The causative agent of Lyme disease is?

Appeared in: AIIMS Patna NO - 2020

Explanation

Lyme disease is a bacterial infection caused by the spirochete Borrelia burgdorferi.
This bacterium is transmitted to humans through the bite of infected Ixodes ticks, also known as deer ticks.
The disease is named after Lyme, Connecticut, where a cluster of cases was first identified in 1976.
The key differentiator is knowing that Lyme disease is caused by a specific spirochete bacterium, Borrelia, and not a Rickettsia, virus, or protozoan.

Option A: Rickettsia prowazekii is the bacterium responsible for causing epidemic typhus, a disease transmitted by body lice, not ticks.
Option B: Alphavirus is a genus of RNA viruses, not bacteria. Lyme disease is a bacterial infection.
Option D: Trypanosoma brucei gambiense is a protozoan parasite that causes African sleeping sickness, a disease transmitted by the tsetse fly.

Clinical Relevance

Nursing practice connection: Knowing Causative agent of Lyme disease helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses play a crucial role in patient education regarding tick bite prevention, such as using insect repellent, wearing protective clothing in wooded areas, and performing tick checks.
Early recognition of the erythema migrans (bull's-eye) rash is critical for prompt diagnosis and treatment with antibiotics (e.g., doxycycline, amoxicillin) to prevent progression to later, more severe stages of the disease.
What if the patient is a child under 8 years old or a pregnant woman? Doxycycline is generally contraindicated. The nurse should anticipate an order for amoxicillin or cefuroxime instead.

How to Approach the Question

First, identify the core of the question, which is asking for the specific microorganism ('causative agent') that causes 'Lyme disease'.
Access your knowledge of microbiology and infectious diseases. The question requires you to link a specific disease with its pathogen.
Evaluate each option. Consider the type of organism (bacterium, virus, parasite) and the disease it is known to cause.
Eliminate Rickettsia prowazekii (causes typhus), Alphavirus (a virus genus), and Trypanosoma brucei gambiense (causes sleeping sickness).
This process of elimination leaves Borrelia burgdorferi, which is the well-known bacterial spirochete responsible for Lyme disease.
Confirm the association between Borrelia burgdorferi, tick vectors, and the clinical presentation of Lyme disease to finalize your answer.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 1 p. 1490-1492

Practise the full AIIMS Patna NO - 2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.