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

4 Borrelia burgdorferi and Lyme 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.

6 Lyme disease - symptoms bacteremia –acute arthritis cardiac neurologic –chronic *weeks, months later

7 Diagnosis serum antibodies to B. burgdorferi serum antibodies to B. burgdorferi. laboratory strains – grow extremely slowly – tissue culture media – not bacteriological media patient body fluids/tissue sample patient body fluids/tissue sample – almost never growth

8 acute – responds to antibiotic –antibodies not detectable late diagnosis late diagnosis – not curable – antibodies detectable A physicians dilemma

9 Lyme Disease - etiology reactive arthritis similar to reactive arthritis similar to – Reiter's syndrome – rheumatic fever resembles rheumatoid arthritis.

10 Relapsing fever transmission transmission –tick-B. hermsii * rodent, primary host – lice-B. recurrentis * human, primary host

11 “Relapsing” fever “Relapsing” fever immune response developsimmune response develops –disease relapses new antigens expressednew antigens expressed –no immunity –disease reappears

12 Diagnosis no cultureno culture no serological testno serological test detected - blood smeardetected - blood smear

13 Leptospirosis

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 – 1 st week only Urine – 2 nd week of disease, should be examined immediately after voiding Serology – Abs appear by the end of 1 st week & increase till 4 th week of disease. Treatment Should be started early in disease Penicillin I.V., Tetracyclines