A new disease has been identified caused by a luminous bug that has evolved in insects, scientists say.
Insects and human immune systems are similar
There have been about a dozen cases of the bug - Photorhabdus asymbiotica - in the US and Australia, which causes pustulant sores to appear on the body.
In insects, the disease leaves the bodies glowing, the University of Bath and London School of Hygiene and Tropical Medicine scientists said.
They are now warning more insect bugs may mutate to threaten humans.
The team believe the sores caused Photorhabdus asymbiotica may also glow but this has not been proved so far as victims have been treated before tests could be done.
The scientists have also said it could be more common than has been reported as it may have been diagnosed as something else.
The findings, revealed in the latest edition of the Nature Reviews Microbiology website, are part of a wider research project looking at the emergence of diseases.
While the infection can be easily treated and is not considered dangerous, the team said bacteria in insects could soon mutate to throw up potentially deadly diseases.
DNA studies have suggested the bubonic plague, which killed millions of people in the 14th and 17th centuries, emerged from insects as does anthrax.
Malaria, a disease closely associated with insects, is only carried by mosquitos, it is not an insect-based disease as the plague was thought to be.
Similarities between human and insect immune systems mean that many of the bacteria that causes insect diseases have a head start in mutating to attack humans.
Dr Nick Waterfield, from the University of Bath, said: "Most scientists are looking at diseases of farm animals as the biggest threat to humans.
"Insects are numerous and reside in close
proximity to man, yet they have been generally ignored as a potential source of microbes that could be harmful for man.
"As well as passing microbes directly into our bloodstream when they bite us, insects can also act as a reservoir to `cook up' future human diseases.
"Understanding the mechanism that the bacteria use to change their disease-causing ability is important if we are to successfully treat emerging infectious diseases before they get out of control and become epidemics."
He also said the situation was being complicated by climate change, which has meant insects can survive and breed in more places.