3 Aug 2005
Exotic mosquitoes intercepted at Ports of Auckland
Auckland Regional Public Health Service staff are responding to the unexpected finding of exotic mosquitoes at the Ports
of Auckland over the weekend [30-31 Jul 2005].
Ministry of Agriculture and Forestry Quarantine staff captured an exotic adult mosquito while conducting their routine
duties at the Port early on Saturday [30 Jul 2005] evening.
An immediate search of the vicinity revealed a number of exotic mosquito larvae on a cargo hatch that had been
off-loaded from a ship that had arrived in Auckland a few days before the find. The specimens that were found were
_Stegomyia aegypti_ (Yellow Fever Mosquito) and _Stegomyia albopictus_ (Asian Tiger Mosquito) [see moderator's comments
on the use of _Stegomyia_ as a genus at end of this post].
The 2 species are known to be able to spread a number of diseases, including yellow fever, which is one of 3
quarantinable diseases internationally, namely, dengue fever and dengue hemorrhagic fever, and Ross River virus. The
Asian Tiger Mosquito can also spread Japanese encephalitis and West Nile virus.
MAF quarantine staff (MQS) took samples for confirmation and treated the immediate site to kill any mosquitoes. MQS
reported the incident to the Auckland Regional Public Health Services staff, who are treating the habitat and monitoring
the area to detect any further mosquitoes.
Deputy Chief Technical Officer from the Ministry of Health, JR Gardner, says, "The cargo hatch that contained the larvae
has been treated and fumigated. The cargo sheds in the area have been fogged to knock down any other adults that might
be sheltering in them. A survey has been conducted in the vicinity of the finding, and any areas where mosquitoes could
live and breed [have] been treated."
"We're confident that these measures have killed any other mosquitoes that might have been (harboring) in the cargo
hatches, but the Regional Public Health Service are maintaining close surveillance around the area and are conducting
further searches for mosquitoes."
Mr. Gardner said Health protection staff have placed a number of larval and adult mosquito traps in the vicinity, and
the Ports of Auckland are assisting with the operation. "The fact that MQS staff detected the adult mosquito and the
larvae within a short time has been a major bonus for us.
This meant that a rapid response followed and improved the chances of achieving an eradication of this potential
hazard. Biosecurity strategy relies greatly on everybody's participation in keeping our borders secure, in this event,
the MQS staff, the Port Company and the Public Health Services have worked closely together," said Mr. Gardner.
"It is essential that the site is closely monitored for the next few weeks, and it is requested that anyone working in
the vicinity of Jellicoe Wharf who notices any mosquito activity, such as insect biting or 'wrigglers in pooled water'
assist by reporting this to the Public Health Services.
The phone number to ring the Public Health Service is 09 2621855. Of the 2, the Asian Tiger Mosquito [_Aedes
albopictus_] would be the greatest challenge to eradicate if it were to become established in New Zealand. This species
had demonstrated an ability to live in new areas, adapting well to temperate climates and feeding on humans, domestic
and wild mammals and birds. The Yellow Fever Mosquito [_Aedes aegypti_], on the other hand, feeds only on humans, is
climate sensitive, and has a limited flight range.
Health protection staff will monitor the traps in the area for a further 3 weeks to ensure that the mosquitoes have not
escaped into the local environment.
Mr Gardner said the fact that the exotic mosquitoes have been detected at the border shows systems are working
efficiently, and it means it is less likely they will spread in New Zealand. Exotic mosquitoes of public health
significance have been intercepted on 40 occasions since January 1998.
ENDS