| Abstract|| |
Relapsing fever is a complex group of diseases caused by spirochetes of the genus Borrelia transmitted to humans by lice or ticks. The purpose of this study is to present a case of relapsing fever. A 50-year-old female was admitted with fever, headache, nausea, myalgia, and arthralgia. She had history of relapsing fever for 3-5 days with 15-21-day-intervals of apyrexia during the past 3 months. Laboratory exams were normal. Peripheral blood smear showed spirochetes. She was treated with doxycycline to which she showed good response. The patient is asymptomatic and without sequelae since 3 months. In the case we reported, relapsing fever due to spirochetemia was made during the differential diagnosis. Owing to the difficulty in identification, it is important to have a high clinical suspicion of this type of infection.
Keywords: Borreliosis, doxycycline, relapsing fever, spirochetemia
|How to cite this article:|
Veena S, Seema V, Babu R. Borreliosis: Recurrent fever due to spirochetes. Ann Trop Med Public Health 2013;6:482-4
| Introduction|| |
Relapsing fever is an acute febrile illness caused by spirochetes of the genus Borrelia. The disease has two forms: tick-borne, in which human infection is zoonotic, and louse borne, in which humans are the only known reservoir of infection.  Recurrent fever can be caused by various types of spirochetes of the genus Borrelia. Borrelia recurrentis is the only species transmitted by body lice (Pediculus humanus) without an animal vector and represents an epidemic situation. There are other vectors such as soft-bodied tick ornithodoros from rodents and other small mammals, which have an endemic behavior. On the other hand, there are about 15 species of Borrelia worldwide. Among the most common in Africa are Borrelia duttonii, B. recurrentis, Borrelia corcidurae and in North America, Borrelia hermsii and Borrelia turicatae. Infection is transmitted by the vectors indicated and is common among homeless people and refugees. In these groups epidemic outbreaks may occur. In the U.S. and Mexico, most cases occur in persons who have been exposed to infected ticks that, after feeding on the blood of rodents, acquire the infection.
They come in contact with humans while staying in recreational environments or when visiting caves infested by rodents. Soft-bodied ticks are peculiar in that they produce a painless bite that goes unnoticed. The contact of parasite with human occurs between 10 and 30 min and usually overnight. The tick transmits the infection through the saliva after feeding with blood. In contrast, body lice become infected only after feeding on blood of humans with spirochetemia. In these cases, infection is transmitted when the infected lice are crushed and their fluid contaminates the bite or broken skin areas. These vectors are contagious while alive because transmission among humans does not occur. ,
The clinical manifestations of tick-borne and louse-borne relapsing fever are similar, although louse-borne relapsing fever often has a longer incubation period and a longer duration of illness. Bacteremia is heralded by the acute onset of high fever [usually above 39°C (102.2°F)], accompanied by headache, nausea, myalgias, and arthralgias. On average, clinical illness remits in 3 days in tick-borne relapsing fever, but may take 5-6 days in louse-borne relapsing fever. Physical findings may include altered sensorium, petechiae, hepatosplenomegaly, and conjunctival suffusion. The fever culminates in a "crisis," characterized by rigors and a precipitous rise in temperature, pulse, and blood pressure. This is followed by defervescence, diaphoresis, and hypotension. The risk of death is highest during this period and immediately afterwards.
With resolution of the bacteremia, an afebrile period ensues, lasting 4-14 days. Fever then recurs, although usually milder, again associated with bacteremia. On average, people with tick-borne relapsing fever have three febrile relapses; those with louse-borne relapsing fever have one.  Relapse occurs because of antigenic variation, in which a major surface antigen of the spirochete is changed to evade the host's immune system. ,,]
Borrelia may invade organs and the nervous system
With each episode of bacteremia, spirochetes may penetrate the brain, heart, liver, eye, or inner ear. Involvement of the central nervous system is more common with tick-borne than with louse-borne relapsing fever. Nervous system involvement may include facial palsy, myelitis, radiculopathy, aphasia, hemiplegia, stupor, or coma. , Myocarditis, common in both forms of relapsing fever, portends a poor prognosis.  Invasion of the eye or ear may result in visual impairment or dizziness. Bleeding disorders, manifested by epistaxis, petechiae, and ecchymoses, are typical of louse-borne disease and may be associated with low-grade disseminated intravascular coagulation.  Splenomegaly is more common in louse-borne than in tick-borne disease.
