Social networks quickly gather data on possible disease outbreaks after natural disasters, writes biosurveillance expert James Wilson.
When a natural disaster strikes and there is an imminent threat of a disease outbreak, existing public health surveillance systems often cannot hope to meet the emergency operational needs of healthcare teams working in challenging conditions.
This year's massive earthquake in Haiti, for example, killed up to 250,000 people and displaced another two million in the small, under-resourced Caribbean nation. Many of these displaced people continue to live in grossly unsanitary tents where diseases such as malaria, dengue fever, diarrheal illnesses, HIV/AIDS and TB can spread.
But the earthquake also killed a significant number of the medical and public health community, and clinics, offices and hardcopy records were destroyed.
An infectious disease outbreak could overwhelm the fragile medical infrastructure brought into Haiti's quake-affected areas, made up as it is of an often chaotic, diverse set of medical teams, many of whom have never worked in the country before.
In such situations, there is a clear need for an early warning system that provides this hard-pressed medical community with infectious disease surveillance.
A professional discipline called 'operational biosurveillance' has emerged over the past 12 years to address this need. It harnesses the power of the Internet and social networking to monitor social indicators of infectious disease crises and issue early warnings.
Gathering data on disease
Our organisation, Praecipio International, has been at the forefront of operational biosurveillance across the globe — from reporting anthrax outbreaks in Asia to spikes in viral fever cases in India.
In Haiti, we have developed the Haiti Epidemic Advisory System (HEAS) to inform — but not displace — existing public health surveillance capabilities. HEAS is the world's first infectious disease forecasting centre, working rather like a short-range weather service.
It is built on peer-to-peer sharing of the information vital to doctors facing harrowing medical challenges.
We received an alert about the Haiti earthquake 26 minutes after the event, through the Global Disaster Alert and Coordination System. We quickly did a sweep of the Internet and began monitoring Twitter feeds in six languages for the island of Hispaniola, which includes Haiti.
We knew straightaway from media, blogs and text message traffic what was being reported about infectious disease. By consulting peer-reviewed literature, we constructed a baseline for several diseases and issued the first infectious disease forecast report for Haiti on 17 January.
A reporting network in place
Our next step was to build a network of local contacts to provide real-time reports of critical indicators such as public panic or evacuation caused by rumour of disease, abrupt increases in disease prevalence, and acute disease affecting livestock such as poultry and cattle.
Less than a month later, we went to Haiti's capital, Port-au-Prince, and made contact with major non-governmental organisations (NGOs) and Haitian ministry officials within our first ten days on the ground.
Today, HEAS has more than 230 partners from NGOs and medical and public health organisations operating in Haiti. Through an online forum these partners are reporting infectious disease events and commenting on civil issues affecting the logistics of providing healthcare.
The network is a peer-to-peer community for early warning of infectious disease crises in Haiti. It has become the hub for reporting infectious disease events and training people in operational biosurveillance.
HEAS, in partnership with InSTEDD (Innovative Support to Emergencies, Diseases and Disasters) and Ushahidi, a website that visualises and maps information, has now analysed more than 90,000 text messages, thousands of media articles and blog entries, and dozens of direct observations from Port-au-Prince that include suspected outbreaks of meningitis, measles, malaria, diarrheal disease and, most recently, diphtheria.
We issue regular advisories to warn against emerging disease threats and assess future risk. Perhaps our greatest achievement has been to see the major NGOs plan their relief efforts on these advisories.
Scaling up and integrating
We are the same team that provided warning of the swine flu crisis in Mexico last year. Indeed, in the past 12 years we have detected nearly 250,000 infectious disease events involving more than 250 pathogens affecting humans or animals on nearly every country on Earth, including Antarctica.
By integrating forecasting and real-time warning systems with rapid, clinical response, countries in the grip of disaster can control outbreaks of infectious disease and potentially save thousands of lives. This is a vital, if often overlooked, component of not only response and recovery but also preparedness and ultimately, community resilience.
Certainly for Haiti, anything that can be done to stop further loss of life and build a foundation for community resilience should be pursued. Through operational biosurveillance, Haiti can become the first country in the world to anticipate and intervene to halt disease outbreaks and epidemics, and serve as a model for the rest of the world.
James Wilson is executive director of Praecipio International and the Haiti Epidemic Advisory System.