Dengue Fever outbreaks in northern Pacific

Medical authorities say a dengue fever outbreak that has claimed at least two lives in the northern Pacific has peaked.

In the state of Yap in the Federated States of Micronesia more than 900 people remain infected, while in Marshall Islands where 1,400 people were infected just a few new cases are being reported each day.

A World Health Organisation medical epidemiologist based in Suva, Dr Eric Nilles says there's no connection between the outbreaks as they are different strains of the fever.

Presenter:Brian Abbott Speaker:Dr Eric Nilles, medical epidemiologist, World Health Organisation, Suva

BA: Dr Eric Nilles, a medical epidemieologist with the World Health Organisation in Suva.

Listen: Windows Media

NILLES: In the Marshall Islands the situation has improved significantly, they have had almost 14-hundred suspected cases but the number now is down to just a few cases per day, down from about 40 or 50 cases per day, so the situation has significantly improved in the Marshall Islands. In Yap in the Federal States of Micronesia it appears that has also peaked the outbreak and now is starting to decline as well. So actually in both countries the situation is improving. Maybe one thing I should clarify is that the type of dengue in the Marshall Islands is not the same as the type of dengue in Yap in Micronesia, so these are not related actually, so it didn't spread from one to the other, they came independently, most likely from Southeast Asia where all of the four zero types of dengue do circulate all year round.

ABBOTT: Are those two types of dengue fever current anywhere else in the Pacific?

NILLES: Well in general type four and type two of dengue have been circulating in the Pacific for about the past ten years. So there are often cases throughout the Pacific of these two zero types, it's not unusual. Actually type two we have not seen really in the Pacific for over ten years, 12, 13 years, something like that, and in some countries even longer actually. So the type two zero type we have not seen this is this time new since the late 90s.

ABBOTT: What's the reason that this outbreak has continued two to three months, that seems a long time?

NILLES: Well it's a whole host of factors actually, it depends on how effective the mosquito is at transmitting it, it depends on the density of the population, and on a lot of other environmental ecological factors. But this is not a particularly long outbreak. The one in Yap in Micronesia actually started really at the beginning of September, so that has continued on for quite a long time considering the size of the population there. But the outbreak in Marshall Islands actually peaked quite rapidly and then declined relatively quickly as well. So although they have been going on for several months, it takes time for these viruses to circulate around the population, so it's not particularly surprising that we're still seeing some cases at this time.

ABBOTT: Does the length of the outbreak say anything about mosquito control in Yap or Marshall Islands?

NILLES: Well there's probably lots of places that we could improve mosquito control, it's much easier said than done, it requires a lot of resources to really do it effectively, and they're certainly working on that now. But in general if there's lot more mosquitoes then you can expect to see a more explosive type of outbreak. If there's few mosquitoes then a more gentler outbreak. But again there's so many variables that go into this equation that it's hard to boil it down and simplify it too much.