Leptospirosis - caused by pathogenic leptospires. Water-bourne route.

1. @WinnerzKlub

2.  Is an infectious disease caused by pathogenic
leptospires.
 In its mild form, it may present as an influenza-
like illness with headaches & myalgias.
 Severe leptospirosis, characterized by jaundice,
renal dysfunction, & hemorrhagic diathesis, is
referred to as Weil’s syndrome.
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3.  Leptospires are spirochetes.
 Are coiled, thin, highly motile organisms with
hooked ends & two periplasmic flagella, which
enables it to burrow into tissues.
 Organisms are 6-20 µm long and about 0.1 µm
wide.
 Stain poorly but can be seen microscopically by
dark-field examination.
 Requires special media for growth & may take
weeks for cultures to be positive.
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4.  Leptospires may enter host through abrasions in skin or
through intact mucous membranes, especially conjunctiva
& lining of oro- & nasopharynx.
 Drinking of contaminated water.
 Leptospiremia develops, with subsequent spread to all
organs.
 Multiplication takes place in blood & in tissues.
 Leptospires can be isolated from blood & CSF during first
4-10 days of illness.
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5.  Leptospire-inflicted damage to capillary endothelium
results in vasculitis.
 Any organ can be affected but it primarily involves the
kidneys & the liver.
 In kidney, leptospires migrate to the interstitium, renal
tubules, & tubular lumen, causing interstitial nephritis &
tubular necrosis.
 Hypovolemia due to dehydration or altered capillary
permeability may contribute to the development of renal
failure.
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6.  In the liver, centrilobular necrosis with proliferation of Kupffer
cells may be found.
 Severe hepatocellular necrosis is not a feature of leptospirosis.
 Pulmonary involvement is the result of hemorrhage & not of
inflammation.
 Invasion of skeletal muscles by leptospires results in swelling,
vacuolation of the myofibrils, focal necrosis.
 In severe leptospirosis, vasculitis may ultimately impair the
microcirculation & increase capillary permeability, resulting in
fluid leakage & hypovolemia.
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7.  When antibodies are formed, leptospires are
eliminated from all sites except the eye, the
proximal renal tubules (PCT), & perhaps the brain.
 The persistence of leptospires in the aqueous
humor occasionally causes chronic or recurrent
uveitis.
 The systemic immune response is effective in
eradicating the organism but may also produce
symptomatic inflammatory reactions.
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8.  More than 90% of symptomatic patients have the relatively
mild & usually anicteric form of leptospirosis, with or
without meningitis.
 Severe leptospirosis with profound jaundice (Weil’s
syndrome) develops in 5-10% of infected individuals
 Incubation period is usually 1-2 weeks but ranges from 2-
26 days.
 Typically, an acute leptospiremic phase is followed by an
immune-leptospiruric phase.
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9.  Anicteric Leptospirosis:
› May present with influenza-like illness, with fever, chills,
severe headache, N/V, & myalgias.
› Muscle pain, which especially affects the calves, back,
and abdomen, is an important feature of leptospiral
infection.
› Less common features include sore throat & rash.
› Mental confusion may be present.
› Most common finding on P/E is FEVER with conjunctival
suffusion.
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10.  Severe Leptospirosis (Weil’s Syndrome):
› Characterized by jaundice, renal dysfunction, hemorrhagic diathesis, &
high mortality.
› Generally develops after 4-9 days.
› Jaundice not associated with severe hepatic necrosis.
› Hepatomegaly & RUQ pain usually detected.
› Splenomegaly is found in 20% of cases.
› Hypovolemia & decreased renal perfusion contribute to the
development of acute tubular necrosis with oliguria or anuria.
› Dialysis sometimes REQUIRED.
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11.  Pulmonary involvement occurs frequently, resulting in
cough, dyspnea, chest pain, & blood-stained sputum in
hemoptysis or even respiratory failure.
 Hemorrhagic manifestations are seen in Weil’s syndrome:
epistaxis, petechiae, purpura, & ecchymoses.
 Rhabdomyolysis, hemolysis, myocarditis, pericarditis,
congestive heart failure, cardiogenic shock, adult
respiratory distress syndrome & multiorgan failure have all
been described during severe leptospirosis.
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12.  Kidneys:
› Urinary sediment changes (leukocytes, RBCs, & hyaline/granular
casts)
› Mild/moderate proteinuria
› Renal failure & azotemia (severe)
 ESR elevated
 Mild thrombocytopenia (associated with renal failure)
 PT time may be elevated (Vit. K to correct)
 Elevated creatinine phosphokinase
› In first weeks-may help differentiate from viral hepatitis.
 Pulmonary radiographic abnormalities (severe):
› Patchy alveolar pattern that corresponds to scattered alveolar
hemorrhage.
› Abnormalities most often affect the lower lobes in the periphery of the
lung fields.
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13.  Leptospirosis should be differentiated from other febrile
illnesses associated with headache & muscle pain:
› Malaria
› Enteric fever (typhoid)
› Viral hepatitis
› Dengue
› Hantavirus infections
› Rickettsial diseases
 When patients have a flu-like disease with
disproportionately severe myalgia or aseptic meningitis, a
diagnosis of leptospirosis should be considered.
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14.  Should be initiated early as possible.
 NB: treatment after first 4 days of illness is
effective.
 Antimicrobial therapy for mild febrile form of
leptospirosis is controversial, but such
treatment is indicated for more severe forms.
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15. Purpose of drug administration Regimen:
Mild leptospirosis Doxycycline, 100mg PO bid
or
Ampicillin, 500-700mg PO qid
or
Amoxicillin, 500mg PO qid
Moderate/severe leptospirosis Penicillin G, 1.5million units IV qid
or
Ampicillin, 1g IV qid
or
Amoxicillin, 1g IV qid
or
Erythromycin, 500mg IV qid
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16. Purpose of drug administration: Regimen:
Chemoprophylaxis Doxycycline, 200 mg PO once a week
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17.  References:
› Emedicine.com
› www.researchgate.com
› Harrison’s Principles of Internal Medicine, 14th
Ed.
› Davidson’s Principles & Practice of Medicine,
22nd Ed.
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