From Featuring Dr Chris Steele MBE

Pigeons carry harmful diseases

But birds unaffected by germs

Pigeons are often considered to be a pest in public places such as London's Trafalgar Square. Now a new study suggests that there is a good scientific reason to shun them - they carry diseases that can be harmful to humans.

Scientists from the Animal Health Research Centre, Madrid, Spain analysed samples from over 100 pigeons. They found that half of the birds were infected with the bacteria Chlamydophila psittaci and nearly 70 per cent with Campylobacter jejuni.

Both types of bacteria can cause disease in humans. In fact, in the UK and in other countries Campylobacter jejuni causes more cases of acute diarrhoea than infection by the more familiar Salmonella family of bacteria.

Study leader Fernando Esperón points out that while there have been few reported cases of humans becoming directly infected after contact with a pigeon, the bacteria can be spread by aerosols, direct contact or indirect contact through food and water contamination. Therefore pigeons may be directly responsible for infection of humans through these mechanisms.

He further notes that the birds themselves do not show any symptoms of infection, so they may be an unnoticed source of the bacteria. He warned that "These birds may therefore pose a public health risk to the human population"

The study is published in BioMed Central's open access journal Acta Veterinaria Scandinavica.

This article was published on Tue 22 June 2010