Yellow fever mozzie found at port

By ANNE BESTON environment reporter

Another disease-carrying mosquito has jumped ship in Auckland, the second time within a month an exotic variety has been found at the port.

Larvae and pupae from the yellow fever mosquito - "one of the world's top nasties," according to a top public health official - were discovered in a rubbish skip at Freyberg Wharf last weekend.

Last month, live larvae and a dead adult Asian tiger mosquito were found at Queen's Wharf.

Health officials are also tracking the spread of the southern saltmarsh mosquito, another potential disease carrier already established in Northland.

The yellow fever mosquito, Aedes aegypti, can infect humans with yellow fever, dengue fever, Barmah Forest virus and Ross River virus.

Some strains of yellow fever and dengue can be fatal.

Samples of the mosquito larvae and pupae have been sent to Australia for identification, said the Ministry of Health's chief technical officer for biosecurity, Dr Bob Boyd.

The skip, surrounding buildings and stormwater drains had been fumigated. Traps had been set but inspection of a 400m zone around the skip had not revealed any more evidence of the mosquito, he said.

Freyberg Wharf handles container cargo and imported used vehicles and Machinery.

The Asian tiger find last month prompted health officials to go on alert at ports in Auckland, Wellington and Christchurch.

The southern saltmarsh mosquito was discovered in Hawkes Bay in 1998, then Gisborne and this year in the Kaipara Harbour.

It was found on the southern side of the harbour in February, and a few weeks later on the northern side.

Health officials are investigating the spread of the mosquito so eradication options can be handed to the Government next month.

All the mosquitoes are potential carriers of a range of exotic diseases including yellow fever, dengue fever and Ross River virus.

The yellow fever mosquito is one of the world's top nasties, said Auckland medical officer of health Dr Virginia Hope. "We really don't want it here. We'd rather we never saw it."

The mild symptoms of yellow fever are flu-like but more advanced symptoms include nausea and vomiting, fever, headache and muscle pain.

Dengue is also known as "break-bone fever," and symptoms include a facial flush, fever, upset stomach and severe restlessness.

Barmah Forest virus has similar symptoms to Ross River virus. Both cause fever, tiredness, painful joints and skin rash. Neither is fatal and most people recover within a year.

New Zealand's biosecurity is under constant threat. The white-spotted tussock moth was found in Auckland's eastern suburbs in 1996, sparking a $12 million aerial spraying programme to eradicate it.

Early last year, the varroa mite, which kills bees, was discovered here. The Government committed $7.6 million to controlling the mite in the North Island after deciding it would cost too much to eradicate.

Other pests to have sneaked in are the painted apple moth (in Auckland) and the aggressive Argentine ant (Tiritiri Matangi Island in the Hauraki Gulf, and Nelson).

Scorpions, African beetles and redback spiders have all caused biosecurity scares and red fire ants, which sting like wasps, were found at Auckland Airport last month.