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Undergraduate class room lecture
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Leptospirosis2008 Batch- V Term
Infectious Diseases Series
It’s raining diseases with monsoon in stateExpress News ServicePosted: Sep 01, 2010 at 0210 hrs ISTAhmedabad/Vadodara/Surat• While the good spell of monsoon has brought in cheer, the health
barometer has been a cause for concern this month. Gujarat health department recorded outbreak of at least six diseases in a week in six different areas across the state. Kutch reported 349 suspected cases of Chikungunya on August 17, a Gandhinagar taluka reported two cholera cases on August 18, 24-odd cases of gastroenteritis were reported in Surat district while 35 cases of unknown fever were reported in Surat on the same day. According to the state health department, 20 more jaundice cases were reported in Ahmedabad on August 20. They are unlikely to be due to viral hepatitis due to the unusual association of kidney failure. leptospirosis is suspected but not confirmed. In another incident, 10 cases of diarrhoea were reported in Surat on August 21.
Leptospirosis: meaning
• Leptospira (from the Greek leptos, meaning fine or thin, and the Latin spira, meaning coil) is a genus of spirochaete bacteria, including a small number of ...
Alternate Names• Weil’s disease• Ictero-hemorrhagic fever• Swineherd's disease• Rice-field fever• Cane-cutter fever• Swamp fever• Mud fever• Hemorrhagic jaundice• Stuttgart disease• Canicola fever
Butchers, tourists, residents, animals
Butchers, tourists, residents, animals
Learning Objectives
• Historical Perspective• Introduction• Pathogenesis• Clinical Features• Complications• Diagnosis• Treatment
Historical Perspective• A syndrome of severe multisystem disease
presenting as profound jaundice and renal function impairment was described by Weil in Heidelberg in 1886
• Earlier descriptions also exist • Leptospires were first visualized in autopsy
specimens in a case thought to be Yellow Fever• Simultaneously isolated in Japan and Germany• Many researchers (Stokes, Noguchi, others) died of
the disease
IntroductionZoonosis: Leptospirosis is a bacterial disease that affects
both humans and animals.
Not well documented, often overlooked & under-reported
Emerging Infectious Disease: Several recent outbreaks in Asia, South America & USA
• In the wake of hurricane Mitch in 1995, an outbreak with pulmonary hemorrhages was reported in Nicaragua.
• In 1998, there were outbreaks in USA, Peru and Ecuador. • A post-cyclone outbreak was reported in Orissa, India in 1999
• During outbreaks and in high-risk groups >100 per 100 000 may be infected.
Pathogenesis
Pathogenesis- contamination of soil and water
Soil and water contamination
Pathogenesis: Agent
• Order:Spirochetales• Family: Leptospirideae• Genus: Leptospira • Species: interrogans (pathogenic) biflexa• Serovars: > 200• Serogroups: > 25; icterohemorrhagica,
gryppotyphosa, caniciola, pomona, andmanii, etc
Pathogenesis: Agent
Pathogenesis: Agent
• Can survive outside the body for long• Organism is excreted in the urine even
after clinical infection settles down (symbiotic)
• Leptospirosis is maintained in nature by chronic renal infection of carrier animals
Animal Urine
Pathogenesis: Agent
• Coiled, thin, highly motile• Hooked ends and flagellae• Stain poorly• Seen by DGI & Silver impregnation• Need special media • Take long for culture
Pathogenesis: Agent
• DGI
Pathogenesis: Host
Mammals - wild and domestic• Animals- Rodents, insectivores, dogs, cattle, pigs,
horses, etc • Humans
• Direct contact with urine of infected animals • Urine-contaminated surface water, soil and plants
• Even some birds• Micro-abrasions, intact skin and mucosa• Infected animal tissues and blood
Pathogenesis: Host• Occupational hazard: people who work
outdoors /with animals– rice and sugar-cane field workers, farmers – sewer workers – veterinarians and dairy workers – butchers and abattoirs – military personnel
• Recreational hazard:• tourists, Water sports
Flooding, Farming, Camping waterlogging
Butchers, tourists, residents, animals
Pathogenesis: Environment• Worldwide• Both rural and urban areas • Temperate and tropical climates• Incidence peaks during the rainy season and
during flooding• Tourism in tropics with adventure water sports
Distribution
Environment
Pathogenesis
• Entry: through cuts and abrasions in skin & mucous membranes of the eyes, nose and mouth
