Summary about Disease
Relapsing fever is a bacterial infection characterized by recurring episodes of fever separated by periods without fever. It is caused by various species of Borrelia bacteria transmitted to humans through the bites of infected ticks or lice. The disease is named for its characteristic pattern of recurring fevers.
Symptoms
Symptoms of relapsing fever typically include:
High fever (often 104-106°F or 40-41°C)
Chills
Headache
Muscle and joint aches
Nausea and vomiting
Abdominal pain
Cough
Eye pain
Sometimes, a rash These symptoms usually last for 3-6 days, followed by a period of 2-14 days without fever. The fever and other symptoms then return, repeating the cycle.
Causes
Relapsing fever is caused by bacteria of the genus Borrelia. The bacteria are transmitted to humans through the bites of:
Ticks: Tick-borne relapsing fever is typically caused by Borrelia hermsii, Borrelia turicatae, or Borrelia parkeri in North America, or other species in other parts of the world. Ticks acquire the bacteria from rodent reservoirs.
Lice: Louse-borne relapsing fever is caused by Borrelia recurrentis. It is transmitted from human to human via body lice.
Medicine Used
The primary treatment for relapsing fever is antibiotics. Commonly used antibiotics include:
Tetracycline (e.g., doxycycline)
Erythromycin (or other macrolides)
Penicillin The choice of antibiotic and the duration of treatment will depend on the severity of the infection and the patient's overall health. A Jarisch-Herxheimer reaction (fever, chills, and other systemic symptoms) can occur shortly after starting antibiotic treatment due to the release of toxins from dying bacteria. This is usually self-limiting but can require supportive care.
Is Communicable
?
Louse-borne relapsing fever: Yes, directly communicable from person to person via body lice.
Tick-borne relapsing fever: No, not directly communicable from person to person. It requires transmission through a tick vector.
Precautions
Precautions to prevent relapsing fever include:
Avoid tick bites:
Wear long sleeves and pants when in wooded or grassy areas.
Use insect repellent containing DEET or picaridin.
Check yourself and your pets for ticks regularly.
Remove ticks promptly and carefully.
Avoid lice infestation:
Practice good hygiene.
Avoid close contact with infested individuals.
Wash clothing and bedding frequently in hot water.
Control rodent populations:
Seal cracks and holes in buildings to prevent rodent entry.
Store food in rodent-proof containers.
How long does an outbreak last?
The duration of an outbreak can vary depending on the source of the infection (ticks or lice) and the effectiveness of control measures.
Louse-borne outbreaks: Can last for extended periods (months to years) in areas with poor sanitation and overcrowding, until the louse infestation is controlled.
Tick-borne cases: Occur sporadically or in small clusters, primarily during seasons when ticks are active. Outbreaks are less common but can occur if there is an increase in rodent populations or human exposure to tick-infested areas.
How is it diagnosed?
Relapsing fever is diagnosed based on:
Clinical symptoms: Recurring episodes of fever and other characteristic symptoms.
Microscopic examination of blood: The Borrelia bacteria can often be seen in blood smears taken during a fever episode. This is the most rapid and specific diagnostic method.
Serological tests: Antibody tests can be used to detect antibodies against Borrelia bacteria, but they may not be reliable early in the infection.
PCR Testing: Molecular tests like PCR can detect Borrelia DNA in the blood.
Timeline of Symptoms
The typical timeline of symptoms is as follows:
Incubation period: 2-18 days after the bite of an infected tick or louse.
First febrile episode: Sudden onset of high fever, chills, headache, muscle aches, lasting 3-6 days.
Afebrile period: A period of 2-14 days without fever or other symptoms.
Relapse: Recurrence of fever and other symptoms, similar to the initial episode, lasting 3-6 days. Relapses can occur multiple times (3-10 or more) if untreated.
Important Considerations
Relapsing fever can be fatal if untreated, particularly in vulnerable populations (e.g., pregnant women, young children, elderly individuals).
Early diagnosis and treatment with antibiotics are crucial for a successful outcome.
The Jarisch-Herxheimer reaction is a common complication of treatment. Monitoring and supportive care are important during the initial stages of antibiotic therapy.
Prevention measures (avoiding tick and louse bites, practicing good hygiene) are essential for controlling the spread of the disease.
Specific species identification of Borrelia can be challenging and may require specialized laboratory testing.