What you need to know about the increasing geographical range of Lyme disease

Tick-borne diseases, especially Lyme disease, are expanding their footprints more widely over time. In the US, the threat of the disease is growing as time goes on, the number of positive cases increasing because of new germ discoveries and the emergence of novel tick species.

Tick-borne diseases have been getting our attention for the last two decades, during which seven new tick-borne pathogens have been identified in the US. In 2017, health departments reported an increase in the trends of Lyme disease and other tick-associated infections. In 2016, the reported cases were 48,610, which jumped in the next year to more than 59,000 reported cases of infections associated with tick bites.

One factor in the increased incidence of Lyme disease is that its geographical range is growing day by day. The number of counties at high risk for Lyme disease has increased more than 300% in the United States, illustrating the dramatic increase in the geographical range of ticks.

Reasons for spread

Well, there is no exact reason for the spread of tick-borne diseases, as there is no one factor behind it. The precise cause of the spread is unclear. We can take an example of Lyme disease, in which more than one factor is believed to cause the spread of this disease. 

For several decades, the patterns of land use, including reforestation, have been considered the cause. Climate patterns have also been changing, contributing to the spread of Lyme disease. As tick-borne disease has strong correlations with the environment and ecology, we can expect that climate change can affect its spread. Due to strong ecological links, changes in seasonality and location of spread may occur.

There is no exact way to predict the spread or the number of infections in the upcoming season. Predicting epidemiology is complicated. Several factors affect the lifespan of ticks, including temperature, humidity, rainfall, and availability of hosts for feeding.

 Although we can’t forecast the spread of Lyme disease in an area, we know that ticks bite hundreds of thousands of individual animals every year, so everyone should take sound steps to prevent tick-borne infections.