Mosquito alert widens to Coromandel

Health authorities are scrambling to contain a mosquito known to carry the Ross River virus after the discovery of three new breeding sites on the Coromandel Peninsula.

The discovery of southern saltmarsh mosquito larvae in a remote area just north of Colville is the latest in the Aussie invader's long line of incursions into New Zealand territory.

The mosquito, which is common throughout Australia's southern coast, was first discovered in Napier in December 1998. Since then, it has been found in Muriwai, Mahia, Porangahau, Whitford, Whangaparaoa and the Kaipara and Mangawhai Harbours, despite a $40 million bid to eradicate the species. The last infestation was found in Wairau last year.

John Gardner, the Health Ministry's deputy chief technical officer, said the discovery was disappointing but demonstrated the efficiency of the mosquito surveillance programme.

"The next few days and weeks are important as this finding will be followed up by intensive surveys to clearly delimit the size of the incursion."

The mosquito is a potential carrier for Ross River virus, which can cause joint and muscle pain, flu symptoms and rashes. Symptoms occur three to 21 days after the mosquito bites and may persist for months or years.

Health authorities are concerned that if the population is left unchecked, a risk exists for an epidemic.

New Zealand and Antarctica are the only places in the world where a local outbreak of mosquito-borne illness has never been recorded.

The latest finds were made by surveillance teams deployed to the area after recent heavy rainfall. The mosquito is believed to have infested an area of about 10ha.

Mr Gardner said people who have seen unusual mosquitoes or had unusual bites should ring 0800 Mozzie (0800 669-943) or the Ministry of Agriculture and Forestry exotic pest and diseases hotline on 0800 809-966.


ROSS RIVER VIRUS

* Australia's leading mosquito-borne illness, infecting about 3800 Australians each year

* Symptoms range from flu-like fever, chills, sweating and headaches to pain in all joints

* Symptoms can last for months or years

* Apart from Antarctica, New Zealand is the only place in the world to have never recorded a local outbreak of mosquito-borne illness