Note: Before you dive into this blog, it is important to remember that ticks are most active NOW! During November, ticks are actively searching for hosts to provide them with a blood meal. This month it is especially crucial to do a tick check on yourself, others, and your pets after spending time outdoors to reduce your risk of tick-borne illness.
Most Common Tick During Fall: The Deer Tick
Even after the first few frosts, ticks will still be active! In Autumn, people generally encounter one type of tick, the adult blacklegged tick, more commonly known as a deer tick.
The tiny poppy seed-sized nymph ticks that got a blood meal in late spring or summer have now grown into their adult form. Black colored deer ticks are males looking for mates, whereas the black and red colored females are actively looking for blood meals. Their first choice of host is deer, but they will also feed on people and their pets.
Female deer ticks are particularly dangerous because around 50% of them are infected with the Lyme disease bacteria in the New England, mid-Atlantic, and Upper Midwestern states. The likelihood of disease increases the longer a tick is attached and feeding. In addition to the Lyme disease bacteria, blacklegged ticks may also carry the germs that cause babesiosis, anaplasmosis, borrelia, and the deadly Powassan virus.
Ticks remain active as long as the temperature stays above freezing, making it crucial to stay vigilant of the signs and symptoms of tick-borne illnesses, even as the weather cools down. Babesiosis is a tick-borne illnesses that is steadily rising, caused by a parasite that infects red blood cells, unlike Lyme which is caused by a bacterial infection. It has been spreading in the Northeast and upper Midwest, with Vermont experiencing a 1,602% increase in cases from 2011 to 2019.
Babesiosis symptoms can resemble the flu, i can be diagnosed through a blood test, and treatment involves antimicrobial drugs or blood transfusion. Prevention involves reducing the risk of tick bites through measures such as doing a proper tick check after outdoor activities, showering after exposure, using safe repellents, and wearing protective clothing. Taking these precautions, especially in areas where ticks are common, can significantly reduce your risk of tick-borne illnesses. Edouard Vannier, an assistant professor at the School of Medicine, received over $1 million in grant funding from the National Institute of Health and the Department of Defense for research to prevent the tick-borne illness babesiosis.
The Tick App
The Tick App is a smartphone application designed to help users identify ticks and track their exposure. It was designed in 2018 with the intent of gathering information on human behaviors and movement related to tick exposure. The app integrates self-report data and GPS coordinates to better understand tick encounter locations. The app utilized digital photo guides of tick species, life stage, and blood-fed status identification.
Over the course of a 2019-2021 study, the app users provided a better understanding of the spacial and temperal patterns of tick exposure in the United States. More than half of the app users had traveled outside their home county in the four days prior to tick detection and many users spent a high degree of time on agricultural land in the four days prior to tick detection. Most encounters recorded on the app involved human hosts, but 25% involved animals.
Tick-borne infections in the United States have been increasing, particularly in the Northeast and Midwest regions. Understanding local tick-borne disease risk is crucial. If you find a tick, use the Tick App to identify the species and life stage all while contributing to public health data in your community.
Forest Fragmentation & Ticks
Forest fragmentation occurs when large blocks of forest are continuously divided into smaller patches to make space for housing developments, roads, buildings, and agriculture. Forests are wooded areas that can support a diversity of animal species. Yet, these animals depend on stable environmental conditions like sunlight. humidity, and temperature to survive. Disturbing these forest interiors from providing these consistent conditions for its inhabitants has caused the reduction of many populations.
Due to the loss of diversity caused by forest fragmentation, the decline of their predators has allowed white-footed mice to thrive. These animals are a main source of Lyme disease because they do not groom ticks off their bodies, contributing to the population of infected ticks. White-tailed deer also thrive in fragmented forests. Although deer do not carry Lyme disease, they play an important role in the tick lifecycle, determining tick abundance for future generations. Adult ticks primarily feed on deer, so their movement carries ticks to into new locations.
The interactions between ecosystems that are occurring more commonly in fragmented forests are both complex and understudied. It is important to understand that expanding human development into forests brings people into closer contact with areas where ticks may live, increasing their exposure to tick-borne illnesses.
