YOKOYAMA Naoaki Professor

My DreamControl of animal piroplasmosis through international research collaboration

ThemeDevelopment of innovative methods to control animal piroplasmosis by unraveling pathogenesis and immunology


Veterinary Medicine, Protozoology, Epidemiology, Animal Health


Babesia, Theileria, Piroplasmosis, Cattle, Horse, International Animal Health Organization, Diagnosis, Treatment, Prevention

Instructable research topic for doctoral thesis


  • 原虫の感染・増殖に関する分子生物学的研究
  • 原虫のワクチン開発に関する応用研究
  • 原虫感染による病態形成に関する臨床病理学的及び免疫学的研究
  • 原虫の流行・分布状況を把握するための国際フィールド・サーベーランス



Academic degree D.V.M., Ph. D.
License Veterinarian
Self introduction

Influenced by a book on animal behavior that I had read as a student at Handa High School, I decided to become a veterinarian, and joined Gifu University. During my undergraduate studies, I was interested in infectious diseases of animals. Therefore, after graduation, I moved to a Graduate School at the University of Tokyo, and continued my research on the infectious diseases. To date, I have conducted the research on several microorganisms causing severe infectious diseases in animals. I worked with bacteria in the undergraduate school, viruses in the graduate school, tumor viruses at Aichi Cancer Research Institute, and protozoa at NRCPD. At the NRCPD, my research interest focuses on bovine and equine piroplasmosis, which are diseases caused by Babesia and Theileria parasites and characterized by hemolytic anemia. I conduct research to elucidate the pathogenesis and mechanisms of cellular invasion and multiplication of these protozan parasites, and to develop innovative methods for the diagnosis, treatment, and prevention. My hobbies are fishing and collecting insects.

Room addressNational Research Center for Protozoan Diseases
Room number105
Mail address yokoyama atmark obihiro.ac.jp


National Research Center for Protozoan Diseases/Department of Disease Control/Research Unit for Molecular DiagnosticsNational Research Center for Protozoan Diseases/Department of Global Cooperation/Research Unit for International SurveillanceResearch Center for Global Agromedicine/Department of Veterinary Medicine


Piroplasmas (Theileria and Babesia) are tick-borne protozoa that cause piroplasmosis, which is a disease characterized by hemolytic anemia, in domestic animals, such as cattle and horses. Piroplasmosis is one of the major diseases, leading to serious economic damage to the cattle and equine industry. However, there are no effective methods to control the bovine and equine piroplasmosis. Therefore, our research interest focuses on the development of innovative methods to control this disease for improving animal health and reducing economic damage. In particular, we conduct the risk assessments to formulate disease control guidelines and train young researchers from endemic countries under our human resource development program. We are now working toward expanding our international collaborative network to expedite the research on piroplasmosis. The International Organization for Animal Health (OIE) has accredited our laboratory as OIE Reference Laboratory for bovine babesiosis and equine piroplasmosis. Using this platform, we have expanded our services to the international community worldwide.


List of current research topics

  • Global surveillance of bovine and equine piroplasmosis
  • Molecular epidemiological and clinicopathological investigations on bovine piroplasmosis in Japan
  • Molecular epidemiological survey of cervine piroplasmas
  • Epidemiology of bovine piroplasmas in tick vectors
  • Basic research to develop diagnostic, therapeutic, and preventive methods for bovine and equine piroplasmosis
Related industries International Quarantine, Animal Health, Veterinary Industry, Veterinary Medicine
Affiliated academic society The Japanese Society of Veterinary Science, Japanese Society of Veterinary Parasitologists, Japanese Society of Parasitology, Japanese Society of Tropical Medicine, Japan Society of Medical Entomology and Zoology
Academic background 1988-1994 Undergraduate Program (D.V.M.), Veterinary Medicine, Gifu University, Gifu, Japan
1994-1997 PhD Program, Veterinary Medicine (Virology), The University of Tokyo, Tokyo, Japan
1997-2000 Researcher, Department of Virology, Aichi Cancer Research Institute, Aichi, Japan
2000- Assistant Professor - Professor, National Research Center for Protozoan Diseases (NRCPD), Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan