Ticks and Vector-Borne Disease
Vector-Borne Disease
Vector-borne diseases are illnesses carried by animals or insects that spread diseases
between populations. Common vector-borne diseases include Zika Virus, Dengue,
Malaria, Lyme, and Scarlet Fever. Vector-borne diseases are on the rise due to climate
change and the native habitat loss for reservoir species, causing higher encroachment on
human populations.
Understanding Ticks and Their Risks
Ticks are highly successful vector species, carrying the most significant number of pathogens of any other disease-carrying invertebrates. Tick-borne diseases (TBDs) pose serious health, welfare, and environmental risks to surrounding ecosystems and human populations. Ticks are the vector species for a wide variety of illnesses, the most notable of which include Borrelia burgdorferi (Human Lyme Disease), R. helvetica, R. monacensis (spotted fevers), and Francisella tularensis (tularemia), all of which can cause deadly diseases in human populations. Unlike most disease-carrying vectors, ticks have a three host lifecycle, which increases the likelihood of disease transmission from reservoir species, such as birds, mice, and other small mammals to humans.
A tick’s life cycle consists of three separate stages: larvae, nymphs, and adults, with most disease transmission to humans occurring during the nymph stage. Ticks spend much of their life cycle in the external environment when not directly attached to a host.
The life cycle of a tick typically begins in the warmer months, commonly May, when egg laying begins. Once hatched, tick larvae feed small mammals, typically mice, as their first blood meal. During this process, the tick is exposed to pathogens such as B. burgdorferi and becomes a vector species. As the weather cools and winter begins, the larvae enter dormancy and stop feeding. In the spring, as warmer temperatures start, tick larvae emerge as nymphs and seek larger blood meals.
Many tick-borne diseases (TBDs) are transmitted through the nymph stage, which attaches to larger mammals such as humans. Nymphs are hard to detect, small, and their bites do not cause inflammation. Most who are bitten by a nymph are never aware of the bite.
How This Affects You
- In the warm months, apply tick-specific repellent before venturing into tall grasses, trails with overgrown foliage, or areas with a high tick population.
- Check yourself for ticks after returning from the outdoors, making sure to closely examine the scalp, back of knees, between toes, and in the private areas.
- Talk with your doctor if you notice abnormal symptoms, especially following a known bite. Early detection is key to preventing long-term illnesses.
- Vaccinate and protect family pets with monthly treatments, as ticks can detach from dogs and cats and be brought into the home.