When health workers in Arequipa, Peru, started thinking like immune cells instead of soldiers, they found something remarkable: far more insects spreading a deadly disease.
A new study shows that a surveillance method modeled on the human immune system detected 4.6 times more homes infested with kissing bugs—insects that spread Chagas disease—than the traditional approach. The research, led by scientists from the University of Pennsylvania and Universidad Peruana Cayetano Heredia in Peru, was published in the journal PLOS Neglected Tropical Diseases.
Chagas disease is a parasitic illness that can cause heart failure and other serious problems. It spreads through the bite of triatomine insects, nicknamed "kissing bugs" because they often bite people's faces near the mouth. In Peru, these insects are called "chirimachas." Arequipa is a city of about 1 million people, and public health workers have long struggled to keep the insects from returning after spraying homes with insecticide.
The old method of tracking the bugs was rigid and top-down, said lead author Michael Levy, a professor of epidemiology. "Personnel are treated as soldiers and sent to find the bugs—the enemy—following strict rules and quotas," he explained.
Levy and his team instead imagined surveillance as something organic—like the body's immune system. Just as immune cells communicate and rush to fight infections wherever they appear, the new approach let local health workers respond flexibly to reports of infestations.
The team created a system called AlertaChirimacha, where people could report bug sightings by phone calls, text messages, Facebook posts, or WhatsApp messages. When inspectors found an infested home, nearby health workers would swarm the area—distributing flyers, posting signs in local shops, and targeting social media ads to residents living nearby for 10 days. Once the insects were gone, the response would scale back.
Researchers tested both methods from October 2021 to March 2023. They divided Arequipa into 60 neighborhoods, each with about 2,300 homes. Thirty neighborhoods used the conventional approach, and thirty used the immune-inspired method.
The results were striking. The new strategy found 23 infested households: 10 reported directly by residents and 13 more discovered through expanded outreach to neighboring areas. The traditional approach uncovered only 5 infested homes total.
The findings suggest that empowering communities and local health workers may work better than rigid, centralized systems when tracking disease-carrying insects. "Since the current approaches are extremely top-down and rigid, we believe that we found a more effective way to tackle these problems by encouraging the initiative of households and local health workers," Levy said.
The approach could help other cities fighting similar diseases, offering a model where surveillance grows and shrinks naturally based on where the threat actually exists.