831. Use of a PCR panel for diagnosis of tick-borne disease: human granulocytic anaplasmosis at a suburban Massachusetts hospital
Session: Oral Abstract Session: Advances in Diagnostics
Saturday, October 22, 2011: 8:30 AM
Room: 151AB
Background: Human granulocytic anaplasmosis (HGA) can cause severe illness and is an underrecognized cause of tick-borne disease. We describe a series HGA infections at a suburban Boston hospital during the 2009 transmission season.

Methods: Medical records were reviewed for inpatients and outpatients at Newton-Wellesley Hospital with a positive polymerase chain reaction (PCR) result for Anaplasma phagocytophilum between March 1 through November 30 2009. A PCR tick-associated pathogen panel was used, which includes detection of Babesia microti, A. phagocytophilum, Ehrlichia chaffeensis, Ehrlichia ewingii and Borrelia burgdorferi. Postal zip code data from the patients’ areas of residence were used to estimate the area of likely disease transmission.

Results: Thirty-three cases of HGA were confirmed during the 2009 transmission season. Thrombocytopenia and/or leukopenia were observed at the time of presentation in 30/33 (91%) patients, and 28/33 (85%) reported fever. Two patients had a rash at presentation. Cases were geographically distributed diffusely throughout the hospital catchment area in 21 zip code regions, with the exception of one cluster of seven cases in a single zip code area. Medical records indicate that many patients participated in outdoor activities and that physicians frequently suspected Lyme disease as the cause of illness. Other tick-borne diseases were infrequently recorded in the differential diagnosis.

Conclusion: Diagnosis of HGA requires a high suspicion for infection. Use of a PCR tick-associated pathogen panel that includes several organisms could improve disease detection of lesser known tick-borne diseases in endemic areas.

Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Ana Weil, MD, MPH1, Elinor Baron, MD, DTMH2, Catherine Brown, DVM, MSc, MPH3 and Mark Drapkin, MD2, (1)Department of Medicine, Massachusetts General Hospital, Boston, MA, (2)Division of Geographic Medicine and Infectious Diseases, Tufts University School of Medicine, Boston, MA, (3)Hinton State Laboratory Institute, Massachusetts Department of Public Health, Jamaica Plain, MA


A. Weil, None

E. Baron, None

C. Brown, None

M. Drapkin, None

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