Slide 28 of 50
Notes:
a.A compatible clinical presentation in a severely ill patient with a tick bite is sufficient for presumptive diagnosis and treatment.
b. Laboratory testing typically reveals hyponatremia and thrombocytopenia. A white blood cell count and cerebrospinal fluid test results are normal. These results are not specific markers of the illness but support the diagnosis.
c.Peripheral petechiae provide strong clinical evidence for the diagnosis. Biopsy of the petechiae reveals obliterative endarteritis with thrombi.
d. Serologic testing for IgM (first two weeks) or IgG antibodies (positive more than two weeks after infection) to R. rickettsii can confirm the presence of the illness.
