Taxonomy and Classification of Human Parasitic Protozoa and Helminths

Abstract

This chapter deals with the taxonomy and classification of the parasitic protozoa and helminths that are commonly encountered in humans together with a number that are only occasionally encountered. The concept of species as the basic unit that underlies the logical classification of all eukaryotes is scientifically sound but does not necessarily meet the needs of those whose interests are in the diseases caused by parasites and not the parasites themselves. This subject is discussed in some detail by Tibayrenc, who points out that there have been some 24 concepts of species and that "Biological researchers need more-pragmatic approaches that can be understood by non-specialists. Decision makers need precise answers for cost-effective and efficient control measures against transmissible diseases.” Classification of parasitic protozoa and helminths that infect human are listed in this chapter. The levels of the taxa used differ between the protozoa and helminths, and this is deliberate. In the classification of the Protozoa, the higher taxa, subkingdoms and infrakingdoms, have been omitted for simplicity and protozoans are classified as far as orders, as this is the lowest taxonomic level normally used by parasitologists.