Can digital epidemiology indicate the emergence and current distribution of canine dirofilariosis?

The emergence and spread of vector-borne pathogens, such as the mosquito-borne parasite Dirofilaria immitis, the causative agent of canine heartworm disease pose increasing challenges for public and veterinary health. These parasites have expanded from Southern Europe into Central and Eastern Europe, where locally acquired transmission is increasingly documented in pets and wild animals, and is now considered an emerging infectious disease. Understanding the dynamics of its emergence and public awareness is essential for effective surveillance and intervention. Here, we evaluated whether human online search behavior, as measured by Google Trends (GT), reflects patterns of dirofilariosis emergence in Hungary. We analyzed GT data for heartworm-related terms from 2012 to 2025, exploring geographical and temporal trends. Our analyses revealed a sustained increase in search interest over time beginning in 2012, with pronounced rise after 2015. Spatially, the highest relative search volumes were concentrated in southeastern Hungary. We found a strong positive association between regional search activity and mosquito infection rate. These findings demonstrate that GT-derived data accurately mirror both the temporal increase and geographic distribution of canine dirofilariosis, supporting the use of digital epidemiology as a complementary surveillance tool to inform public health and veterinary strategies for emerging vector-borne diseases.