TB Questions Answered on the Disease in Cattle

Article excerpt

THERE has been much discussion recently with regard to TB and cattle, how it is spread and what, if any, the effects can be on humans.

Following several calls to the Farming Life office after an article in FL2 on Wednesday, December 18, Farming Life's RICHARD MULLIGAN gives a brief overview on the disease and its links (Source: National Farmers' Union) in a hope to answer some of the questions raised.

What is TB?

TB is disease caused by types of bacteria. It most usually affects the lungs. The strain of TB most commonly caught by humans is not the same as that caught by cattle - bovine TB - though humans can also catch bovine TB. This is most unusual in Britain.

How can you catch bovine TB?

Bovine TB is rarely found in humans and the government believes that those few cases that have occurred in the UK were contracted overseas or through unpasteurised milk. Though theoretically TB can be transferred to those working closely with cattle, no such cases have been found in the UK.

What precautions are taken against the transfer of TB to humans?

All milk sold in shops is pasteurised, which kills the TB bacteria. This eliminates any risk to human health. Unpasteurised milk, such as that sold in farm shops and labelled as unpasteurised, will come from herds free of TB.

When meat is cooked bacteria are killed and therefore the risk of the disease being transferred through meat from infected cattle is negligible.

All herds are regularly tested for TB, with tests of each herd taking place every one to four years.

In addition, the Meat Hygiene Service conducts random TB tests on slaughtered animals. If the disease is discovered the herd from which the animal comes will be placed under movement restrictions and tested.

Why is it important now?

Levels of bovine TB have been increasing in recent years. This is why the Government has initiated extensive research into the disease and its spread.

Why are badgers thought to spread the disease?

It is not always clear how TB spreads. However, TB is known to spread where there has been no obvious cattle to cattle contact such as in closed herds, or the disease appeared to have jumped a significant distance.

Badgers may not be the only potential vector for the spread of the disease, with birds, deer and cats all being suspects too.

What is the Krebs trial?

In 1998 the British Government set up a trial - known as the Krebs trial - to try to establish the best means of controlling the spread of TB in cattle. The trial is designed to find out if badgers help to spread the disease, and if so what proportion of the disease is due to badgers, and whether culling badgers is a cost-effective way to control the spread of the disease.

By culling badgers in certain areas and testing the badger carcases for TB, the Government hopes to establish the relationship between badger colonies and disease levels within them, with the levels of infection in cattle. …