Table 1. Comparing the ABO and RhD blood types of Babesia-NAT reactive and non-reactive blood donors.

CI = confidence interval.

Blood type	A	B	AB	O	RhD+
Northeast
Non-reactive	212,884	68,111	24,670	307,823	496,269
Reactive	235	92	23	336	533
Chi-square	0.06	3.70	0.79	0.39	4.53
p-value	0.81	0.054	0.37	0.531	0.033
OR	0.98	1.24	0.83	0.95	0.82
95% CI	0.84–1.15	1.00–1.55	0.55–1.26	0.82–1.11	0.69–0.99
Midwest
Non-reactive	93,128	26,570	10,866	116,892	197,393
Reactive	30	9	3	40	61
Chi-square	0.04	0.005	0.10	0.08	1.47
p-value	0.84	0.94	0.75	0.78	0.23
OR	0.96	1.03	0.83	1.06	0.74
95% CI	0.61–1.50	0.51–2.05	0.26–2.62	0.69–1.64	0.45–1.21
All 10 States
Non-reactive	306,012	94,681	35,536	424,715	693,662
Reactive	265	101	26	376	594
Chi-square	0.36	3.64	1.07	0.04	5.10
p-value	0.55	0.057	0.30	0.84	0.024
OR	0.96	1.23	0.81	0.99	0.82
95% CI	0.82–1.11	0.99–1.51	0.55–1.20	0.86–1.14	0.70–0.97