Babesiosis

Clear→ stable

Vector-borne

Current NYS Status

748 cases in 2024 — near the 5-year baseline of ~520.

2024 statewide cases: 748

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

What is it?

Babesiosis is caused by microscopic parasites that infect red blood cells, transmitted by blacklegged ticks. NYS had 748 cases in 2024, concentrated in Suffolk County and Long Island. In severe cases it can cause hemolytic anemia.

How it spreads

Transmitted by the bite of infected blacklegged ticks. Can also be transmitted through blood transfusion. Peak season is June through August.

Symptoms

Ranges from asymptomatic to severe. When symptomatic: fever, chills, sweats, fatigue, headache, body aches, nausea. Severe cases involve hemolytic anemia, low platelet count, and organ failure.

Who is at risk?

Adults over 50, people who have had their spleen removed, and immunocompromised individuals are at high risk for severe disease. Anyone in tick-endemic areas is at risk for infection.

What you can do

🛡Use tick repellent and check for ticks after outdoor activities in endemic areas

🛡Promptly remove attached ticks

⚕️Seek medical care for fever and fatigue following a tick bite, especially if you are immunocompromised

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.