Flesh-eating disease on rise

Otago University researchers have identified a sevenfold increase of necrotising fasciitis and drawn links between infection rates and poverty. Photo / Thinkstock

A "flesh-eating" skin disease is killing more New Zealanders every year than meningococcal disease.

Otago University researchers have identified a sevenfold increase of necrotising fasciitis and drawn links between infection rates and poverty.

Dr Dilip Das and Associate Professor Michael Baker found infection rates had risen from 10 recorded cases a year in 1990 to more than 70 in 2006.

"At the moment, necrotising fasciitis appears to be a very difficult disease to prevent," said Dr Baker.

He said meningococcal disease was more common and a "more important" focus of public health.

However, necrotising fasciitis had a fatality risk of about 21 per cent and killed on average about 10 people each year, compared with the five to eight killed by meningococcal disease.

The study, published in the international Journal of Infection, is the first in the world to assess the societal factors that may increase vulnerability to the disease.

It found that there were 148 deaths in 812 cases of necrotising fasciitis between 1990 and 2006 in New Zealand.

Maori and Pacific Islanders, diabetes sufferers, elderly arthritis suffers and men were the groups most at risk.

"Although this disease remains uncommon, it is feared because of its speed of onset, high fatality rate, and the severe tissue damage it causes."

Necrotising fasciitis can be caused by a cocktail of nasty bacteria, including Group A streptococcus, a bug better known for causing common "strep throat". It can kill in 48 hours.

A patient's ordeal may start with a minor cut before progressing to "excruciating" pain and swelling as toxins released by the tiny bacterium created a gas that dissolves deep soft tissue.

Victims undergo extensive surgery and are often forced to have their limbs amputated to prevent the infection spreading and potentially claiming their lives.

Medical authorities are focusing on meningococcal disease after a raft of infections and several deaths, with Northland offering free immunisation against the disease.