Lyme Disease Transmission and Tick Life Cycle

Adult ticks, which are comparable in size to sesame seeds, are the most active throughout spring to late summer when people are most likely to spend time outdoors. However, exposure is possible at any time of the year, making it important to take precautions to avoid tick bites as much as possible.

Lyme disease is caused by the bacterium Borrelia burgdorferi and, less commonly, Borrelia mayonii. It is primarily transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis), commonly known as deer ticks. These ticks are typically found in wooded and grassy areas, making Lyme disease a particular concern for people living in or visiting these regions.

Understanding the Lyme disease transmission process and tick life cycle is crucial for prevention and early treatment. Keep reading to find out how to prevent Lyme disease or seek effective treatment for your symptoms from Sierra Integrative Medical Center if you already have it.

Tick Life Cycle

The life cycle of the black-legged tick, which is responsible for most cases of Lyme disease, spans up to two years and involves four life stages: egg, larva, nymph, and adult. However, most will die if they cannot find the next host for feeding.

Unlike the brown dog tick, which spreads the bacteria that causes Rocky Mountain spotted fever, black-legged ticks don't feed on the first host they find at the beginning of their life cycle. Instead, they must find a new host for every stage to survive.

1. Egg: The cycle begins in spring when female ticks lay eggs. After completing their two-year life cycle, adult female ticks lay thousands of eggs on the ground every spring.
2. Larva: The eggs hatch into larvae during the summer. At this stage, larvae are not yet infected with Lyme disease. They become infected after feeding on an infected host. While rare, some larval ticks can become infected from adult female ticks through the eggs and spread tick-borne illnesses.
3. Nymph: In the next stage, larvae transform into nymphs the following spring. Nymphal ticks are tiny and difficult to see, about the size of a poppy seed, making them more likely to transmit Lyme disease to humans because they often go unnoticed.
4. Adult: By fall, nymphs mature into adults, which are more likely to feed on larger mammals, such as deer (hence the name deer tick).

The Transmission Process

For transmission to humans, the tick must be attached and feed for at least 36-48 hours, as the bacterium needs time to migrate from the tick's gut to its salivary glands. Feeding ticks acquire the bacterium by biting infected animals, primarily small mammals like mice. They also feed on other mammals, birds, reptiles, and even amphibians, which serve as hosts for their blood meal. This is why prompt detection and removal of ticks are crucial to preventing Lyme disease.

1. Tick Bite: The primary transmission mode is through the bite of an infected tick. These ticks are usually in the nymph stage of their life cycle, as they are small and difficult to see, increasing the likelihood of a longer, unnoticed attachment to the host. However, adult ticks can also transmit Lyme disease to humans.‍
2. Attachment and Feeding: For the transmission of Lyme disease bacteria to occur, the tick generally needs to be attached and feed on the host's blood for at least 36-48 hours. This is because the bacteria reside in the tick's gut and need time to migrate to the tick's salivary glands before being transmitted to the host through the saliva.‍
3. Bacteria Transmission: Once the bacteria enter the host's skin through the tick's saliva, they begin to spread within the skin and can move into the bloodstream, disseminating to various parts of the body.

Initial Symptoms of a Tick Bite

You won't always know when you get bitten by a tick. In addition to their small size, tick bites often don't hurt. That's why it's important to check yourself, your loved ones, and your pets after you have spent time outdoors where ticks may be present.

The best way to find a tick is to complete a body check by running your hands over your skin and through your hair. The most common places to find them on your body are between fingers and toes, behind the knee, and in the underarms. But remember to check the top of your head, your hairline, neck, and belly button in case they found a place to hide.

If you get bitten, the symptoms following a tick bite can vary depending on the type of tick, whether it was carrying any diseases, and how long it remained attached to the skin. Most tick bites are harmless and don't cause any noticeable symptoms. However, some can lead to allergic reactions or transmit pathogens that cause diseases, including Lyme disease, Rocky Mountain spotted fever, and others.

Here are some early symptoms that can occur after a tick bite.

Immediate to Early Symptoms Post-Bite

• Red spot or rash: A small red spot or rash is common near the bite site, especially if the tick was removed improperly.
• Itching: A tick bite may cause an intense itch at the site of the bite.
• Swelling: Some swelling around the bite area can occur.
• Pain or discomfort: The area of the bite may feel tender or painful.

