Transcript EPIDEMIOLOGY OF LEPTOSPIROSIS & CONTROL MEASURES Dr.I.Selvaraj • Leptospirosis is an acute anthropozoonotic infection • It occurs in tropical, subtropical and temperate zones. • Weil Disease,

EPIDEMIOLOGY OF
LEPTOSPIROSIS &
CONTROL MEASURES
Dr.I.Selvaraj
• Leptospirosis is an acute anthropozoonotic infection
• It occurs in tropical, subtropical and
temperate zones.
• Weil Disease, Hemorrhagic Jaundice,
Mud Fever, Swineherd
Disease,Canicola Fever, seven-day
fever found commonly in Japan, Cane
cutter’s disease in Australia, Rice field
Leptospirosis in Indonesia , Fort Bragg
fever in U.S.Andaman haemorrhagic
fever(AHF)
L2 - Endemic
Locations where the infection is commonplace,
caused by high rainfall, close human contact
with livestock or wild animals, poor sanitation or
workplace exposure (rice farming, etc). Example
countries in class L2 are India, Central America
and certain areas of the Pacific Rim.
L1 - General
Locations where the infection is at the
international average of 0.05 cases per 100,000,
and infection is usually the result of accidental
exposure through wild rats, livestock or direct
contact with water through leisure or
occupation. Example countries in class L1 are
North America, Europe, Australia and the former
Soviet territories.
• 1883 it was recognized as an occupational
disease of sewer workers
• 1886 first description (by Weil, Professor of
Medicine at Heidelberg (1886) ) of the clinical
manifestations seen in men (severe
jaundice, fever, and hemorrhage with renal
involvement)
• 1907- Stimson described the lesion in the
renal tubules who died of so called yellow
fever.
• 1916 the causal agent was identified by Inada
in Japan
• Noguchi proposed the name ‘Leptospira’
(thin spirals) in 1918
SERO POSITIVITY RATE - INDIA
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2000-2001 – 0 to 46.8%
S.India
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25.6%
N.India
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8.3%
W.India –
3.5%
E.India
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3.1%
&C.India –
3.3%
INDIA
• The first of its kind in India was reported in the
1920s from Andaman and Nicobar Islands.
• In 1993, a serosurvey of conservancy workers in
Madras (using MAT) revealed a prevalence rate of
32.9%.
• In 1994, an increase in the number of individuals
with uveitis was noted at Aravind Eye hospital,
Madurai, India after an epidemic of leptospirosis
in South India; the epidemic followed severe
flooding of the Tamil Nadu District in the autumn
of 1993
• In 1995, a seroprevalence rate of 12%
leptospirosis was found among febrile and
jaundice patients in Pondicherry
LEPTOSPIROSIS IN INDIA
In 1905, Chowdry presented 585 cases of the disease
in the Andaman islands, calling it "malaria with
jaundice".
In the Andamans, this disease was also called as
"Andaman haemorrhagic fever" with a predominance
of haemorrhagic signs.
In Kerala, it was the same type as seen in the
Andamans.
In Chennai city, the most severe form was jaundice
and a haemorrhagic type.
Of late, eye disorders as late complications of
leptospirosis have been recorded in Madurai.
Cardiac arrhythmias in Mysore are the latest reports
on the manifestations of the disease.
Classification:
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Phylum:
Class:
Order:
Species:
Family:
Spirochaetes
Spirochaetes
Spirochaetales
Leptospira
Leptospiraceae
• The genera Leptospira contains three
species, namely L interrogans, L biflexa
and L parva. The first includes 23
serogroups and more than 250 serovars
and is the principal cause of
leptospirosis in humans and animals.
most common being L. canicola, L.
hardjo and L. hebdomadis.
• Two types of leptospirosis:
1. Anicteric leptospirosis or self-limited illness
(85% to 90% of the cases)
2. Icteric leptospirosisor weil’s syndrome
(5% to 10% )
• The etiologic agent of leptospirosis is
Leptospira interrogans.
• It is a thin spiral organism 0.1mm x 6 20mm, with tightly set coils
• It is characterized by very active motility, by
rotating (“spinning”) and bending. Usually
one or both ends of this single-cell organism
are bent or hooked
• Because of their narrow diameter, the
leptospires are best visualized by dark-field
illumination or phase contrast microscopy
and they do not stain readily with aniline
dyes.
•A microscopic view of
LeptospiraI bacteria stained
apple green with a fluorescent
dye (from the CDC’s Public
Health Image Library)
Reservoirs
Wild and domestic animals rodents,
livestock (cattle, horses, sheep, goats,
swine), canines, and wild mammals are
the reservoir for leptospirosis. Many
animals have prolonged leptospiruria
without suffering from the disease
themselves.
Modes of Transmission
• By direct or indirect contact of nasal, oral, or
eye mucosal membranes or abraded or
traumatized skin with urine or carcasses of
infected animals.
• Urine: Indirect exposure through water, soil,
or foods contaminated by urine from infected
animals is the most common route. After a
short period of circulating high levels of the
spirochete in their blood, animals shed the
spirochete in their urine, contaminating the
environment.
• Inhalation of droplet aerosols of
contaminated fluids can occasionally occur.
• Incubation period
• The incubation period is usually 2-26
days, but usually (7 – 12 days) days.
• Period of Communicability or Infectious
Period
Humans with leptospirosis usually
excrete the organism in the urine for
4-6 weeks and occasionally for as long
as 18 weeks.
• Person-to-person transmission is considered
extremely rare.
