| Disease/Syndrome |
Ehrlichiosis |
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| Category |
Infection, Occupational |
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| Acute/Chronic |
Acute-Severe |
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| Synonyms |
Human monocytic ehrlichiosis (HME or Ehrlichia chaffeensis infection); Human granulocytic ehrlichiosis (HGE or Anaplasma phagocytophilum infection); Sennetsu fever (Neorickettsia sennetsu); [ID, p. 1481] |
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| Biomedical References |
Search PubMed |
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| Comments |
Human monocytic ehrlichosis (HME) is caused by Ehrlichia chaffeensis. Human granulocytic ehrlichiosis (HGE) is caused by Anaplasma phagocytophilium. Ticks are the vectors for HME and HGE. Meningoencephalitis is present in about 20% of patients. The Japanese form of ehrlichiosis (Sennetsu fever) resembles mononucleosis with sore throat, increased lymphocytes, and enlarged cervical lymph nodes. [CCDM, p. 187-90] The agents causing ehrlichiosis are related to the genus Rickettsia. HME complications include meningoencephalitis, shock, respiratory distress, and acute renal failure. In one series of 211 cases, 36% of the patients with HME had a rash. Thrombocytopenia, leukopenia, and elevated liver transaminases are characteristic of HME and HGE infections. The case-fatality rate was 1% to 2%. HGE complications include shock, seizures, pneumonitis, hemorrhage, rhabdomyolysis, and acute renal failure. Serological surveys show that organisms similar to E. chaffeensis infect humans in Europe, Africa, and Latin America. [Guerrant, p. 564-70] Compared to Rocky Mountain spotted fever, leukopenia is more common, and rash is less common and less likely to be petechial. Other findings are diarrhea, anemia, and transient pulmonary infiltrates. [Lexi-ID, p. 115] Thousands of cases of HME have been diagnosed. Hospitalization is required in about 40-60% of cases. Leukopenia is usually in the range of 1300-4000 cells/microliter, and thrombocytopenia is usually in the range of 50,000-140,000 platelets/microliter. The CDC has identified about 1300 cases of HGA since 1990. Rash is present in less than 10% of cases. Morulae can be seen in neutrophils in about 20-80% of patients. [PPID, p. 2310-15] |
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| Latency/Incubation |
7-14 days |
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| Diagnostic |
Paired sera (4-fold rise); Blood smears for morulae (rarely seen); PCR and immunohistochemistry (Tests done in special labs only.); [CCDM, p. 188; Lexi-ID, p. 115] |
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| ICD-9 Code |
083.8 |
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| Effective Antimicrobics |
Yes |
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| Scope |
HME: California, south central, & SE USA; HGE: upper Midwest & NE USA + Europe & Asia; Sennetsu fever: Japan & Malaysia; [CCDM, p. 189] |
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| Reference Link |
CDC - Erhlichiosis |
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| Related Information in Haz-Map |
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| Symptoms/Findings |
Symptoms/Findings associated with this disease:
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| Job Tasks |
High risk job tasks associated with this disease:
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