<prompt> The characteristic tetrads in RBC occur inMalariaBabesiosisLyme diseasePlague  <response>: Tetrad forms in RBCs which represent budding merozoites from the trophozoites in the red blood cells are called Maltese cross. These are seen in babesiosis or piroplasmosis Babesiosis is an emerging tick-borne infectious disease caused by protozoan parasites of the genus Babesia that invade and eventually lyse red blood cells RBCs. fig:- maltese cross apperence seen in RBC Babesiosis In malaria diffent form of life cycle are seen according to infecton of species of malaria. Plague and Lyme disease not infect RBCs 