Epidemiology, Prevention, Control of Leptospirosis

1. Leptospirosis
Dr. Anil Bindu S, Professor of Community Medicine

2. LEPTOSPIROSIS
An acute anthropo-
zoonotic infection
of worldwide
significance
Caused by
spirochaete
Leptospira
interrogans
Has 23 serogroups
and >200 serovars.

3. LEPTOSPIRA
Leptospira was first observed in 1907
from a postmortem renal tissue slice
Disease was first described by Adolf
Weil in 1886

4. Weil’s
disease
• An acute form of human
infection known as Weil's
disease, where the patient
suffers from jaundice.

5. Causative Agent : Leptospira
• Corkscrew-shaped bacteria - spirochaete
• Only strains of L.interrogans are pathogenic
• L.interrogans strains have 24 serogroups
• Each serogroup consists of several strains designated as seorovars
• Nearly 300 host adopted leptospiral serovars are naturally carried
by more than a dozen species of rodents/animals.

6. Source of infection
Urine of infected animals
• Entire lifetime 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
• Dogs

7. Environmental
factors
Drainage, congestion and water logging
Heavy concentrated rainfall leaves
Developmental activities like canal network, roads and
railway lines obstruct natural drainage of rainwater causing
its accumulation for longer periods
The waterlogged areas force the rodent population to
abandon their burrows and contaminate the stagnant
water by their urine
The farmers and agricultural labourers working in the
waterlogged contaminated fields acquire the infection

8. Host factors
Human infection is accidental

9. Age and sex
distribution:
Both men and women are at equal risk.
M >F: greater occupational exposure to
infected animals and contaminated
environment.
More frequently in persons 20-45 years of age
group.
Rare in young children and infants, possibly,
because of minimal exposure.

10. Seasonal variation
• Usually, a seasonal disease that starts at
the onset of the rainy season and declines
as the rains recede.
• Sporadic cases may occur throughout the
year.
• More commonly associated during post-
monsoon period in India.
• In natural disasters such as Floods it may
assume epidemic potential

11. High risk groups
Agricultural workers such
as rice field planters,
sugar cane and pineapple
field harvesters
Labourers engaged in canal
cleaning operations and
Livestock
handlers

12. High risk groups..
• Fishermen, Sewer workers
• Lorry drivers: as they may use
contaminated water to wash their vehicles
and
• Masons: while preparing the cement and
sand mixture for construction work with
contaminated water.

13. Mode of transmission
Through contact of abraded skin
and/or mucus membrane with the
environment contaminated with
urine of rodents, carrier or diseased
animals.
Direct transmission of leptospirosis
is rare

14. Clinical
presentation
Incubation Period:
Average 5-14 days
with a range 2-30
days.
Case Fatality Rate:
0-15%

15. Clinical presentation
Anicteric
leptospirosis
Icteric leptospirosis
Severe leptospirosis

16. Anicteric
leptospirosis
Milder form of the disease
Fever
Myalgia - Calf, abdominal & lumbosacral
muscles are very painful & severely tender.
Conjunctival suffusion
Headache

18. Clinical presentation
Icteric leptospirosis
severe form of the disease, characterized by jaundice and is usually associated with
involvement of other organs
About 5-10% of patients have these type of manifestation
Severe leptospirosis
Haemorrhage , Acute renal failure , Acute respiratory failure, Multiorgan failure

19. Case definition
Suspected Case
• Acute febrile illness with
headache, myalgia and
prostration associated with a
history of exposure to infected
animals or an environment
contaminated with animal urine
with one or more of the
following
Suspected Case
Calf muscle tenderness
Conjunctival suffusion
Anuria or oliguria and/or proteinuria
Jaundice
Hemorrhagic manifestations (intestines, lung)
Meningeal irritation
Nausea, Vomiting, Abdominal pain, Diarrhoea

20. Recommended case definition
Probable case:
Suspected case with positive presumptive
laboratory diagnosis.
Confirmed case: Suspect/Probable case
with confirmatory laboratory test.

