relapsing fever

Relapsing Fever 

Definition

Relapsing fever refers to two similar illnesses, both of which cause high fevers. The fevers resolve, only to recur again within about a week.

Description

Relapsing fever is caused by spiral-shaped bacteria of the genus Borrelia. This bacterium lives in rodents and in insects, specifically ticks and body lice. The form of relapsing fever acquired from ticks is slightly different from that acquired from body lice.

In tick-borne relapsing fever (TBRF), rodents (rats, mice, chipmunks, and squirrels) which carry Borrelia are fed upon by ticks. The ticks then acquire the bacteria, and are able to pass it on to humans. TBRF is most common in sub-Saharan Africa, parts of the Mediterranean, areas in the Middle East, India, China, and the south of Russia. Also, Borrelia causing TBRF exist in the western regions of the United States, particularly in mountainous areas. The disease is said to be endemic to these areas, meaning that the causative agents occur naturally and consistently within these locations.

In louse-borne relapsing fever (LBRF), lice acquire Borrelia from humans who are already infected. These lice can then go on to infect other humans. LBRF is said to be epidemic, as opposed to endemic, meaning that it can occur suddenly in large numbers in specific communities of people. LBRF occurs in places where poverty and overcrowding predispose to human infestation with lice. LBRF has flared during wars, when conditions are crowded and good hygiene is next to impossible. At this time, LBRF is found in areas of east and central Africa, China, and in the Andes Mountains of Peru.

Causes and symptoms

In TBRF, humans contract Borrelia when they are fed upon by ticks. Ticks often feed on humans at night, so many people who have been bitten are unaware that they have been. The bacteria is passed on to humans through the infected body fluids of the tick.

In LBRF, a louse must be crushed or smashed in order for Borrelia to be released. The bacteria then enter the human body through areas where the person may have scratched him or herself.

Both types of relapsing fever occur some days after having acquired the bacteria. About a week after becoming infected, symptoms begin. The patient spikes a very high fever, with chills, sweating, terrible headache, nausea, vomiting, severe pain in the muscles and joints, and extreme weakness. The patient may become dizzy and confused. The eyes may be bloodshot and very sensitive to light. A cough may develop. The heart rate is greatly increased, and the liver and spleen may be swollen. Because the substances responsible for blood clotting may be disturbed during the illness, tiny purple marks may appear on the skin, which are evidence of minor bleeding occurring under the skin. The patient may suffer from a nosebleed, or may cough up bloody sputum. All of these symptoms last for about three days in TBRF, and about five days in LBRF.

With or without treatment, a crisis may occur as the bacteria are cleared from the blood. This crisis, called a Jarisch-Herxheimer reaction, results in a new spike in fever, chills, and an initial rise in blood pressure. The blood pressure then falls drastically, which may deprive tissues and organs of appropriate blood flow (shock). This reaction usually lasts for about a day.

Recurrent episodes of fever with less severe symptoms occur after about a week. In untreated infections, fevers recur about three times in TBRF, and only once or twice in LBRF.

Diagnosis

Diagnosis of relapsing fever is relatively easy, because the causative bacteria can be found by examining a sample of blood under the microscope. The characteristically spiral-shaped bacteria are easily identifiable. The blood is best drawn during the period of high fever, because the bacteria are present in the blood in great numbers at that time.

Treatment

Either tetracycline or erythromycin is effective against both forms of relapsing fever. The medications are given for about a week for cases of TBRF; LBRF requires only a single dose. Children and pregnant women should receive either erythromycin or penicillin. Because of the risk of the Jarish-Herxheimer reaction, patients must be very carefully monitored during the initial administration of antibiotic medications. Solutions containing salts must be given through a needle in the vein (intravenously) to keep the blood pressure from dropping too drastically. Patients with extreme reactions may need medications to improve blood circulation until the reaction resolves.

Prognosis

In epidemics of LBRF, death rates among untreated victims have run as high as 30%. With treatment, and careful monitoring for the development of the Jarish-Herxheimer reaction, prognosis is good for both LBRF and TBRF.

