The difference between our estimate and the estimate reported by Busch et al. (9) for the year 2003 (1 NID case/256 WNV infections) may reflect yearly variations of the disease, data quality, or, most probably, the differences in the WNV NAT positivity window used in the study by Busch et al. (6.9 days) and in our study (15.1 days), which could have resulted in an overestimate of WNV incidence and NID ratio in 2003. The gene discussed is BRD2; the disease is infection.