EPIDEMIOLOGY OF LEPTOSPIROSIS

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EPIDEMIOLOGY OF LEPTOSPIROSIS
CONTROL MEASURES
Dr.I.Selvaraj
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• Leptospirosis is an acute anthropo-zoonotic
  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 cutters disease in
  Australia, Rice field Leptospirosis in Indonesia
  , Fort Bragg fever in U.S.Andaman haemorrhagic
  fever(AHF)

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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.
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• 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
•  

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SERO POSITIVITY RATE - INDIA

• 2000-2001 0 to 46.8
• S.India 25.6
• N.India 8.3
• W.India 3.5
• E.India 3.1
• C.India 3.3

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• 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

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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.
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• Classification
• Phylum Spirochaetes
• Class Spirochaetes
• Order Spirochaetales
• Species Leptospira
• Family Leptospiraceae

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• 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 weils syndrome
  (5 to 10 )

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• 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.

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• A microscopic view of LeptospiraI bacteria
  stained apple green with a fluorescent dye (from
  the CDCs Public Health Image Library)

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• 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.

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• 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.

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• 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.

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• 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.
• Rodents are displaced from their burrows and
  drains by the water.
• High humidity and heavy rainfall intensify the
  outbreak.
• Rats and bandicoots distribute more virulent
  leptospires through their urine into the
  environment than other animals.

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• COMPLICATIONS
• Azotemia
• Oliguria
• Hemorrhage
• Purpura
• Hemolysis
• Gastrointestinal bleeding
• Hypoprothrombinemia and Thrombocytopenia

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Differential diagnosis

• Influenza
• Meningitis (encephalitis)
• Viral hepatitis
• Rickettsiosis
• Typhoid fever
• Septicemia
• Toxoplasmosis
• Legionnaires disease
• If with jaundice during or after an acute
  febrile illness,
• Malaria,septicemia, alcoholic hepatitis and
  typhoid fever

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• Direct Evidence
• Demonstration of leptospires or their products
• Microscopy
• Dark-field microscopy
• Phase contrast microscopy

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• Indirect Evidence
• Detection of antibodies to leptospira
• 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

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• 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.

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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 animals 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

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• 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.

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• 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.

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Disinfection

• Leptospira species can be inactivated by 1sodium
  hypochlorite
• 70ethanol,
• 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.

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• HIGH RISK GROUPS
• DAIRY FARMERS AND MILKERS
• SLAUGHTER-HOUSE WORKERS
• MEAT INSPECTORS
• VETERINARIANS AND MEAT CARRIERS IN FOOD
  INDUSTRIES
• PEOPLE WHO WORK HABITUALLY IN WET OCCUPATIONS
  (RICE FARMERS, SUGAR CANE HARVESTERS, DRAINERS,
  SEWER WORKERS, MINERS)
• ADVENTURE TRAVELLERS (CAVE EXPLORATION, WHITE
  WATER RAFTING, WATER SPORTS)
• AND MILITARY OR CIVIL EMERGENCY PERSONNEL.

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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.
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In the ICD10 disease classification system,
leptospirosis is code A27.
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The International Leptospirosis Society (ILS) was
formed in 1994 to promote knowledge on
leptospirosis through the organisation of
regional and global leptospirosis meetings.
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• 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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