Volume 21, Number 10—October 2015
Research
Human Infection with Ehrlichia muris–like Pathogen, United States, 2007–20131
Table 2
Clinical features and laboratory findings among patients infected with the EML pathogen, United States, 2007–2013*
| Clinical features |
Value |
|---|---|
| Patient age at illness onset, y | |
| Range | 15–94 |
| Mean | 60.8 |
| Median |
62 |
| Sex† | |
| M | 44/69 (64%) |
| F |
25/69 (36%) |
| Period from symptom onset to testing, d | |
| Range | 0–145 |
| Mean | 9.5 |
| Median |
4 |
| Immunocompromised state† | 13/49 (27%) |
| Solid organ allograft recipient | 7 |
| Receipt of chemotherapy for malignancy | 2 |
| Receipt of systemic steroids for autoimmune disease‡ |
4 |
| Patient symptoms† | |
| Fever | 60/69 (87%) |
| Malaise/fatigue | 47/62 (76%) |
| Headache | 46/69 (67%) |
| Myalgia | 41/68 (60%) |
| Nausea/vomiting | 15/69 (22%) |
| Rash |
8/69 (12%) |
| Laboratory findings†§ | |
| Anemia | 18/50 (36%) |
| Leukopenia | 20/51 (39%) |
| Lymphopenia | 17/32 (53%) |
| Thrombocytopenia | 34/51 (67%) |
| Elevated AST or ALT | 18/23 (78%) |
| Ehrlichia chaffeensis positive serology, acute | 1/6 (17%) |
| Anaplasma phagocytophilum positive serology, acute | 1/6 (17%) |
| Borrelia burgdorferi positive serology or PCR |
2/28 (7%) |
| Doxycycline treatment†¶ | 66/68 (96%) |
| Length of treatment, d | |
| Range | 7–30 |
| Mean | 15.0 |
| Median |
14 |
| Hospitalization†# | 16/69 (23%) |
| Length of stay, d | |
| Range | 2–15 |
| Mean | 6.1 |
| Median |
4 |
| Immunocompromised patients† | 10/15 (67%) |
| Death† | 0/69 (0%) |
*ALT, alanine aminotransferase; AST, aspartate aminotransferase; EML, Ehrlichia muris–like.
†Expressed as number of patients with a specific risk factor, symptom, laboratory finding, or outcome, divided by the number of patients with available data. Corresponding percentage is also provided.
‡Of the 4 patients receiving systemic steroids for an autoimmune condition, 3 had rheumatoid arthritis, and 1 had mixed connective tissue disease.
§Anemia, hemoglobin <13.5g/dL for male or <12.0g/dL for female patients; leukopenia, <3.5 cells x 10−9/liter; thrombocytopenia, <150 cells × 10−9/liter; elevated AST, >48 U/liter; elevated ALT, >55 U/liter; positive Ehrlichia chaffeensis or Anaplasma phagocytophilum serology, reciprocal IgG titer >64.
¶Two patients recovered without treatment. Treatment information was unavailable for 1 patient.
#Length of stay was unknown for 2 of the 16 hospitalized patients.
1Preliminary data from this study were presented at the American Society for Clinical Laboratory Science–Minnesota meeting, March 8, 2012, St. Cloud, Minnesota, USA; the Interscience Conference of Antimicrobial Pathogens and Chemotherapy, September 9–12, 2012, San Francisco, California, USA; the Emerging Infections in Clinical Practice and Public Health Continuing Medical Education Conference, November 16, 2012, Minneapolis, Minnesota, USA; the Interscience Conference of Antimicrobial Pathogens and Chemotherapy, September 10–13, 2013, Washington, DC, USA; the Entomological Society of America annual meeting, November 10–13, 2013, Austin, Texas, USA; the American Society of Tropical Medicine and Hygiene annual meeting, November 13–17, 2013, Washington, DC, USA; the European Congress of Clinical Microbiology and Infectious Diseases, May 10–13, 2014, Barcelona, Spain; and the International Conference on Diseases in Nature Communicable to Man, August 10–12, 2014, Vancouver, British Columbia, Canada.
2These authors contributed equally to this article.