# Mapping Global Trends in Dirofilaria immitis Research Within the One Health Framework (1945–2025): A Bibliometric Perspective

## TL;DR

This study maps 80 years of global research on heartworm disease, showing a shift from basic biology to a One Health approach involving genetics and environmental factors.

## Contribution

The paper provides the first comprehensive bibliometric analysis of Dirofilaria immitis research, revealing its scientific evolution and global collaboration trends.

## Key findings

- Heartworm research has grown steadily with the U.S. and Italy as leading hubs, but Global South participation is increasing.
- Early studies focused on parasite morphology, while recent work emphasizes genetics, Wolbachia symbiosis, and drug resistance.
- Climate change and drug resistance are driving a shift toward integrative One Health strategies combining genomics and environmental tracking.

## Abstract

Heartworm disease, caused by the parasite Dirofilaria immitis, is a major health threat to dogs and a growing concern for human health. Despite decades of study, the evolution of scientific interest in this parasite has never been mapped. This study reviewed 80 years of global research (from 1945 to 2025) by analyzing 3589 scientific documents. We found that heartworm research has grown steadily, primarily led by the United States and Italy, although researchers from heavily affected regions in the Global South are increasingly participating. The focus of these studies has changed dramatically. Early research mainly described the parasite’s appearance and the clinical symptoms it caused. Today, scientists are focused on its genetics, a symbiotic bacterium it carries called Wolbachia, and the alarming issue of the parasite becoming resistant to preventative drugs. Ultimately, studying heartworm is no longer just about basic biology; it requires a global “One Health” approach connecting animal, human, and environmental health. Because climate change is helping the mosquitoes that spread the disease expand to new areas, future strategies must combine genetic monitoring with environmental tracking to control this widespread threat.

Dirofilaria immitis constitutes a significant global veterinary burden and an emerging zoonotic risk. Despite decades of study, the structural evolution of its scientific landscape remains unexplored. This study provides a comprehensive longitudinal analysis of global research on D. immitis to evaluate its trajectory, intellectual structure, and conceptual shifts over the last eight decades. A systematic bibliometric analysis was conducted following PRISMA guidelines adapted for bibliometrics. Data were retrieved from Web of Science Core Collection and Scopus, covering the period from 1945 to 2025. After deduplication and manual screening, a final corpus of 3589 documents was analyzed using performance indicators and science mapping techniques to assess growth patterns, geographic leadership, collaboration networks, and thematic evolution. The field exhibits a mature profile with a sustained mean annual growth rate of 2.39%. Production is geographically polarized, with the United States and Italy acting as the primary research hubs, though international collaboration networks are increasingly integrating endemic regions in the Global South. Thematic analysis reveals a profound paradigm shift: while early research (1945–1980) focused on parasite morphology and clinical description, the 21st century is characterized by a multidisciplinary approach dominated by molecular biology, the study of the endosymbiont Wolbachia, and the genetic mechanisms of macrocyclic lactone resistance. The intellectual structure is currently organized into distinct but interconnected clusters, linking established clinical pathology with emerging genomic and environmental control strategies. Research on D. immitis has evolved from a classical parasitology discipline into a complex biomedical ecosystem aligned with the One Health framework. The persistence of the disease, driven by drug resistance and climate-mediated vector expansion, has catalyzed a transition toward integrative research models. Future control strategies must transcend geographic borders, combining advanced genomic surveillance with ecological modeling to mitigate the impact of this transboundary disease on both animal and human health.