KALA AZAR

Source: IASGYAN

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Context

• India has successfully achieved its target to eliminate visceral leishmaniasis, commonly known as kala-azar, according to data from the National Centre for Vector Borne Diseases Control (NCVBDC).

Details

• This achievement comes after persistent efforts and government interventions over the years.
• As per the WHO, in 2020, India accounted for 18 per cent of the global burden of kala-azar.
• Kala-azar, a vector-borne disease, has posed a significant health challenge for decades, particularly in states like Bihar, Jharkhand, West Bengal, and Uttar Pradesh.

Background

• Kala-Azar: Visceral leishmaniasis, commonly known as kala-azar, is a chronic and potentially fatal disease caused by the protozoan parasite Leishmania donovani. It is transmitted through the bites of infected sandflies.
• Target Extension: Initially aimed to eliminate kala-azar by 2010, the target was extended until 2023 due to persistent challenges in disease control.

Achievement

• Reduction in Cases: In 2023, India reported only 520 cases of kala-azar across the country. This significant reduction in cases is a testament to the effectiveness of various control measures implemented to combat the disease.
• Additionally, there were 286 cases of post-kala azar dermal leishmaniasis (PKDL).
• Elimination Criteria: India met the elimination criteria set by the World Health Organization (WHO), which defines elimination as no block in the country reporting more than one case per 10,000 people.

Government Interventions and Strategies

• Indoor Residual Spraying: Rigorous indoor residual spraying efforts have been conducted to curb sandfly breeding sites and reduce disease transmission.
• Sealing Breeding Sites: Measures such as sealing potential breeding sites and using special soil to seal crevices in mud walls have been employed to prevent sandflies from nesting.
• Treatment Compliance: Mobilization of healthcare workers, including the ASHA network, has ensured proper treatment completion for Post Kala-azar dermal leishmaniasis (PKDL) patients, who require a 12-week course of Miltefosine.

Challenges

• Persistent Challenges: While significant progress has been made, challenges persist, particularly in states like Bihar and Jharkhand, where cases of PKDL remain relatively high.
• Continued Surveillance: Public health experts emphasize the importance of continued surveillance, robust healthcare infrastructure, and community engagement to prevent the resurgence of kala-azar and other vector-borne diseases.
• Sustaining Progress: Sustaining the progress made is crucial for India to maintain its kala-azar-free status. Efforts to strengthen healthcare systems and improve access to diagnosis and treatment will be essential in achieving this goal.

What is Kala Azar (Visceral Leishmaniasis)?

• Kala Azar is a severe and potentially fatal parasitic disease caused by Leishmania parasites.
• It primarily affects the internal organs, particularly the liver, spleen, and bone marrow.
• Kala Azar is transmitted to humans through the bites of infected female sandflies.
• It is commonly known as Black Fever or Dumdum Fever.
• In India, Leishmania donovani is the primary parasite responsible for causing this disease.

Causes:

• Parasite: Kala Azar is caused by protozoan parasites of the Leishmania genus, primarily Leishmania donovani and Leishmania infantum, with Phlebotomus argentipes being the primary vector in India.
• Transmission: The parasites are transmitted to humans through the bite of infected female sandflies of the genus Phlebotomus in the Old World (Africa, Asia, and Europe) and Lutzomyia in the New World (Central and South America).

Symptoms:

• Fever: Persistent and irregular fever is a hallmark symptom.
• Enlarged Spleen (Splenomegaly): The spleen becomes enlarged, causing abdominal discomfort and pain.
• Enlarged Liver (Hepatomegaly): Liver enlargement may occur, leading to abdominal swelling and tenderness.
• Weight Loss: Significant and unexplained weight loss is common.
• Weakness and Fatigue: Patients often experience weakness and fatigue due to the systemic effects of the disease.
• Anemia: Kala Azar can lead to severe anemia, resulting in weakness, pallor, and shortness of breath.
• Bleeding Disorders: In some cases, bleeding disorders may occur due to a decrease in platelet count (thrombocytopenia).
• Secondary Infections: Patients with weakened immune systems due to Kala Azar are susceptible to secondary infections.
• If left untreated, it can be fatal in 95% of cases.

Diagnosis:

• Clinical Evaluation: Symptoms such as prolonged fever, splenomegaly, and hepatomegaly raise suspicion for Kala Azar.
• Laboratory Tests: Blood tests, bone marrow aspiration, and serological tests (such as rK39 rapid diagnostic tests) are used to confirm the diagnosis by detecting the presence of Leishmania parasites or antibodies.

Treatment:

• Antimonial Drugs: Pentavalent antimonials (such as sodium stibogluconate and meglumine antimoniate) have been the mainstay of treatment for decades.
• Other Medications: In regions with antimonial resistance, alternative treatments include liposomal amphotericin B, miltefosine, and paromomycin.
• Combination Therapy: Combination regimens may be used for severe or relapsing cases.

Prevention:

• Vector Control: Efforts to control sandfly populations and reduce human-vector contact through insecticide spraying, bed nets, and environmental management.
• Reservoir Control: Controlling reservoir hosts (such as dogs) in regions where they contribute to the transmission cycle.
• Early Diagnosis and Treatment: Prompt diagnosis and treatment of cases to reduce transmission and prevent complications.

Epidemiology:

• Kala Azar is endemic in regions of the Indian subcontinent, East Africa, parts of Latin America, and the Mediterranean basin.
• Vulnerable populations include those living in poverty, with limited access to healthcare, and in areas with poor sanitation and hygiene conditions.

Post Kala-azar Dermal Leishmaniasis (PKDL):

• PKDL occurs when Leishmania donovani infiltrates and thrives within skin cells, leading to the formation of skin lesions.
• It can emerge after treatment for Kala-Azar, but there's evidence suggesting that PKDL might occur without preceding the visceral stage. However, more research is needed to understand its development fully.

Conclusion

India's achievement in eliminating kala-azar is a significant milestone in public health. Continued efforts and investments in disease surveillance, vector control, and healthcare infrastructure will be essential to sustain this progress and improve overall public health outcomes in the country.

Sources:

Business Standard

PRACTICE QUESTION Q.   India has successfully achieved its target to eliminate visceral leishmaniasis, commonly known as kala-azar, according to data from the National Centre for Vector Borne Diseases Control. Discuss the significance of continued efforts and investments in disease surveillance, vector control, and healthcare infrastructure in achieving the target. (250 Words)