Mechanism:
(1) A tick may rarely be infected with more than one pathogen.
(2) The patient received multiple bites involving different ticks.
A single Ixodes tick may be able to spread:
(1) Borrelia burfdorferi
(2) anaplasmosis
(3) babesiosis
(4) tickborne encephalitis
Indications of co-infection may include:
(1) failure to respond as expected to appropriate therapy
(2) atypical presentation or clinical course
(3) more severe clinical findings
(4) persistent signs and symptoms
Differential diagnosis:
(1) antibiotic resistance
(2) noncompliance
(3) inappropriate antibiotic selection
(4) comorbid condition
Evaluation of the patient may include:
(1) capturing the tick and submitting it for pathogen testing
(2) testing the patient for all tick-borne infectious agents
