A global team, including WorldPop researchers Dr Eimear Cleary and Dr Shengjie Lai, has found that staying away from sick areas can make outbreaks worse. This happens if local case reports are not accurate. The study shows how travel habits can distort health data. It can mislead the public in a big way.
When a disease spreads, people try to stay safe. They do this by avoiding high-risk zones. But the new study shows this relies on a big assumption. It assumes we know where the virus is. For many diseases, places where people get sick are far from clinics. This mismatch creates huge blind spots.
The team used high-resolution geospatial mapping to see how people travel. They analysed anonymised smartphone location data across a 100m grid cell. They found a clear divide between urban and rural trips. Visits to shops and doctors are closely linked. But trips to nature parks within five kilometres are strongly negatively linked with clinic visits.
Dr Cleary comments: “When health care is far from where you get sick, staying safe is hard. If a disease spreads in rural parks, people may not visit a doctor. Then, local case numbers look low. This can tempt others to visit those risky spots.”
For respiratory diseases like flu, risk zones and clinics are both in crowded cities. This positive link helps health systems find and report cases fast. But for vector-borne diseases like Lyme disease, the risk is in green spaces. This is far from clinics. This negative link can cause data to hide the real risk. This mismatch affects both rich areas and low- and middle-income countries.
The study strongly indicates that better reporting in rural zones is vital to protecting lives.
This study is a product of Fear of “Here” a National Science Foundation-funded project that integrates travel behaviour into disease models.
