New mosquitoes put city on alert

By Philip English

The discovery of two species of introduced mosquito colonising a part of Napier has put city public health officials on alert as they wait for confirmation of the insects' identity from Australia.

One of the breeds is thought to be a carrier of dangerous Ross River virus in Australia, but no disease outbreak has been reported.

The other species does not usually bite people.

Both mosquitoes have never been present in New Zealand before.

In 1997 the Ministry of Health concluded New Zealand was at risk from new mosquito-borne diseases, but predicted the first cases would be in Auckland or Northland.

The mosquitoes were found breeding in and around the Ahuriri Estuary area north of Napier after locals had complained about being bitten by particularly aggressive mosquitoes.

An Auckland expert has identified both species, which have also been sent to Australia for confirmation of the identification.

Health protection officer Steve Garner said results would be back by the middle of next week.

Any eradication programme would depend on the species being confirmed and a health risk assessment being prepared by Healthcare Hawkes Bay , the Wellington School of Medicine, the Ministry of Health and other specialist advisers.

The mosquitoes, thought to be tolerant of cold weather, lived around briny swamps but Mr Garner said because of the dry, warm weather their numbers were reducing.

The likelihood of disease breaking out seemed low, said Mr Garner.

The Ross River viral infection has a range of symptoms including tiredness, headache, muscle pain, rashes and fever.

The most serious symptom is arthritis in the wrists, knees and ankles, which can last for weeks or months.

No cure is known, so the best precaution is to avoid being bitten.