Less than 50% of public health agencies monitor ticks in US and only 12% involve in control measures: Study
While the prevalence of Lyme disease and other illnesses spread by ticks has steadily increased in the US over the past 20 years, a new study of the state of American tick surveillance and control reveals an inconsistent and often under-supported patchwork of programs across the country. The analysis shows that tick surveillance and control lag significantly in US: less than half of public health and vector-control agencies engage in active tick surveillance and only 12% directly conduct or otherwise support tick-control efforts.
The study has been conducted by university researchers at the US Centers for Disease Control and Prevention or CDC's five Vector-Borne Disease Regional Centers of Excellence. "Ticks are responsible for the majority of our vector-borne illnesses in the US, and our programming does not adequately meet the need in its current form, for both surveillance and control," says lead author of the study Emily M Mader in the analysis published in the Journal of Medical Entomology. Mader is a program manager at the Northeast Regional Center for Excellence in Vector-Borne Diseases, housed at Cornell University.
According to the CDC, the annually reported cases of tickborne disease more than doubled between 2004 and 2018, while seven new tickborne germs were discovered in that same timeframe. However, the current analysis highlights a clear gap in US public health infrastructure, say researchers who have conducted the first survey of the nation's tick management programs. The team surveyed 140 vector-borne disease professionals working at the state, county and local agencies in the fall of 2018 to learn about their program objectives and capabilities for tick surveillance and control, testing ticks for disease-causing germs and barriers to success. Reaching even that many respondents proved challenging, as no central database of tick-management programs or contacts was available, say experts.
The researchers found information and data sharing on ticks and public health is falling behind. Less than a quarter of respondents said their tick-management programs disseminate information to local health departments (23%) or report data to the CDC (14%). To improve tick-management programs, respondents commonly cited the need for stable funding, training for personnel and standardized, research-based guidance and protocols.
The analysis shows that less than half of tick-management programs proactively collect ticks in their area. While about two-thirds of respondents (65%) said their programs engage in passive tick surveillance, such as accepting tick samples submitted by the public, only 46% said their programs engage in routine active tick surveillance, such as the focused collection of tick samples within their community.
Pathogen testing is an essential component of surveillance and is needed to understand tick-borne disease risk to communities. But the study found that only a quarter of tick-management programs test ticks for disease-causing germs. Just 26% of survey respondents said their jurisdiction conducts or financially supports testing of tick samples for disease-causing pathogens. Only 7% said their programs work to evaluate the presence of such pathogens in the animal hosts (such as mice and other rodents) from which ticks acquire those pathogens in their area. "There appears to be a significant barrier for many tick-surveillance programs across the country to access pathogen-testing services," says Mader.
The capacity for public tick-control efforts is also low, with only 12% of respondents saying that their jurisdiction conducts or financially supports tick control, with those efforts primarily focused on reducing tick presence on animal hosts (such as deer and rodents). According to experts, limited resources imply tick-management programs need reliable, proven control methods. "They are not going to invest in a strategy unless it has been investigated and shown to make a difference in reducing the burden of ticks and tickborne diseases. Right now, supporting this research is a major need. These kinds of evaluations often take at least three years to complete and require a significant investment," says Mader.
According to Dr Nohra Mateus-Pinilla, a co-author on the study and director of the Veterinary Epidemiology Laboratory at the University of Illinois' Illinois Natural History Survey, tick-work demands a long-term commitment as ticks can take years to complete their life cycle, use different hosts to move around, and take advantage of weather and habitat changes. "As such, research on these vectors requires a long-term and sustained commitment to research, surveillance, and partnerships across a broad range of disciplines, health professionals, and the public," says Mateus-Pinilla.