It (whatever it is) is all connected. In the summer of 2016, the ticks were the worst of my life. Both in numbers and in species, we had it all. This year I can count on one hand the number of ticks I have had and they were all Star Ticks. None of those infernal, no-see-um turkey ticks. I thought this article might explain, but no. The only truth I can pull out of this is that local conditions, quite literally conditions on the ground, rule!
Still a good read and humbling to think about how the complexity of a tick is incomprehensible. I stocked up on tick repellant and did not even use it. If you can’t use research like this to predict, what good is it?
You might have heard that the Lyme apocalypse is upon us this year. In spring, media outlets from NPR to USA Today to the New Scientist were forecasting a black-legged tick population eruption with a consequent outbreak of Lyme disease in the American Northeast. Transmitted by tick bite, Lyme can cause symptoms such as fatigue, fever, headache, and a characteristic bull’s-eye skin rash called erythema migrans. If untreated, the disease can spread to joints, the heart, and even lead to neurological complications such as Bell palsy.
Today, Lyme is North America’s leading “vector-borne” disease—a term used to describe any disease transmitted from animal to human via live host. Despite decades of research and control efforts, new cases of Lyme in humans continue to climb. Confirmed cases reached a total of 28,500 in the U.S. in 2015 (plus an additional 9,600 probable cases). That’s more than double the number found when they were first recorded in 1995, according to the Centers for Disease Control and Prevention, though the trajectory has not been straight up, and increases may be partially related to heightened awareness. The number of counties in the U.S. that are considered Lyme disease hot spots has also more than tripled in that time, though the overwhelming majority of these is concentrated in just 14 states.
The problem is not confined to North America. Europe is witnessing a rise in confirmed cases of Lyme, and the disease is extending its geographic reach in both Europe and the temperate, forested parts of Asia. Some scientists believe now that the disease originated in Europe rather than in the northeastern U.S.—based on genetic sequencing of Borrelia burgdorferi—the Lyme-causing bacteria. The only known organism that doesn’t use iron to make proteins and enzymes, B. burgdorferi is particularly difficult for human bodies to kill because our immune system often tackles pathogens by starving them of iron. B. burgdorferi also lacks many other features common to bacterial pathogens, such as toxins and specialized secretion systems, which human immune systems use to detect and fight foreign invaders.