Table 1.
Protozoa causing intestinal infections. The protozoa presented in this review are in bold.
| Species |
Classification
(Super Groups) |
Incidence | Pathogenicity | Localization | ||
| World 1 | US 2 | EU 3 | ||||
| Balantidium coli | Cliliata (Diaphoretickes) |
Rare | colon | |||
| Blastocystis sp. | Stramenopile (Diaphoretickes) |
Very high | opportunistic (?) | colon | ||
| Cryptosporidium parvum |
Apicomplexa
(Diaphoretickes) |
nk | 8–9 | 7 | obligate | duodenum, jejunum, ileum |
| Dientamoeba fragilis | Trichomonadina (Excavata) |
Common | unclear, most likely same as G. lamblia | colon | ||
| Entamoeba histolytica |
Amoebozoa
(Amorphea) |
100 | rare | rare | obligate | colon, liver |
| Giardia lamblia |
Diplomonadida
(Excavata) |
250 | 15 | 18 | obligate | duodenum, jejunum, ileum |
| Microsporidia sp. | Fungi (Amorphea) |
Very high | opportunistic | colon | ||
1 WHO (World health organization), NIH (National Institute of Health) (×106/year); 2 CDC (Center of Disease Control), data for 2011–2012; 3 ECDC (European Center of Disease Control), data for 2014–2015 (both ×103/year). nk, not known. Websites: ecdc.europa.eu; www.cdc.gov; www.nlm.nih.gov; www.who.int.