This summer was a particularly severe season for ticks and tick-borne diseases in many parts of the Northeastern United States. According to an article in The New York Times, high tick levels this year can be traced back to bumper crops of acorns in 2015.
Many people associate the spread of ticks with deer, but mice are the primary culprits according to Richard Ostfeld, who has studied mouse population ecology for 25 years. Ostfeld went on to say that plentiful crops of acorns allow mice to survive the winter and reach “plague levels,” providing opportunities for infection to spread. In addition, Ostfeld said the lack of natural mouse predators such as foxes may be influencing the increase in tick levels, a trend which has been noted since 2001. While this season’s spike is unusual, rising tick levels will likely remain a problem in the future.
Lyme disease is the most common tick-borne disease. “Reported cases of Lyme have tripled in the past few decades,” said epidemiologist Kirsten Kugeler at the Centers for Disease Control (CDC). She continued, “Today, we think that the true burden of Lyme disease in the U.S. is about 300,000 cases each year.” Typical symptoms of Lyme disease are fever, headache, fatigue, and a characteristic skin rash called erythema migrans, according to the CDC. If Lyme disease is caught early, it can be treated with antibiotics to prevent development of more severe symptoms.
According to a press release by the New York State Department of Health, however, Lyme disease is not the only tick-borne infection being spread this season. The state increased surveillance efforts this August after confirmation of 3 cases of Powassan virus in Saratoga County. Powassan virus is a rare infection that can cause encephalitis, permanent neurological damage, and even death. Powassan virus can be transmitted from a tick to its host in 10-15 minutes, while Lyme disease takes around 36 hours to be transmitted, according to TIME.
Risk for tick-borne diseases is rising, and experts emphasize preventative measures such as regular tick checks, repellent spray, and avoidance of wooded areas. However, an article for The New York Times points out that there is currently no vaccine to prevent the most common tick-borne infection, Lyme disease.
In 1998, a vaccine that was 80% effective against Lyme after three doses was developed and put on the market. The marketing campaign for this vaccine failed because of several factors, as an article for The New York Times reports. Instead of focusing on marketing the vaccine to physicians who could recommend the vaccine to their patients, the manufacturer marketed the vaccine directly to the public. This tactic was unsuccessful, as people are unlikely to push to be vaccinated when their physician is unaware of a vaccine’s existence.
The most significant blow to the success of the Lyme disease vaccine came when volunteer study participants reported developing arthritis after receiving the vaccine. Although rates of arthritis did not differ significantly between the control and experimental groups, sales plummeted, and in 2002 the Lyme disease vaccine was pulled from the market. At this time, there is no vaccine available to help prevent Lyme disease in humans, though dogs can be vaccinated. Experimental vaccines for Lyme disease have been studied since 2002, but manufacturers have remained uncertain after the failure of the first vaccine.
For those who regularly spend time outside in areas where Lyme disease and other tick-borne diseases are present, the best advice is vigilance. Daily tick checks should be routine. If a tick bite occurs, remove it properly and seek medical help if the tick may have been attached for 24-36 hours. Ultimately, don’t panic, but be aware of potential risks.