Overview

Definition:
-Leptospirosis is a systemic infection caused by pathogenic spirochetes of the genus Leptospira
-In tropical exposures, it frequently presents with hepatic involvement leading to jaundice, a severe manifestation often termed Weil's disease.
Epidemiology:
-Endemic in tropical and subtropical regions worldwide, particularly in areas with poor sanitation, heavy rainfall, and close contact with animal reservoirs (rodents, livestock)
-Peak incidence often coincides with monsoon seasons
-Pediatric cases are reported globally but are more common in agricultural and flood-prone communities.
Clinical Significance:
-Leptospirosis is a significant cause of acute febrile illness and jaundice in children returning from or residing in endemic areas
-Early recognition and prompt management are crucial to prevent severe complications like acute kidney injury, hepatic failure, and pulmonary hemorrhage, which can be life-threatening.

Clinical Presentation

Symptoms:
-Sudden onset fever
-Severe headache, often retro-orbital
-Myalgia, particularly in the calves and lumbar region
-Conjunctival suffusion without exudate
-Nausea and vomiting
-Abdominal pain
-Progressive jaundice
-Oliguria or anuria
-Hemorrhagic manifestations like epistaxis, purpura, or hematemesis may occur.
Signs:
-Fever >38.5°C
-Tachycardia
-Icteric sclera and skin
-Hepatomegaly, often tender
-Splenomegaly may be present
-Signs of dehydration
-Possible meningeal irritation
-Evidence of acute kidney injury (reduced urine output, edema)
-Pulmonary crackles or signs of respiratory distress in severe cases.
Diagnostic Criteria:
-No single universally accepted pediatric diagnostic criteria for leptospirosis
-diagnosis is based on a combination of epidemiological risk, clinical features, and laboratory confirmation
-The criteria for Weil's disease (severe leptospirosis) typically include jaundice, renal impairment, and hemorrhage.

Diagnostic Approach

History Taking:
-Detailed travel history to or residence in endemic areas
-Exposure to contaminated water or soil (swimming, wading, farming, cleaning drains)
-Contact with animal urine (rodents, dogs, cattle)
-History of recent floods or heavy rainfall
-Onset and progression of symptoms
-Prodromal symptoms
-Previous similar episodes.
Physical Examination:
-Thorough systemic examination focusing on vital signs, hydration status, presence of jaundice, liver and spleen size, presence of edema, and signs of bleeding or respiratory distress
-Neurological examination for meningeal signs or altered mental status.
Investigations:
-Leptospira serology (MAT - microscopic agglutination test is gold standard, ELISA, IgM antibodies) - typically positive after 7-10 days
-PCR on blood or urine during early illness
-Complete blood count (CBC) with differential, platelet count
-Liver function tests (LFTs) - elevated bilirubin (predominantly conjugated), elevated ALT/AST, elevated alkaline phosphatase
-Renal function tests (RFTs) - elevated BUN/creatinine
-Urinalysis - proteinuria, hematuria, casts
-Coagulation profile if bleeding is present
-Chest X-ray if pulmonary involvement suspected.
Differential Diagnosis:
-Viral hepatitis (Hepatitis A, E)
-Dengue fever
-Malaria
-Typhoid fever
-Rickettsial infections
-Hemolytic uremic syndrome (HUS)
-Drug-induced liver injury
-Sepsis with multi-organ dysfunction
-Yellow fever
-G6PD deficiency with hemolysis.

Management

Initial Management:
-Supportive care is paramount
-Fluid resuscitation for dehydration
-Monitoring of vital signs, urine output, and electrolyte balance
-Aggressive management of multi-organ failure.
Medical Management:
-Antibiotics are indicated in suspected or confirmed cases, especially in severe illness, to reduce duration and severity
-Penicillin G (IV) is the drug of choice for severe leptospirosis: 1-2 million units (or 25,000-50,000 U/kg/day) divided into 3-4 doses for 7-14 days
-Alternatives for penicillin-allergic patients include doxycycline (oral, >8 years old) or azithromycin (oral/IV)
-For milder cases, oral doxycycline or azithromycin may be used.
Surgical Management:
-Rarely indicated
-May be considered for complications like severe gastrointestinal bleeding requiring transfusion or, in extremely rare instances, hepatic transplantation if fulminant hepatic failure occurs.
Supportive Care:
-Intensive monitoring in a hospital setting for severe cases
-Management of electrolyte imbalances, acid-base disturbances
-Nutritional support, often requiring nasogastric feeding or parenteral nutrition if oral intake is compromised
-Management of renal failure with hemodialysis if indicated
-Respiratory support with oxygen or mechanical ventilation if pulmonary involvement is significant.

Complications

Early Complications:
-Acute kidney injury (AKI) - ranging from mild oliguria to anuria requiring dialysis
-Hepatic dysfunction and jaundice - can be profound, leading to coagulopathy
-Pulmonary hemorrhage and acute respiratory distress syndrome (ARDS)
-Myocarditis
-Meningitis/encephalitis
-Rhabdomyolysis.
Late Complications:
-Post-leptospirosis uveitis
-Chronic meningitis
-Hepatic granulomas
-Renal scarring.
Prevention Strategies:
-Avoidance of contact with contaminated water and soil, especially during monsoon season
-Use of protective footwear in endemic areas
-Rodent control measures
-Public health education regarding risks and preventive behaviors
-Prompt antibiotic treatment for exposed individuals in high-risk scenarios, though this is not standard practice for prophylaxis.

Prognosis

Factors Affecting Prognosis: Age of the patient (younger children may have poorer outcomes), severity of initial illness, presence and severity of organ involvement (especially renal and pulmonary), promptness of diagnosis and initiation of treatment, presence of co-morbidities.
Outcomes:
-With timely and appropriate management, many children recover fully
-However, severe leptospirosis (Weil's disease) can have a mortality rate of 10-40% if untreated or inadequately managed
-Survivors may have sequelae.
Follow Up:
-Regular follow-up is essential for children who have had severe leptospirosis, particularly to monitor for renal function, liver enzyme levels, and any signs of ocular or neurological sequelae
-Annual check-ups for a period of 1-2 years may be recommended.

Key Points

Exam Focus:
-Leptospirosis is a zoonotic infection
-Jaundice and renal failure are hallmarks of severe disease (Weil's disease)
-Travel history to tropical/subtropical regions is a critical clue
-Definitive diagnosis relies on serology (MAT) or PCR
-Penicillin G is the drug of choice for severe illness.
Clinical Pearls:
-Always consider leptospirosis in a febrile child with jaundice, especially with a history of potential exposure to contaminated water or animal urine in endemic areas
-Conjunctival suffusion is a classic, albeit non-specific, sign
-Early antibiotics can significantly alter the course of severe disease.
Common Mistakes:
-Delayed diagnosis due to atypical presentation or lack of awareness
-Inadequate antibiotic therapy (wrong drug, dose, or duration) in severe cases
-Over-reliance on serology without considering the timing of sample collection
-Failing to consider leptospirosis in the differential diagnosis of acute febrile jaundice in pediatric patients.