Appendicitis may be triggered by a viral infection



A viral infection could explain why appendicitis appears more common in certain years and during the summer. (Posed by model)

A flu-like virus could be the hidden cause of appendicitis, scientists claim.

Although one in ten of us will experience the condition - in which the appendix becomes dangerously inflamed - doctors have always been baffled by what triggers it.

A viral cause would fit in with another of the researchers' findings - that appendicitis appears to be more common in certain years and during the summer.

The illness occurs when the appendix, a worm-like cul- de- sac connected to the colon on the right side of the body, becomes inflamed.

A perforated appendix that has swollen and burst is life-threatening because the abdomen is filled with infected material. In fact, appendicitis is the most common reason for emergency surgery.

In the latest study, researchers examined American hospital admissions for appendicitis, influenza and gastric viral infections over 36 years.

Their analysis showed appendicitis peaked in the years 1977, 1981, 1984, 1987, 1994 and 1998.

That clustering pattern suggested outbreaks were typical of viral infections.

Seasonal trends were also uncovered, showing a slight increase in the number of appendicitis cases over the summer months.

'The peaks and valleys of appendicitis cases generally matched up over time,' said Dr Edward Livingston, from the University of Texas who led the study. However the scientists ruled out any connection with flu and other common infections, as well as several types of intestinal viruses.

'Though appendicitis is fairly common, it still remains a frustrating medical mystery,' Dr Livingston said.

Other evidence suggested that appendicitis did not always warrant immediate surgery.

The researchers looked at cases of sailors at sea without access to medical facilities and children who could not safely have surgery.

In many instances, their nonperforated appendicitis simply resolved itself.

'Just as the traditional appendix scar across the abdomen is fast becoming history, thanks to new single-incision surgery techniques, so too may the conventional wisdom that patients with appendicitis need to be operated on as soon as they enter the hospital,' Dr Livingston said.

'Patients still need to be seen quickly by a physician, but emergency surgery is now in question.'

Appendicitis was first described as a medical condition in 1886 but debate remains today about its causes and treatment.

Everything from undigested food to high pollution levels has been put forward as a possible cause.

Although the appendix appears to serve no useful purpose, Charles Darwin suggested our ancient human ancestors needed it to digest tough vegetable material such as tree bark.