Big increase in potentially fatal necrotising fasciitis disease

There has been a significant increase in necrotising fasciitis (NF) or ‘flesh-eating disease’ in New Zealand between 1990 and 2006 according to the first ever nation-wide assessment of the incidence of this disease.

University of Otago, Wellington researchers, Dr Dilip Das and Associate Professor Michael Baker, have shown that NF has risen from fewer than 10 cases a year in 1990 to more than 70 cases a year in 2006. The study has just been published in the international Journal of Infection

Necrotising fasciitis is a severe bacterial infection commonly caused by Group A Streptococcus (GAS). It results in the rapid destruction of soft tissue, with most severely affected people requiring extensive surgery and sometimes amputation of limbs to prevent infection spread.

The study identified 812 NF cases between 1990 and 2006, of whom 148 died, giving a 21% fatality risk.

“Although this disease remains uncommon, it’s feared because of its speed of onset, high fatality rate, and the severe tissue damage its causes,” says Associate Professor Baker.

“This infection can follow from just a minor skin injury or wound. If anyone is suffering severe local pain and fever following even a small skin wound they should immediately see a doctor,” he says.

“The pain is caused by a very rapid spread of the infection into deep soft tissue and is not always obvious from first inspection of the skin. Rapid treatment is absolutely vital to save lives with NF.”

This research found that Maori and Pacific peoples are particularly vulnerable, as are older people, and males compared to females. The reasons why these groups have higher rates of NF is not clear at present.

The rise in NF is part of a worrying increase in serious infectious diseases in New Zealand, says Associate Professor Baker. This paper follows a release from the University of Otago, Wellington earlier in the year (April 27) that identified nearly a 100% increase in hospitalisations for serious skin infections in children since 1990.

Associate Professor Baker says that the causes of the NF increase are not known, but may include greater virulence of the infecting bacteria, decreased resistance because of other chronic illnesses, environmental factors such as a rise in household overcrowding, and decreased access to health services because of rising socio-economic inequality.

He says the causes for this increase need further research to identify prevention measures.

This study was funded by the Ministry of Health.