Table 2.
Association between B. microti Entomological Risk Index (ERI) and human babesiosis incidence rates in New York State, 2008-2015.
| Year | Number of counties | Mean nymph density (ticks/m) | Mean ERI* | Mean Babesiosis incidence | Spearman correlation | P-value |
|---|---|---|---|---|---|---|
| 2008 | 18 | 0.466 | 0.009 | 2.283 | 0.681 | 0.0019 |
| 2009 | 23 | 0.428 | 0.003 | 1.530 | 0.502 | 0.0146 |
| 2010 | 21 | 0.207 | 0.002 | 1.681 | 0.472 | 0.0308 |
| 2011 | 20 | 0.424 | 0.005 | 2.590 | 0.572 | 0.0084 |
| 2012 | 24 | 0.191 | 0.005 | 1.625 | 0.699 | 0.0001 |
| 2013 | 32 | 0.426 | 0.020 | 4.281 | 0.776 | <0.0001 |
| 2014 | 54 | 0.135 | 0.004 | 2.367 | 0.612 | <0.0001 |
| 2015 | 50 | 0.189 | 0.004 | 3.532 | 0.681 | <0.0001 |
*
Entomological Risk Index; the product of B. microti prevalence in host-seeking ticks and tick abundance.