Immune System-Inspired Surveillance Strategy Improves Detection of Disease-Carrying Insects

A study in PLOS Neglected Tropical Diseases shows that a decentralized disease surveillance strategy modeled on the human immune system improves the detection of disease-carrying kissing bugs. In a trial in Arequipa, Peru, the immune-inspired approach uncovered 23 infested households compared to only five found by traditional top-down methods. This flexible system leverages community reporting via the AlertaChirimacha platform and empowers local inspectors to use their judgment to combat Chagas disease.

Immune-inspired surveillance strategy

• ▪The immune-inspired surveillance strategy operates as a system of independent actors who communicate and flexibly expand or contract in response to the size of the infestation problem.
• ▪A disease surveillance strategy modeled on the human immune system detected more disease-carrying insects than the traditional top-down approach in a study published in PLOS Neglected Tropical Diseases.

Chagas disease transmission

• ▪Chagas disease represents a significant public health threat targeted by researchers in the city of Arequipa, Peru, which has a population of 1 million residents.
• ▪Chagas disease is a deadly parasitic affliction that can cause heart failure and is transmitted to humans by blood-sucking triatomine insects known as kissing bugs or chirimachas.

Kissing bug vector control

• ▪Traditional public health efforts to reduce Chagas disease focus on eliminating chirimacha infestations by treating houses with insecticides and monitoring them to prevent the insects from returning.
• ▪The conventional vector control approach features a central public health authority that directs personnel to likely areas of infestation to inspect households and spray insecticide.

Arequipa randomized trial results

• ▪A randomized trial conducted in Arequipa, Peru, from October 2021 to March 2023 compared the conventional surveillance strategy against the immune-inspired strategy across 60 clusters of about 2,300 households each.
• ▪Out of the 23 infested households detected by the immune-inspired approach, 10 were found through primary reports and 13 were uncovered through expanded coverage in nearby areas.
• ▪The immune-inspired surveillance approach uncovered 23 infested households, whereas the conventional surveillance strategy detected only five infested households during the randomized trial in Arequipa, Peru.
• ▪The conventional surveillance approach uncovered only one primary infestation and four additional infestations in surrounding households during the Arequipa trial.

Decentralized detection methods

• ▪When an infestation was found under the immune-inspired strategy, public health staff from nearby areas expanded outreach by distributing flyers, placing posters, and targeting social media posts to nearby residents for 10 days.
• ▪Under the immune-inspired strategy, vector control inspectors received neighborhood-level infestation risk estimates but were permitted to use their own judgment to decide where to conduct inspections.

Community-based reporting systems

• ▪The decentralized surveillance system allowed local public health staff in Peru to accept reports of insect infestations from residents through phone calls, social media, text messages, and WhatsApp messages.
• ▪The community-based reporting system utilized a well-publicized platform named "AlertaChirimacha" to facilitate the reporting of kissing bug infestations by households.

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