Introduction to the Invasive Tick Species
An invasive tick species is creeping its way into more parts of the country, as warming temperatures help it spread a little-known infection that can leave people with debilitating symptoms, and in rare cases, dead.
Discovery of the Longhorned Tick
In May, scientists at the Connecticut Agricultural Experiment Station in New Haven discovered for the first time that the longhorned tick had become a carrier for the bacteria that causes the Ehrlichiosis infection. With cases already on the rise, that was a big cause of concern.
Concerns and Implications
“I am afraid to say that it is a storm brewing,” said Goudarz Molaei, the director of the lab’s tick-testing program. “Climate change eventually will almost eliminate winter in our region. And this tick, like other tick species, will be active year round.” Warming temperatures, which have already translated into shorter winters, allow the longhorned tick and other tick species to wake up early from hibernation, increasing the risk of getting bitten.
Geographic Expansion of the Longhorned Tick
The longhorned tick, which is native to East Asia, first invaded places like Australia, New Zealand and the Pacific Islands. It has now been detected in at least 21 states in the U.S. with Michigan reporting its first sighting at the end of June. Researchers aren’t sure how the tick made it to the U.S., but it’s likely it arrived on the backs of imported livestock or other animals.
History of the Longhorned Tick in the U.S.
In 2017, scientists identified the country’s first longhorned tick in New Jersey, though it’s likely the species has been in the U.S. since at least 2010. “The fact it was here for so long without us actually knowing about it was really a wakeup call,” said Dana Price, an associate research professor in the department of entomology at Rutgers University.
Environmental Suitability and Threat
Modeling indicates areas from southern Canada throughout the continental U.S. are environmentally suitable to the longhorned tick. That means the threat is two-fold: The longhorned’s geographic range is expanding and so is the time that they’re active and able to transmit disease, scientists said.
Ehrlichiosis Infection
Ehrlichiosis is becoming so prevalent that there is a region of the country unofficially named after it: The “Ehrlichiosis Belt” stretches from as far north as Connecticut and New York to as far west as Arkansas. The lone star and blacklegged ticks have long carried Ehrlichia chaffeensis, the bacteria that causes Ehrlichiosis. The infection sends about 60% of patients to the hospital and claims the lives of about 1 in 100 patients, according to the Center for Disease Control and Prevention.
Symptoms and Consequences of Ehrlichiosis
Infected individuals will typically experience fever, chills, muscle aches, headaches and fatigue one to two weeks after being bitten. But if people aren’t treated quickly, the infection can sometimes lead to brain and nervous system damage, respiratory failure, uncontrolled bleeding and organ failure.
Rise in Ehrlichiosis Cases
The number of Ehrlichiosis cases has risen steadily since 2000 when the CDC reported 200 cases of Ehrlichiosis compared with 2,093 in 2019. Studies suggest that the number of annual Ehrlichiosis cases are grossly underreported with one study from Rutgers University researchers saying 99% of cases go undetected.
Recent Developments and Precautions
The CDC reported earlier this month that there have been more emergency room visits in July for tick bites than the past eight Julys. In early July, officials closed Pleasure Beach, a popular swim spot in Bridgeport, Connecticut, for the summer after discovering an infestation of several tick species including the longhorned tick. Manisha Juthani, the commissioner of the Connecticut Department of Public Health, said that as climate change makes “tick season” less predictable, Connecticut residents should take precautions like wearing long pants, tucking them into their socks and conducting tick checks on family members and pets after being outdoors for extended periods of time.
Unique Biology of the Longhorned Tick
While longhorned ticks often prefer the blood of livestock to humans, entomologists say their unique biology makes them a formidable public health hazard. They can establish populations of thousands from a single female because, like bees, they have the ability to reproduce without a mate. They can also ingest and become carriers for pathogens typically carried by other tick species if they happen to feed on the same host.
Transmission of Pathogens
Molaei said his recent discovery of the Ehrlichiosis-causing bacteria in the longhorned tick raises concerns about what other pathogens the tick may be able to contract and transmit to humans. The longhorned tick and the lone star tick, one of the original carriers of ehrlichia, both feed on similar hosts, like white-tailed deer.
Personal Experience with Tick-Borne Diseases
Jennifer Platt was bitten by a tick during that time. She contracted Ehrlichiosis from a tick bite in North Carolina in the summer of 2011. When she couldn’t pick up and carry her 2-year-old son, her friend, who is a nurse, suggested she go to the hospital immediately. The friend suspected Platt might have a tick-borne infection.
Recovery and Advocacy
Platt was sick and on antibiotics for months after her diagnosis. Her shoulder locked due to the infection — a rare but contractable chronic symptom of tick-borne disease — leading to months of physical therapy and putting her out of work for three months. It took her more than a year to fully recover from the lasting impacts of the infection. Platt, who co-founded the advocacy nonprofit Tick-Borne Conditions United, said she hopes the recent discovery of the Ehrlichia bacteria in the longhorned tick will help raise awareness among doctors and the general public about the threat of tick-borne diseases, especially little-known ones like Ehrlichiosis.
Conclusion
The invasive longhorned tick species poses a significant threat to public health, particularly with its ability to transmit the Ehrlichiosis infection. As climate change continues to alter the environment, it is essential for individuals to take precautions and for healthcare professionals to be aware of the risks associated with tick-borne diseases. By understanding the unique biology of the longhorned tick and the symptoms of Ehrlichiosis, we can work towards mitigating the impact of this invasive species.
FAQs
- Q: What is the longhorned tick, and where is it originally from?
A: The longhorned tick is an invasive tick species originally from East Asia. - Q: What disease does the longhorned tick transmit?
A: The longhorned tick transmits the Ehrlichiosis infection, which can cause debilitating symptoms and, in rare cases, death. - Q: How can individuals protect themselves from tick-borne diseases?
A: Individuals can protect themselves by wearing long pants, tucking them into their socks, and conducting tick checks on family members and pets after being outdoors for extended periods. - Q: What is the "Ehrlichiosis Belt"?
A: The "Ehrlichiosis Belt" refers to the region in the U.S. where Ehrlichiosis is most prevalent, stretching from Connecticut and New York to Arkansas. - Q: How many cases of Ehrlichiosis are reported each year, and how many go undetected?
A: According to the CDC, there were 2,093 reported cases of Ehrlichiosis in 2019, but studies suggest that 99% of cases go undetected.
