← Back to Other Tick-borne Diseases
Disease overviewWorldwide

What is anaplasmosis?

Anaplasmosis is a bacterial tick-borne illness. In the United States it is caused by Anaplasma phagocytophilum and is spread mainly by blacklegged ticks.

Reviewed by VuxLore® Knowledge Team For Everyone

Short answer

Anaplasmosis is a bacterial tick-borne illness. In the United States it is caused by Anaplasma phagocytophilum and is spread mainly by blacklegged ticks.

At a glance

Fever, headache, chills and muscle aches can begin one to two weeks after a bite, although many people do not remember the bite.

Key takeaways

• Symptoms can overlap with other infections.

• Delayed treatment can lead to severe illness.

• Distribution and vectors vary by region.

Recognise the exposure pattern

CDC identifies the blacklegged tick and western blacklegged tick as the main US vectors. Related Anaplasma infections also affect animals, but species, hosts and clinical guidance differ.

Prompt assessment matters

A clinician may use blood tests, exposure history and symptoms. CDC advises that suspected anaplasmosis treatment should not be delayed while waiting for laboratory confirmation.

Sources and further reading

US Centers for Disease Control and Prevention: About Anaplasmosis

US Centers for Disease Control and Prevention: Tickborne Diseases of the United States

European Centre for Disease Prevention and Control: Tick-borne diseases