Prevention

Prevention of TBRF requires rodent control, especially in and near homes. Careful use of insecticides on skin and clothing is important for people who may be enjoying outdoor recreation in areas known to harbor the disease-carrying ticks.

Prevention of LBRF is possible, but probably more difficult. Good hygiene and decent living conditions would prevent the spread of LBRF, but these may be difficult for those people most at risk for the disease.

Key terms

Endemic — Refers to a particular organism which consistently exists in a particular location under normal conditions.

Epidemic — Refers to a condition suddenly acquired by a large number of people within a specific community, and which spreads rapidly throughout that community.

Shock — A state in which the blood pressure is so low that organs and tissues are not receiving an appropriate flow of blood.

Resources

Organizations

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

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fever /fe·ver/ (fe´ver)

1. pyrexia; elevation of body temperature above the normal (37°C).

2. any disease characterized by elevation of body temperature.

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blackwater fever  a dangerous complication of falciparum malaria, with passage of dark red to black urine, severe toxicity, and high mortality.

boutonneuse fever  a tickborne disease endemic in the Mediterranean area, Crimea, Africa, and India, due to infection with Rickettsia conorii, with chills, fever, primary skin lesion (tache noire), and rash appearing on the second to fourth day.

cat-scratch fever  see under disease.

central fever  sustained fever resulting from damage to the thermoregulatory centers of the hypothalamus.

childbed fever  puerperal septicemia.

Colorado tick fever  a tickborne, nonexanthematous, febrile, viral disease caused by an arenavirus and seen in the Rocky Mountain area of the United States.

continued fever  one that varies only slightly in 24 hours.

Crimean-Congo hemorrhagic fever  a hemorrhagic fever caused by the Crimean-Congo hemorrhagic fever virus, transmitted by ticks and by contact with blood, secretions, or fluids from infected animals or humans; it occurs in the Crimea, Central Asia, and regions of Africa.

drug fever  febrile reaction to a therapeutic agent, such as a vaccine, antineoplastic, or antibiotic.

elephantoid fever  a recurrent acute febrile condition occurring with filariasis; it may be associated with elephantiasis or lymphangitis.

enteric fever  any of a group of febrile illnesses associated with enteric symptoms caused by salmonellae, especially typhoid fever and paratyphoid fever.

epidemic hemorrhagic fever  an acute infectious disease characterized by fever, purpura, peripheral vascular collapse, and acute renal failure, caused by viruses of the genus Hantavirus, thought to be transmitted to humans by contact with saliva and excreta of infected rodents.

familial Mediterranean fever  a hereditary disease usually seen in Armenians and Sephardic Jews, with short recurrent attacks of fever, pain in the abdomen, chest, or joints, and erythema like that of erysipelas; it may be complicated by amyloidosis.

Haverhill fever  the bacillary form of rat-bite fever, due to Streptobacillus moniliformis, and transmitted through contaminated raw milk and its products.

hay fever  a seasonal form of allergic rhinitis, with acute conjunctivitis, lacrimation, itching, swelling of the nasal mucosa, nasal catarrh, and attacks of sneezing, an anaphylactic or allergic reaction excited by a specific allergen (such as pollen).

hemorrhagic fevers  a group of diverse, severe viral infections seen around the world but mainly in the tropics, usually transmitted to humans by arthropod bites or contact with virus-infected rodents; they all have certain common features, including fever, hemorrhagic manifestations, thrombocytopenia, shock, and neurologic disturbances.

humidifier fever  malaise, fever, cough, and myalgia caused by inhalation of air that has been passed through humidifiers, dehumidifiers, or air conditioners contaminated by fungi, amebas, or thermophilic actinomycetes.

intermittent fever  an attack of malaria or other fever, with recurring fever episodes separated by times of normal temperature.

Katayama fever  fever associated with severe schistosomal infections, accompanied by hepatosplenomegaly and by eosinophilia.

