Pet Cats spread TB to Four People
Two people have developed tuberculosis (TB) after coming into contact with a domestic cat, in the first ever recorded cases of cat-to-human transmission, Public Health England (PHE) has said. There were two additional cases of latent TB, meaning the people had been exposed to TB at some point but did not have an active infection.
Experts stressed that cat-to-human transmission is very rare.
However, PHE said it believed the risk of transmission from cats to humans was "very low".
Professor Danielle Gunn-Moore, a researcher in feline medicine who has been studying the presence of TB in cats, warned that people had become complacent about watching for the warning signs of the disease because there have been relatively few cases in recent years.
“We’ve all become rather complacent because we haven’t been seeing TB for so many years but bovis is back with a little bit more significance,” she said.
“It’s important we don’t get blinkered and think it’s only badgers and cattle that get infected. This is a bacteria that is not very fussy about who it infects.”
She said she had dealt with cases in which dogs had also passed on Mycobacterium bovis to humans.
Nine cases of Mycobacterium bovis infection in domestic cats in Berkshire and Hampshire were investigated by the Animal Health and Veterinary Laboratories Agency (AHVLA) and PHE last year.
PHE said it had offered TB screening to 39 people identified as having had contact with the nine infected cats.
Of these, 24 people accepted screening. Two were found to have active TB and there were two cases of latent TB, which means they had been exposed to TB at some point but did not have an active infection.
Both people with active TB disease have confirmed infection with Mycobacterium bovis.
PHE said there have been no further cases of TB in cats reported in Berkshire or Hampshire since March 2013.
Dr Dilys Morgan, head of gastrointestinal, emerging and zoonotic diseases department at PHE, said: "It's important to remember that this was a very unusual cluster of TB in domestic cats".
Transmission of ‘M. bovis’ from infected animals to humans can occur by inhaling or ingesting bacteria shed by the animal or through contamination of unprotected cuts in the skin while handling infected animals or their carcasses.
Professor Noel Smith, Head of the Bovine TB Genotyping Group at AHVLA, said:
"Testing of nearby herds revealed a small number of infected cattle with the same strain of ‘M. bovis’ as the cats. However, direct contact of the cats with these cattle was unlikely considering their roaming ranges. The most likely source of infection is infected wildlife, but cat-to-cat transmission cannot be ruled out".
Cattle herds with confirmed cases of bovine TB in the area have all been placed under movement restrictions to prevent the spread of disease.
Local human and animal health professionals are remaining vigilant for the occurrence of any further cases of disease caused by ‘M. bovis’ in humans, cats or any other pet and livestock animal species.
Experts stressed that cat-to-human transmission is very rare and the risk of transmission from cats to humans is "very low".
TB is a serious condition but can be cured with proper treatment, namely antibiotics taken for at least six months. The disease mainly affects the lungs but can affect any part of the body, including the bones and nervous system.
Typical symptoms include having a persistent cough for more than three weeks that brings up phlegm (which may be bloody), weight loss and night sweats.
People can also experience a fever, tiredness and fatigue and a loss of appetite.
Usually, TB only spreads after prolonged exposure to someone with the illness, such as living in the same house.
In 2012, 8,751 cases of TB were reported in the UK (unrelated to cats).