According to global news reports, U.S. germ-busting microbiologist Dr Charles Gerba has been brought to New Zealand by a cleaning company advising employers on simple steps to reduce staff sick days.

He says regularly sanitising work surfaces with disinfecting wipes has been shown to reduce absenteeism of office workers by up to 30 per cent and school children by more than 50 per cent.

He also says the phone and the desktop are the "germiest" items in the office, with the number of bacteria per square centimetre on a desk top typically 400 times greater than on a toilet seat.