under the microscope
under the microscope
By Priya Dhagat, MS, MLS( ASCP) CM, CIC
Lemons or Lyme? Stay Aware of this Summer-time Spirochete
Early symptoms of Lyme infection include flu-like symptoms, but the most recognizable symptom of early, untreated Lyme disease is the“ bull’ s- eye rash”, or erythema migrans, which typically develops 7 to 14 days after the tick bite and can enlarge to 12 to 35 cm in diameter. The“ bulls-eye rash” appears as a red center surrounded by a region of clearing and a red outer ring.”
Just as winter turns into spring, flu season turns into vector-borne disease season. With changes in temperatures and precipitation – coupled with increased seasonal travel and outdoor activities – the risk of contracting tickborne infectious diseases increases. Among these vector-borne disease is Lyme disease, caused by an infection with Borrelia burgdefori, which spreads to people by the bite of an infected blacklegged tick, also known as a deer tick.
In the United States, two species of ticks are associated with Lyme disease: Ixodes scapularis and Ixodes pacificus. Ixodes scapularis is found in the U. S. Northeast and North Central states and Ixodes pacificus In the U. S. Northwest states. About 90 percent of all reported Lyme disease cases are from 15 jurisdictions in the Northeast, mid-Atlantic, and upper-Midwest regions, with Maine, Rhode Island, and Vermont having the highest prevalence. According to the Centers for Disease Control and Prevention( CDC), approximately 476,000 people may be diagnosed and treated for Lyme disease each year in the United States. The life cycle of ticks is strongly influenced by temperature, as they are mostly active above 45˚F with at least 85 percent humidity. Warming temperatures associated with climate change may influence and increase suitable tick habitats, which could extend the period when ticks are active each year.
The blacklegged tick goes through three main stages of development during its life cycle: larva stage, nymph stage, and adult stage. Most cases of Lyme disease are transmitted during the nymph stage, when then ticks are about the size of a poppy seed, making them difficult to see when attached to the skin. After a tick bites the skin, it can remain attached for several days as it feeds. During this time, the bacterium Borrelia burgdefori can be transmitted, usually between 24 to 36 hours after the bite. This unique bacterium – motile, slender, and tightly coiled like a cork-screw – causes an equally unique rash and can even lead to long-term systemic complications.
Early symptoms of Lyme infection include flu-like symptoms, but the most recognizable symptom of early, untreated Lyme disease is the“ bull’ s-eye rash”, or erythema migrans, which typically develops 7 to 14 days after the tick bite and can enlarge to 12 to 35 cm in diameter. The“ bulls-eye rash” appears as a red center surrounded by a region of clearing and a red outer ring. However, erythema migrans may also appear as a flat rash with no central clearing or a rash with no central redness at varying times during the infection. The unique appearance of a“ bull’ s- eye” is caused by a combination of two reactions: an inflammatory reaction to the tick’ s saliva and an immune reaction to the bacterial skin infection. The innate immune response kicks into action by first reacting to the salivary proteins at the site of the bite, and then to the motile, spirochetes that are replicating at the point of entry and moving outward through the tissue. The inflammatory and immune response continues, leading to the expansion of the rash and the“ bull’ s-eye” appearance. If left untreated, infection can spread to joints, the heart, and the nervous system leading to arthritis, carditis, and neurologic impairment( e. g., brain fog, vertigo, difficulty sleeping).
Enzyme-linked immunoassay followed by Western blot for confirmation is the standard two-tiered testing method recommended by the CDC. However, false-positive results are possible due to antibodies present in serum that may cross-react with unrelated bacterial antigens. Epidemiological risk factors( e. g., possible tick bite) coupled with clinical features of infection are more commonly used to diagnose and treat Lyme disease. A single 200 mg dose of doxycycline has been recommended for prophylaxis after tick attachment for prevention of Lyme disease. A 10- to 14-day course of antibiotics is recommended for early Lyme disease treatment.
As we enjoy the warm weather, don’ t let Lyme disease sour your summer. Here are five reminders to promote awareness prevent infection:
➊ Use insect repellent
➋ Wear protective clothing
➌ Check for ticks after being outdoors
➍ Seek medical attention if you develop symptoms after a potential tick bite
➎ Complete antibiotic treatment if caught early
Priya Dhagat, MS, MLS( ASCP) CM, CIC, is an infection preventionist and the associate director of the system-wide Special Pathogens Program within the Department of Emergency Management at New York City Health + Hospitals, overseeing special pathogen preparedness and response efforts across New York City Health + Hospitals frontline healthcare facilities. Additionally, she supports and offers subject matter expertise for infection prevention topics for the National Emerging Special Pathogens Training and Education Center( NETEC).
References: https:// www. ccjm. org / content / 86 / 11 / 751 https:// asm. org / articles / 2018 / april / going-skin-deepinvestigating-the-cutaneous-host-p https:// pmc. ncbi. nlm. nih. gov / articles / PMC3676011 / https:// www. merckmanuals. com / professional / infectiousdiseases / spirochetes / lyme-disease # Symptoms-and-Signs _ v1008018
6 • www. healthcarehygienemagazine. com • may-june 2025