Symptoms of Tick-borne Diseases

If the tick was carrying pathogens, the following symptoms could develop days to weeks after the bite:

• Rash: Lyme disease, an expanding red rash that sometimes resembles a bull's eye, known as erythema migrans, occurs in 70-80% of infected individuals. Rocky Mountain spotted fever can cause a rash that starts a few days after the fever, beginning on the wrists, forearms, and ankles and then spreading to the trunk.
• Fever/chills: A sudden high fever can indicate a tick-borne disease.
• Aches and pains: Tick-borne disease symptoms include headache, fatigue, and muscle aches. Joint pain can also occur with Lyme disease.
• Nausea: Feeling nauseous or vomiting can be symptoms of certain tick-borne diseases.
• Neck stiffness: In the case of Lyme disease, meningitis (inflammation of the membranes surrounding the brain and spinal cord) can develop, leading to neck stiffness, headaches, and light sensitivity.
• Swollen lymph nodes: Lymph nodes near the bite site may swell as a response to the infection.
• Dizziness or difficulty breathing: These are less common but more serious symptoms associated with severe allergic reactions to tick bites or advanced stages of tick-borne diseases.

When to Seek Medical Attention for Tick Bites

Tick bites are not always a cause for concern. But see a doctor if you are unable to entirely remove the tick from your body or experience any of these situations:

• If a tick has been attached for 24 hours or longer, especially if it's engorged, the risk of disease transmission increases with time.
• If symptoms of tick-borne diseases develop, particularly if you've been in areas where ticks are prevalent.
• If the bite site develops severe redness or swelling or becomes increasingly painful, this could indicate an infection or allergic reaction.

Prompt removal of ticks and proper skin care afterward are crucial steps in preventing the symptoms and complications associated with tick bites. Early diagnosis and treatment are important to prevent serious health issues if a tick-borne disease is suspected.

The initial symptoms of Lyme disease often appear within 3 to 30 days after a tick bite, varying from person to person. However, symptoms may not occur until months or even a few years after direct contact.

Common early signs include:

• Erythema migrans (EM) rash: This is the hallmark symptom, appearing in approximately 70-80% of infected persons. The rash begins at the site of the tick bite after a delay of 3 to 30 days (an average of about 7 days). It may expand over several days to several weeks, forming a circular or oval-shaped rash that sometimes resembles a bull's-eye pattern. The rash is typically not itchy or painful.
• Flu-like symptoms: Fever, chills, fatigue, body aches, headache, neck stiffness, and swollen lymph nodes can accompany the rash.

Different Ways Humans Can Get Lyme Disease

• Direct Tick Bite: The most common method of contracting Lyme disease is through direct bites from infected ticks. People who spend time in grassy or wooded areas, like the forest floor, where these ticks are prevalent, are at higher risk.
• Indirect Contact: While less common, it is theoretically possible to get Lyme disease from coming into contact with crushed ticks or their body fluids. However, this mode of transmission is rare and not well documented.
• Other Modes: There is no evidence to suggest that Lyme disease can be transmitted through air, food, or water or from person to person via touching, kissing, or sexual contact. It is also not transmitted through blood transfusions.

Prevention and Early Detection 

Emphasizing the importance of prevention and early detection can greatly reduce your chances of getting Lyme disease or reducing the severity of your symptoms. Prevention strategies include:

• Environmental Management: Reducing exposure to ticks by managing the environment, such as clearing leaf litter and tall grasses from around homes and creating tick-safe zones.
• Personal Protection: Using tick or insect repellents, wearing protective clothing, and performing regular tick checks after being outdoors.
• Pet Care: Regular tick checks and treatments for pets, as they can bring ticks into the home and become infected if they are bitten.

Preventative measures, such as using insect repellent, wearing long sleeves and pants, avoiding tick-infested areas, and performing regular tick checks, are key to preventing Lyme disease.

If you find a tick attached to your body, prompt and proper removal is critical to avoid infection. If Lyme disease is suspected, especially if early signs such as the EM rash or flu-like symptoms are present, seeking medical advice is crucial for prompt diagnosis and treatment.

Get Comprehensive Treatment for Lyme Disease at Sierra Integrative Medical Center

For those diagnosed with Lyme disease, an integrative approach might include antibiotic treatment to address the infection and supportive therapies to relieve symptoms and promote overall health. Alternative therapies include nutritional support, herbal remedies, physical therapy, and stress management techniques for a comprehensive treatment approach.

Understanding the transmission vectors and life cycle of ticks plays a crucial role in both prevention and treatment strategies for Lyme disease. By combining this knowledge with a comprehensive approach to health, Sierra Integrative Medical Center can provide effective education, prevention, and treatment strategies for individuals at risk of or suffering from Lyme disease. Contact us to make an appointment with one of our Lyme disease specialists today!