Leptospirosis PDF: Infectious Diseases II

Infectious Diseases II Leptospirosis I & II  Leptospirosis I & II Nilda J. Zapata Molina, MD Micro II – 644 - Infectious Diseases II Objectives 1. Explain pathogenesis of Leptospirosis. 2. Describe clinical manifestation of Leptospirosis according to different phases. 3. Compa...

Infectious Diseases II Leptospirosis I & II  Leptospirosis I & II Nilda J. Zapata Molina, MD Micro II – 644 - Infectious Diseases II Objectives 1. Explain pathogenesis of Leptospirosis. 2. Describe clinical manifestation of Leptospirosis according to different phases. 3. Compare anicteric with icteric Leptospirosis. 4. Identify different complications of Leptospirosis. 5. Explain the different diagnostic methods available. 3 Leptospirosis Definition: Spirochetal infection acquired by animals and humans primarily through direct or indirect contact of skin or mucous membranes with contaminated urine. 4 Etiology Leptospira interrogans – 200 serovars spirochete, GNB, (LPS) motile. obligate aerobic, slow growing. water, soils, moist organic matter. infected urine, parturition tissue. may survive weeks to months. 5 6 Pathogenesis: cuts, abraded or soft skin mucous membranes, conjunctivae Inhalation, ingestion blood stream, lymphatics, organs systemic vasculitis, hemorrhage renal failure – ischemia jaundice-hepatic cell dysfunction myalgias – necrosis myofibrils, hemorrhage intrauterine infections 7 Clinical Manifestations incubation period 5-30 days anicteric leptospirosis icteric leptospirosis – Weil’s syndrome 8 Septicemic phase-anicteric (90%) high fever (38-40ºC) headache, chills, rigors meningeal irritation abdominal pain, anorexia myalgias, conjunctival suffusion nausea, vomiting, diarrhea cough, pharyngitis, hemoptysis maculopapular rash 9 Weil’s syndrome – icteric (10%) hepatic, renal dysfunction hemorrhagic pneumonitis, ARDS cardiac arrhythmia circulatory collapse jaundice>7th day adrenal hemorrhage – sudden death hepatosplenomegaly 25% hypoprothrombinemia ↑CPK thrombocytopenia interstitial nephritis congestive heart failure myocarditis 10 11 Diagnosis Confirmatory tests MAT microscopic agglutination Test-acute and convalescence nt serum samples PCR Urine antigen – 1 week after symptoms Pathology – CDC Formalin fixed Supportive Tests IGm 12  Diagnostic Test for Leptospirosis Diagnostic Test Method Sensitivity Microscopy Gram stain Organisms cannot be seen Darkfield Intensive, nonspecific Direct fluorescent Insensitive, generally antibody unavailable Culture Blood Positive during first week CSF Positive during final or second week Serology Positive after first week Urine Microscopic Sensitive, specific, positive agglutination after second week, peaks after 5 to 6 weeks, and may persist for months 13 Laboratories proteinuria pyuria, hematuria ↑ creatinine ↑ liver enzymes ↑ bilirubin < 20mg/dl ↑PT ↑WBC’s, ↓Hgb, ↓plat CSF: pleocytosis, normal glucose mild ↑protein 14 Prevention ↓contact infected animals, contaminated water, soil, mud animals vaccine? chemoprophylaxis (95%) 15  Agents Recommended for Chemoprophylaxis and Treatment Indication Drug Dosage Chemoprophylaxis Doxycycline 200mg once a week Treatment of mild Doxycycline 100mg 10 bid leptospirosis Ampicillin 500-750mg q6h Amoxicillin 500mg q6h Treatment of Penicillin G 1.5million UIV g6h moderate to severe Ampicillin 0.5-Ig IV q6h leptospirosis 16