Table 1.
Case Ascertainment, Patient Demographics, Laboratory Data, and Treatment Profiles of Diagnosed Lyme Disease Cases
| Case ascertainment, No. (%) | |
| ICD-9 code (088.81) | 908 |
| Met CDC definitiona | 773 |
| Clinical diagnosisb | 262 (34) |
| IgM+/IgG− | 193 (25) |
| IgM−/IgG+ | 121 (16) |
| IgM+/IgG+ | 197 (25) |
| Demographics, No. (%) | |
| Age, y | |
| 0–4 | 171 (22) |
| 5–9 | 347 (45) |
| ≥10 | 255 (33) |
| Sex | |
| Male | 457 (59) |
| Female | 316 (41) |
| Race | |
| White | 718 (93) |
| African American | 22 (3) |
| Asian | 1 (<1) |
| Unknown | 32 (4) |
| Tick bite | |
| Yes | 222 (29) |
| No | 551 (71) |
| Month of diagnosis | |
| January–April | 77 (10) |
| May–August | 478 (62) |
| September–December | 218 (28) |
| Laboratory data, median (IQR) No. (%) | |
| CSF (n = 61) | |
| WBCs/µL | 21 (2–78) |
| Neutrophils, % | 6 (3–22) |
| Lymphocytes, % | 71 (52–81) |
| Monocytes, % | 12 (6–20) |
| Joint (n = 86) | |
| WBCs/µL | 41000 (25000–63000) |
| Neutrophils, % | 90 (82–95) |
| Lymphocytes, % | 4 (2–6) |
| Monocytes, % | 6 (4–11) |
| Treatment, No. (%) | |
| Doxycycline | 367 (47) |
| Amoxicillin | 346 (45) |
| Cephalosporin | 31 (4) |
| Home intravenous antibiotics | 16 (2) |
Abbreviations: CDC, Centers for Disease Control and Prevention; CSF, cerebrospinal fluid; ICD-9, International Classification of Disease, Ninth Revision; IgG, immunoglobulin G; IgM, immunoglobulin M; IQR, interquartile range; WBCs, white blood cells.
aCDC case definition according to 2011 guidelines.
bAll clinically diagnosed cases had a single erythema migrans rash without serologic diagnosis.