RESUMEN
INTRODUCTION: To manage the rapid rise of misleading information on the coronavirus disease (COVID-19) during the pandemic, the Breakthrough ACTION project developed a theory-based rumor-tracking system to inform Guyana's COVID-19 communication campaign. METHODS: The rumor-tracking project used the extended parallel processing model (EPPM) to identify and categorize rumors reflecting perceived high versus low vulnerability to COVID-19 and high versus low efficacy of engaging in recommended COVID-19 prevention behaviors. The project designed contextually relevant social and behavior change messages, called "MythBusters," responded to rumor categories with the following objectives: (1) high perceived vulnerability and high efficacy rumors included a call to action; high perceived vulnerability and low efficacy rumors educated about effective and achievable solutions; (3) low perceived vulnerability and high efficacy rumors educated about risk; and (4) low perceived vulnerability and low efficacy rumors educated about risk and effective and achievable solutions. RESULTS: Most rumors emanated from regions 4 and 8 (29%). Over two-thirds of the rumors (71%) recurred. Rumors were typically related to COVID-19 treatment or prevention (40%) and transmission (35%). Most rumors (48%) reflected low perceived vulnerability and low efficacy, 29% reflected high perceived vulnerability and low efficacy, 13% reflected low perceived vulnerability and high efficacy, and 10% reflected high perceived vulnerability and high efficacy. The project rapidly developed 12 MythBusters from June through December 2020 and integrated them into the national COVID-19 communication campaign, disseminated via radio, television, and Facebook. Estimates indicate that they have reached most of the target Guyanese population. DISCUSSION: The EPPM was a particularly useful tool, giving direction to countering myths with appropriate messaging to affect relevant behaviors. The COVID-19 MythBusters provided the Guyanese public with valid and verifiable information and promoted preventive and protective behaviors.