An Israeli doctoral student has invented a blood test that could help put an end to the over-prescription of antibiotics.

Antibiotics are meant to treat bacterial infections, but some patients suffering from viral infections - which they do not cure - are told to take them. This is because tests to establish the nature of infections are slow, taking 24 to 48 hours, meaning doctors are faced with either delaying treatment pending tests or incorrectly prescribing antibiotics.

Both options are problematic - if the doctor delays treatment the patient suffers for longer; if antibiotics are given unnecessarily, they can make the patient's body less receptive to antibiotics in the future.

Working with academics at Ben Gurion University, where she is studying for her PhD, 29-year-old Daria Prilutsky has developed a way of examining the glow given off by a patient's blood to determine the nature of an infection in just two hours. So far it has a 90 per cent accuracy rate, and while her test is a long way from reaching the market, when it does "it's going to really help lower the possibility of people resisting antibiotics", said Ms Prilutsky. She also claims that her glow test can give doctors information about the ability of a particular patient's cells to cope with specific treatments.