US: Elevated anaplasmosis activity in the Middle Atlantic states, especially in the state of New York, during August /update 2

Event

American health officials have reported an additional 567 cases of anaplasmosis July 18-Aug. 7 in the Middle Atlantic states. This brings the total case count reported between Jan. 1-Aug 7 to 2,021. This is compared to 805 cases reported over a similar period in 2020. New York is the most affected state (1,555 cases), followed by Pennsylvania (379 cases) and New Jersey (87 cases). This represents the most recent data available as of Aug. 18.

Context

Anaplasmosis is a year-round risk in the US. However, higher disease activity is normally observed in the summer months, peaking in June and July. Historically, most cases are observed in the upper Midwestern and northeastern states, although sporadic cases have been reported in other regions. Authorities reported 3,209 anaplasmosis cases in the US in 2020, 5,655 in 2019, 4,008 in 2018, and 5,762 cases in 2020.

Anaplasmosis is treated with antibiotics and is most effective if administered within five days of symptom development. Transmission of anaplasmosis occurs through the bite of an infected tick. Symptoms of anaplasmosis include fever, headache, muscle and/or joint pain, fatigue, chills, nausea and abdominal pain, cough, and confusion. Symptoms typically begin 1-2 weeks after the bite of an infected tick. People infected with anaplasmosis may not develop all of the symptoms, and the combination and severity of symptoms can vary. People with compromised immune systems often develop severe symptoms, including difficulty breathing, hemorrhage (uncontrolled bleeding), kidney failure, and neurological problems.

Advice

Avoid tick bites. Bathe or shower as soon as possible after being in a tick habitat, and conduct a full-body tick check using a hand-held or full-length mirror to view all parts of the body after being in wooded areas where ticks may be present. Seek medical attention if symptoms develop within two weeks of being in an affected area, especially if you remember being bitten by a tick. Wear clothing that covers arms and legs. Use an insect repellent containing DEET (around 35 percent) on clothing and exposed skin when outdoors.