Leptospirosis

Introduction

It is a ubiquitous enzootic disease. Reservoir of infection includes rodents, foxes, domestic livestock, dogs and frogs. When human contact occurs with infected tissues, fluids or contaminated water, they get the illness. Transmission may occur through cuts, mucous membranes and possibly intact skin.

Clinical Presentation

Two phases can be distinguished in typical cases. Very often, in our patients, it is not distinguished and probably septicaemic phase is closely followed by the immune phase.

1. Septicaemic phase
2. Immune phase Incubation period: 7-12 days Depending on the dose of organism and host factor, the disease may present as:

a. Mild form

b. Severe form In the mild form, the disease may present as nonspecific fever and can be diagnosed only by high index of suspicion and by serological test. Severe form is usually known as Weil’s disease which presents with jaundice and multiorgan involvement, especially as hepatorenal syndrome within 3-4 days after the onset of fever. Leptospirosis can also present without jaundice, with mild clinical manifestations. In general, 90% cases are anicteric

Diagnosis

Diagnosis basically is based on clinical features, the findings from simple investigations help us to differentiate it from conditions like hepatitis, enteric fever, malaria and dengue fever.

• Hematological
• Leucocytosis with neutrophilia is very commonly seen
• ESR is raised
• Thrombocytopenia is common
• Mild anaemia can occur
• Renal — Urine

a. Mild proteinuria

b. Cellular elements: Leucocyturia >5 cells/hpf

c. Erythrocyturia d. Granular cast

• Blood urea and serum creatinine levels raised in 65% of cases
• Hepatic: Cholestatic type of jaundice with increased serum alkaline phosphatase and serum bilirubin, accompanied by only moderate elevation of transaminases (opposite to that in viral hepatitis)
• Enzymes: CPK may be elevated due to muscle involvement

Treatment

To be effective, Penicillin or Tetracycline should be administered within 48 hours of the onset of illness or at least within 4-7 days of the onset. Early administration of antibiotics can prevent complications. Adults: Parenteral Aqueous Benzyl Penicillin (crystalline penicillin) 20 lakh unit 6th hrly for 1 week in uncomplicated cases. In ARF, the dose of penicillin is to be modified as perurine output and creatinine clearance. Inj. CP 10 L IV 6th hrly is found better in our set up, as the leptospirae are very sensitive to benzyl penicillin. It is also reported that antimicrobial treatment started late in the course of illness also is effective. If penicillin hypersensitivity is present: Tetracycline 500 mg 6 hrly may be given for 1 week. If renal failure is present, Doxycycline 200 mg OD is preferred to Tetracycline.