Introduction:
Leptospirosis is an important zoonotic disease, which is common in the post-monsoon season. It is caused by Leptospira bacteria, which is a member of the family called Spirochetes. It is so-called because of its spiral shape. The disease can range from a minor and symptomless form to a serious life-threatening one, which can be fatal if left untreated.
What Causes Leptospirosis?
Leptospirosis is brought on by a bacteria known as Leptospira interrogans. The organism resides in the kidneys of many mammals. Their pee causes it to enter the soil and water.
Scratches, open sores, or dry spots on the skin are examples of skin breaks through which the germs can enter the body if one is near soil or water where an infected animal has urinated. Additionally, it may enter through the mouth, nose, or genitalia. They pass through the bloodstream and accumulate in the kidneys. The kidneys filter out harmful or extra materials from the urine. Bacteria leave the body through urine and may cause the spread of infection to other animals or humans.
What Is the Mode of Transmission in Leptospirosis?
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Leptospirosis is transmitted through surface water contaminated with the urine of infected animals. Pathogenic bacteria enter the host through minor cuts and abrasions over the skin. Swallowing contaminated water can theoretically cause the disease, but few cases are reported. Human-to-human transmission also has not been reported.
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People who are at risk are sewage workers, farmers, veterinarians, military personnel, sewer, and slaughterhouse workers. Any person who is exposed to running surface water is at risk of developing leptospirosis.
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Leptospirosis typically shows seasonal variation. The disease burden is significantly more in the post-monsoon season. Both rural and urban populations are equally affected, and the prevalence is a little bit higher in rapidly urbanizing cities may be because of inadequate sewage treatment facilities and improper drainage systems. Poor sanitation leading to rodent infestation can cause leptospirosis outbreaks, especially in underprivileged areas.
What Are the Clinical Features of Leptospirosis?
Clinical features of leptospirosis are diverse, ranging from undiagnosed asymptomatic illness to rapidly progressing fatal forms called Weil's disease. The symptoms of Leptospira infection occur after an incubation period of 7 to 10 days.
The common clinical features include the following:
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High-grade fever is associated with rigor and chills.
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Severe headaches and retro-orbital pain.
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Extreme muscle pain and tenderness, particularly in the calf and lower back.
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Red eyes, nausea, vomiting, and extreme exhaustion.
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Severe leptospirosis or Weil's disease starts after three to ten days of infection.
Weil's Disease:
Weil's disease is a rapidly progressing form of leptospirosis which can be fatal unless proper treatment is given. It is characterized by a combination of bleeding manifestation, jaundice, hypotension, and acute renal failure. It can also affect the brain and mimic symptoms of meningitis like nausea, vomiting, neck rigidity, and altered mental states. If left untreated, it can cause fatal complications and may result in death.
What Are the Phases of Leptospirosis?
The disease can be divided into two phases.
1. Leptospiremic Phase
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Acute phase or also called the septicemic phase.
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Sudden onset of flu-like symptoms, which starts 2 to 14 days after infection.
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This phase lasts 3 to ten days.
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Bacterial presence in blood and moving to organs. Blood tests show signs of infection.
2. Immune Phase
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Bacteria present in the bloodstream have moved to organs.
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The concentration of bacteria occurs in the kidney. Urine tests show signs of bacteria and antibodies against leptospira in the bloodstream.
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People with Weil's syndrome show internal bleeding, kidney damage, and severe yellowing of the skin and eyes.
Who Is at Risk of Developing Leptospirosis?
Although leptospirosis is more prevalent in tropical regions, it can also arise in impoverished neighborhoods of major cities in developing countries that are not near tropical regions.
The WHO states that periods of heavy rain and flooding increase the risk. It is more common for leptospirosis to occur in Asia, Central America, and Africa's East Sub-Saharan region.
How Is Leptospirosis Diagnosed?
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The suspected cases of leptospirosis should be evaluated by a physician at the earliest because early treatment significantly reduces the chances of complications.
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During the initial stages, the symptoms are nonspecific, and it might cause initial misdiagnosis because many diseases have similar symptoms to leptospirosis.
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Biochemical and hematological tests are non-specific in the early stages, and many diseases show a similar pattern.
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Chest X-rays and Electrocardiogram ( ECG) should be taken to rule out cardiac and pulmonary involvement respectively.
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Serological assays are the mainstays of diagnosing leptospirosis. Leptospirosis can be confirmed by detecting the presence of IgM antibodies against Leptospira bacteria by ELISA (enzyme-linked immunosorbent assay) or agglutination tests.
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MAT (microscopic agglutination test) is the most distinct among the investigations.
What Is the Differential Diagnosis for Leptospirosis?
Due to diverse clinical manifestations and wide geographical distribution, many clinical conditions have to be ruled out before making a diagnosis. The following are the possible differential diagnosis.
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Rickettsial diseases like scrub typhus and spotted fever.
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Viral hepatitis.
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Chikungunya.
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Viral hemorrhagic fever.
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Typhoid fever.
How Is Leptospirosis Treated?
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Highly efficient antibiotics are available against Leptospira. Penicillins and tetracyclines are used as first-line drugs.
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Cephalosporins like Ceftriaxone and Cefotaxime are also used. Antibiotics are effective in the early stages of the disease and in later stages their role is controversial.
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In the advanced stages of the disease and Weil's disease, the patient might require intensive treatment.
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The patient has to be hospitalized and might need intravenous antibiotics. Fluid and electrolyte balance has to be well maintained. Bleeding manifestations and shock have to be managed accordingly.
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Cardiac monitoring in the form of continuous ECG monitoring may be needed in case of complications like myocarditis.
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Patients with renal failure might require dialysis.
What Is the Prognosis of Leptospirosis?
The majority of the patients infected with Leptospira experience a complete recovery. The severity of the illness regarding renal and pulmonary dysfunctions are the most important determinants of prognosis. The extremes of age, evident pulmonary involvement, bleeding manifestations, renal failure, and thrombocytopenia are associated with poor outcomes. The common causes of death in leptospirosis patients are renal failure, shock, and myocarditis.
How Is Leptospirosis Prevented?
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No effective vaccine is available for human leptospirosis. Some research is undergoing, but the clinical results are unsatisfactory.
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Antibiotic prophylaxis is moderately effective and is the method used for prevention. Doxycycline is used for chemoprophylaxis in extremely high-risk individuals such as manual laborers exposed to contaminated surface running water.
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Rodent control with pesticides and proper disposal of sewage are useful methods to prevent outbreaks.
Conclusion:
Leptospirosis is an uncommon disease that shows mild to severe symptoms. Prevention of diseases is more important than treating the condition. Contact with contaminated water should be avoided. If there are some cuts or wounds present, a person should avoid contact with contaminated water. People at high risk like sewage cleaning workers should be taught about the diseases and tips to prevent them. If there are any symptoms, stop working and consult a doctor immediately
