Anaplasmosis
The bacterium Anaplasmosis phagocytophilium has been identified in blacklegged ticks in the KFL&A area. Active surveillance conducted by the University of Ottawa in the Fall of 2021 confirmed the presence of Anaplasmosis.
In September of 2021, Kingston Health Sciences conducted a chart review of people presenting to the local emergency department and reported to KFL&A Public Health a total of 16 confirmed cases.
Based on recent tick-related surveillance and disease data, we believe there is an emerging risk to the health of the public, both those who live and visit in the KFL&A region.
If assessing a patient with a suspected exposure to ticks, it is important to consider anaplasmosis, along with Lyme disease.
Treatment should not be delayed pending results of serology.
Background
Anaplasmosis, also known as human granulocytic anaplasmosis (HGA), is a disease caused by the bacterium Anaplasma phagocytophilum and is transmitted to humans by the blacklegged tick, Ixodes scapularis, (the same tick that transmits Lyme disease). The first symptoms usually appear within 1-2 weeks following the bite of an infected tick. Anaplasmosis is not a Disease of Public Health Significance in Ontario so there is limited data on the number of cases that occur each year in the province.
In 2021, the eastern region of Ontario noted a few people that tested positive for the tick-borne pathogen anaplasmosis. There were also additional reports of ten human cases in Quebec. In subsequent tick surveillance activities, high levels of Anaplasma (n=24/87) were found in blacklegged ticks at Murphy’s Point Provincial Park; along with small numbers of ticks testing positive in the Ottawa (n=2/68) and Kingston (n=2/24) areas. Therefore, if seeing a patient with a suspected exposure to ticks, it is important to now also consider anaplasmosis, along with Lyme disease.
Clinical Assessment
Symptoms
Commonly include fever, headache, chills, muscle aches and gastrointestinal symptoms. Severe symptoms may include difficulty breathing, hemorrhage, renal failure or neurological problems.
Testing
Acute and convalescent serology can assist with anaplasmosis diagnosis. The National Microbiology Laboratory also offers PCR testing upon a physician’s request.
Diagnosis
Symptoms vary from patient to patient and can be difficult to distinguish from other diseases. It is important to treat patients based on clinical signs and symptoms as laboratory confirmation may not be present.
Treatment: Doxycycline is the first line treatment for patients of all ages. Treatment is more likely to be effective if started early in the course of disease.
To help differentiate the clinical presentation of anaplasmosis and Lyme disease view Human granulocytic anaplasmosis acquired from a blacklegged tick in Ontario from the Canadian Medical Association Journal.
Case reporting
Please notify KFL&A Public Health if you have a suspected or confirmed case of anaplasmosis online or by calling 613-549-1232, ext. 2300