1. Cases are seen sporadically throughout the
year. But an outbreak occurs during the rainy
season because of widespread contamination
by infected rodent urine in flood water.
2. Rodents are displaced from their burrows and
drains by the water.
3. High humidity and heavy rainfall intensify the
outbreak.
4. Rats and bandicoots distribute more virulent
leptospires through their urine into the
environment than other animals.
COMPLICATIONS
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Azotemia
Oliguria
Hemorrhage
Purpura
Hemolysis
Gastrointestinal bleeding
Hypoprothrombinemia and
Thrombocytopenia
Differential diagnosis
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Influenza
Meningitis (encephalitis)
Viral hepatitis
Rickettsiosis
Typhoid fever
Septicemia
Toxoplasmosis
Legionnaire’s disease
If with jaundice during or after an acute febrile
illness,
• Malaria,septicemia, alcoholic hepatitis and
typhoid fever
Direct Evidence
• Demonstration of leptospires or their
products:
• Microscopy
• Dark-field microscopy
• Phase contrast microscopy
Indirect Evidence
Detection of antibodies to leptospira:
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Macroscopic agglutination test (MSAT)
Indirect fluorescent antibody test (IFAT)
Indirect haemagglutination test (IHA)
Counter immuno electrophoresis (CIEP)
Complement fixation test (CFT)
Newer techniques
ELISA
Microcapsule agglutination test (MCAT)
Lepto-Dipstick
Serogroup/serovar specific tests
Microscopic agglutination test (MAT)
Serovar specific ELISA
• Demonstration of a rise in antibody levels
either through MAT or ELISA is essential by
repeating the sampling at least four days after
taking the first sample.
• In Chennai, the MAT test is available at the
Veterinary University, Madhvaram, the MGR
Medical University, Guindy and the
microbiology department of the Madras
Medical College.
• The IgM dip stick ELISA is commercially
available from Organon Teknika (Infar India)
and Pan Bio (Australia). Using this test could
help detect leptospirosis during the acute
(early) phase of the illness.
TREATMENT
• Penicillin 6 million units daily I.V (10-14
days)
• Amoxycillin, Erythromycin, &
Doxycycline
• Patients with MOF(Multi organ failure) to
be observed and treated in intensive
care unit
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PREVENTION
Environmental Measures
To prevent illness, prevent contamination of living,
working and recreational areas by urine of infected
animals.
•Control rodent populations in areas of human
habitation.
•Domestic animal owners should take necessary
precautions to minimize their animal’s potential
contact with wildlife ( e.g., do not feed pets outside or
allow animals to roam unsupervised).
•Do not allow animals to urinate in or near ponds or
pools.
•Keep animals away from gardens, playgrounds,
sandboxes, and other places children may play.
•Among domesticated animals, vaccination of swine,
cattle, and dogs.
Cont…
• Chlorination is seldom useful, as virulent
leptospires withstand up to 4 ppm in potable water.
• Filtered water is not safe.
• Using boiled or ultraviolet irradiated water is
advisable.
• Water tanks must be sealed if possible.
• Food articles must be stored in properly fitting
containers.
• Bathroom and kitchen waste pipes must be
blocked at night.
• Try avoiding walking in flood water. If you have to,
wear gum boots.
• Heavy drinking and smoking predispose damage to
the liver and the kidneys which in turn become
vulnerable to leptospiral infection.
PREVENTION
• Protected water supply to all.
• Proper collection, transport, treatment
and secured disposal of garbage.
• Drinking boiled water.
• Disinfections of contaminated work
areas.
• Providing proper protective clothing,
shoes, gloves, etc. to high-risk
Occupational groups.
Disinfection
• Leptospira species can be inactivated
by 1%sodium hypochlorite
• 70%ethanol,
• glutaraldehyde,
• formaldehyde,
• detergents and acid.
• This organism is sensitive to moist
heat (121 ° C for a minimum of 15
min))and is also killed by
pasteurization.
HIGH RISK GROUPS
1. DAIRY FARMERS AND MILKERS
2. SLAUGHTER-HOUSE WORKERS
3. MEAT INSPECTORS
4. VETERINARIANS AND MEAT CARRIERS IN FOOD
INDUSTRIES
5. PEOPLE WHO WORK HABITUALLY IN WET
OCCUPATIONS (RICE FARMERS, SUGAR CANE
HARVESTERS, DRAINERS, SEWER WORKERS,
MINERS)
6. ADVENTURE TRAVELLERS (CAVE EXPLORATION,
WHITE WATER RAFTING, WATER SPORTS)
7. AND MILITARY OR CIVIL EMERGENCY PERSONNEL.
All the people involved in high-risk
activities should wear protective clothing
and need to adopt a reasonable standard
of hygiene. Impervious knee-high boots,
aprons, gloves, face masks or eye
protection should be used wherever
indicated.Immunization of high risk
groups (USSR, CHINA,ITALY)
Chemo prophylaxis: Doxycycline can
prevent leptospirosis, if given before and
during exposure.
In the ICD10 disease classification
system, leptospirosis is code A27.
The International Leptospirosis Society (ILS)
was formed in 1994 to promote knowledge on
leptospirosis through the organisation of
regional and global leptospirosis meetings.
REFERNCE
Leptospirosis in India and the Rest of the
World
Rao R. Sambasiva, Gupta Naveen, Bhalla P.
and Agarwal S.K
- Nursing Journal of India, Jul 2002 by Xavier,
Shalini
- Leptospirosis – An overview by TK Dutta,
M.Christopher (JAPI.VOL.53.JUNE 2005)
-k.park 18 th edition
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