Clinical Overview of Leptospirosis

At a glance

Leptospirosis is a disease that affects both people and animals. It is caused by bacterium from the genus Leptospira. Healthcare providers can learn more about leptospirosis in people, including transmission, symptoms, treatment, surveillance, incidence, and resources. Early treatment could lessen disease severity and contribute to better health outcomes.

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Overview

The Leptospira bacterium that causes leptospirosis spreads through the urine of infected livestock, pets, rodents, marine mammals, and wild animals. If the urine from an infected animal has contaminated a water source or soil, the bacterial can persist for several weeks to months.

People can become infected through:

  • Contact with water or soil containing urine or bodily fluids from infected animals.
  • Contact with contaminated water or soil, especially after hurricanes, flooding, or heavy rainfall.
  • Directly touching urine or body fluids from an infected animal.
  • Eating food or drinking water contaminated by urine.

In people, leptospirosis can cause a wide range of non-specific symptoms and can be confused with other diseases. Some people who are infected may have no symptoms at all.

People can lower their risk of getting leptospirosis by not drinking, bathing, swimming in, or wading in water that might be contaminated with animal urine, especially after hurricanes or floods. They should also avoid contact with animals that may be infected.

Types

Leptospires are the bacteria that cause leptospirosis. They:

  • Are long, thin, motile spirochetes.
  • Spread in the urine and body fluids of infected animals.
  • Survive for weeks to months in fresh water and wet soil in warm areas.

Leptospires are classified into over 300 pathogenic serovars based on antigenic properties, though antigenic properties are not a predictor of species designation. The serovars and species can vary by region. Leptospirosis occurs worldwide, and it's more common in temperate or tropical climates.

Signs and symptoms

The incubation period of leptospirosis is 5-14 days with a range of 2-30 days. The disease presents like many other conditions and has a wide range of non-specific symptoms:

  • Fever
  • Headache
  • Chills
  • Muscle aches
  • Vomiting
  • Nausea
  • Diarrhea
  • Abdominal pain
  • Cough
  • Jaundice
  • Conjunctival suffusion
  • Sometimes rash

Untreated patients could develop kidney failure, jaundice, respiratory distress or failure, liver failure, and meningitis. In some cases, death occurs.

Surveillance and Laboratory Submissions

Leptospirosis is a nationally notifiable condition.

The case report form is available in English and Spanish as a fillable PDF that can be completed electronically, or it can be printed and filled by hand. Completed forms can be emailed, faxed, or mailed to CDC using the information on the form.

State health departments can directly report leptospirosis cases via DCIPHER. Access to the Bacterial Special Pathogens Branch (BSPB) DCIPHER portal is granted via SAMS credentialing. Contact the BSPB team for more information.

To request DCIPHER access, for more information about the system, or if there are other surveillance-related questions, contact BSPB at bspb@cdc.gov.

Find out more about laboratory submissions by visiting CDC Laboratory Submissions.

Treatment and recovery

Early treatment may decrease the severity and duration of disease. For patients with a high clinical suspicion of leptospirosis, start antibiotic treatment as soon as possible without waiting for laboratory results.

For patients with mild symptoms, doxycycline is the drug of choice (100 mg orally, twice daily for 7 days), if not contraindicated.

Other options include:

  • Azithromycin (500 mg orally, once daily for 3 days)
  • Ampicillin (500-750 mg orally, every 6 hours for 7 days)
  • Amoxicillin (500 mg orally, every 6 hours for 7 days).

For patients with severe disease:

  • IV penicillin is the drug of choice (1.5 million units IV, every 6 hours), OR
  • Ceftriaxone (1 g IV, every 24 hours)

Disease trends

  • An estimated 1 million cases occur globally each year, resulting in nearly 60,000 deaths.
  • It occurs most frequently in tropical and subtropical climates.
  • Leptospirosis has been reported throughout the United States from many states and jurisdictions.
  • Cases of leptospirosis can increase after hurricanes or flooding when people may have to wade through contaminated water or use it for drinking or bathing.
  • Leptospirosis is among the leading zoonotic disease causes of illness worldwide. The disease is underdiagnosed and underreported; true numbers are likely higher.

Resources

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Content Source:
; National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)