A47 respectively,¡± Defra said on its website. Within the restricted zone, poultry keepers must keep their birds from wild birds. Movements of poultry need to be licensed. In the meantime, the national general license on bird gatherings has been revoked and bird shows and pigeon racing will no longer be allowed. Defra also said keepers of birds should be vigilant and exercise good biosecurity. Any owners that suspect disease should act quickly and consult their vet, and report to the local Division Veterinary Manager in the State Veterinary Service. Health officials said the bird flu outbreak does not pose any risk on the public. Avian flu is primarily a disease of birds and extremely close contact with infected birds is needed for humans to get infected with bird flu from sick poultry. The Food Standards Agency advises consumers that properly cooked poultry and poultry products, including eggs, are safe to eat. The World Health Organization (WHO) has advised earlier that in areas free from the disease, people can cook and eat poultry as usual with no fear of contracting the H5N1 virus. The food watchdog says those who handle raw infected poultry are at high risk of bird flu though. They should wash their hands thoroughly and clean surfaces and utensils in contact with the poultry products carefully. The highly virulent H5N1 virus has infected at least more than 260 people, killing more than 164 in ten countries worldwide since 2003 when the virus reappeared in Asia. Government officials and scientists have been worried that the persistent worldwide outbreaks of H5N1 may lead to a mutation in the virus making it more infectious yet less lethal. As a result, it may infect millions of people and kill hundreds of thousands worldwide. So far, the virus has caused deaths or destruction of more than 200 million of domestic poultry worldwide. Migrating wildfowl is believed to be the main vehicle for the transmission of bird flu among birds. The bird flu outbreak in Britain was surprising as the virus was not expected to be so active at this time of year. High activity of the virus should be in spring when migrating birds are expected to come back, according to bird flu expert Colin Butter of the Institute of Animal Health. "The next thing we need to know is if this is a primary or secondary case. If this is a secondary case, it is much more serious. If this is the first case, or 'reference case', and we can stamp it out, the outbreak will be controlled," Butter was quoted by Reuters as saying. |
