By Laurie Sullivan
Travelvax Australia has renewed its advice to Australians holidaying in the Pacific this summer to be on guard against mosquitoes.
The new warning comes as a World Health Organisation (WHO) expert this week predicted that the Chikungunya epidemic sweeping through the region could continue island-hopping for another 2 years, potentially reaching some island nations for the first time.
Outbreaks of Chikungunya are often widespread and protracted.
A year on, the epidemic spreading across the Caribbean and the Americas has now killed at least 155 people and sickened over 900,000 others – with no sign it will ease soon.
In the Pacific, the viral disease has now taken over from two other circulating mosquito-borne viruses – dengue fever and Zika virus – as the region’s principal mosquito-borne health risk.
Disease is sweeping through region
Successive Pacific nations have felt the impact of the painful and debilitating disease this year, including:
FRENCH POLYNESIA – 4 people have died, over 18,000 treated, and more than 200 hospitalised in the past 7 weeks. As well as the heavily impacted main islands of Tahiti and Moorea, Chikungunya is now moving on to smaller islands in the group, such as Raiatea and Bora Bora, as well as the Leeward Islands. French Polynesian communities have experienced concurrent outbreaks of Chikungunya, dengue, and Zika this year.
SAMOA – Over 2000 confirmed cases and many more unconfirmed infections have been recorded and all areas of Samoa are now affected. Worryingly, the rainy season has now begun, meaning more mosquitoes and more cases.
NEW CALEDONIA – Noumea is one of the next ports-of-call for the Chikungunya epidemic, with cases already being imported by infected travellers arriving from French Polynesia.
AMERICAN SAMOA – More than 800 probable cases were reported in the US territory between July and October.
TAKELAU ISLANDS – A significant, first-time outbreak in October led to a health emergency in the tiny island group, an overseas territory of New Zealand.
TONGA – Tonga’s first-ever epidemic of Chikungunya saw more than 10,000 people receive treatment for symptoms in April. It was the first recorded outbreak in the South Pacific area.
YAP – More than 1000 people were infected in the second half of 2013 and early 2014.
Disease cycles bring long-running epidemics
While Chikungunya is relatively ‘new’ to the Pacific, during the last 50 years outbreaks and epidemics have taken place in West, Central and Southern Africa, SE and South Asia, Europe (Italy, 2007), and the island nations of the Indian and Pacific oceans. Major epidemics occur in cycles ranging from every 7-8 years to as long as 20 years, with half the local population in an outbreak area experiencing symptoms.
Since 2005, more than 2 million cases have been reported in Southeast Asia – our favourite holiday region. The disease bobbed up for the first time in the western hemisphere on the Caribbean island of St Martin last December.
The rapid spread of Chikungunya in the Pacific is not surprising. Aedes aegypti and Aedes albopictus (the so-called ‘Asian Tiger’ mosquito) are well established across the region, including Australia’s north.
Both also transmit dengue fever in the world’s tropical and sub-tropical countries, as well as yellow fever in much of Africa and South America. Other local mosquitoes such as Aedes polynesiensis or Ae. hensilli are also known to transmit the viruses in the Pacific.
Costly outbreaks disrupting vital tourism
Along with the threat of Ebola arriving by air from West Africa, Chikungunya is now one of Oceania’s major public health issues, according to the Dr Eric Nilles, a WHO epidemiologist based in Fiji.
“We predict that we will probably continue to see this wave for the next one to two years,” Dr Nilles told NZRadio this week.
Chikungunya was high on the agenda as the Pacific’s senior health officials met in Fiji to discuss the implementation of international health regulations. While Fiji had a major outbreak of dengue earlier this year, authorities there have not reported local cases of Chikungunya.
The ongoing outbreaks of mosquito-borne diseases are straining the limited public health budgets of the small, island nations and impacting on vital tourism income.
Outbreaks may occur at short notice
Long before Asia became Australia’s number one holiday playground, the fabled Pacific islands were among our favourite destinations. The love affair continues.
“Besides their tropical beauty, Australians love the Pacific islands because they don’t involve long-haul flights and offer good holiday value – especially for those living on the eastern seaboard,” said Dr Eddy Bajrovic, Medical Director of Travelvax Australia.
“They are also more laid back and child-friendly than other holiday destinations.
“But, outbreaks of the Chikungunya, dengue or Zika viruses can begin abruptly and develop quickly. And, there’s no vaccine or preventative medication for them.
“Travellers need to be on guard anytime they are outdoors during the day. A personal repellent should be every traveller’s first line of defence – whether they are on a cruise stopover lasting a couple of hours or staying a couple of weeks.”
Some travellers more susceptible
The word ‘Chikungunya’ is derived from a Tanzanian word in the Kimakonde language, meaning ‘to become contorted’ and describes the stooped appearance of sufferers with joint pain.
For many people Chikungunya is painful, but generally mild. Symptoms typically include fever, joint and muscle pain, headaches, nausea, fatigue, and a rash.
However, pregnant women, young children, the elderly, and people with chronic diseases are more likely to experience more severe illness.
Both Aedes species bite during the daylight hours and live and breed in urban setting close to humans – their favourite source of the bloodmeal females need to lay eggs. The female mosquito takes in the virus when she bites an infected person and passes it on to the next person she bites.
Dr Bajrovic said it’s especially important that travellers are aware of the latest mosquito disease threat if they are visiting the region this summer and take steps to avoid mosquitoes bites.
Avoid bites and prevent infection
Travelvax advises travellers to:
– Use an insect repellent containing an effective active ingredient (DEET, Picaridin (KBR 3023), oil of Lemon Eucalyptus/PMD, or IR3535) and use as directed. (If you will also be using sunscreen, apply it BEFORE you apply insect repellent.)
– Wear loose, long-sleeved shirts and long pants when outdoors – especially in the early morning and the evening (the peak times when mosquitoes feed).
– Move inside at peak mosquito feeding times – especially around dawn and dusk.
– Check around your accommodation for anything that may hold even a small amount of water that mozzies could breed in. Either remove it or turn it over so it can no longer serve as a nursery for mozzie larvae.
– If you are staying in budget accommodation (no window or door screens, and no air-conditioning) sleep under a permethrin-impregnated bed net. You can buy a treated net or a DIY kit to treat your own net, along with clothing.
Travellers who develop a fever and aching joints after arriving home should see their doctor without delay, telling them about their recent travel.
Clearly, getting Chikungunya is no fun and best avoided. If there is one positive it’s that, unlike dengue fever, you can only get it once.
Travelling the tropics? Get more advice on recommended vaccinations, insect-borne diseases, and other issues specific to your destination from Travelvax Australia’s travel health information service on 1300 360 164 (toll free from landlines within Australia).