Anaplasmosis

Clear↑ rising

Vector-borne

Current NYS Status

2,025 cases in 2024 — near the 5-year baseline of ~1,967.

2024 statewide cases: 2,025

Source: NYSDOH Annual Communicable Disease Report 2024 + 5-yr baseline

What is it?

Anaplasmosis is caused by Anaplasma phagocytophilum and transmitted by blacklegged deer ticks — the same ticks that spread Lyme disease. NYS had 2,025 cases in 2024, concentrated in the Hudson Valley, Capital Region, and Long Island. It can be serious if not treated promptly.

How it spreads

Transmitted by the bite of infected blacklegged ticks. The tick must be attached for several hours before bacteria can be transmitted. Active from April through October; peak risk in late spring and early summer.

Symptoms

Fever, severe headache, muscle aches, and malaise appearing 1–2 weeks after a tick bite. Unlike Lyme disease, a rash is NOT typical with anaplasmosis. Abnormal lab findings include low white blood cell count, low platelet count, and elevated liver enzymes.

Who is at risk?

Anyone in tick-endemic areas. Older adults, immunocompromised individuals, and people with certain underlying conditions are at higher risk for severe illness. Anaplasmosis can be life-threatening without prompt treatment.

What you can do

🛡Use tick repellent and perform full-body tick checks after outdoor activities in wooded areas

🛡Remove attached ticks promptly with fine-tipped tweezers

⚕️Seek medical care promptly for fever and flu-like symptoms after a tick bite — tell your provider about the exposure

⚕️Treatment with doxycycline is highly effective; do not wait for lab confirmation before starting treatment

Tier B — Annual report tracking

Based on NYSDOH annual communicable disease report. Threat level reflects 2024 case counts compared to the 5-year baseline.

Seasonality: tick season

This information is for general public health awareness and is not a substitute for professional medical advice, diagnosis, or treatment.