Leishmaniasis

Leishmaniasis is a parasitic disease classified among the neglected tropical diseases (NTDs). It is caused by protozoan parasites belonging to the genus Leishmania, which are transmitted to humans through the bites of infected female phlebotomine sandflies. The disease can take several forms, ranging from self-healing skin ulcers to potentially fatal visceral infections. It is endemic in tropical and subtropical regions, especially affecting vulnerable communities in parts of Asia, Africa, the Americas, and the Mediterranean.

Leishmaniasis is not just a medical condition—it is a social and economic burden. It disproportionately impacts poor and marginalised populations with limited access to healthcare. Understanding the disease, its types, symptoms, and preventive measures is essential to control its spread and support affected individuals.

Leishmaniasis is an infectious disease caused by Leishmania parasites, transmitted to humans by sandflies. When a sandfly bites an infected person or animal, it ingests the parasites, which then multiply in the sandfly and are transmitted to the next person it bites.

The disease presents in three main clinical forms:

• Cutaneous leishmaniasis (CL): Affects the skin, causing ulcers and lesions.
• Mucocutaneous leishmaniasis (MCL): Affects the mucous membranes of the nose, mouth, and throat.
• Visceral leishmaniasis (VL): Also known as kala-azar, it affects internal organs such as the liver, spleen, and bone marrow.

Leishmaniasis is not contagious from person to person; it requires a sandfly vector. However, untreated individuals with VL or post-kala-azar dermal leishmaniasis (PKDL) can act as reservoirs of infection.

Worldwide Prevalence

Leishmaniasis is endemic in more than 90 countries, with an estimated 700,000 to 1 million new cases annually. Around 12 million people are currently infected worldwide. The disease burden is highest in Brazil, Ethiopia, India, Kenya, Somalia, South Sudan, and Sudan. Approximately 50,000 to 90,000 new cases of visceral leishmaniasis occur globally each year.

Prevalence in India

India has historically contributed significantly to the global burden of visceral leishmaniasis, particularly in states like Bihar, Jharkhand, Uttar Pradesh, and West Bengal. According to the World Health Organization (WHO), India accounted for nearly half of the global VL cases in the early 2000s. However, thanks to the National Kala-azar Elimination Programme, the incidence has drastically declined. As of 2023, fewer than 500 new VL cases were reported annually in the country.

Leishmaniasis manifests in three primary forms:

1. Cutaneous Leishmaniasis (CL)
   
   • The most common form.
   • Causes skin sores that develop into ulcers.
   • Usually heals without treatment but can leave permanent scars.
2. Mucocutaneous Leishmaniasis (MCL)
   
   • Affects mucous membranes of the nose, mouth, and throat.
   • Typically develops from untreated CL.
   • Can lead to severe facial disfigurement.
3. Visceral Leishmaniasis (VL) or Kala-azar
   
   • The most severe form.
   • Affects internal organs: spleen, liver, and bone marrow.
   • Fatal if left untreated.
4. Post-Kala-azar Dermal Leishmaniasis (PKDL)
   
   • Occurs in some individuals after VL treatment.
   • Presents as skin rashes or nodules.
   • Acts as a reservoir of the parasite, risking further transmission.

Leishmaniasis is caused by parasites of the Leishmania genus. These parasites are transmitted by the bite of infected female phlebotomine sandflies. More than 20 species of Leishmania can cause the disease in humans. The sandfly becomes infected by feeding on infected animals or humans.

Major causes include:

• Bites from infected sandflies.
• Poor sanitation and living conditions.
• Environmental changes like deforestation and urbanisation.
• Migration to and from endemic regions.
• Lack of vector control and public health infrastructure.

Symptoms vary depending on the type of leishmaniasis:

Cutaneous Leishmaniasis:

• Red papules or nodules on exposed skin.
• Lesions that turn into ulcers.
• Crusting and scarring over time.
• Usually painless but may become infected.

Mucocutaneous Leishmaniasis:

• Nasal congestion and bleeding.
• Swelling of the lips and nose.
• Ulcers in the mouth and throat.
• Facial disfigurement in severe cases.

Visceral Leishmaniasis:

• Irregular bouts of fever.
• Weight loss and fatigue.
• Enlargement of the spleen and liver.
• Anaemia and low blood counts.
• Weakness and susceptibility to other infections.

