Use the following choices to answer the question given below:
a. Brucellosis
b. Malaria
c. Relapsing fever
d. Rocky Mountain spotted fever
e. Ebola
The patient was hospitalized with fever and headache. Spirochetes were observed in her blood. What is your diagnosis?

Verified step by step guidance

1. Step 1: Identify the key clinical features and laboratory findings from the problem. Here, the patient has fever and headache, and spirochetes were observed in the blood.
2. Step 2: Recall that spirochetes are a group of spiral-shaped bacteria. Among the diseases listed, only relapsing fever is caused by spirochetes (specifically Borrelia species).
3. Step 3: Understand that brucellosis, malaria, Rocky Mountain spotted fever, and Ebola are caused by different types of pathogens (Brucella bacteria, Plasmodium protozoa, Rickettsia bacteria, and Ebola virus, respectively) and do not involve spirochetes.
4. Step 4: Use the presence of spirochetes in the blood as a definitive clue to narrow down the diagnosis to relapsing fever.
5. Step 5: Conclude that the diagnosis is relapsing fever based on the observation of spirochetes in the blood combined with the clinical symptoms.

Key Concepts

Spirochetes and Their Characteristics

Spirochetes are a group of spiral-shaped bacteria known for their unique corkscrew motion. They are responsible for diseases such as relapsing fever, Lyme disease, and syphilis. Identifying spirochetes in blood smears is crucial for diagnosing infections caused by these bacteria.

Relapsing Fever

Relapsing fever is a bacterial infection caused by spirochetes of the genus Borrelia. It is characterized by recurring episodes of fever, headache, and muscle pain. The presence of spirochetes in the blood during febrile episodes is a key diagnostic feature.

Differential Diagnosis of Febrile Illnesses with Blood Parasites

Febrile illnesses like malaria and relapsing fever can present with fever and headache, but malaria involves protozoan parasites, not spirochetes. Recognizing the type of pathogen in blood (bacteria vs. protozoa) helps differentiate diseases and guides appropriate treatment.