Weils Disease

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Weils Disease

• Neela Goswami
• DRH Morning Report
• June 10, 2009

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Leptospirosis

• AKA Mud fever, Swamp fever, Canefield fever, Fort
  Bragg fever
• Caused by spirochete bacteria leptospira
• gt250 serovars
• L. icterohaemorrhagiae
• L. canicola
• L. hardjo
• L. pomona

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Route of Transmission

• Main resevoir rodents, domestic animals
• Replicates in renal tubules, excreted in urine
  for mos-yrs
• Human infection occurs with direct contact with
  infected urine, or indirect exposure to organisms
  in wet soil or water
• Often results from cccupational exposure to
  rat-infected water

• High risk occupations
• Rice/taro farming
• Mining
• Sewage/canal work
• Cane harvesting
• Fish farming

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Mechanism of Disease

• Systemic vasculitis occurs, facilitating
  migration of spirochetes into organs
• Hepatocellular damage with jaundice, inc INR
• Acute tubular necrosis of kidney
• Increased capillary fragility ? hemorrhage can
  occur in any internal organ (pulmonary
  hemorrhage)

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Clinical Presentation Early Phase

• Incubation period 2-20 days (median 11 days)
• Early phase (day 4-7)
• Symptoms
• HA, myalgias, chills, back pain, anorexia, sore
  throat nausea/vomiting
• Hemoptysis, cough, SOB
• Signs
• Acute febrile illness (40oC)
• Conjunctival suffusion
• Nontender transient pretibial raised erythematous
  patches
• Hepatomegaly
• Meningitis
• Labs thrombocytopenia, proteinuria, elevated WBC
  with neutrophilic predominance, CSF shows
  lymphoyctes, increased protein, nl glucose

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Clinical Presentation Late Phase

• Second (Immune) phase day 7
• Patient develops antibodies to the organism
• Meningitis or hepatorenal manifestations more
  prominent
• Fevers may subside, then pt becomes more
  jaundiced, can bleed into skin, mucous membranes,
  lungs
• Oliguric renal failure, shock, myocarditis,
  arrythmias can follow

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Weils Disease

• Severe form of leptospirosis
• Described by Weil in 1886 as a clinical syndrome
  in 4 men with severe jaundice, fever, hemorrhage,
  and renal involvement
• Inada et al identified the causal agent in Japan
  in 1916
• Most severe cases, with hepatorenal involvement
  and jaundice, can have a mortality rate of 20-40

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Diagnosis

• Direct visualization of leptospires in blood
  (early phase) or urine (late phase) by darkfield
  microscopic examination
• Low sensitivity (40.2) and specificity (61.5)
• Need special media (Fletcher's, Ellinghausen's,
  polysorbate 80)
• Takes 2-3 weeks to be positive
• IgM antibodies appear in late phase (5-7 days)
• Microscopic agglutination test (MAT), ELISA
• Titer gt1100 helps, but fourfold rise in titer is
  diagnostic (need convalescent sample)

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Treatment

• IV penicillin for severe disease
• Oral doxycycline for mild illness
• Jarisch-Herxheimer reactions have been reported
  in patients treated with penicillin

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Prevention

• Rodent control measures
• Immunization of animals with killed vaccines
  short-lived, requires boosters
• Protective clothing, footwear
• Burning canefield prior to harvest (young shoots
  can cut hands)
• Doxycycline prophylaxis for high-risk workers
  (Takafugi ET, NEJM 1984)

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Leptospirosis in Sri Lanka

• Outbreak every 4-5 years
• Incidence in 2008 was 35.7 per 100,000
• Of 1957 lepto pts (Epi Unit, Columbo)
• Mean age 40
• 61 exposed to paddy fields
• 98.6 fever
• 91 myalgia
• 72 conjunctival suffusion
• 5 hemorrhagic manifestations

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Fort Bragg Fever

• August 1942, an unusual acute febrile illness
  (99.8 to 105.6F) occurred in a group of
  soldiers at Fort Bragg, N.C.
• Soldiers quartered near a small stream and its
  tributaries
• 40 patients with sudden onset malaise, mild
  aches, lumbar pain, severe headaches
• Bilaterally symmetrical rash limited in to the
  pretibial areas on the fourth day
• Similar outbreaks 1946 and 1947 among soldiers
  quartered in the same area of the post

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References

• Cook, Gordon. Mansons Tropical Diseases. 1996.
• UpToDate. Leptospirosis.
• Mérien F, Baranton G, Pérolat P Comparison of
  polymerase chain reaction with microagglutination
  test and culture for diagnosis of leptospirosis.
  J Infect Dis 1995 172281-285.
• Takafuji ET, et al. An efficacy trial of
  doxycycline chemoprophylaxis against
  leptospirosis. N Engl J Med 1984 Feb
  23310(8)497-500.
• Panaphut T, Domrongkitchaiporn S, Vibhagool A, et
  al Ceftriaxone compared with sodium penicillin G
  for treatment of severe leptospirosis. Clin
  Infect Dis 2003 361507-1513.
• Fort Bragg Fever. http//history.amedd.army.mil/
  booksdocs/wwii/infectiousdisvolii/chapter13.htm

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