Anaplasma phagocytophilum: Difference between revisions
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Anaplasma phagocytophilum
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| − | = Microbiology = |
+ | == Microbiology == |
* Small, obligate intracellular Gram-negative bacterium |
* Small, obligate intracellular Gram-negative bacterium |
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* Tropism for neutrophils |
* Tropism for neutrophils |
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| − | = Clinical Presentation = |
+ | == Clinical Presentation == |
* Incubation period of 1 to 2 weeks |
* Incubation period of 1 to 2 weeks |
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* Abnormal liver enzymes are common in the first 7 days |
* Abnormal liver enzymes are common in the first 7 days |
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| − | = Diagnosis = |
+ | == Diagnosis == |
* 20-80% of patients will have circulating neutrophils with detectable '''morulae''' on blood film (in neutrophils/granulocytes) |
* 20-80% of patients will have circulating neutrophils with detectable '''morulae''' on blood film (in neutrophils/granulocytes) |
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* PCR possible |
* PCR possible |
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| − | = Management = |
+ | == Management == |
* Doxycycline 100 mg po bid |
* Doxycycline 100 mg po bid |
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{{DISPLAYTITLE:''Anaplasma phagocytophilum''}} |
{{DISPLAYTITLE:''Anaplasma phagocytophilum''}} |
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| − | [[Category: |
+ | [[Category:Rickettsioses]] |
Revision as of 06:42, 16 August 2019
Microbiology
- Small, obligate intracellular Gram-negative bacterium
- Related to Ehrlichia and Rickettsiae
- Tropism for neutrophils
Clinical Presentation
- Incubation period of 1 to 2 weeks
- Usually an acute undifferentiated fever
- Can be mild or severe
- Fever, headache, malaise, and myalgias are common
- Can also cause nausea, vomiting, diarrhea, cough, arthralgias, nuchal rigidity, and confusion
- Less than 10% have rash, most of which is concurrent Lyme disease
- 36% of cases require hospitalization, and it is severe in 3 to 7%
- Severe complications include respiratory failure, septic shock, rhabdomyolysis, hemorrhage, and opportunistic infections
- Rare meningoencephalitis
- Higher case-fatality rate in Shandong Province in China, for no clear reason (16% versus 2.6%)
- Thrombocytopenia, lerkopenia, and mild anemia are common
- Return to normal range within 14 days, but with persistent left shift
- Abnormal liver enzymes are common in the first 7 days
Diagnosis
- 20-80% of patients will have circulating neutrophils with detectable morulae on blood film (in neutrophils/granulocytes)
- Serology used to diagnose, by measuring IgG levels ≥1:64 or a fourfold rise
- IgM testing less sensitive and specific
- Culture not done routinely
- PCR possible
Management
- Doxycycline 100 mg po bid
