Leptospirosis is caused by Leptospira bacteria. It is a zoonotic disease spread primarily through contact with infected animal urine. Leptospira appear as tightly coiled spiral bacteria seen best with dark field microscopy. They infect humans through breaks in skin or mucous membranes. Symptoms include fever, jaundice, hemorrhage and kidney or liver damage. Diagnosis involves culture, microscopy and serological tests. Treatment is with doxycycline or penicillin. Control relies on rodent control and vaccination of animals to prevent human exposure.

2. Morphology
• The Leptospira appear tightly
coiled thin flexible Spirochetes
5 – 15 microns long.
• Fine spiral of 0.1 – 0.2
microns
• One end appears bent forms a
hook.
• Actively motile
• Seen best with dark field
Microscopy.

3. Greater Understanding with Electron
Microscopy
• Electron Microscopy show
thin axial filament and a
delicate membrane.
• In dark field it may appear
as chain of miniature cocci.

4. Pathogenic strains x Non pathogenic
Leptospirosis
• There are several species of Leptospira only few are
pathogenic to Humans, rest to some Animals and
Many in Nature as saprophytes.
• Leptospira Interrogans is Pathogenic there are 200
serovars.
• Leptospira biflexa Non Pathogenic there are 60
serovars.
• Further classifications are made on shared antigens.

5. What Is Leptospirosis?
• Leptospirosis, also known as canicola fever,
hemorrhagic jaundice, infectious jaundice, mud
fever, spirochetal jaundice, swamp fever,
swineherd's disease, caver's flu or sewerman's flu,
is a bacterial infection resulting from exposure to
the Leptospira interrogans bacterium.

6. Leptospirosis
A Major Zoonotic Infection
• Weil's disease is comparatively rare, though 'mild'
cases of leptospirosis happen everywhere there
are carriers, and it is believed that leptospirosis is
one of the most common zoonotic infections in
the world.
• Millions of people are infected each year, but
information and treatment can be limited,
especially in the developed world where cases are
considered 'rare' by the medical community.

7. Animals spread Leptospirosis
• Rats, Mice, Wild Rodents, Dogs, Swine, Cattle are
principle source of infection.
• The above animals excrete Leptospira both in active
infection and Asymptomatic stage.
• The Leptospira survive and remain viable for several
weeks in stagnant water.

8. What causes Leptospirosis ?
• Leptospirosis is a bacterial disease that affects
humans and animals.
• Leptospira bacteria are found worldwide and
there are many different types or serovars
capable of causing disease.
• Disease caused by Leptospira bacteria is most
common in temperate or tropical climates
and appears to be rare in North America.

9. Epidemiology
• Leptospirosis causes several animal infections
• Most wide spread zoonotic infection in Nature
• Human infections are accidental associated with
contamination of water, other materials contaminated
with excreta and animal flesh.
• Animal carriers often excrete up to 100million
leptospirosis per ml of urine.

10. Epidemiology-Occupation
• Certain occupational groups such as agriculture workers
in rice and cane fields, miners and sever cleaners are
potential victims.

11. How Man gets Infected
• Water the great source
• Drinking
• Swimming
• Bathing, as the urine of Rodents
chronically infected contaminate
water sources
• Children get infected when in
contact with infected Dogs

12. Pathogenesis
• Leptospira are present in the water bodies.
• Enter through breaks in the skin ( cuts and
abrasions ) and mucous membranes.
• Enters through Mouth – Nose – Conjunctive.
• Rarely enters though ingestion.
• Incubation period 1 – 2 weeks.
• When multiples blood stream produces fever.
• May establish organ involvement in Kidney and
Liver
• May produce hemorrhage and necrosis in the
tissues and initiates dysfunction of these organs.

13. Sequence of Leptospira Infection

15. Weil’s Syndrome
• Weil's syndrome is a severe form of leptospirosis
that causes a continuous fever, stupor, and a
reduction in the blood's ability to clot, which
leads to bleeding within tissues. Blood tests reveal
anemia.
• By the third to sixth day, signs of kidney damage
and liver injury appear. Kidney abnormalities may
cause blood in the urine and painful urination.
• Liver injury tends to be mild and usually heals
completely.

16. May present with
• Jaundice
• Hemorrhage
• Nitrogen retention
• The Illness is Biphasic with initial temperature when
the second phase comes with raise of IgM titers raise
• Aseptic meningitis – initial headache, stiffness of
neck, pleocytosis of Cerebro-spinal fluid.

17. Presenting with Jaundice is significant and
Important, Serious Manifestation

18. May present with Major Complications
• Nephritis
• Hepatitis
• Manifestations in eye
• Muscular lesions
• Many infections are mild and subclinical

19. Nephritis - Leptospirosis
• Kidney involvement in animals produce chronic
disease of the kidney and the infected animal starts
shedding large number of Leptospira and main source
of environmental contamination of bacteria and
results I human infections.
• Human urine also contain Spirochetes in the second
and third week of infection.

20. Hepatitis - Leptospirosis
• Hepatitis is the frequent
complication.
• Elevation of serum creatine
phospholipase enzyme raise
differentiates from Viral
hepatitis where the enzyme is
not raised.

21. Early and Prompt Diagnosis is Highly
Essential
• The development of simpler, rapid assays for
diagnosis has been based largely on the
recognition that early initiation of antibiotic
therapy is important in acute disease but also
on the need for assays which can be used more
widely.

22. Laboratory Diagnosis
1. Blood to be collected in a heparin tube
2. CSF, Tissues (Microscopic examination)
3. Urine to be collected with great care to avoid
contamination
4. Serum for agglutination tests
5. ALT,AST,CPK,ESR.

23. Culturing Leptospira
• Blood and Urine be cultured in Fletcher’s semisolid
agar or other media chemically defined protein-free
media for the growth of Leptospira have been
proposed.
• In order to obtain the desired rapid and abundant
growth of organisms necessary for the efficient
production of vaccines, it has been necessary to
supplement such media with a source of fatty acids,

24. Serology
• Agglutinating antibodies raise to very high titers
• 1 : 10,000 or higher (occurs 5 – 10 weeks after onset
of infection)

25. Serology - ELISA
• Several Immunoassays are available as commercial
kits.
• Detection of IgM and razing titers of IgG will guide
in association with clinical history will help in
Diagnosis

26. Treatment

27. Treatment

28. Treatment

30. Chemoprophylaxis
• Doxycycline 200 mg
orally once a week is
simple effective
measure. When heavy
exposure is anticipated.

31. Control of Leptospirosis
• Rodent control is most important.
• Human’s should avoid contact with water
contaminated with animal contact.

32. Vaccination in humans
• Vaccination for humans is justified where they cannot
be separated from animal sources or where the
animals cannot be immunized successfully.
• Necessity of human vaccinated will arise where
people live and work in proximity to rodents in wet,
tropical conditions, in wet rice planting and
harvesting, in military operations, or working in
sewers.
• Yet no universally accepted vaccine is available for
humans

33. Vaccination of Animals
• Vaccinating animals have a dual purpose
1-Protecting animals.
2-Protecting humans who may contract leptospirosis from
them.
• It is probably true as that immunization of animals will
prevent leptospirosis in people in contact with them.
• It proved true in 1980 when extensive vaccination of
dairy cows in New Zealand lead to marked decreased
incidence in Humans.
• Animals immunized experimentally with polysaccharide
derived from Leptospira LPS linked to diphtheria Toxoid
were protected against challenges
• Several other vaccines in use to suit local needs.