Table 1.
Characteristics of patients and isolates from domestically acquired and travel-associated typhoid fever cases, United States, 1999–2010
| Characteristic | Domestically acquired typhoid fever cases | Travel-associated typhoid fever cases | P value‡ | ||||
|---|---|---|---|---|---|---|---|
| n | N | (%) | n | N | (%) | ||
| Child (⩽5 years) | 126 | 588 | (21) | 398 | 2655 | (15) | <0·001 |
| Adult (>60 years) | 55 | 588 | (9) | 69 | 2655 | (3) | <0·001 |
| Female | 280 | 609 | (46) | 1304 | 2734 | (48) | 0·40 |
| Hospitalized | 412 | 578 | (71) | 2020 | 2652 | (76) | 0·01 |
| Died | 1 | 561 | (<1) | 4 | 2529 | (<1) | >0·99 |
| Vaccinated within 5 years before illness onset | 7 | 494 | (1) | 112 | 1994 | (6) | <0·001 |
| Multidrug-resistant isolate*† | 7 | 356 | (2) | 257 | 1669 | (15) | <0·001 |
| Nalidixic acid-resistant isolate* | 48 | 356 | (13) | 1006 | 1669 | (60) | <0·001 |
*
Minimum inhibitory concentrations were interpreted by using the Clinical and Laboratory Standards Institute criteria when available: ampicillin (⩾32); chloramphenicol (⩾32); trimethoprim-sulfamethoxazole (⩾4/76); nalidixic acid (resistance breakpoint, ⩾32).
†
Resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole.
‡
χ2 test or Fisher's exact test (when expected cell frequencies were <5).