Epidemiology of Balantidiasis


Balantidium coli has a worldwide, or cosmopolitan, distribution.  It is reported to be more common in the tropics, yet this observation may be confounded by others factors.  For example, the keeping of pigs is an inexpensive and common practice in tropical regions and many developing countries in the tropical region lack proper water systems and livestock containment structures for much of the poor, rural population.  Countries that are known to have had incidences of Balantidium coli infection include, Bolivia, the Philippines, and Papua New Guinea.


Few studies have been conducted to determine the prevalence of infection.  Those surveys that have been done generally report prevalence rates of less than 1%.  A study was recently conducted on Balantidiasis in Aymara schoolchildren of the northern Bolivia Altiplano.  The Aymara are indigenous Indians who practice livestock breeding, including pigs, and agriculture.  They region is impoverished and has overall poor health.  Other parasitic diseases, such as cryptosporidiosis, are considered endemic to the northern Bolivian Altiplano.


Researchers collected stool samples from schoolchildren in 22 communities over a five-year period (2,124 total children surveyed) and examined them for the presence of Balantidium coli.  Half of the communities had some Balantidium coli infection.  Still, prevalences were low, ranging from 1% to 5.3% with an overall prevalence of 1.2%.  The children did not show symptoms of Balantidiasis, and were apparently asymptomatic carriers.  Investigators also collected stool samples from 50 pigs in the communities, and detected the presence of Balantidium coli in 54% of them.  Nearly all of the families in the communities studied kept pigs.  Though low, the prevalences found are among the highest to be reported and infection with Balantidium coli must be considered as a disease endemic to the area.


Almost all of the children surveyed were infected with one or more parasites (protozoan or worm/helminth species) in addition to Balantidium coli.  Co-infections likely aggravate the damage wrought by each individual parasite, and they likely share common sources of infection (i.e. contaminated water).  Public Health Interventions aimed at Balantidium coli control can reduce the prevalence of other parasitic diseases, too.




The Parasite


Life Cycle


Animal Reservoirs

Clinical Presentation





Public Health Interventions


Glossary of terms

References and links