When all four of Taloa Lam Shong's children were struck down with dengue fever in Samoa, she was on high alert.
"I was scared and worried, knowing dengue fever had claimed children's lives," she said.
Nearly 8,000 people have been diagnosed with the disease in Samoa this year, with children accounting for more than 70 per cent of cases, and six deaths reported.
"Many of our people have been infected with dengue fever, but I believe the children have borne the heaviest burden, as it has tragically claimed their lives," Ms Shong said.
Cases are escalating fast in Samoa, which recorded more than 1,900 clinically diagnosed dengue cases last week.
The Pacific's health authorities are scrambling to contain its spread across the region. It has killed 18 people, and the World Health Organization (WHO) says it is the largest outbreak in at least a decade.
"This year has been another big peak of dengue, but the peak has been much bigger than any of the other peaks we've seen before," said Mark Jacobs, director of Pacific technical support at the WHO.
Dengue fever is a viral infection transmitted between mosquitoes and humans, and outbreaks are often triggered by an infected person entering a country.
When local mosquitoes bite them, they later transmit the disease by biting other people.
Symptoms of dengue fever include high temperature, muscle aches, joint pain, nausea and vomiting.
While most people recover within a week, in some cases worse symptoms arise after seven days — a sign that severe dengue fever is developing.
"Really bad stomach pain, lots of vomiting, really rapid breathing, you can get bleeding from your gums, nose, or in your bowel movements, or in vomit," Dr Jacobs said.
Samoan authorities are trying to contain the disease, fumigating schools and other facilities, and warning the public to take precautions.
"It is important to heed the advice from the Ministry of Health," Samoa's prime minister, Fiame Naomi Mata'afa, said in a video broadcast online last week.
"Please seek immediate medical assistance if your child develops dengue fever symptoms, do not wait until it is too late.
"Early treatment can save lives."
Climate makes Pacific vulnerable to outbreak
Experts say dengue fever has spread across the Pacific as people carrying the infection have travelled across the region.
American Samoa, Tonga, French Polynesia, Kiribati and Tuvalu are grappling with cases.
And in Samoa, Cook Islands and Nauru, the outbreak is still growing.
In Nauru, the government said a 15-year-old boy and seven-year-old girl died on July 31 from dengue fever.
Dr Jacobs said there had been 23,500 suspected cases of dengue fever, and more than 16,000 laboratory confirmed cases, across the Pacific this year.
He said the region's climate made it vulnerable to outbreaks.
"It can be easier for the mosquito to breed faster, or to pass on the virus to somebody when there's the right combination of temperature and humidity," Dr Jacobs said.
Fiji has been the worst-hit among Pacific countries this year, reporting more than 14,000 suspected cases and 11,000 lab confirmed cases.
But the outbreak in Fiji has peaked already and case numbers are decreasing.
Its tourism authority has warned visitors to take precautions, and says Fiji's popular tourist areas and resorts are treated for mosquitoes.
"If they're coming across to Fiji and they're staying in a modern resort or island resort or similar to that, the owners, general managers and staff of those locations are taking all the precautions they possibly can and putting a lot of things in place," Tourism Fiji chief executive Brent Hill said.
"We haven't had too many reports [of infection] coming back from tourists.
"We take it seriously and we try and do everything we can to minimise the risk.
"Sadly, the prevalence of dengue fever in places like Fiji is often in our villages and often in parts of Fiji where tourists don't go."
'No bite, no dengue'
Dr Jacobs said it was estimated about half the world's population lived in areas at risk of dengue fever, and that 100 to 400 million cases were recorded each year.
While there are no medications for it, experts say there are simple ways to avoid infection, including:
- Wearing long-sleeve and loose-fitting tops and trousers
- Covering windows and doors with screens at home
- Wearing effective insect repellent
- Using mosquito coils indoors
- Removing any still or stagnant water used by mosquitoes as breeding habitats
"If you don't get bitten by mosquitoes, you don't get dengue," Dr Jacobs said.
But he said people were not protected from severe cases if they had previously had dengue fever.
"If you're getting dengue for the second time, you're much more likely to get severe dengue," he said.
Dr Jacobs said anyone experiencing symptoms of severe dengue fever needed to act quickly.
"If you go off and you get good quality care, then you're much less likely to die as a result of that."
Dengue research
As the world awaits vaccines and medications for dengue fever, scientists looking to eliminate the disease are putting their hopes in bacteria called Wolbachia that live inside insects.
University of Melbourne research fellow Perran Ross said they could block the transmission of viruses spread by mosquitoes.
"It actually alters the reproduction, so that when the male mosquitoes have Wolbachia and the female mosquitoes don't, they don't produce any viable offspring," he said.
"If you get enough mosquitoes in the wild that carry the Wolbachia, that can actually reduce their ability to spread viruses."
Dr Ross said it had been used in places like Queensland, and was the reason the state no longer had local dengue transmission.
"The bacteria that are being released around the world, it's reducing dengue by more than 50 per cent in some locations," he said.
But Dr Ross said climate change was complicating efforts to control dengue fever, by increasing the number of habitats where disease-carrying mosquitoes could live and breed.
"We do expect dengue to get worse as things get warmer and wetter," he said.
In Samoa, families are monitoring for symptoms of dengue fever.
"Many children in our family were infected with dengue fever, including all five of my sister's children and my 15-year-old daughter," Faalaniga Repoamo, a mother of six, said.
"When our daughter was sick, we didn't leave it until it was too late, we saw the symptoms and rushed her to seek help.
"Parents should stay alert and identify the symptoms early and take them to the hospital before their condition worsens."
