Signs and Symptoms
- Anaplasmosis typically causes an acute febrile illness.
- Signs and symptoms vary greatly from person to person.
- Most people will have mild or moderate illness, though severe illness and death are possible.
- Signs and symptoms typically begin within 5–14 days after the bite of an infected tick. However, because tick bites are not painful, many people will not remember a tick bite.
- Healthcare providers should consider anaplasmosis or other tickborne infections in the differential diagnosis for patients with a non-specific febrile illness of unknown origin, particularly during spring and summer months when ticks are most active.
The following is a list of signs and symptoms commonly seen in the first few days of illness (days 1-5):
- Fever, chills, rigors
- Severe headache
- Gastrointestinal symptoms (nausea, vomiting, diarrhea, anorexia) in about 20% of cases
- Rash (<10% of cases) in patients with anaplasmosis. The presence of a rash might indicate a coinfection with Lyme disease, or another tickborne disease.
- Nervous system involvement (e.g., meningoencephalitis, focal paralysis, etc.)
If treatment is delayed and anaplasmosis is allowed to continue, disease may become severe. Severe illness is rare, but may involve:
- Renal or respiratory failure
- Peripheral neuropathies
- Disseminated intravascular coagulation (DIC)-like coagulopathies
Risk factors for severe disease
- Delayed treatment
- Older age
- Immune compromising conditions, e.g., advanced HIV, persons receiving chemotherapy, or other immune suppressing medications
Healthcare providers should also look at routine blood tests, such as a complete blood cell count and a chemistry panel when making the diagnosis.
- General laboratory findings can include mild anemia, thrombocytopenia, leukopenia (characterized by relative and absolute lymphopenia and a left shift) and mild to moderate elevations in hepatic transaminases.
- Abnormal laboratory findings can appear in the first week of illness; however, normal laboratory findings do not rule out possible infection.
Progression of disease varies greatly from person to person and may depend on patient age, co-morbid conditions, immune status and time of treatment. Patients who are treated early may recover quickly with outpatient treatment with oral antibiotics, while those who experience a more severe course might require intravenous antibiotics, prolonged hospitalization or intensive care.
For more in-depth information about signs and symptoms of anaplasmosis, see: Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis — United States: A Practical Guide for Health Care and Public Health Professionals (2016) pdf icon[PDF – 48 pages]