This document summarizes leptospirosis, a zoonotic bacterial disease caused by Leptospira interrogans. It is transmitted through contact with urine from infected animals like rodents, cattle, and dogs. Symptoms include fever, headache, jaundice, and kidney damage. Diagnosis involves microscopy of urine or blood samples to detect the spiral-shaped bacteria, culture which is the gold standard, or serological tests. Treatment consists of antibiotics like doxycycline or penicillin. Prevention focuses on controlling rodents and infected animals, along with doxycycline prophylaxis for at-risk groups like farmers and sewer workers.

1. Leptospirosis
Dr Mallika Sengupta

2. Causative Organism
 Phylum : Spirochaetes
 Order: Spirochaetales
 Family: Leptospiraceae
 Genus : Leptospira

3. Classification
Based on biochemical and serologic property
pathogenic species, free-living
nonpathogenic species
Leptospira interrogans Leptospira biflexa.
– 200 serogroups - 60 serogroups
Icterohaemorrhagiae
Copenhageni
Canicola
Pyrogenes
Autumnalis
Australis
Pomona
Hebdomadis
Grippotyphosa, & others

4. Morphology
 Tightly coiled, thin, flexible spirochetes
 Spiral bacteria
 0.1um by 6-20um
 Pointed ends bent in hooks (umbrella handle)
 Actively motile (darkfield microscope)
 Movement- translational and rotational
 Axial filaments- periplasmic flagella

5. Epidemiology
 Worldwide zoonosis
 Reservoirs
wild animals such as rodents
domestic animals - important source
shed leptospires throughout their lifetimes
 Tropical countries
 Major means of transmission:
Contact with urine containing virulent leptospires
 Urine-contaminated soil can remain infective for as
long as 14 days.

6. Transmission

7. Exposure
1. Rainfall and flooding
3. Exposure to animals
4. Poor sanitation and inadequate waste disposal

8. Animals associated
 The animals that commonly develop or spread leptospirosis
include:
Rodents
Raccoons
Cattle
Swine
Dogs
Horses
Buffaloes
Sheep
Goats

9. Risk factors
Contact with infected animals or
soil/water where the bacteria are
present.
 Farmers
 Sewer Workers
 Slaughterhouse Workers
 Veterinarians/Animal Caretakers
 Fishermen – fresh water
 Dairy Farmers
 Military Personnel
Those involved in outdoor
freshwater activities like
• Swimming
• Rafting
• Kayaking

10. Pathogenesis
 Enters  mucosa & broken
skin  bacteremia
(leptospiremia)
 IP 1–2 weeks,
 Spirochetes multiply organs
(CNS, kidneys & liver)
 Persist and multiply in the
kidney tubules

11. Clinical manifestations
 Febrile disease
 Typically- biphasic
 Acute leptospiremic phase
 Immune leptospiruric phase
 Organ systems: CNS, kidneys, and liver
 Average incubation period of 7 to 14 days

12. Clinical features
 Acute febrile illness with headache, myalgia (particularly
calf muscle) and prostration associated with any of the
following
 Conjunctival suffusion
 Anuria or oliguria
 Jaundice
 Cough, haemoptysis and breathlessness
 Haemorrhages
 Meningeal irritation
 Cardiac arrhythmia or failure
 Skin rash
 Nausea, vomiting, abdominal pain, diarrhoea, arthralgia

13. Laboratory Diagnosis - Sample
 Blood – daily for culture in first week
 Urine – second to sixth week; intermittent shedding
 CSF
 Body fluids and tissues
 Serum – serology

14. Processing of urine sample
 Freshly voided urine centrifuged at 3000 rpm for 10 min
 Sediment examined by darkfield microscopy
 Processed immediately-
i) sensitive to acid urine
ii) lysed by antibodies present in urine

15. Microscopy
Dark field microscopy Electron microscopy

16. Silver Staining of Leptospira, Treponema, Borrelia
Leptospira
Borrelia

17. Silver Staining of Treponema, Leptospira, Borrelia
Characteristics Treponema Leptospira Borrelia
Length 5-15u 6-20u 10-30u
Width 0.2u 0.1-0.3u 0.3-7u
Primary coil Closely wound Very closely
wound
Loosely wound
Winding Regular Regular Irregular

18. Culture
 Gold standard
 Aerobic conditions at 28–30 °C
 Serum-containing semisolid media (Fletcher's, Stuart's).
 Semisynthetic – EMJH (Ellinghausen, McCullough,
Johnson, Harris)
 Examined weekly up to 13 weeks

19. Culture

20. Culture
 Chorioallantoic membrane (chick embryo)
 Intraperitoneal inoculation into Guinea pigs

21. Laboratory Diagnosis - Serology
 Immunofluorsecence Assay
 Microscopic agglutination test:
reference lab standard test
 IgM ELISA
 PCR

22. Treatment
 Mild illness: Oral Doxycycline or Ampicillin or
Amoxicillin
 Moderate & severe: IV Penicillin or Ampicillin

23. Prevention
Identifying and controlling the source
of infection
Control of disease in dogs, certified
cattle herds
Rodent control
Doxycycline, 200mg once weekly

24. Thank you