Definition

Leptospirosis is an infection caused by the bacterium Leptospira spp. This bacterium is classified into pathogenic (causing disease) and non-pathogenic. Rats are the main carriers of this bacterium, as it naturally proliferates in their bodies and is excreted through rat urine.

In most cases, leptospirosis presents symptoms such as malaise, resembling flu-like symptoms, typically lasting less than a week. Symptoms appear within less than 2 weeks to 1 month after infection but sometimes may be asymptomatic altogether. The first symptom is usually fever, followed by headache, muscle pain, skin pain, jaundice (yellowing of the skin and eyes), vomiting, diarrhea, and skin redness, especially in more severe infections.

Leptospirosis is commonly found in countries with humid climates, although the bacteria can exist worldwide. It is particularly prevalent in Australia, Africa, Southeast Asia, South America, and the Caribbean.

Causes

Gram-negative bacteria from the Spirochaeta group cause leptospirosis, specifically Leptospira sp. These bacteria enter the body through wounds or abrasions on the skin, eyes, nose, or mouth and then enter the bloodstream, targeting organs, especially the kidneys. Bacteria filtered in the kidneys are subsequently excreted in urine, allowing leptospirosis to spread to other people or animals, especially rats. As a zoonotic disease, leptospirosis can be transmitted between animals and humans. Infection can occur through:

• Direct contact with urine or reproductive fluids from infected animals
• Contact with contaminated water or soil
• Consumption of contaminated food or water

Risk factor

You are at risk of experiencing leptospirosis, especially if you live in tropical areas and countries with warm climates and high annual rainfall, resulting in high humidity. Living or traveling to these areas, including Oceania (Australia, New Zealand, and the Pacific islands), the Caribbean, sub-Saharan Africa, Latin America, South Asia, and Southeast Asia, puts you at a higher risk of contracting leptospirosis.

Symptoms

Leptospirosis typically presents symptoms resembling the common flu; in some cases, individuals may not show any symptoms. However, in severe cases, leptospirosis can lead to internal bleeding and organ damage. 

During acute leptospirosis, symptoms may suddenly appear. These can include high fever, red eyes, headache, chills, muscle pain, abdominal pain, nausea and vomiting, diarrhea, jaundice of the skin and eyes, and even a reddish skin rash.

In more severe cases, symptoms may manifest 3 to 10 days later, including coughing up blood (hemoptysis), chest pain, difficulty breathing, prominent jaundice of the skin and eyes, black stools, blood in urine, and bleeding under the skin.

Diagnosis

The doctor will inquire about your symptoms, travel history, and whether you've had contact with animals or areas with poor hygiene, such as locations with stagnant water or flooding. Next, the doctor will conduct several examinations to diagnose leptospirosis, including a physical examination, blood tests, and urine tests. 

During the physical examination, vital signs will be checked, and the presence of yellowing in the eyes or body and any signs of bleeding or skin rash will be assessed. 

Blood or urine tests will be conducted to evaluate kidney function, detect signs of bleeding in urine, and identify indicators of inflammation. If severe infection symptoms are present, you may be advised to undergo imaging examinations such as chest X-rays or CT scans to assess for abnormalities or organ damage caused by severe infection.

Management

The doctor will treat leptospirosis with antibiotics. For mild cases or those with less severe symptoms, home treatment combined with mild symptomatic relief may be recommended. However, hospitalization may be necessary for severe symptoms. In such cases, antibiotics and supportive treatment for affected organs will be administered intravenously.

• Fluid therapy and fever management

In moderate cases of leptospirosis, treatment may involve ensuring adequate fluid intake, rest, and pain and fever relievers.

• Antibiotics

Common antibiotics used to treat leptospirosis include penicillin derivatives like amoxicillin, and ampicillin, intravenous formulations such as penicillin G, and cephalosporins like ceftriaxone. The specific antibiotic prescribed will depend on your symptoms. The antibiotic type will be adjusted in pediatric cases to ensure safety and minimise side effects.

• Ventilator support

Mechanical ventilation may be necessary if the lungs are infected, causing difficulty breathing. Sedative medication will be given while you're connected to the ventilator.

• Plasmapheresis

This procedure involves replacing blood plasma and may be recommended if there's a risk of organ damage from leptospirosis. During plasmapheresis, a machine separates plasma from the blood, replaces it with a substitute plasma, and then returns the blood to your body through another tube.

Complications

Treatment can indeed significantly reduce the severity of leptospirosis and prevent complications.  Without proper treatment, leptospirosis can progress to more serious complications such as meningitis, liver failure, kidney damage resulting in kidney failure, respiratory distress, hemodynamic collapse (shock), and even fetal death in pregnant women.

Prevention

These preventive measures are crucial for reducing the risk of leptospirosis:

• Avoid swimming or playing in dirty water, especially during floods, as it may contain contaminated animal fluids.
• Consider preventive medication if traveling to high-risk areas and consulting a doctor for appropriate prophylactic treatment.
• Avoiding contact with animals that may carry leptospirosis.
• Wear protective clothing and shoes when working in areas with potential exposure to contaminated environments.
• Refraining from water sports and swimming in natural water bodies after floods or during periods of water contamination.
• Ensuring proper treatment and sterilization of drinking water, especially when sourced from rivers, lakes, or canals.
• Using gloves when handling dead animals to prevent direct contact with potentially infected tissues.
• Cover any open wounds or scratches with waterproof bandages or plasters to minimise the risk of bacterial entry into the body.

When to see a doctor?

Seek medical attention promptly if you exhibit symptoms of leptospirosis, particularly after potential exposure to contaminated water or animals. In severe symptoms such as coughing up blood, chest pain, breathing difficulties, red eyes, blood in urine, reduced urine output, or rash-like red spots on the skin, it's imperative to go to the Emergency Department without delay.

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