Researchers from the Ondokuz Mayis University in Turkey led by Fatma Ulger tested the phones and dominant hands of 200 doctors and nurses working in hospital operating rooms and intensive care units.

Ninety-five percent of the mobile phones were contaminated with at least one type of bacteria, with the potential to cause illness ranging from minor skin irritations to deadly disease.

Nearly 35 percent carried two types of bacteria, and more than 11 percent carried three or more different species of bugs, the study found.

Most worring, one in eight of the handsets showed methicillin-resistant Staphylococcus aureus (MRSA), a virulent strain that has emerged as a major health threat in hospitals around the world.

Only 10 percent of staff regularly cleaned their phones, even if most followed hygiene guidelines for hand washing, the study noted.

"These mobile phones could act as a reservoir of infection which may facilitate patient-to-patient transmission of bacteria in a hospital setting," the authors warned.

Several strains of drug-resistant bacteria are generally harmless to healthy people but can become lethal to hospital patients in weakened conditions. The bacteria slip into open wounds and through catheters or ventilator tubes, typically causing pneumonia or bloodstream infections.

The researchers noted that more studies were needed to confirm their findings, which were based on a relatively small sampling.

But they called for commonsense measures to help reduce the risk of contamination, especially frequent cleaning of phones with alcohol-based disinfectants or the use of anti-microbial materials.

Banning phone use in hospital settings is probably not practical, they concluded, because the devices are often used for work in emergencies.

The study was published in BioMed Central's Annals of Clinical Microbiology and Antimicrobials.

In the United States, where national statistics are available, MRSA is the cause of more than 60 percent of all hospital infections. According to the Centers for Disease Control and Prevention, MRSA in 2005 infected 94,000 people and killed 19,000 in the United States.

(c) 2009 AFP