Leptospirosis

Presented by:

Pauline Teo Siew Chin

13th May, 2009

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OUTLINE Introduction Leptospira interrogans Transmission Clinical features Diagnosis Management Prevention Conclusion

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Leptospirosis A zoonotic disease Caused by Leptospira interrogans Geographically widespread Most common in tropical and subtropical

areas with high rainfall First detected in 1886 by Adolph Weil Synonyms: Rat fever, fish handler's

disease, mouse fever & rice field fever

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Leptospira interrogans Flexible, filamentous bacteria made up of

fine spirals with hook-shaped ends Gram -ve Spirochetes > 200 known serotypes Obligate aerobes Slow growing in culture Survives in a moist environment for

weeks-months

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Transmission Wild & domesticated animal hosts Human Common reservoirs: rodents, dogs & farm

animals Human: incidental, “dead-end” hosts Contact with soil, water & feed contaminated by

urine or tissue of infected animals

Occupational exposure

Recreational activities Enter through broken skin or mucous membranes

or conjunctiva

6Adapted from http://www.pasteur.fr/

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Clinical Features Incubation period: 2 - 30 days Clinical presentations range from a self-

limited febrile illness to a severe illness associated with multi-organ damage

Mortality rate in severe cases: 10-15%

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Clinical Progression of Anicteric & Icteric Leptospirosis

(pigmented part of eye)

Anicteric LeptospirosisIcteric Leptospirosis

( Weil’s Syndrome)

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Clinical Features (con’t)

conjunctival suffusionpetechial rash

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Diagnosis

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Management1. General Close temperature, BP, PR & RR

monitoring, I/O chart Adequate hydration, keep temp <38oC

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Management (con’t)2. Antibiotics Most effective if initiated within 1 week of disease onset Mild:

treated as out-patient

given oral antibiotics

Drugs Adult Dose Children Dose

Doxycycline 100mg bd2 mg/kg/day in 2 equally

divided doses

Amoxycillin 1g qid 10 – 25 mg/kg tds

Ampicillin 1g qid 10 – 25mg/kg qid

Erythromycin 250 - 500 mg qid 10 - 25 mg/kg qid

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Management (con’t)2. Antibiotics (con’t) Severe:

intravenous antibiotics

Duration: 1 week A Jarisch-Herxheimer reaction can occasionally be triggered by penicillin therapy

Drugs Adult Dose Children Dose

Benzylpenicillin

(Penicillin G)1.5mU qid

250,000-400,000 units/kg/day in 4-6 divided doses

Ampicillin 500 mg – 1 g qid 10 – 25 mg/kg qid

Amoxycillin 500 mg – 1 g tds 10 – 25 mg/kg tds

Ceftriaxone 1 g od 80-100 mg/kg OD

Cefotaxime 1 g qid150-200 mg/kg/day in 3-4 equally

divided doses

Erythromycin 250mg qid20 - 50 mg/kg/day in 3 - 4 divided

doses

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3. Supportive ICU care in severe cases Fluid & electrolyte therapy Dialysis support for renal failure Ventilatory support for respiratory failure

Management (con’t)

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Vaccination of domestic mammals Avoid contact with potentially infected

animals and contaminated water & soil Protective clothing, boots & gloves Effective rat control Antimicrobial prevention

doxycycline 200mg/week

Prevention

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Conclusion Leptospirosis or rat fever is caused by

Leptospira interrogans which is found in rodents, dogs, farm animals & wild mammals

Transmit through exposure to infected urine or contaminated water, soil or mud

Various antibacterial medications are useful in treatment of leptospirosis

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REFERENCESAberg JA, Goldman MP, Gray LD & Long JK 2006. Infectious Disease Handbook

(6th edition). Lexi-Comp, IncAntony SJ. Leptospirosis- An emerging pathogen in travel medicine: A review of its

clinical mainifestations and management. J Travel Med 1996;3:113-118Howell D & Cole D. Leptospirosis: A waterborne zoonotic disease of global

importance. Georgia Epidermiology Report August 2006;22(08)Khairani-Bejo S, Norhamizah AR, Bahaman AR & Kadir AA 2006. Determination of

susceptibility of Malaysian Leptospira isolate to antimicrobial agents. Journal of Animal and Veterinary 2006;5(2):111-113

MacAllister C. Leptospirosis. Oklahoma Cooperative Extension Service.McBride AJA, Athanazio DA, Reis MG & Ko Al 2005. Leptospirosis. Current

Opinion in Infectious Diseases 2005;18:376-386Pappas G & Cascio A. Optimal treatment of leptospirosis: queries and projections.

International Journal of Antimicrobial Agents 2006;28:491-496

Saunders J 1979. Clinical features and management of leptospirosis in Malaysia. Malaysian J Pathol 1979;2:7-9

Soo HH, Lau LG & Chew PH 2005. Sarawak Handbook of Medical Emergencies (2nd edition). C.E. Publishing

2007 UpToDate® Database

THANK YOU!

13th May, 2009