Accurate diagnosis is essential for effective treatment. Diagnosis involves clinical assessment and laboratory confirmation:

• Medical history and examination: Including travel to endemic regions.
• Microscopy: Visual identification of Leishmania parasites in tissue samples.
• Serological tests: Like rK39 antigen-based rapid diagnostic tests (especially for VL).
• Polymerase Chain Reaction (PCR): Detects Leishmania DNA.
• Culture: Parasite growth in specialised media.
• Montenegro skin test: Indicates prior exposure, useful in CL and MCL.

Treatment depends on the form of leishmaniasis, severity of symptoms, and geographic region.

Visceral Leishmaniasis:

• Liposomal Amphotericin B (preferred in India).
• Miltefosine: First oral drug for VL. (Impavido capsule)
• Pentavalent antimonials: Still used in some countries. (Xylocaine drop)
• Combination therapy: Reduces resistance and improves efficacy.

Cutaneous and Mucocutaneous Leishmaniasis:

• Local treatments (cryotherapy, thermotherapy).
• Intralesional injections.
• Systemic treatment for severe or multiple lesions.

Monitoring during treatment is crucial to manage potential side effects like kidney damage (with amphotericin) or gastrointestinal issues (with miltefosine).

Alternative or complementary therapies should not replace standard medical treatment. However, they may support recovery:

• Nutritional support: Protein and vitamin-rich diets can help immune recovery.
• Herbal applications: Neem and turmeric have anti-inflammatory properties but lack clinical validation.
• Home care: Keeping ulcers clean, covered, and preventing secondary infections.

Always consult a healthcare provider before starting any non-standard treatment.

Several factors increase the risk of leishmaniasis:

• Living or travelling in endemic areas.
• Poor housing conditions and sanitation.
• Sleeping outdoors or without bed nets.
• Malnutrition, which weakens the immune system.
• HIV co-infection, especially for VL.
• Occupations involving forest or soil exposure (e.g., farmers, forest workers).

If not treated timely, leishmaniasis can lead to serious complications:

• Cutaneous: Scarring, bacterial infections, social stigma.
• Mucocutaneous: Disfigurement of nose, lips, and throat.
• Visceral: Severe anaemia, malnutrition, spleen rupture, secondary infections.
• PKDL: Can prolong transmission cycle, complicate control efforts.
• Mortality: Particularly high in untreated VL cases.

For those diagnosed with leishmaniasis, the following tips can aid in recovery:

• Follow the treatment plan strictly.
• Attend all follow-up appointments.
• Maintain a nutritious diet to boost immunity.
• Clean skin lesions daily and avoid scratching.
• Protect yourself from further sandfly bites.
• Seek psychological support if dealing with scarring or stigma.

1. "It only affects the skin."
   
   • False. Visceral forms can be life-threatening.
2. "It is contagious."
   
   • No. It requires sandfly transmission.
3. "It only exists in Africa."
   
   • Wrong. It is also common in India, South America, and the Middle East.
4. "Only poor people get it."
   
   • While poverty increases risk, anyone in endemic regions can contract it.
5. "Once treated, it never comes back."
   
   • PKDL can appear months or years after VL.

Seek medical attention if you:

• Have persistent skin sores that do not heal.
• Experience prolonged fever with fatigue and weight loss.
• Notice swelling in the abdomen.
• Have travelled to or live in an endemic area.
• Are experiencing nasal bleeding or mouth ulcers.

Early diagnosis and treatment can prevent severe complications and death.

• What type of leishmaniasis do I have?
• What tests do I need for confirmation?
• What is the best treatment option for my case?
• What are the side effects of the medications?
• How long will the treatment take?
• Can my family members also be at risk?
• What precautions should I take to avoid reinfection?
   

Support from family and friends plays a crucial role in recovery:

• Accompany them to medical appointments.
• Help manage medications and wound care.
• Encourage them to rest and maintain nutrition.
• Provide emotional support, especially if they face stigma.
• Educate others to reduce discrimination and misinformation.
• Ensure they take preventive measures against sandfly bites.
   

Leishmaniasis remains a major global health challenge, particularly in tropical and subtropical regions. Though it is treatable, the disease can cause significant suffering and long-term disability if ignored. With increased awareness, early diagnosis, and comprehensive public health strategies, we can work toward controlling and eventually eliminating leishmaniasis. India has made commendable progress in reducing VL cases, serving as a global example of successful disease control.

Whether you are a health professional, policymaker, or community member, staying informed about leishmaniasis is a critical step toward ensuring a healthier future.