See More on Facebook

Analysis, Environment

Could data help us tell Dengue’s future?

Scientists and officials are looking for new ways to use data to predict the deadly disease.


Written by

Updated: August 27, 2019

 

2019 is one of the worst years for dengue outbreaks.

In the Philippines more than 622 people—most of whom are children under five years old—have died from dengue so far this year.

The country is seeing more than 5,100 new cases each week. In at least one province, tents are serving as makeshift treatment centers to deal with the crush of patients. The Philippines declared the outbreak a National Epidemic in August.

The Philippines isn’t alone.

In Bangladesh, the dengue outbreak is the country’s worst ever.

The sheer number of dengue patients—some days there are more than 2,000 new cases in just a 24 hour period—is placing immense strain health systems. There’s been a shortage of the quick-test kits that are able to detect early stages of dengue. Demand for blood and platelets is reportedly outstripping the supply at many donation centers.

In Cambodia, representatives of one hospital say the outbreak has the potential to be the worst they have seen since the hospital opened 20 years ago.

Angkor Hospital for Children has treated more than 2,937 dengue patients thus far in 2019—42 percent more than the same time in 2012, which was previously the hospital’s worst dengue year on record.

And the cases are more severe than normal.

“Usually with dengue, the severe cases are around 10 percent of admissions,” Dr. Ngeth Pises, Angkor Hospital’s medical director told Asia News Network.

“But this year, more than 50 percent of cases have been hospitalized. We have seen more serious cases than ever,” he added.

The hospital is running out of room for patients, and has resorted to setting up mattresses on hallway floors.

Not all dengue years are this bad. One of the key hallmarks of the disease is that peak outbreak years come in cycles, usually around 3-4 years apart. But, scientists don’t fully understand why that is or, even more crucially, how to predict when and where a major outbreak is coming.

And that means that even where dengue has long been endemic, places like the Philippines, Bangladesh, and Cambodia can be caught off guard.

That’s partly to do with the unique ways the dengue virus works. But it’s also partly because of issues with our data collection: to predict dengue, we need better data and more of it.

Richard Maude is the head of the Epidemiology Department at Mahidol-Oxford Tropical Medicine Research Unit. His Bangkok-based team provides support to governments in Thailand, Myanmar and indirectly in the Philippines. One of the forms that support takes is mathematical modelling.

The team is using new approaches to account for variables that have otherwise been difficult to account for—the movement of people, for example—to develop models intended to predict future dengue outbreaks.

To create a Thailand-specific model  takes humans and their comings and goings into account, Maude and his team turned to the data-creation devices we all keep in our pockets: our cell phones.

Maude’s team took data from Thai phone users that has been scrubbed of identifying information, turned that information into matrices of how much people are moving and plugged it into a model that cross-references that data with the locations where the dengue virus has cropped up over time.

The real measure of success for a model like this one, Maude says, is that “these predictions have to be good enough that the government could then use it to make a plan, to act on the predictions.”

If governments know when a bad year is coming, for example, they might be able to prevent the shortages of dengue tests and hospital beds that are happening right now in Bangladesh, Cambodia and the Philippines.

But there’s a lot of work that still has to be done before a model like this one can be used in that way.

“The performance of these predictive models is good in some locations and it’s not so good in others and you end up with lots of different models that work in different areas.”

So far, “there is no single predictive model that will accurately predict dengue,” said Maude.

“One of the reasons for that,” Maude explained, “is because there’s multiple different factors affecting the likelihood of having a dengue epidemic and those factors are not necessarily well understood.”

And, complicating the matter further, factors that logically should indicate increased risk of dengue don’t always work in predictable ways.

For example: “We know you can get large numbers of dengue mosquitoes [in this case Aedes aegypti] and then not have lots of dengue in some places, it doesn’t always follow,” Maude said.

Maybe the biggest problem holding these predictive models back is the data.

“We know about rainfall driving mosquito numbers, we know that people spread dengue when they travel around,” said Maude. “But there’s also things that we are not able to include—like immunity to dengue over time in the population.”

Data about population immunity are critical to predicting how dengue will circulate through a community, as well as how severe those cases will turn out to be. Patients who recover from an infection of one dengue serotype will have lifelong immunity against that particular strand of the virus. But subsequent infection by other serotypes increases the risk that person will develop severe dengue. But, unhelpfully, data about immunity just aren’t collected routinely enough to be accounted for in these models.

Likewise, reliable data about the prevalence of dengue’s four unique strains, or serotypes, are hard for researchers like Maude to come by. In fact, according to Maude, “most countries only have a minority of people who have information on what serotype they have.”

“That’s limited trying to develop models using that data up to now,” explained Maude.

Data about climate—temperature, rainfall, etc.—can be spotty, and, on a very basic level, the data about dengue cases aren’t always reliable. The number of cases can be overstated—in health systems that choose to treat dengue-like symptoms without actually testing for dengue—and understated—in places where people have the virus but don’t seek treatment.

Maude is quick to point out that gaps in the dengue data aren’t necessarily the fault of any one country’s dengue control program.

“It’s the whole health system and the population that are responsible for that data,” says Maude.

To get complete and accurate data, Maude says scientists are, in essence “relying on huge numbers of people to do something consistently.” A big ask, even in the best conditions.

There’s just no incentive for every single doctor to report every single case of dengue.

As Maude puts it, that data collection, “it’s just more work.”

Are any countries already using prediction models to anticipated dengue outbreaks?

The only government Maude is aware of that’s already putting predictive models to use is Singapore.

One model developed in Singapore with the help of machine learning was able to forecast major dengue outbreaks in 2013 and 2014 more than 10 weeks in advance, allowing the government to prepare hospital beds, diagnostic kits, deploy extra personnel for on-the-ground mosquito control and community outreach.

