Table 1.

The degree of pathogenicity and immunization of avian Eimeria species.

Species	Localization in the intestine	Pathogenicity*	Immunization⁎⁎	No. of exposure (life cycles) to achieve immunity
E. acervulina	Duodenum, jejunum	++	++	2-3
E. maxima	Duodenum, jejunum, ileum	++	+++	1
E. brunetti	Ileum, rectum	+++	+++	1-2
E. tenella	Caeca	++++	+	3-4
E. necatrix	Jejunum, caeca	++++	+	4-5
E. praecox	Duodenum, jejunum	+	+++	1
E. mitis	Duodenum, jejunum	+	++	2-3

^⁎+ low pathogenic; ++ moderately pathogenic; +++ moderately to highly pathogenic; ++++ highly pathogenic.

^⁎⁎+ low immunogenic; ++ moderately immunogenic; +++ highly immunogenic.