Tests in Japan and the Philippines show that after three days with the skin patch, those infected with Mycobacteriumtuberculosis, the germ that causes tuberculosis, develop redness and swelling round it.
Researchers writing in The Lancet do not know exactly why Mycobacterium abscessus - which is distantly related to the bacteria that causes tuberculosis - is more likely to infect people with cystic fibrosis but it could be related to problems with the immune system.