EPERYTHROZOON - A LESSON FOR ARBOVIROLOGISTS

Eperythrozoon was detected in suckling mice inoculated with a suspensi on of nymphal Ixodes ricinus ticks. The organism was filterable throug h 220 nm Millipore membranes, moderately sensitive to diethyl ether, p athogenic to suckling but not to adult mice when given intracerebrally , intraperitoneally or subcutaneously, and mimicked an arbovirus. Eper ythrozoon should be considered as an agent potentially interfering wit h experiments performed on laboratory mice.