Anaplasma spp. Forecast 2021

20210406 Capc Forecast Maps Display V1 Anaplasmosis

The CAPC Prevalence and Forecast Maps represent actual and predicted exposure to both Anaplasma phagocytophilum and Anaplasma platys - infected ticks. The two pathogens are transmitted by different tick vectors (Ixodes spp. and Rhipicephalus sanguineus, respectively) with overlapping geographical ranges. The overlap in ranges prevents distinction between A. phagocytophilum and A. platys on the CAPC Prevalence and Forecast Maps. Prevention of both requires limiting exposure to tick habitats, routine use of acaricides, and regular tick checks of pets.

  • Throughout much of the contiguous United States the seroprevalence of Anaplasma spp. in dogs remains the same compared to the previous nine years.
  • The seroprevalence of Anaplasma spp. in dogs continues to follow the expanding range of Ixodes scapularis. When the 2021 forecasted risk of anaplasmosis is compared to historical (2012-2020) risk forecasts, there are demonstrable increases to the north and east of its traditional New England prevalence. The major areas of increased risk for dogs is expected to be the western regions of Pennsylvania and New York. Veterinarians throughout this region should reinforce the recommendations to their clients on the year-round use of tick preventives and encourage owners to check their dogs for ticks and remove them promptly. Annual testing can aid in assessing risk for dogs in hyper-endemic areas.
  • Risk of Anaplasma infections also remains high in Wisconsin, Minnesota and eastern North Dakota.
  • Focal areas of higher than average seroprevalence are expected in portions of Virginia, West Virginia, west and south Texas, and northern California. These areas and much of the surrounding regions have historically demonstrated lower risk, so veterinarians and clients should be particularly vigilant in light of these predicted changes.

Year-round protection, annual testing

The best way to protect your patients is to advise owners of the importance of year-round prevention, even during the winter months. You can use the CAPC Parasite Prevalence Maps to support your recommendation by underscoring the risks in your area and in regions of the country your clients may travel with their pets. It is also critical to emphasize the importance of compliance and using products correctly.

CAPC Parasite Prevalence maps and Forecast maps are validated tools for increasing client willingness to engage in parasite prevention. Sign up to receive local alerts on parasite testing results down to the county level today by visiting the CAPC Parasite Prevalence Maps and selecting "Get Updates".

Monthly Pet Parasite Forecasts

Veterinary professionals and pet owners who want to monitor parasite activity in their county throughout the year, can also access 30-Day Parasite Forecast Maps at These maps, developed exclusively by CAPC, provide a local forecast for every county in the continental United States on a monthly basis.

The Science Behind the Forecasts

Vector-borne disease is dynamic and ever changing, driven by multiple factors that affect the development of arthropod vectors and the pathogens they carry. Leading parasitologists work in collaboration with a team of statisticians to identify regions of the country that may experience higher parasite incidence in the months ahead. Numerous factors are analyzed, including the number of positive tests and the influence of weather patterns, vegetation indices, and human population density. Using this multi-disciplinary approach, we are leveraging everyone’s expertise to focus on a single common interest: forecasting the risk of exposure to vector-borne pathogens. While these forecasts predict the potential risk of a dog testing positive, they do not necessarily reflect the occurrence of clinical disease.

To learn more about the science behind the maps, full access to our manuscripts describing the methodology and fidelity of our forecasts can be found here.