21. DIAGNOSIS
Presumptive diagnosis
• A positive result in IgM based
immune- assays, slide
agglutination test or latex
agglutination test or
immunochromatographic test
• A Microscopic Agglutination Test
• Demonstration of leptospira
directly or by staining methods

22. DIAGNOSIS
Confirmatory diagnosis
• Isolation of leptospires from clinical specimen
• Four fold or greater rise in the MAT titre between acute and
convalescent phase serum specimens run in parallel.
• Positive by any two different type of rapid test.
• Sero-conversion.
• PCR test.

23. Treatment
Treatment should be started as
early as possible.
Any case of fever in leptospira
endemic areas during monsoon and
post-monsoon season should be
administered antibiotics as follows

24. How to treat clinically suspected Leptospirosis
at PHC?
Adults: Doxycycline 100 mg twice a day for
seven days
Pregnant & lactating mothers: Ampicillin
500 mg *6 hourly
Children< 8 years: Amoxycillin/ Ampicillin
30-50 mg/kg/day in divided doses for 7 days

25. When to shift to higher centre?
Renal : Decreased urine output (< 400 ml per day),
High blood urea (> 60 mg. % ), High S. Creatinine
(> 2.5 mg% ) , Clinical features of uremia,
breathlessness, convulsion, delirium, and / or
altered level of consciousness
Hepatic : Jaundice, High S. Bilirubin(>3.0m.g. %)
Blood : Bleeding tendency, Low platelet count
Neurological : Altered level of consciousness

26. Treatment at tertiary level health care facility
Adults:
Doxycycline 100 mg twice a day for seven days
• Inj. Crystalline penicillin 20 lacs IU IV every 6 hourly after sensitivity
test.
If sensitive to penicillin group of drugs:
• Ceftriaxone 1 gm IVx 6 hourly for 7 days OR
• Cefotaxime 1 gm IVx 6 hourly for 7 days OR
• Erythromycin 500 mg IVx 6 hourly for 7 days

27. PREVENTION &
CONTROL
• Personal protection: Workers in flooded fields
should be advised to use rubber shoes and
gloves
• Health education: intensive educational
campaign, IEC templates/software for audio
visual, print, press, outdoor outreach modes,
new and emerging electronic media

28. PREVENTION &
CONTROL..
Chemoprophylaxis:
• During the peak transmission season
• Doxycycline 200 mg, once a week for 6
weeks
• May be given to agricultural, canal cleaning
workers, from where clustering of cases has
been reported.
• Never to be extended for more than eight
weeks

29. Rodent control
• 1. Identifying the reservoir species of affected area
• 2. Delineating areas for anti rodent activities
• 3. Completion of activities in pre monsoon months.
• 4. Adopting appropriate technology for anti rodent operations.
This includes correct inputs and appropriate application
technology.
• 5. Capacity building
• 6. Creating awareness in general community and community
participation.

30. Programe for
Prevention
and Control of
leptospirosis in
India
• Launched in the endemic states in India viz.
Gujarat, Kerala, Tamil Nadu, Maharashtra,
Karnataka and UT of Andaman &Nicobar
Islands.
• Objective: to reduce the morbidity and
mortality due to leptospirosis in Humans.

31. Programe for
Prevention
and Control of
leptospirosis
in India:
Strategies
1.Development of trained manpower
2.Strengthening the surveillance of
Leptospirosis in humans.
3.Strengthen diagnostic laboratory
4.Create awareness regarding timely
detection and appropriate treatment of
patients
5.Advocacy for strengthening of patient
management facilities
6.Strengthening Inter-Sectoral
Coordination at state and district level
for outbreak detection, prevention and
control of leptospirosis

32. Vaccination of animals
Confer a limited duration
of immunity.
Boosters are needed every
one to two years.
Vaccination should
however be very selective
and used only in endemic
situations having high
incidence of leptospirosis.
The vaccine must contain
the dominant local
serovars
While this prevents illness,
it does not necessarily
protect from infection and
renal shedding.

33. thank
you