Staying Safe on the Trails
While walking the trails we categorized the terrain by the following characteristics:
Low tick density– hard packed soil; gravel walkways; short, maintained grass
Medium tick density- oak trees; acorns on the trail; decomposing leaf and plant matter
High tick density- knee high, dense foliage; fragmentation or breaks in the forest
The way to maintain the most safety from infected ticks while hiking the trial is to be aware of the changing terrain and stay in the middle of the trail. The probability of encountering a tick greatly increases the closer you get to the edge of the trail where it meets the forest.
Background
Lyme Disease was first identified in 1976 in the town of Lyme, Connecticut when multiple children were reported to have juvenile rheumatoid arthritis. After looking into those cases a little more, it was found that all of these children were suffering arthritic symptoms due to a transmission of a specific bacterium after being bit by a tick.
Since its insurgence, Lyme Disease has spread from Connecticut to all of the states in the northeastern region of the USA. This spread has happened so quickly over the past 50 years that it has been classified as an endemic in all 57 counties of upstate New York. According to the CDC there are about 476,000 cases of Lyme Disease per year in the USA alone. Read below for details on Lyme Disease in Otsego County.
What Causes Lyme Disease?
Lyme Disease is caused by a spirochete bacteria in the Borrelia species. These different bacteria are localized to different regions of the world. In North America the primary bacterium that causes Lyme Disease is Borrelia burgdorferi.
The only species of tick that carries the B. burgdorferi bacterium is Ixodes scapularis, more commonly known as the blacklegged tick or the deer tick. These ticks live off of different host animals during certain stages of their lives. In the nymphal stage of development the blacklegged tick hosts off of the white-footed mouse but in the adult stage, these ticks host off of the white tailed deer.
Life Cycle of the Blacklegged Tick
The life cycle of a tick undergoes four stages which take two full years.
The first stage of the life cycle is the egg. These eggs are laid late in the fall, usually in dead leaf and plant matter.
These eggs will then hatch late in the following spring. This marks the larval stage of the life of a tick. These tick larvae find a small rodent to be the host of their first feed before autumn, marking the end of the first year of their life cycle. This host is often a white-footed mouse. This is the stage of the cycle where the Lyme disease causing B. burgdorferi bacterium is transmitted to only the female ticks.
The next stage of the tick is the nymphal stage. This occurs during the spring. The ticks are still on their rodent host but they are starting to outgrow them. The peak feeding season off these rodents are from May until July. After this feed the nymph will try and find a larger host, primarily deer, so they can grow into their adult size.
By the last autumn season of the tick’s life cycle the nymphal tick has found a deer and has grown to adult stage. By the end of this season the female ticks will lay their eggs and then die. If these female ticks do not find a host and lay eggs, they will try again to find a host the next spring, only if they survive the winter.
When Do Ticks Infect Humans With Lyme Disease?
During the second spring of the tick’s life the nymphs are taking their last feed off their rodent host before searching for deer to be their adult host. During this time the nymphal ticks may accidentally attach to a human instead of a deer. If that tick has the B. burgdorferi bacteria it may then transmit the bacteria to the human, resulting in Lyme Disease. Ticks primarily infect humans during their nymphal stage, meaning the peak season of infection is the late spring into summer.
The History of Lyme Disease in Otsego County
When investigating the number of Lyme Disease cases in Otsego County, a website called Tickcheck.com was found during our research. The website noted the total number of Lyme Disease cases in Otsego County from the year 2000 to 2018 to be 455. However, that number is only the reported confirmed cases by the CDC and the actual number is greater than that. The total estimated number of Lyme Disease cases in Otsego County is 4,550 true cases. So then after recalculating how many cases of Lyme disease that should have been reported each year, the graph obtain is shown below. Also the information for 2019 was retrieved from New York State Community Health Indicator Reports (CHRIS) Now looking at the two graphs below we can see from 2000 to 2006 the number of Lyme disease cases were about the same, but after 2006 the population size of Otsego county decreased and the number of Lyme disease cases increased. It is possible that is no relationship with the infection rate and population size. However, that does not mean the weather is not a factor.
Now the question to answer; Did the temperature through 2000 to 2019 keep consistent during the Winter season? Looking at the temperatures throughout the years from the month of May to December the minimum temperatures overall were increasing after 2006. The website where these temperatures were found is National Weather Service. Even if just a slight increase, they could still survive and be active in temperature above 35°F. So, because of the temperature increase, the Blacklegged Ticks would still be active during September and maybe October. As the minimum temperatures increased from 2006 to 2019 the number of Lyme disease cases also increased. Another factor could be as the population size of humans in Otsego County decreased after 2006, there could be an increase in the deer population. Therefore causing an increase in the infection rate of Lyme disease during the winter.
