Archive for April 2009
Thermal scanners purchased after the SARS outbreak have been mobilized for border screening. Super-cool, but do they work to stop the spread of an epidemic?
The New York Times led with this image, but now the story link has been updated. Here’s the original text by Donald G. McNeil, Jr. on border controls:
Given extensive human-to-human transmission, the World Health Organization raised its global pandemic flu alert level on Monday, but it recommended that borders not be closed nor travel bans imposed, noting that that the virus had already spread and that infected travelers might now show any symptoms.
However, many countries are tightening border and immigration controls, and on Tuesday Britain advised against any nonessential travel to Mexico. Japan announced that it would no longer allow Mexican travelers to obtain visas upon arrival. The United States, France and Germany have also warned against nonessential travel to Mexico.
Here’s my understanding of how it works: the thermal scanner camera detects infrared radiation (IR). Basically any object emits IR which intensifies as it gets hotter. The camera has a sensor which detects IR and converts it into a temperature reading. In this system it does it visually.
However, when you first get flu, you don’t have a temperature, and the thermal scanner only measures skin temperature on your face, so an early fever (which raises your core temperature) is also not detectable.
So – does it work? Work done by Bitar et al as a followup to SARS control was published in February 2009: International travels and fever screening during epidemics: a literature review on the effectiveness and potential use of non-contact infrared thermometers In the early stages of a pandemic when less than 1% of people will be feverish, fever screening at the border is of limited use – from the paper “When we fixed fever prevalence at 1% in all studies to allow comparisons, the derived positive predictive value varied from 3.5% to 65.4% ” So thermal scanners aren’t very useful when very few people have fever.
However, check out this view from William Saletan in Slate: Heat Check – Swine Flu, Body Heat and Airport Scanner
On another note, I’m wondering why journalists don’t seem to have quick access to infectious disease specialists. In the New York Times, an environmental health epidemiologist is quoted in the debate, and here in the Cape Times, a sociologist who now specializes in the public understanding of biology. Where are the infectious disease experts? Maybe the CDC needs to draw up a list of media contacts among their top virologists and infectious disease specialists. Maybe part of science education should be a course in writing on science for the public, as well as how to write (and read!) papers.
Swine flu is in. In the rush to cover this latest possible pandemic, newswires are alive with activity, blogs and social networking sites are buzzing, and the CDC and WHO are back in the limelight. This despite the fact that the number of cases are limited (only 40 confirmed infections have occurred in the US).
The rush of news has been accompanied by a rush to track that news. The WSJ, amongst others, has a tracking website, including a map of infections in North America. Best of all, Google has a map showing how the infection is traveling.
This rush was started by Google Flu Trends, a website that tracks flu-related search queries to estimate influenza levels in different US states. Further studies suggested the same approach might work for other diseases as well.
Analyzing Google Trends
So how has Google Trends, the broader application of the Flu Trends concept, performed in the current scenario? A quick analysis shows that Google search results did in fact increase over the past few days (see chart – source: Google Trends).
A quick analysis shows three items worth mentioning:
- First, while Google Trends does show an increase in search activity on “swine flu,” the first uptick in activity only occurred on April 23. By contrast, the first news stories appeared on April 21 when two cases were confirmed in California.
- Second, Google Trends reports that the majority of search queries were from New Zealand, USA, UK, Canada, and Australia. Only a very small minority were from Mexico. Yet, Mexico is the country supposedly at the heart of the pandemic.
Explaining the Discrepencies
I had used a Google Trends like methodology two years ago to track the evolution of climate change as an issue in news coverage. Having worked on that, I can propose a few general reasons that explain why Google Trends is limited in this case.
First, it appears that Google Trends follows with some time lag, actual infections. This should not be surprising, as people are not likely to search for a disease before having had some exposure to it. This does not mean that it is not a useful tool for tracking diseases over the long term. At the very least, the response time of a system based on GT might be lower.
Second, the current scenario shows that Google Trends is highly susceptible to “noise.” Prior to this outbreak, swine flu was probably not a commonly known disease, and queries on it were extremely rare (if not non-existent). Thus, even the slightest uptick in search activity would show up as a major change. That uptick was provided by the highly charged media coverage of the subject. Given this, one wonders if the search results are more “noise” and less people with a genuine interest in the subject. So, Google Trends is likely to be more accurate where general knowledge of a subject (the baseline) is high, and media coverage (noise) is low.
Finally, and most interestingly, why is it that most of the search results came from the US, while Mexico is more exposed to it? Not surprisingly, this methodology only works where both a large number of the population and media are on the internet.
What Next for Google Trends?
