For more than 30 years, Professor Richard Ostfeld, from the Cary Institute of Ecosystem Studies, has been involved in field and laboratory research on the ecology of tick-borne diseases.
Ticks worldwide are important sources of disease-causing agents in people, pets and livestock and wild animals. Once a tick embeds its mouthparts into a host, the microorganisms that reside in it can enter the host, causing different types of diseases.
“When ticks bite some wildlife hosts, they can also acquire pathogens that they can then transmit. In North America and Europe, ticks are the most important source of human diseases transmitted by vectors, more important than mosquitoes”, explains the professor to CNN .
An example is the case of spotted fever, caused by bacteria of the genus Rickettsia, transmitted by the bite of the star tick. In 2023, the state of São Paulo registered 12 cases, including six deaths, two under investigation and four patients cured. In Brazil, this year, 53 cases of the disease have already been confirmed, of which eight resulted in deaths. The highest concentration of cases is seen in the Southeast and South regions, and generally occur sporadically.
“Here in the Northeastern United States, we are at the epicenter of several tick-borne diseases. I research the ecological factors that affect the risk of human exposure to these diseases. We focus on the biology of rodents, their predators, their food, human-caused reductions in biodiversity and climate. We have successfully predicted bad years for Lyme disease as well as risky places in the landscape.”
A curious fact involves researcher Richard Ostfeld: he developed a type of immunity to tick bites.
“When I am bitten by a tick, I seem to mount a rapid immune response to the tick itself, likely to antigens in the tick’s saliva. This results in the tick dying before it is able to swallow my blood. I notice an attempt at a tick bite when I feel an itch or burning sensation at the site of the bite, strong enough to wake me up during the night, if it occurs during sleep”, he says.
Ostfeld says that when removing the tick, it is usually dead and not fed. “I also form a welt at the site of the bite that can last for several days, suggesting that the inflammation persists. Despite countless tick bites, I was never diagnosed for Lyme disease or any other tick-borne illness,” he reports.
Resistance against tick bites
The possibility of host resistance, including people, to tick bites is a context that requires more comprehensive scientific studies.
“Some hosts can quickly mount an immune response to proteins, or antigens, in the tick’s saliva, allowing them to attack and even kill the tick. If this happens before the pathogens leave the tick and enter the host, protection against disease can result. It seems that such resistance requires previous experience of the immune system to these antigens, so that resistance is acquired after previous tick bites, but not in all hosts”, explains Ostfeld.
The researcher believes that the study of resistance can help in the development of potential vaccines.
“If the right antigens can be identified, it is at least theoretically possible to design vaccines against tick bites. Because ticks can transmit so many pathogens, Lyme disease agents, babesiosis, anaplasmosis, Powassan virus disease and more, this vaccine could potentially protect against many diseases.”
“Vaccines must be considered safe and effective before their use is permitted, but I hope that such studies will be vigorously pursued,” he concludes.
Source: CNN Brasil
I am an experienced journalist and writer with a career in the news industry. My focus is on covering Top News stories for World Stock Market, where I provide comprehensive analysis and commentary on markets around the world. I have expertise in writing both long-form articles and shorter pieces that deliver timely, relevant updates to readers.