Lassa fever  a highly fatal, acute, febrile disease seen in West Africa, caused by a virulent arenavirus and characterized by increasing prostration, sore throat, ulcerations of the mouth or throat, rash, and general aching.

metal fume fever  a disease of welders and others working with volatilized metals, marked by sudden thirst, metallic taste in the mouth, high fever with chills, sweating, and leukocytosis.

mud fever  a type of leptospirosis seen in workers in flooded fields and swamps in Germany and Russia.

nonseasonal hay fever , hay fever, perennial nonseasonal allergic rhinitis.

Oroya fever  see Carrión's disease.

paratyphoid fever  paratyphoid.

parenteric fever  a disease clinically resembling typhoid fever and paratyphoid, but not caused by Salmonella.

parrot fever  psittacosis.

pharyngoconjunctival fever  an epidemic disease due to an adenovirus, seen mainly in school children, with fever, pharyngitis, conjunctivitis, rhinitis, and enlarged cervical lymph nodes.

phlebotomus fever  a febrile viral disease of short duration, transmitted by the sandfly Phlebotomus papatasi, with dengue-like symptoms, seen in Mediterranean and Middle Eastern countries.

Pontiac fever  a self-limited disease marked by fever, cough, muscle aches, chills, headache, chest pain, confusion, and pleuritis, caused by a strain of Legionella pneumophila.

pretibial fever  an infection due to a serovar of Leptospira interrogans, marked by a rash on the pretibial region, with lumbar and postorbital pain, malaise, coryza, and fever.

puerperal fever  septicemia accompanied by fever, in which the focus of infection is a lesion of the mucous membrane of the parturient canal due to trauma during childbirth; usually due to a streptococcus.

Q fever  a febrile rickettsial infection, usually respiratory, first described in Australia, caused by Coxiella burnetii.

rat-bite fever  either of two clinically similar acute infectious diseases, usually transmitted through a rat bite, one form (bacillary) of which is caused by Streptobacillus moniliformis and the other form (spirillary) by Spirillum minor.

recurrent fever 

1. relapsing f.

2. recurrent paroxysmal fever occurring in various diseases, such as malaria.

relapsing fever  any of a group of infectious diseases due to various species of Borrelia, marked by alternating periods of fever and apyrexia, each lasting from five to seven days.

remittent fever  one that shows significant variations in 24 hours but without return to normal temperature.

rheumatic fever  a febrile disease occurring as a sequela to Group A hemolytic streptococcal infections, characterized by multiple focal inflammatory lesions of connective tissue structures, especially of the heart, blood vessels, and joints, and by Aschoff bodies in the myocardium and skin.

Rift Valley fever  a zoonotic febrile disease with dengue-like symptoms, due to an arbovirus, transmitted to humans by mosquitoes or by contact with diseased animals; first observed in the Rift Valley, Kenya.

Rocky Mountain spotted fever  infection with Rickettsia rickettsii, transmitted by ticks, marked by fever, muscle pain, and weakness followed by a macular petechial eruption that begins on the hands and feet and spreads to the trunk and face, with other symptoms in the central nervous system and elsewhere.

rose fever  a form of hay fever caused by grass pollens released while roses or other flowers are blooming.

scarlet fever  an acute disease caused by Group A β-hemolytic streptococci, marked by pharyngotonsillitis and a skin rash caused by an erythrogenic toxin produced by the organism; the rash is a diffuse, bright red erythema, and desquamation of the skin begins as fine scaling with eventual peeling of the palms and soles.

Sennetsu fever  a febrile disease seen in Japan and Malaysia and caused by Ehrlichia sennetsu, characterized by headache, nausea, lymphocytosis, and lymphadenopathy.

septic fever  fever due to septicemia.

South African tickbite fever  boutonneuse f.

trench fever  a louse-borne rickettsial disease due to Bartonella quintana, transmitted by the body louse, Pediculus humanus corporis, and characterized by intermittent fever, generalized aches and pains, particularly severe in the shins, chills, sweating, vertigo, malaise, typhus-like rash, and multiple relapses.

typhoid fever  infection by Salmonella typhi chiefly involving the lymphoid follicles of the ileum, with chills, fever, headache, cough, prostration, abdominal distention, splenomegaly, and a maculopapular rash; perforation of the bowel may occur in untreated cases.

fever of unknown origin  (FUO) a febrile illness of at least three weeks' duration (some authorities permit a shorter duration), with a temperature of at least 38.3°C on at least three occasions and failure to establish a diagnosis in spite of intensive inpatient or outpatient evaluation (three outpatient visits or three days' hospitalization).

