Table 4.

Comparison of the experimental infection of the patient’s cells and HL-60 cells with two A phagocytophilum isolates*

	% Infected cells
	Day 4		Day 5		Day 6
	NY-33	NY-37	NY-33	NY-37	NY-33	NY-37
Patient’s cells	16	31	14	25	2	16
HL-60 cells	0	0	1	1	0	0

*Anaplasma phagocytophilum isolates are NY-33 and NY-37.

The percentage of infected patient’s cells was significantly different from that of infected HL-60 cells at each of the times indicated (p<0.001; Fisher’s exact test). Healthy donor cells are not shown because they did not survive past day 4 of incubation.