Date of Award

January 2020

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Linda Niccolai


Human granulocytic anaplasmosis is a tickborne zoonosis caused by the bacterium Anaplasma phagocytophilum and first became a nationally notifiable human disease in 1999. In 2008, the Connecticut Department of Public Health (CT DPH) added it to the list of reportable diseases for the state. In 2019, there was a three-fold increase in case counts compared to previous years. To understand trends in anaplasmosis and generate hypotheses regarding this increase, descriptive analyses were performed on confirmed cases reported to the CT DPH from 2014 to 2019. Percentage of cases by gender, age, county, and month were calculated for each year, and chi-square analyses and two-sample t-tests were performed to discern statistically significant differences between cases in 2019 compared to cases from 2014 to 2018. Cases were mapped by zip code per year using ArcGIS Pro, and Anselin Moran’s I cluster analyses were performed. During 2014 to 2019, a total of 869 confirmed cases were reported to CT DPH; 315 of those cases were reported in 2019. The majority of cases were male and aged 50-69 years. There was a statistically significant association between year and county of residence. While the county with the highest number of cases was Windham county in eastern Connecticut in 2014, by 2019, the majority of cases were in Litchfield and Fairfield counties in western Connecticut; case clusters were also detected in western Connecticut. This increase in cases may reflect a true increase in disease, increased laboratory testing and reporting, or a combination of these factors, particularly in western Connecticut. Future surveillance measures should aim to gather more comprehensive demographic information, reduce missing data, and collect clinical data in order to fully understand the epidemiology of human granulocytic anaplasmosis in Connecticut.


This is an Open Access Thesis.

Open Access

This Article is Open Access