Deer Tick Surveillance: Nymphs (May to Sept) Powassan Virus Only: Beginning 2009 | Last Updated 1 May 2024

This dataset provides the results from collecting and testing nymph deer ticks, also known as blacklegged ticks, or by their scientific name <i>Ixodes scapularis</i>. Collection and testing take place across New York State (excluding New York City) from May to September, when nymph deer ticks are most commonly seen. Nymph deer ticks are tested in “pools”, or groups of up to ten adult ticks per pool, for the Powassan virus, also known as Deer tick virus. These data should simply be used to educate people that there is a risk of coming in contact with ticks and tick-borne diseases. These data only provide nymph tick minimum infection rates at a precise location and at one point in time. Both measures, tick population density and minimum infection percentages, can vary greatly within a very small area and within a county. These data should not be used to broadly predict disease risk for a county. Further below on this page you can find links to tick prevention tips, a video on how to safely remove a tick, and more datasets with tick testing results. Interactive charts and maps provide an easier way to view the data.

Tags: tick, ticks, ixodes, scapularis, powassan, deer tick virus, community health and chronic disease, powassanonly

This dataset has the following 10 columns:

Column NameAPI Column NameData TypeDescriptionSample Values
YearyeartextYear in which ticks (all species and life stages) were collected.
CountycountytextThe county where ticks (all species and life stages) were collected. Ticks are often collected from multiple publicly accessible sites in each county.
Total Sites Visitedtotal_sites_visitednumberThe total number of publicly accessible sites visited in the county. For the nymph dataset, this means publicly accessible sites visited from May to September.
Total Ticks Collectedtotal_ticks_collectednumberThe total number of ticks (all species and life stages) collected in the county during visits to publicly accessible sites from May to September.
Tick Population Densitynymphal_densitynumberThe average number of nymph deer ticks (also known as blacklegged ticks or their scientific name Ixodes scapularis) collected per 1,000 meters sampled in the county. Tick population density is calculated only from the total nymph deer ticks collected (and does not include other species or life stages collected at the time of the site visit). Note: When taken in conjunction with Minimum Infection Rate (MIR) for Powassan virus, this field can give a sense of risk of encountering an infected tick. But tick population density and MIR can vary widely at different publicly accessible sites within a county, as well as from year to year. Statewide testing of ticks for Powassan virus began in 2009.
Total Ticks Testedtotal_ticks_testednumberTotal number of nymph deer ticks that were tested for Powassan virus.
Pools Testedpools_testednumberThe number of pools of nymph deer ticks tested for Powassan virus. Typically, 5-10 ticks are processed together in one tube and tested as one unit (called a “pool”). Note: Testing is for the Powassan group of viruses, which includes Powassan virus and Deer Tick virus. Because of the low expected infection rate of Powassan virus in deer ticks, they are not tested individually, but in pools.
Pools Positivepools_positivenumberTotal number of nymph deer tick pools that tested positive for Powassan virus. Note: This testing will detect both Powassan virus and Deer Tick virus, but does not differentiate between the two. It is expected that the vast majority of nymph deer ticks testing positive are infected with Deer Tick virus.
Minimum Infection Rateminimum_infection_ratenumberWhen tick pools test positive, it is assumed that one tick in the pool was positive. Minimum Infection Rate (MIR) is the measure used to address this. MIR is the ratio of the number of positive pools to the total number of nymph ticks tested. Note: This field can give a sense of ticks infected with Powassan virus in a particular area. But tick population density and (MIR) can vary widely at different publicly accessible sites within a county, as well as from year to year.
County Locationcounty_locationlocationThis is a centroid location within the county. It is used strictly for mapping purposes and does not reflect any specific place of the listed locality or county..