Two Billion Infected: An Inexpensive Method to Measure Latent Toxoplasmosis and its Economic Consequences^*

Abstract

Over two billion people worldwide are infected with the protozoan Toxoplasma gondii, which influences human behavior and cognition. Standard diagnosis methods involve costly medical tests, which prevents widespread testing and hinders the study of the infection's effects. We propose and validate an inexpensive and easy-to deploy diagnostic method for latent Toxoplasmosis infections using response times and finite-mixture models. A clinical study showed that the method is sensitive and accurate. A large, representative UK study showed that the infection's consequences are relevant and pervasive, both economically (decrease in yearly income and employment) and behaviorally (increase in risky behaviors, stress, and depression).