Docstoc

EPIDEMIOLOGY OF LEPTOSPIROSIS and CONTROL MEASURES

Document Sample
EPIDEMIOLOGY OF LEPTOSPIROSIS and CONTROL MEASURES Powered By Docstoc
					 EPIDEMIOLOGY OF
 LEPTOSPIROSIS &
CONTROL MEASURES

   Dr.I.Selvaraj
• 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
  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

•   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%
                      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:

•   Phylum:    Spirochaetes
•   Class:     Spirochaetes
•   Order:     Spirochaetales
•   Species:   Leptospira
•   Family:    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
•   Azotemia
•   Oliguria
•   Hemorrhage
•   Purpura
•   Hemolysis
•   Gastrointestinal bleeding
•   Hypoprothrombinemia and
    Thrombocytopenia
            Differential diagnosis
• 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:
•   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
                          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
THANK YOU

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:287
posted:4/2/2008
language:English
pages:33