• Inhalation- rare• Ingestion- rare • Human-to-human transmission –rare
• Incubation Period: 5 to 14 days (mean 10 days)
Pathogenesis
• Leptospiremic/ Septicaemic phase– Systemic vasculitis– Migration of organisms into tissues-
inflammation and multi-organ dysfunction from direct cyto-toxicity
• Immune phase/ Leptospiruric Phase– Second fever and organ involvement
through immunological mechanisms-• Persistence of organisms
– Renal tubules, aqueous humor
Pathogenesis
Renal Failure: – Migrate to interstitium,
renal tubules and tubular lumen – interstitial nephritis and tubular necrosis
– Hypovolemia – dehydration and leakage
Liver
Liver: – Centrilobular necrosis
and Kupffer cell hyperplasia
– No hepatocellular necrosis
Pathogenesis
Pulmonary: Hemorrhage
and not much inflammation- hemoptysis, patchy lung - infiltrates and ARDS
Muscles: Direct cytotoxicity
CNS: Organisms in the CSF X 2 weeks with
mild CSF changes
Meningitis in immune phase
Jaundice & Red eyes
Clinical Features
Wide range of severity and clinical features
A. Subclinical infection
B. Self limited systemic illness 90 %
C. Severe potentially fatal illness consisting of• Renal failure 15 %• Liver failure 15%• Pneumonitis >30 to 40% mortality• Hemorrhagic diathesis
Bimodal illness
• Leptospiremic/ Septicaemic phase• Immune phase/ Leptospiruric Phase
• Distinction maybe blurred
Clinical Features
Factors influencing severity: • Serovar• Size of innoculum• Prior infection• Early antibiotic use• Pregnancy
Clinical Features- early (5 -7 days)
• High fever and chills• Severe headache, eyeball pain,
photophobia• Mental confusion• Muscle pain & tenderness (calves and
back)• Redness in the eyes & conjunctival injection• Sore throat• Rash- maculopapular
Clinical Features- early (5 to 7 days)
• Abdominal pain• Vomiting and diarrhea • Jaundice, hepatosplenomegaly• Lymphadenopathy -rare • Hemorrhages in skin and mucous
membranes • Cough, chest pain & hemoptysis
Clinical Features- Late(A) Anicteric Variety
After 2 to 3 days of seeming recovery• New fever• Milder myalgias• Aseptic meningitis- similar to viral
meningitis- clue- Neutrophilic leucocytosis• Uveitis (Iridocyclitis)• Choreoretinitis
Clinical Features- Late(B) Icteric Variety
Severe Leptospirosis (Weil’s Disease)• Jaundice• Renal Dysfunction• Hemorrhagic Diathesis
Mortality 5 to 15 %
To Sum Up Clinical Features
• Bacteraemic Leptospirosis• Aseptic Meningitis• Icteric Leptospirosis with Renal involvement• Pulmonary Syndrome
Other Complications
• Rhabdomyolysis• Hemolysis • Myocarditis • Pericarditis • CHF • Necrotising Pancreatitis • MOF
Differential Diagnosis
• Ac Febrile Syndrome (Dengue, Chick, Malaria, Influenza, Typhus, Mono, Enteric, Hanta)
• Jaundice (VH, Yellow Fever, Complicated Malaria)
• Aseptic Meningitis (.., .., .. )
Lab Diagnosis
• Urine: Sediment (RBCs, WBCs, Casts) & proteinuria• Blood Counts:
– PMN –Leucocytosis,– ESR elevation – Thrombocytopenia
• Biochemistry: LFT (Enzymes not very high); KFT• Coagulation Profile -Vit K dep factors low• CPK MM• CSF Abnormalities• X Ray Chest- patchy alveolar pattern- lower lobes
Lab Diagnosis
Antigen Detection:• DGI and Silver impregnation
staining- urine, CSF• Culture (EMJH )• PCR
Lab DiagnosisAntigen Detection:• DGI and Silver impregnation staining- urine, CSF• Culture (EMJH )• PCR
Antibody Detection (second week)
IgM & IgG• MAT• ELISA• Indirect Hemagglutination Test• Microcapsule Agg test
Treatment
• General and Supportive Care– Antipyretics– Rest– Hydration– Ventilator support– Liver support– Renal support– Transfusion support
Treatment
• General and Supportive Care• Penecillin G• Amoxycillin• Ampicillin• Tetracyclines• Doxycycline• Ceftriaxone• JH Reaction
Prevention
• Rodent and wild plus peri-domestic animal control
• Avoid exposure to urine and tissues of animals• Avoid wading through water collections• Vaccination of animals• Chemoprophylaxis- weekly Doxycycline (200
mg)
Take Home Messages• Leptospirosis is an infectious disease (zoonosis) caused by a bacterium.• Leptospirosis is transmitted to humans by direct exposure
to urine or tissue of an infected animal.• Leptospirosis typically progresses through two phases of
nonspecific symptoms.• Leptospirosis can be diagnosed by culture of infected
blood, urine, or spinal fluid, as well as using antibody testing.
• Animals are also at risk for contracting Leptospirosis.• Leptospirosis is treated with antibiotics and is rarely fatal.
Every jaundice is not viral Hepatitis