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Bovine TB "still threatens human health in the UK"

Bovine tuberculosis (TB) still remains a threat to human health in the UK, although the overall risk of infection is considered to be small, reveals research published in the journal Thorax.

The researchers detail three cases of TB infection arising in rural Cornwall, South West England.

Two confirmed cases arose in a woman and her pet dog. A third case of latent infection occurred in the woman's 12-year-old daughter, who had not been vaccinated against TB.

Before diagnosis, the 42-year-old woman had felt generally unwell for a month and had had a chesty cough.

Neither the woman nor her daughter had drunk unpasteurised milk, recently travelled abroad or had a compromised immune system — all factors associated with an increased risk of M bovis TB infection in the UK.

However, the mother had worked as a veterinary nurse in the South West of England, and the strain of M bovis she had is a common cause of TB in cattle and badgers in this area.

As part of routine procedures, household members were also tested for TB. Only the woman's daughter tested positive, although she did not have any symptoms.

This particular form of TB infection remains "a serious animal health problem in the UK, despite longstanding statutory surveillance and control measures," say the authors.

But they emphasise that their case reports should not cause undue alarm. Despite the rise in the number of cases of TB infection identified in cattle since the mid-1980s, bovine TB infections account for less than 1% of laboratory confirmed cases of TB in people.

Nonetheless, the authors warn that doctors, vets, and public health officials need to remain vigilant for signs of this "often forgotten infection."