It’s retail season again, North America. As the weather warms and people move outdoors, the chances of encountering a bloodsucking arthropod increase. In fact, tick problems today appear to be worse than they were 50 to 60 years ago, experts told Live Science.
It is worth being careful. Ticks cause at least 50,000 cases of disease in the United States each year, and these are just the diseases diagnosed and reported to the Centers for Disease Control and Prevention (CDC).
In fact, the actual incidence rates of tick-borne diseases are likely to be much higher. for example, A estimate for the year 2021 It indicates that 476,000 Americans are treated for Lyme disease alone each year. (This may overstate the actual number of Lyme infections, according to the CDC, because sometimes people are treated for Lyme as a precaution after being bitten by a tick.)
Although there is no single national surveillance system that detects all cases of tick-borne disease, the risk varies from state to state. In the northeast, where deer ticks (Ixodes scapularisThrive, not a concern. In the southeast, where the dog tick (Variants of dermacentor) tends to reside, and spotted fevers dominate, including Rocky Mountain spotted fever somewhat misleadingly.
Related: 9 out of 10 ticks in this Pennsylvania park carry a deadly neurovirus
Tick encounters on the rise
Ticks are an effective way to spread disease because they can feed on many host animals and because they remain attached to their hosts for several days, allowing enough time for pathogens to travel, said Jerome Goddard, extension professor of medical entomology at Mississippi State University.
Goddard told Live Science that increasing deer numbers is one of the main reasons for the increase in tick encounters. He said that ticks find food by ambushing passing animals, and if the tick does not find a host, it dies. When there are more deer, more ticks survive, which means that the deer and tick populations are closely related. Rural development, bringing people in close contact with ticks, also plays a role, According to the Center for Disease Control and Prevention. finally, Climate change It may alter the ranges of ticks and tick pathogens in ways that are not yet fully understood, and it also potentially increases the likelihood that people will interact with ticks.
According to the Centers for Disease Control and Prevention tick bite tracker dataMay and June are the peak months for tick bites that send people to the emergency room. During these months, the Northeast sees the most emergency visits for ticks per 100,000 people, followed by the Midwest and then the Southeast.
Lyme disease, which is caused by bacteria Borrelia burgdorferi It is transmitted by deer ticks, and usually infects people in the Northeast and Midwest, as is the case with anaplasmosis, another bacterial disease spread by deer ticks. People in the mid-Atlantic and Southeast are at risk for spotted fever, including Rocky Mountain spotted fever, which is caused by bacteria rickettsia rickettsia.
Ehrlichiosis, a bacterial infection spread by both deer ticks and lone star ticks (Amblyomma americanum), most common in the mid-Atlantic and southern and in Arkansas, Missouri, Oklahoma and Kansas.
This tick-borne bacterial infection usually presents with symptoms such as fever, headache, rash, and chills. They can all be treated with antibiotics when caught early, but a missed infection can be fatal. The infection can also cause long-term problems. For example, a subset of people who develop Ehrlichiosis later develop an allergy to red meat, Live Science previously reported.
These bacterial diseases have always been the result of tick bites. Recently, though, doctors and scientists have identified a group of viral diseases that ticks also transmit. These include Heartland and Bourbon viruses, which have been reported mostly from the South and Midwest. These viruses can cause fever, fatigue, headache, diarrhea, joint pain, and sometimes low platelet and white blood cell counts. There are no treatments for these viruses. Most people recover, but some patients have died. The most dangerous is the Poisan virus, often spread by ticks in the northeastern regions of the Great Lakes, and is capable of infecting the brain and the membranes surrounding the spinal cord.
Fighting tick-borne diseases
As tick-borne disease is a growing problem, researchers are looking for ways to respond. At State University of New York Abstat Medical Center in Syracuse, New York, microbiologist and immunologist Saravanan Thangamani and his team are working to develop vaccines for emerging tick-borne viruses, particularly Poasan virus. These viruses are transmitted immediately when a tick is bitten, Thangamani told Live Science, so vaccinations are necessary to prevent viruses from multiplying in the human body and spreading outside the skin.
Bacterial disease is another story. In most cases, the bacteria that cause these diseases take 24 to 36 hours after the initial bite to transmit. Rather than trying to develop vaccines for each disease individually, Thangamani and other scientists are seeking vaccines that target ticks themselves.
An effective anti-tick vaccine will work by targeting a mixture of proteins found in the tick’s saliva. Ticks inject a dynamic mixture of these proteins during the days when they are feeding to numb the skin and avoid the host. immune system. Animal experiments led by Yale University researchers showed that The anti-tick vaccine can interfere with the feeding of ticks And it caused them to quickly leave their host, Live Science previously reported.
“I feel that in the next three to five years we should have some good candidates” for vaccines, Thangamani said.
In the meantime, the best defense is a good attack. Goddard advises that to avoid tick bites in the first place, wear appropriate clothing when you are in tick-dense areas. Tucking your pants into rubber boots — or at least into your socks — can keep ticks away.
“If you’re wearing boots, leather boots that reach your ankles, and the legs of your pants are flapping in the breeze, that’s an Interstate Highway above your pants legs,” Goddard said.
Treating your clothes with a spray containing the insecticide permethrin will kill ticks on contact. (Goddard said insect sprays containing DEET also help, but not as effective.) Finally, checking your body for ticks after outdoor activities is key, Goddard said. If you find a tick attached, remove it immediately with tweezers by holding it close to the skin and pulling it straight.
Goddard said tick bites are on the calendar so if you get sick in the next several weeks, you can tell your doctor you were bitten and the date of the bite. There are some paid services that will test ticks for disease, as well as a limited number of government health departments and research institutions that will do the same for free. one of these organizations, NYticks.org, operated by Thangamani Laboratory. The researchers tested nearly 20,000 ticks, mostly from New York state, and have a real-time state dashboard showing which pathogens are present in counties.
“Viewing data in real time is very unique and very powerful,” Thangamani said.
Originally published on Live Science