Laboratory findings include normocytic anemia, leukocytosis, and thrombocytopenia. Liver enzyme levels may be elevated and coagulation tests may be prolonged. Patients with cardiac involvement may have a prolonged QTc interval. Cardiomegaly and pulmonary edema may be seen on chest radiography. The cerebrospinal fluid in patients with neurologic involvement has a mononuclear pleocytosis and a mildly elevated protein concentration.
The diagnosis should be suspected in endemic areas in patients with recurrent fever who have been exposed to ticks or lice. A definitive diagnosis is made by blood smear examination during a febrile period. Spirochetes can be seen on thin or thick smears using Wright, Giemsa stains and Leishmans stain.  The organisms are not detectable between febrile episodes. Serological assays may be unreliable, and false-positive tests for other treponemal illnesses (Lyme disease and syphilis) may occur.
| Clinical Case|| |
We present the case of a 50-year-old female from a medium/high socioeconomic status who presented to us with fever, nausea, mylgia, and arthralgia. On examination she gave history of recurrent fever for 3-5 days in the past 3 months.
Physical examination revealed a weight of 55 kg, height 156 cms, HR 96/min, RR 18/min, temperature 38.7°C. Eyes showed normal pupillary reflexes without photophobia at that time, oropharynx was normal, neck was without lymphadenopathy, normal thyroid, thorax with normal mobility, normal heart sounds and breathing, abdomen without organomegaly, extremities were within normal range of motion, and sensory and neurological examination remained without change.
Blood count showed hemoglobin 12 g/%, leukocytes 6,800/mm 3 , neutrophils 61%, lymphocytes 28%, monocytes 5%, eosinophils 6%, platelets 1,57,000/mm 3 , erythrocyte sedimentation rate (ESR) of 60 mm/h, C-reactive protein (CRP) 10.6 mg/l. Urinalysis, glucose, urea, creatinine, and serum electrolytes were normal. Widal and Dengue tests were negative, QBC was negative and there were no malarial parasites in smear. Instead smear showed thin spiral bacteria [Figure 1] and [Figure 2]. She was treated with usual dose of oral doxycycline 200 mg on the first day of treatment (administered 100 mg every 12 hours or 50 mg every 6 hours) followed by a maintenance dose of 100 mg/day to which she responded very well. We followed-up the patient for 3 months and she was asymtomatic and is doing well.
| Discussion|| |
The genus Borrelia consists of two main groups: the first is Lyme disease. Lyme disease is known as relapsing fever, which corresponds to the second group and is a disease that is diagnosed infrequently in our environment.  The main characteristic of this condition is the presence of recurrent fever of 39.5-40°C of sudden onset, accompanied by headache, profuse sweating, severe chills, epistaxis, muscle and joint pain, progressive weakness and malaise. Macular rash may also occur in the chest of short duration. These signs and symptoms that characterize the clinical picture are consistent with those exhibited by the patient described in this report. Relapsing fever caused by spirochetes of the genus Borrelia may be caused by different types of Borrelia and may vary by geographic regions. B. recurrentis has been identified in the Congo, Tanzania and Ethiopia, B. duttoni in Mauritania and West Africa, B. crocidurae, in the U.S.
B. hermsii, B. turicatae and B. parkeri, and in Spain, B. hispanica. Other types of Borrelia are B. gallinarum, B.lonestari, B. johnsonii, B. texasensis, B. caucasica, B. persica and B. latyschewii. ,,,
Tick-borne relapsing fever (TBRF) is definitively confirmed in the laboratory with direct observation of spirochetes in peripheral blood smears during episodes of fever. A thin smear or thick drop of blood is deposited on a microscope slide, which is then stained with either Wright or Giemsa, and examined under oil immersion. Peripheral blood smears yield a sensitivity of 70%,  and the technique is more sensitive in TBRF than in louse-borne relapsing fever (LBRF).
Smears performed between relapses do not demonstrate the organism and should be repeated when the fever reappears. Inexperience in reading smears or a low index of suspicion for the infection may also result in false-negative blood smear results. 
- Direct or immunofluorescence staining: These techniques may also be used to visualize spirochetes using a fluorescence microscope.
- Dark-field microscopy: This may show spirochetes in the blood.
- Peripheral blood wet mounts: This may show red cells colliding with spirochetes.
Nonspecific laboratory findings: These include normal to mildly increased leukocyte counts, anemia, thrombocytopenia, increased liver enzyme levels, and prolonged coagulation parameters can be seen.
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Department of Pathology, Shimoga Institute of Medical Sciences, Shimoga - 577 201, Karnataka
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2]