West Nile fever  see under encephalitis.

yellow fever  an acute, infectious, mosquito-borne viral disease, endemic primarily in tropical South America and Africa, marked by fever, jaundice due to necrosis of the liver, and albuminuria.

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re·laps·ing fever (r-lpsng)

n.

An acute infectious disease caused by a strain of Borrelia transmitted by lice or ticks and marked by recurring febrile attacks lasting about six days and separated from one other by apyretic intervals of about the same length. Also called recurrent fever.

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relapsing fever,

any one of several acute infectious diseases marked by recurrent febrile episodes, caused by various strains of the spirochete Borrelia. The disease is transmitted by both lice and ticks and is often seen during wars and famines. It has occurred in several western states of the United States but is more commonly found in South America, Asia, and Africa. The first episode usually starts with a sudden high fever (104° F to 105° F, or 40° C to 40.56° C), accompanied by chills, headache, neuromuscular pains, and nausea. A rash may appear over the trunk and extremities, and jaundice is common during the later stages. Each attack lasts 2 or 3 days and culminates in a crisis of high fever, profuse sweating, and a rise in heart and respiratory rate. This is followed by an abrupt drop in temperature and a return to normal blood pressure. People typically relapse after 7 to 10 days of normal temperature but eventually recover completely. In louseborne disease there is usually only a single relapse; in tickborne disease several successively milder relapses may occur. See also African tick fever.

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relapsing fever 

any of a group of similar infectious diseases transmitted to humans by the bites of lice and ticks, and marked by alternating periods of normal temperature and periods of fever relapse. The diseases in the group are caused by several different species of spirochetes belonging to the genus Borrelia. Called also recurrent fever.

Symptoms and Diagnosis. Generally, relapsing fever starts with a sudden high fever of 40° to 40.5°C (104° to 105°F), accompanied by chills, headache, muscle aches, nausea, and vomiting. There may also be jaundice and a rash. The attack lasts 2 or 3 days, after which the symptoms disappear by crisis, with profuse sweating accompanying the rapid drop in temperature. In elderly people this may be accompanied by collapse, in which the heart and respiratory system function poorly. After 3 or 4 days there is a relapse and the symptoms return in their former severity. The cycle continues through four or more attacks before the disease has run its course. Relapsing fevers are rarely fatal, but they can be serious.

Treatment and Prevention. Treatment is with antibiotics. Sponge baths and aspirin help to control the fever and comfort the patient. Although tickborne relapsing fever still occurs in the western United States as well as in other parts of the world, louse-borne fever is now largely confined to underdeveloped parts of Asia, Africa, and Latin America. Improved public sanitation and louse and tick control account for the decline in the incidence of the disease.

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relapsing fever

A tick-born bacterial infection seen primarily in the western US, characterized by multiple episodes of fever interspersed with disease free intervals Epidemic borreliosis B recurrentis–louse-borne–Pediculus humanis and transmitted person-to-person Clinical History of recent outdoor camping, fevers with 'negative' blood cultures, Jarisch-Herxheimer-like hypotensive 'crises' after therapy with antibiotics, thrombocytopenia Endemic borreliosis B recurrentis, B hemisi, B turicatae, B parkeri and others–transmitted by ticks–Ornithodoros spp, which inject borrelia during a blood meal Clinical Abrupt onset of high fever, rash, headache, photophobia, N&V, myalgias, arthralgias, abdominal and chest pain, hematuria, hematemesis, epistaxis, productive cough and minimal respiratory distress; after febrile wave passes, diaphoresis, weakness, hypotension, hypothermia; ±1 wk later, the cycle repeats itself; each successive cycle is less severe than previous one; late relapses typically involve the CNS–meningismus, peripheral neuritis, cranial nerve paralysis, seizures, coma; late disease may cause hepatitis, potentially fatal myocarditis Treatment Tetracycline, erythromycin, chloramphenicol