Lyme disease, transmitted by the blacklegged tick, Ixodes scapularis, is the most commonly reported vector transmitted disease in the United States and its prevalence and geographic range continues to increase. Moreover, a total of six previously undescribed tick-borne pathogens have spread across the northeastern and midwestern United States in the last 50 years due to the expanding range of I. scapularis.
The majority of tick-borne disease studies have been conducted in areas of low intensity residential development and in natural areas. However, there is increasing concern about the growing health threats from tick-borne diseases in and around urban environments. Green spaces, such as parks within urban centers, can provide suitable habitat for ticks infected with various tick-borne pathogens. With increasing incidences of locally acquired cases of Lyme disease on Staten Island, it is critical to understand the ecological characteristics of this urban landscape that may mediate tick abundances, the distribution of tick-borne disease risk and human-tick contacts.
The risk of Lyme disease in humans will depend not only on the density and distribution of ticks but also on human behavior that will determine where and how often they become exposed to ticks. Therefore, we need to understand the transmission of these diseases in all its fronts.
Our resarch has 2 main components:
(1) Studying the natural transmission and the risk of exposure to ticks in public parks on Staten Island
(2) Understanding where and how are people getting exposed to ticks
This study will aid in designing control measures tailored to Staten Island and study the cost-effectiveness of potential interventions to reduce health risks.
Ixodes ticks only move a few meters during each life stage, therefore hosts’ movement and habitat usage greatly determine tick dispersal patterns. While locally dispersing or migrating passerine birds play a role in moving ticks longer distances, white-tailed deer are key host for adult ticks and enable the establishment of new tick populations.
To better understand landscape and host impacts on the dispersal of infectious ticks we will examine deer spatial distribution, aggregation and habitat usage, Borrelia burgdorferi prevalence in white-footed mice and the abundance and distribution of I. scapularis nymphs across Staten Island.
To address these questions, we will first conduct tick sampling in Staten Island parks, which vary in deer and tick habitat. Additionally, to link population dynamics of ticks, mice and deer, we will establish 3-5 1 hectare grids in forested areas to live trap, mark and recapture mice, collect blood samples and ticks from mice, and count deer pellets along transects.
In Northeast U.S., human tick exposure has mainly been reported to occur in their yards, although recreational exposure in parks also occurs. To understand how and where are people encountering ticks in urban areas, we have designed a smartphone application that includes several interactive features that will help us gather information while providing the general public with resources to learn more about the biology and ecology of ticks, how to identify them and how to protect themselves. It will provide us with data about people’s activities and general risk factors that increases people’s chances of encountering ticks, including residence features associated with increased tick abundance. This app is currently being developed and will be launched soon. In Staten Island this app is going to be coupled to a household survey study in which we will assess the density of ticks in those houses adjacent to parks, during June and July 2019.