MKS Publication

Chapter 5

Balantidium coli - A neglected zoonotic parasite from Public Health perspective

Abstract/Preface

Balantidium coli is a neglected zoonotic protozoan and the only ciliated parasite known to infect humans. Although human balantidiasis is relatively uncommon, it remains an important public health concern in regions where pig farming, inadequate sanitation, and contaminated food and water facilitate faeco-oral transmission. Domestic pigs serve as the principal reservoir, highlighting the significance of the human–animal–environment interface in disease transmission. Most infections are asymptomatic; however, invasive disease may manifest as chronic colitis, acute dysentery, or, rarely, life-threatening complications such as intestinal perforation and extraintestinal involvement may occur, particularly in immunocompromised  individuals. Laboratory diagnosis relies primarily on microscopic identification of trophozoites or cysts in stool specimens, with molecular methods increasingly contributing to epidemiological investigations. Tetracycline remains the treatment of choice, while improvements in water, sanitation, hygiene, livestock management, and public health education constitute the cornerstone of prevention. This chapter reviews the taxonomy, morphology, life cycle, pathogenesis, clinical features, epidemiology, laboratory diagnosis, treatment, and prevention of B. coli, with particular emphasis on its zoonotic importance and the relevance of the One Health approach in controlling this neglected parasitic infection.