When discussing why most search queries occurred in the US, it is worth noting another fact about the swine flu outbreak – that it has traveled extremely fast. Originating in Mexico, it has been carried to the USA, Spain, and New Zealand. This brings into question the validity of using the geographic source of search queries as a reliable indicator of where the disease actually is.
Still, it may also offer a way to enhance Google Trends. What if Google Trends data was combined with travel data on the number of people traveling from a “hotspot” of an infectious disease. It would be logical to assume that popular destinations, or ones which receive travel groups, would be the most likely next locations for further infections. Thus, a map could potentially be created of not only where the disease is generating interest, but where it might be headed.
Of course, Google does not have access to such data – though at some point it may decide to acquire a travel operator. But the general lesson is simply that to make Google Trends more useful, search query data needs to be looked at together with real-world data (such as travel data or hospital records).
It is still early days for the swine flu outbreak, but some commentators are already suggesting the “social web” has actually created hysteria rather than help track the disease. That may be true, but it is hardly a problem of the “social web.” As a reader on the FP pointed out, “Twitter is only a natural extension of a typical neighborhood.”
So, in this “typical neighborhood,” what the swine flu outbreak has done is illustrate where Google Trends does well – in tracking general interest amongst heavy Internet users. But it also exposes limitations – the methodology is (not surprisingly) susceptibility to “noise” from media coverage and is biased towards countries and issues that are online. This does not mean that the idea itself is flawed. Just that it must be taken with a pinch of salt, and that it needs work – especially interfacing it with real-world data streams – to make it really useful.
How one communicates a message is critical to what you are trying to accomplish. It amazes me how little upfront investment some organizations/campaigns put into this kind of thing. This recently came to mind when I saw the work of Toby Ng, who has “used information graphics to re-tell the story in another creative way” with the commonly used theme – if the world was 100 people then…Some examples below:
HT (The Atlantic)
Cautionary Note and Counterpoint
The comment thread at Flowing Data suggests an alternate critical argument about using this technique because it is not a “serious attempt to convey information” and it is easy to distort data when you manipulate in such a manner. I am not a graphic design expert and I haven’t read Tufte but this is certainly a fundamental principle (don’t distort the data). Given this warning, this specific style is attractive and can be useful depending on the audience and the goals you have. There is a lot more that can be said on this theme and it would be great to have global health folks brainstorming different ways of communicating messages beyond doom and gloom.
For some inspiration and ideas check out sites like Flowing Data and Jaspal’s previously related post on “Why Bad Presentations Happen to Good Causes“. For audio visual storytelling the talk by Hans Rosling at TED 2006 is a global health classic that pushes us to be more creative story tellers. This has to be one of the best global health videos I have ever seen (which we posted 2 years ago):
First, a bit of housekeeping – we are tinkering with the look of the blog and considering moving it to another platform, if you have any feedback about what you like and don’t like, let us know.
Published today in the CMAJ, Early detection of disease outbreaks using the Internet, is worth skimming:
“The Internet…is revolutionizing how epidemic intelligence is gathered, and it offers solutions to some of these challenges. Freely available Web-based sources of information may allow us to detect disease outbreaks earlier with reduced cost and increased reporting transparency. Because Web-based data sources exist outside traditional reporting channels, they are invaluable to public health agencies that depend on timely information flow across national and subnational borders. These information sources, which can be identified through Internet-based tools, are often capable of detecting the first evidence of an outbreak, especially in areas with a limited capacity for public health surveillance.”
The limitations section includes the below list, but I wish they went into much more detail about what the internet is not good for (probably detecting trends among the elderly for example) and more examples of misinterpreting the data. On a related note to using ICTs for surveillance, Jaspal wrote a fairly detail post on Google Flu Trends that you should also check out.
I recently discovered the UCLA Art|Global Health Center, the mission of which is to “unleash the transformative power of the arts to advance global health“. The arts have the ability to capture issues and tell a story in a way that can make a profound impact on our (social) consciousness and is not something we talk about enough as a tool. One of the more famous examples of this is the AIDS quilt which was conceived of in 1985 by an AIDS activist in memory of Harvey Milk. That quilt has had over 14 million visitors and is the largest community arts project in the world.
The UCLA center has some ongoing projects and last year opened “Make Art | Stop AIDS” that featured traditional art as well as things like condom dresses. Make Art/Stop AIDS “is organized around a series of seven interconnected and at times overlapping concerns expressed in the form of open-ended questions, some of which include direct art historical references to the epidemic: What is AIDS?; Who lives, who dies?; Condoms: what’s the issue?; Is it safe to touch?; When is the last time you cried?; What good does a red ribbon do?; Are you angry enough to do something about AIDS?; and, finally, Art is not enough. Now it’s in your hands.”
Creative art projects have the ability to move the human mind unlike the constant barrage of issues, numbers and headlines that desensitize us over time. If you have seen or heard of any interesting arts based global health projects let us know.
Adriana Bertinin’s condom dresses
Addressing HIV/AIDS-Related Grief and Healing Through Art
History of the AIDS Memorial Quilt
Condom fashion show, China
Please vote for Ben’s mobile payment for health systems project. Voting closes Friday.
VOTE – NETSQUARED: By introducing a smartphone and web-application system for submitting and reviewing claims, we hope to reduce the delays and errors, increase clinics’ profitability and improve communication. Below is a related post by Melissa Ho who is working with Ben on this project which fills a critical gap. Cross posted from ICTDCHICK:
As I have been pre-occupied with writing lectures for my class, and setting up my research, my collaborating partners at Marie Stopes International Uganda have been busy launching a new phase of the output-based aid voucher program, financing in-hospital delivery of babies, in addition to the in-clinic treatment of sexually-transmitted infections (STIs). The new program, called HealthyBaby is eligible to mothers who qualify under a specific poverty baseline and covers four antenatal visits, the delivery, and a postnatal visit. Last week they just started distributing vouchers, and this past weekend was the delivery of the first baby whose birth was covered by the program.
Like the HealthyLife program, the mother purchases a voucher for 3000 USh (approximately 1.50 USD, the HealthyLife program charges 3000USh for a pair of vouchers treating both sexual partners). The voucher then can be broken into several sticker stubs, one of which is submitted with a claim form on each visit.
The hospital then submits the claim form with the voucher to the funding agency (my collaborating organization), who then pays the hospital for the cost of the visit – labs, any prescriptions given, the consultation fee, etc. You can see in the picture to the right the nurse filling out the paper form and the mother putting her thumbprint on it. Filling out the forms can be tedious and error prone – this particular clinic had almost 18% of their STI claims rejected for errors last October. In the same month another clinics had 38.6% of their claims rejected. I am trying to work on digital systems that can help improve communications between the clinics and the funding agency, and also decrease the cost and burden of claims administration.
The Claim Mobile project actually focuses on the HealthyLife program – the STI treatment program, rather than the HealthyBaby program, but I hope to demonstrate the sustainability and replicability of the system that I’m developing by training the engineers here to retool my system for HealthyBaby – so by the time I leave, I am hoping it will be in place for both programs.
By coincidence, this first birth occurred in one of the two clinics where I’m running the pre-pilot of the Claim Mobile system.
The WHO has decided to focus this World Health Day on hospital infrastructure during times of emergency. The folks over at Global Health Progress have a good round of what some bloggers are saying and include health journalism folks as well as thoughts from the AvianFlu diary. I thought I would go off theme and briefly throw out some thoughts on the bigger picture and encourage you to use this day to think about what is the future of global health? In this context of thinking about the future in 10, 20 or 30 years, the world is in turmoil and we are questioning the fundamental nature of market driven economies, why not use this as an opportunity to do the same for global health in a forward looking way? Think about where we are and whether we are prioritizing the right things and moving in the right directions?
Approximately 10 (only TEN!) years ago there was no Google, Kiva, Gates Foundation or knowledge about the cost differences between generic and brand name drugs (see this great talk on the Future of Global Health by Jim Yong Kim and his discussion of how they reduced the price of treating MDR TB patients by 80-90% in 1999) amongst major care organizations (absolutely stunning). Mobile phone penetration was less than 1% in developing countries and social entrepreneurship wasn’t hot, the vast majority of us probably hadn’t even heard of that term.
Where we were ten years ago is arguably a profoundly different world from where we are today and per the video below “we are living in exponential times“. To give you further inspiration to think differently today definitely watch the below (via 2173):
The acceleration of technology for social change and global health is going to increase, in this decade alone the convergence of movements in philanthropy, entrepreneurship and technology all enabled by the internet and mobile phone revolution have allowed people to collaborate, innovate and communicate on an entirely different level. I don’t know what the future of global health is – but I wonder how open source collaborations will contribute to solutions and whether twittering for global health will be around in five years and for whom and what purpose? Or will we just be doing more of the same. I wonder if we will be doing entire marketing and health education campaigns via mobile phones and how this will evolve. Will there be convergence of people and ideas working on global and domestic health? Will the flow of innovation and products from “South” to “North” become the next hot topic? I wonder if we will have a TED just for Global Health?
We might face a global crisis in 2030 but we will also be better equipped to face that crisis.Today is a day we should be thinking about what all the possibilities are and how we can get there in the fastest way possible. The last idea I will throw out as food for thought is to think about what have been the top 10 biggest developments in global health in the last decade and how will these shape the future?