The UK authorities are hot on the trail of avian flu Photo: Chris C

The discovery of a fourth wild swan infected with avian influenza in England has coincided with accusations that the authorities were slow to diagnose and report the latest cases.

The UK's Department of Food, Environment and Rural Affairs (DEFRA) reported that the highly pathogenic H5N1 strain of the virus had been found in three wild mute swans at a swannery in the county of Dorset on January 10th. However, it has emerged that the first bird was discovered on December 27th, and the other two in the same week. All three were stored at the swannery until January 7th, when samples were sent to the Veterinary Laboratories Agency for analysis.

Avian flu in the UK

› UK finds bird flu in wild swans › H5N1 confirmed in UK › Low path avian flu in Wales

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Secretary of State at DEFRA Hilary Benn has countered that the "collection, storage, transportation and analysis of the samples was entirely consistent with international standards". He added that there was no immediate reason to suspect the disease when the birds were first found, since the level of mortality was not unusual in the local swan population.

DEFRA confirmed a fourth case of the disease on the south coast of England, again in a wild mute swan, on January 16th. The bird was found on January 11th as part of the government's increased surveillance in the area. The department says there is no evidence to suggest that the disease is widespread in the wild bird population.

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• UK finds bird flu in wild swans
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• Low path avian flu in Wales
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