Leptospira IgM

Bacterial/ Viral

Report in 8Hrs

At Home

No Fasting Required

Details

Detects IgM antibodies in the blood against Leptospira bacteria, which cause leptospirosis

₹349₹1,100

68% OFF

Leptospira IgM Test Information Guide

Why is it done?
- Test Purpose: Detects IgM antibodies against Leptospira species to diagnose acute leptospirosis infection
- Primary Indications: Suspected acute leptospirosis presenting with fever, myalgia, headache, and jaundice
- Clinical Situations: Occupational exposure (farmers, veterinarians, sewage workers), exposure to contaminated water, travel to endemic regions, or unexplained fever with renal involvement
- Optimal Timing: Performed during the second phase of illness (leptospiremic phase) typically 5-7 days after symptom onset; IgM appears within first week of illness
- Disease Severity Assessment: Helps differentiate between anicteric leptospirosis and severe Weil's disease (icteric leptospirosis with renal failure)
Normal Range
- Negative Result: <1:400 titer or <10 IU/mL (depending on assay method); typically reported as 'Not Detected' or 'Negative'
- Positive Result: ≥1:400 titer or ≥10 IU/mL; indicates acute or recent infection
- Units of Measurement: IU/mL (International Units per milliliter), titer ratios (1:400, 1:800, etc.), or qualitative results
- Borderline/Equivocal: Results near the cutoff threshold; repeat testing after 5-7 days may be recommended to demonstrate seroconversion or rising titers
- Interpretation of Negative: No acute leptospiral infection detected; if tested within first 5 days of illness, may represent early infection and repeat testing is warranted
Interpretation
- Positive IgM Antibodies: Indicates acute or recent leptospiral infection (typically within 1-3 months); patient likely in immune response phase
- High Titers (>1:800): Associated with more severe disease, particularly Weil's disease with significant organ involvement (renal failure, pulmonary hemorrhage, hepatic dysfunction)
- Rising Titers on Serial Testing: Strongly suggestive of acute infection; four-fold rise between acute and convalescent sera is considered diagnostic
- Serovar Identification: When available, identifies specific Leptospira serovar involved; helps determine geographic source and transmission route
- Clinical Correlation: Results must be interpreted with clinical presentation; fever, jaundice, renal involvement, and thrombocytopenia support diagnosis
- Factors Affecting Results: Timing of sample collection, immunocompromised status (may show delayed or weak response), prior vaccination (uncommon), cross-reactivity with other spirochetes (rare)
- IgM Persistence: May remain positive for several months; IgG appears later and persists longer, useful for differentiating past from acute infection
Associated Organs
- Primary Organ Systems Affected: Kidneys, liver, lungs, and nervous system
- Acute Leptospirosis (Anicteric Form): Biphasic illness with mild systemic symptoms, myalgia, headache, and transient renal involvement; mortality <1%
- Weil's Disease (Icteric Form): Severe multiorgan involvement with jaundice, acute kidney injury, pulmonary hemorrhage, cardiac arrhythmias, and hemorrhagic manifestations; mortality 5-15%
- Renal Involvement: Acute interstitial nephritis progressing to acute tubular necrosis; elevated creatinine, BUN, and proteinuria; may require dialysis in severe cases
- Hepatic Involvement: Hepatomegaly, elevated transaminases, hyperbilirubinemia, and jaundice; cholestasis pattern on liver function tests
- Pulmonary Involvement: Pulmonary hemorrhage syndrome, acute respiratory distress syndrome (ARDS), and diffuse alveolar hemorrhage; more common in severe cases
- Neurological Complications: Aseptic meningitis, uveitis, and rarely encephalitis; CSF examination shows lymphocytic pleocytosis
- Hematologic Complications: Thrombocytopenia, anemia, and disseminated intravascular coagulation (DIC) in severe cases
- Risk Factors for Severe Disease: Age >40 years, comorbidities (diabetes, renal disease), immunocompromised status, and delay in treatment initiation
Follow-up Tests
- Leptospira IgG Serology: Appears 5-7 days after IgM; persists for years; helps confirm past infection and assess immunity status
- Microscopic Agglutination Test (MAT): Gold standard reference test for leptospirosis; identifies specific serovar and detects four-fold titer rise in paired sera
- Leptospira PCR: Detects bacterial DNA in blood, urine, or CSF; useful in first 7-10 days of illness before antibodies develop; confirms active infection
- Blood Culture: Can isolate Leptospira during early leptospiremic phase (first week); low sensitivity but confirms diagnosis when positive
- Renal Function Tests: Serum creatinine, BUN, electrolytes, and urinalysis; monitor for acute kidney injury
- Liver Function Tests: AST, ALT, alkaline phosphatase, bilirubin; assess hepatic involvement in Weil's disease
- Complete Blood Count: Monitor for thrombocytopenia, anemia, and leukocytosis; assess for DIC if severe
- Coagulation Studies: PT/INR, aPTT, fibrinogen, D-dimer; evaluate for bleeding complications and DIC
- Cerebrospinal Fluid Analysis: When meningitis suspected; cell count differential, glucose, protein, and culture
- Imaging Studies: Chest X-ray for pulmonary involvement; ultrasound or CT for hepatic and renal assessment in severe disease
- Repeat IgM Testing: If initially negative but high clinical suspicion, repeat 5-7 days later to detect seroconversion
- Monitoring Frequency: Renal function tests should be monitored regularly during acute illness; daily if on dialysis; less frequently during recovery phase
Fasting Required?
- Fasting Requirement: No
- Dietary Restrictions: None; food and fluid intake do not affect serology results
- Medication Restrictions: No specific medication contraindications for test performance; continue current medications unless instructed otherwise by physician
- Blood Collection: Venipuncture to collect 5-10 mL of serum in a standard serum separator tube; no special handling required
- Specimen Handling: Serum should be separated within 1-2 hours; refrigerate at 2-8°C if delays in processing occur; do not freeze unless indicated for long-term storage
- Timing of Sample Collection: Optimal collection during second phase of illness (day 5-7 post-symptom onset); early collection may yield negative results despite active infection
- Special Patient Instructions: Patient should inform healthcare provider of fever, symptoms onset date, and potential exposure history; blood precautions may be implemented for acute phase
- Contraindications: None; test can be performed in patients of all ages and medical conditions with appropriate biohazard precautions

How our test process works!