When a person carrying a potentially dangerous infectious disease travels through airports, hospitals or public spaces before being diagnosed, health authorities launch a process known as track-and-trace to identify people who may have been exposed.
The system is used internationally during infectious disease events and involves reconstructing a patient’s movements and identifying individuals who may have had contact with them while they were infectious.
Patient movements and possible contacts
Medical doctor Juandre van den Berg said the process starts by establishing a timeline of the patient’s movements.
“Authorities will look at where the patient travelled, which flights they boarded, which medical facilities they visited and who they came into contact with,” he said.
Passenger manifests, hospital records, airline crew rosters and transport records may all form part of the investigation.
“It’s a structured process where officials identify possible contacts and then notify those individuals about potential exposure,” Van den Berg said.
Once contacts are identified, health authorities may advise them to monitor symptoms, seek medical attention if they become ill or limit contact with others depending on the level of risk.
Speed critical during outbreaks
Van den Berg said contact tracing systems became widely recognised during the Covid pandemic, but remain a standard public health procedure during outbreaks involving serious infectious diseases.
“People became more aware of track-and-trace during Covid, but these systems have existed in public health for many years,” he said.
“In situations involving international travel, authorities need to move quickly because people may already have travelled to different cities or countries before the diagnosis is confirmed.”
The effectiveness of the system depends on accurate information and rapid identification of contacts.
“The faster you can identify and inform people who may have been exposed, the easier it becomes to manage the situation.”
