Leptospira & Borrelia

Spirochetes-2/2

Key words

• Borrelia– Vincent’s angina– Recurrent fever– Lyme Disease

• Ixodide tick

• Leptospira– L. icterohaemorrhagiae

• erythema chronicum migrans• Weil’ disease (leptospirosis)

– Transmission - urine of rats

B.vincenti

• Normal mouth commensal• May give rise to ulcerative

gingivostomatitis or oropharyngitis (Vincent’s angina) during malnutrition or viral infections

• B. vincenti always associated with fusiform bacilli – fusospirochetosis

• Diagnosis – gram staining of exudates

• Treatment – Penicillin

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Borrelia burgdorferiBorrelia burgdorferi and and Lyme diseaseLyme disease

B. burgdorferi

• Causes Lyme disease, transmitted by the bite of Ixodid ticks (deer tick)

• Characteristic rash – erythema chronicum migrans

• Diagnosis – culture, serological tests• Treatment – Pen, tetracyclines,

cephalosporins in early stages.– Late stage – Antibiotics ineffective.

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Lyme disease - symptomsLyme disease - symptoms• bacteremia

– acute

• arthritis• cardiac• neurologic

– chronic * weeks, months later

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DiagnosisDiagnosis• serum antibodies to serum antibodies to B. burgdorferiB. burgdorferi.

• laboratory strainslaboratory strains– grow extremely slowly grow extremely slowly – tissue culture media tissue culture media – not bacteriological medianot bacteriological media

• patient body fluids/tissue samplepatient body fluids/tissue sample– almost never growthalmost never growth

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• acuteacute– responds to antibioticresponds to antibiotic–antibodies not detectableantibodies not detectable

• late diagnosislate diagnosis– not curablenot curable– antibodies detectableantibodies detectable

A physicians dilemmaA physicians dilemma

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Lyme DiseaseLyme Disease - -etiologyetiology

• reactive arthritis similar to reactive arthritis similar to – Reiter's syndromeReiter's syndrome– rheumatic feverrheumatic fever

• resembles rheumatoid arthritis.resembles rheumatoid arthritis.

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Relapsing feverRelapsing fever

• transmissiontransmission–tick-tick-B. hermsiiB. hermsii* rodent, primary hostrodent, primary host

– lice-lice-B. recurrentisB. recurrentis * human, primary hosthuman, primary host

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““Relapsing” fever Relapsing” fever • immune response develops immune response develops

– disease relapsesdisease relapses

• new antigens expressed new antigens expressed – no immunity no immunity – disease reappearsdisease reappears

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DiagnosisDiagnosis

• no culture no culture

• no serological testno serological test

• detected - blood smeardetected - blood smear

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LeptospirosisLeptospirosis

Leptospira

• Very thin, delicate spirochetes with hooked ends

• 2 species are recognised:1. L. interrogans – include human pathogenic

serogroups: L.icterohaemorrhagiae (rats are the reservoir)

2. L. biflexa – saprophytic, mainly found in surface water.

Laboratory characteristics

• Morphology – stained with Giemsa/ silver impregnation, hooked ends resemble umbrella handles

• Culture – media (semi solid/ liquid) enriched with rabbit serum - Fletcher’s medium

• Pathogenicity – causes Weil’ disease (leptospirosis)

Weil’s disease

• Transmission - Leptospires in water contaminated by the urine of rats; enters the body through cuts or abrasions on the skin or through intact mucosa of mouth, nose or conjunctiva

• Incubation period – about 10 days (2 to 26)• Mild fever to severe or fatal illness with

hepatorenal damage• Fever, rigors, headache, vomiting, icterus,

purpuric hemorrhages

Diagnosis

• Examination of blood – 1st week only• Urine – 2nd week of disease, should be

examined immediately after voiding• Serology – Abs appear by the end of 1st week

& increase till 4th week of disease.

Treatment• Should be started early in disease• Penicillin I.V., Tetracyclines