By CATHERINE QUINN
Chicken pox ‘hidden’ in our guts since childhood could be behind the thousands of cases of unexplained stomach pain and bloating in adulthood.
New research suggests this ‘intestinal’ chicken pox could even trigger stomach ulcers.
Scientists have known for some time that following exposure during childhood (which may or may not cause symptoms), the chicken pox virus is locked away in nerve cells near the brain and spinal cord.
In most people the virus lies dormant without causing any problems, but sometimes it can break free, travelling via nerve cells to the skin, causing the painful condition shingles.
How and why the virus is unleashed is not clear, but one theory is that a period of illness or a weakened immune system allows it to escape.
But now a study from Columbia University in the U.S. suggests the virus — known as varicella zoster — is also locked away in the nerve cells of the gut.
They believe that when it breaks free, it triggers pain and tissue damage, and could be to blame for unexplained conditions such as irritable bowel syndrome (which causes cramping, bloating and pain).
The idea of intestinal chicken pox is a new one, says Professor Michael Gershon, one of the lead researchers from Columbia University.
‘We are now trying to learn whether disorders of the gastro-intestinal tract that have previously been of unknown origin are, in fact, due to the chicken pox virus.’
The researchers’ conclusions are based on several recent studies. In the first, six children who had all had chicken pox were tested and shown to have the virus lying dormant in their intestines.
More recent studies on guinea pigs confirmed the virus can live dormant in the gut, and can be reactivated when the immune system is low.
In the latest study, six patients with gastric ulcers were all found to have the virus in their gut, following samples taken from their stomach lining.
One patient, a 16-year-old boy suffering with a large stomach ulcer, was found to have the chicken pox virus in all the cells surrounding the ulcer after it was surgically removed.
The research is being presented this week at a scientific conference in Calgary.
Professor Gershon believes the virus could even be responsible for unexplained patient deaths.
The weeping ulcers that chicken pox causes on the skin could be very dangerous when replicated in the stomach and bowel, and could possibly trigger lethal bleeding, he suggests.
He also points out that irritable bowel syndrome tends to occur in older people, raising the possibility that a bout of ‘intestinal chicken pox’ has caused ulcers in their gut lining, and prompted the disorder.
Shingles becomes more common after the age of 70, due to a weakened immune system.
And as well as triggering ulcers, the animal studies also suggested that the viral attack could lead to ‘pseudo-obstruction’, a serious digestive condition where the bowel stops pushing food through the gut.
However, the researchers caution that more human studies are needed to confirm if the virus can trigger this condition in people. Other experts are keen to see the findings expanded.
Pritash Patel, a gastroenterogist at St Anthony’s Hospital, Surrey, and Epsom and St Helier NHS Trust says: ‘Professor Gershon is a leading figure, and the fact that chicken pox in the gut might reactivate over time is interesting.
‘It is certainly possible that some unexplained gut disorders are due to the chicken pox virus.’
Shingles strikes 250,000 Britons every year — one in four people over 50 will develop the condition, although it can affect younger people too.
Symptoms usually begin with muscular pain followed by an intensely painful rash of blisters, usually down one side of the face or body.
These symptoms can last up to four weeks.
Scientists have developed a vaccine against shingles, Zostavax, which is given in a single injection and prevents attacks or reduces their severity.
It was recently reported that the jab could be offered on the NHS to all over 50s as early as next year.