The city-state has used information from this predictive model in part to mobilize information campaigns to ramp up awareness of dengue when the data forecasts a bad year.

“The model allows us to confidently warn the public that there could be an outbreak coming,” said Lee-Ching Ng, who is the director of Singapore’s National Environment Agency, in a 2016 journal article on this particular predictive model.

“It’s very difficult to be alert at all times. You get fatigued. The public messaging can’t be done all the time, [so] the model suggests when to intensify our message or to mobilize the community,” she added.

But Singapore has a few key advantages: very high quality data about a very small geographical area.

In the case of other countries, “how well [these models] work depends on what the data in each country looks like, what’s available and the format of that information.”

Until data availability and data accuracy improve, innovations in the prediction space will be slow to come.



Enjoyed this story? Share it.


Quinn Libson
About the Author: Quinn Libson is an Associate Editor at Asia News Network

Eastern Briefings

All you need to know about Asia


Our Eastern Briefings Newsletter presents curated stories from 22 Asian newspapers from South, Southeast and Northeast Asia.

Sign up and stay updated with the latest news.



By providing us with your email address, you agree to our Privacy Policy and Terms of Service.

View Today's Newsletter Here

Analysis, Environment

Ayodhya: Coming full circle

Ishan Joshi writes about the recent Ayodhya verdict. Nearly 27 years to the day when as a raw 20-year-old political reporter for The Statesman I reached Ayodhya to cover the run-up to and, as it happened, the aftermath of the demolition of a medieval mosque on 6 December 1992, my primary concern was to find out whether I would get eggs for breakfast. Information I had picked up on the drive down from the state capital Lucknow to Ayodhya was that the temple town, in keeping with its status as a holy city, did no “non-veg.” Such things were important to me, then.  Now, in an effort to prolong my late youth, as it were, oats/idli/low-fat yogurt and the like are my victuals of choice for breakfast. But that’s not all that’s changed. The Supreme Court’s verdict in the Ayodhya Case last week means a Ram Temple will soon be built


By Ishan Joshi
November 18, 2019

Analysis, Environment

Death of militant heads will stunt recruitment but not kill it

ISIS has a foothold in Southeast Asia. The deaths of Malaysian militant leaders Akel Zainal and Mohd Rafi Udin will reduce the intensity of recruitment for the Islamic State (IS) but not completely kill it, says a terrorism expert. Dr Ahmad El-Muhammady, a political science lecturer at the International Islamic University of Malaysia, said the recruitment of Malaysians into the terror group might continue undetected in some cases. “Their deaths will certainly have an impact among Malaysian IS fighters. While their deaths may reduce the intensity of recruitment, it will not completely kill it, ” he said. Commenting on the power vacuum among Malaysian IS fighters in Syria following the deaths of Akel and Mohd Rafi, Dr Ahmad said there was no longer a central Malaysian figure in Syria.


By The Star
November 15, 2019

Analysis, Environment

Terminating GSOMIA may send ‘wrong’ message to adversaries

Wartime OPCON transfer is contingent upon conditions being met, says top US military official stationed in Korea. By terminating its bilateral intelligence-sharing agreement with Japan, South Korea risks sending the wrong message — that the trilateral alliance of South Korea, the US and Japan is weak — Gen. Robert Abrams, commander of the US-ROK Combined Forces Command, said Tuesday. Marking his first year in office, Abrams, who also commands United States Forces Korea and the United Nations Command, spoke on a series of current issues, including the ongoing defense cost-sharing negotiations and the alliance, during a joint press interview.


By The Korea Herald
November 14, 2019

Analysis, Environment

Uncertainty persists on US – China trade deal

This despite Trump’s comments that US and China close to trade deal. US President Donald Trump said on Tuesday (Nov 12) that the United States and China are close to a trade deal, but made clear that the prospect of tariffs was still on the table, with a warning that the US would raise tariffs on China if no trade deal was reached. His speech at the Economic Club of New York was closely watched by Wall Street but offered no new details on any signing of a much-touted “Phase One” preliminary trade deal with China. China, said President Trump, was dying to make a deal with their “supply chains cracking very badly” almost two years into the trade war. “We’re the ones deciding whether or not we want t


By The Straits Times
November 13, 2019

Analysis, Environment

Myanmar sued for genocide

On behalf of OIC, Gambia files the case at Int’l Court of Justice seeking orders to stop atrocities on Rohingyas immediately.  The Gambia has filed a case at the United Nations’ top court, accusing Myanmar of committing genocide against its Rohingya Muslim minority, more than two years after some 750,000 Rohingyas fled a military crackdown in the Rakhine State. “We have just submitted our application to the ICJ under the Genocide Convention,” Gambian Justice Minister Abubacarr Tambadou said at a news conference yesterday in The Hague, where the court is based. “The aim is to get Myanmar to account for its action against its own people: the Rohingya. It is a shame for our generation that we do nothing while genocide is unfolding right under our own eyes,” he said. The International Court of Justice (ICJ), also known as the World Court, is the U


By Daily Star
November 12, 2019

Analysis, Environment

The government has undermined education

A core value for a country to develop, the federal govenrment must make amends. The High-Level National Education Commission was formed in 2018 to recommend steps to better the country’s education system. After much criticism regarding the secrecy surrounding the findings of the commission, the Education Ministry finally, made public portions of the new education policy. But it seems all is still not well. Analysts and commission members were quick to point out that the new policy has disregarded almost all of the commission’s recommendations, mainly the part where private schools were required to be transformed from ‘for-profit’ to ‘not-for-profit’. Findings of the commission are important documents that ne


By The Kathmandu Post
November 11, 2019