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Leptospirosis

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Leptospirosis, bacterial zoonosis, Weil's Disease

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Leptospirosis

  1. 1. Powerpoint Templates Page 1 LEPTOSPIROSIS Dr. Amandeep Kaur
  2. 2. Powerpoint Templates Page 2 INTRODUCTION • Also known as – field fever, eye cather’s yellows, 7- day fever, cane-field fever • Disease was first described by Adolf Weil in 1886 • Leptospira was first observed in 1907 from a post mortem renal tissue slice • World War I - where the sodden conditions of trench warfare favoured infection • L. icterohaemorrhagiae was identified as the causative agent in pre-World War II outbreaks in Japan • Reinstated as a nationally notifiable disease as of
  3. 3. Powerpoint Templates Page 3 SCOPE OF THE PROBLEM • Number of human cases worldwide is not well- documented • Probably ranges from 0.1 to 1 per 100 000 per year in temperate climates to 10 or more per 100 000 per year in the humid tropics • During outbreaks and in high-risk groups, 100 or more per 100 000 infected • 7-10 million peoples are infected annually
  4. 4. Powerpoint Templates Page 4 SCOPE OF THE PROBLEM • Hurricane Mitch (1995) - outbreak of leptospirosis with pulmonary haemorrhages reported in Nicaragua • 1998 - outbreak in the continental United States. • 1998 - outbreak in Peru and Ecuador following heavy flooding • 1999 - post-cyclone outbreak was reported in Orissa, India
  5. 5. Powerpoint Templates Page 5 EPIDEMIOLOGICAL DETERMINANTS
  6. 6. Powerpoint Templates Page 6 AGENT • Corkscrew-shaped bacteria - spirochaete • Thin and light motile • Only strains of L.interrogans are pathogenic – visible by dark field illumination and silver staining • 21 species identified; 13 species detected in human cases
  7. 7. Powerpoint Templates Page 7 AGENT • About 250 pathogenic serovars based on diverse sugar composition of lipopolysaccharide on surface • Antigenically related serovars are grouped into 24 serogroups - identified using the microscopic agglutination test (MAT) • Given serogroup is often found in more than one species, suggesting that the LPS genes that determine the serovar are exchanged between
  8. 8. Powerpoint Templates Page 8 AGENT • Source of infection: urine of infected animals – entire life time in case of rodents • Animal reservoirs: wild and domestic – Especially rodents – rats, mice, moles – particularly R.norvegicus and Mus musculus – Cattle, sheep, goats, buffalo, pigs, horses – through grazing – Dogs
  9. 9. Powerpoint Templates Page 9 HOST • Human infection is accidental • AGE: Children acquire infection from dogs more frequently • OCCUPATION: veterinarians, slaughterhouse workers, farmers, sewer maintenance workers, waste disposal facility workers, and people who work on derelict buildings; Rowers, kayakers and canoeists also sometimes • IMMUNITY: serovar specific immunity
  10. 10. Powerpoint Templates Page 10 ENVIRONMENT • Leptospira shed in urine survive for weeks in soil and water – high level of environmental contamination were carrier animals frequently urinate • Poor housing • Limited water supply • Inadequate waste disposal
  11. 11. Powerpoint Templates Page 11 TRANSMISSION • DIRECT CONTACT: skin abrasions or intact mucous membrane • INDIRECT CONTACT: – broken skin with contaminated soil, water or vegetation – ingestion of contaminated food or water • DROPLET INFECTION: breathing air polluted with droplets of urine – like while milking cattle
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  13. 13. Powerpoint Templates Page 13 SIGNS & SYMPTOMS • Incubation period: 7–12 days • Biphasic disease - sudden fever with chills, intense headache, severe myalgia, abdominal pain, conjunctival suffusion, and occasionally a skin rash • First phase (septicemic phase) - 3–7 days • Disappearance of symptoms coincides with the appearance of antibodies and disappearance of bacteria from bloodstream - Patient asymptomatic for 3–4 days • Second phase - more severe; the person may have
  14. 14. Powerpoint Templates Page 14 SIGNS & SYMPTOMS • 90 percent of cases of the disease are mild leptospirosis. • Lung affected as the most serious and life-threatening of all complications • Often incorrectly diagnosed due to the nonspecific symptoms • Case fatality rate is 1 to 5%
  15. 15. Powerpoint Templates Page 15 Clinical criteria • History of fever within past 2weeks and at least two of the following clinical findings: myalgia, headache, jaundice, conjunctival suffusion without purulent discharge, or rash (i.e. maculopapular or petechial); OR at least one of the following: – Aseptic meningitis – GI symptoms (abdominal pain, nausea, vomiting, diarrhoea) – Pulmonary complications (cough, breathlessness, haemoptysis) – Cardiac arrhythmias, ECG abnormalities – Renal insufficiency (anuria, oliguria)
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  17. 17. Powerpoint Templates Page 17 DIAGNOSIS • Difficult to diagnose clinically; laboratory support is indispensable • Supportive: – Leptospira agglutination titer of ≥ 200 but < 800 by Microscopic Agglutination Test (MAT) in one or more serum specimens, or – Demonstration of anti-Leptospira antibodies in a clinical specimen by indirect immunofluorescence, or – Demonstration of Leptospira in a clinical specimen by dark-field microscopy, or – Detection of IgM antibodies against Leptospira in an in acute phase serum specimen.
  18. 18. Powerpoint Templates Page 18 DIAGNOSIS • Confirmed: – Isolation of Leptospira from a clinical specimen, or – Fourfold or greater increase in Leptospira agglutination titer between acute- and convalescent-phase serum specimens studied at the same laboratory, or – Demonstration of Leptospira in tissue by direct immunofluorescence, or – Leptospira agglutination titer of ≥ 800 by Microscopic Agglutination Test (MAT) in one or more serum specimens, or – Detection of pathogenic Leptospira DNA (e.g., by PCR) from a clinical specimen.
  19. 19. Powerpoint Templates Page 19 Case definition • Probable A clinically compatible case with at least one of the following: – Involvement in an exposure event (e.g., adventure race, triathlon, flooding) with known associated cases, or – Presumptive laboratory findings, but without confirmatory laboratory evidence of Leptospira infection. • Confirmed – A case with confirmatory laboratory results • Epidemiologic Linkage – Involvement in an exposure event (e.g., adventure race, triathlon, flooding) with associated laboratory-confirmed
  20. 20. Powerpoint Templates Page 20 TREATMENT • Penicillin G – drug of choice – 6million units daily I/V • Other drugs - ampicillin, amoxicillin and Doxycycline • In more severe cases - cefotaxime or ceftriaxone • Glucose and salt solution infusions • Dialysis in serious cases. • Organ specific care and treatment are essential in cases of renal, liver, or heart involvement
  21. 21. Powerpoint Templates Page 21 PREVENTION & CONTROL • Control of infection source (e.g. rodent control, animal vaccination); • Interrupt transmission route (e.g. wearing protective clothing, refrain from contact with infected animals and from swimming in contaminated water, provide clean drinking-water); or • Prevent infection or disease in human host (e.g. vaccination, antibiotic prophylaxis, information to doctors, veterinarians, risk groups and the general population).
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  24. 24. Powerpoint Templates Page 24 PREVENTION & CONTROL • VACCINATION – of pets and occupational risk persons • Italy, Russia, China • Immunity to one serotype does not prevent against other – vaccines should incorporate strains predominant in that area
  25. 25. Powerpoint Templates Page 25 .THANK YOU.

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