Tufts University’s Lyme Disease Initiative has received over $7 million in grants to expand research efforts to prevent Lyme disease and other tick-borne illnesses. Lyme disease was discovered 50 years ago and since then has spread across New England, the upper Midwest, and the Mid-Atlantic states. If you are bit by a deer tick infected with Lyme, the symptoms can range from a bullseye-shaped rash to more severe complications. The grants will focus on identifying the underlying causes of chronic Lyme, improving diagnostic methods, tracking Lyme infection and reinfection, and preventing tick-borne diseases like babesiosis, which we learned about above! Researcher Edouard Vannier and his colleagues received grants specifically to research babesiosis, a tick-borne disease similar to Lyme disease, and explore methods of prevention, including drug treatments and vaccines.
Other research topics included:
- Studying the role of phospholipids in chronic Lyme disease and their potential use in diagnostic tests for persistent infection.
- Studying blood and tissue samples from Lyme patients to identify specific phospholipid autoantibodies that may indicate persistent Lyme disease.
- Investigating an immune system marker called interferon-alpha and its role in triggering lingering symptoms in patients treated for Lyme.
- Innate immune memory and its role in allowing the Lyme bacteria to survive in hosts, potentially leading to persistent symptoms.
- Interactions between the Lyme bacterium and natural hosts to better understand the disease’s life cycle and develop prevention strategies.
Tufts researchers are also working with Tarsus Pharmaceuticals to develop a drug known as lotilaner, that can kill ticks before they transmit infections to humans. The development of lotilaner could be a game-changer in preventing tick-borne diseases, offering protection against multiple tick-borne diseases for 1-3 months. This drug is already used for preventing Lyme disease in dogs. If it proves effective in humans, these research efforts could lead to improved diagnostic tools, better treatments, and prevention strategies for Lyme disease and other tick-borne diseases.
Lyme Vaccine Underway
Lyme disease cases have increased significantly since it was first identified in the 1970s. The CDC suggests 300,000 to 476,000 Americans contract Lyme disease annually from infected blacklegged ticks. On the bright side, Pfizer and Moderna, biopharmaceutical companies that have become household names after the Covid-19 pandemic, are developing vaccines for Lyme disease. Pfizer’s vaccine is in Phase III trials and may be available to consumers by 2026. It is aiming to be a more refined version of a previous Lyme disease vaccine known as Lymerix. Lymerix had a unique mechanism of killing bacteria inside ticks before transmission, but was discontinued in 2002 due to poor sales and side effect concerns.
Moderna is also developing two Lyme disease vaccine candidates using mRNA technology, but no release date is specified. Until vaccines are approved, individuals in tick-infested areas should follow tick prevention protocols. This includes doing daily tick checks, using a safe tick repellent, avoiding out of heavily wooded areas and tall grass, and proper tick removal within 24 hours using fine-tipped tweezers.
New Research Ahead
The Northeast Regional Center for Excellence in Vector-Borne Diseases (NEVBD), led by Cornell University, has received a $8.7 million award from the CDC for five years. The grant aims to train and educate vector-borne disease professionals and evaluate prevention strategies. Collaborating institutions include Cornell, Columbia University, the University of Maryland, and others. The focus of the research is addressing tick-borne infections such as West Nile virus in the Northeast.
Training efforts include providing education for working professionals, hosting meetings, and running a bootcamp training program. The center supports vector biology education programs and offers a Master of Science in Entomology. The grant will continue monitoring mosquito pesticide resistance and evaluating an vaccine for Lyme disease. In this case, the vaccination would be given orally to rodents, which are reservoirs for Lyme disease.
Ticks & The Army
A study conducted by the MilTICK program found that ticks on service members wearing permethrin-treated uniforms were less likely to become engorged. Permethrin-treated clothing protects against ticks and other arthropods. The DOD Insect Repellent System includes permethrin treated uniforms, DEET or Picaridin on exposed skin, properly worn uniforms, and permethrin-treated bed nets. Army personnel were more likely to wear permethrin due to factory-treated uniforms.
The MilTICK program offers tick testing and identification, providing information on tick species, engorgement level, and analysis for tick-borne pathogens. Avoidance is the best way to combat ticks and soldiers are encouraged to use duct tape as a tool to remove crawling ticks in the field and treat field clothes with Permethrin. Immediate tick removal and disinfection are also essential.