Awareness about kala-azar disease

What is Visceral Leishmaniasis (kala-azar)?

Visceral leishmaniasis (kala-azar), is an infectious Neglected Tropical Disease (NTD) characterized by prolonged fever, weight loss, loss of appetite and debility, that is fatal unless treated.

What is Post Kala-azar Dermal Leishmaniasis?

Post Kala-azar Dermal Leishmaniasis (PKDL) is a complication of kala-azar which primarily affects the skin. It occurs in a small proportion of patients long after they have recovered from kala-azar, sometimes years later. However, it sometimes occurs in people who did not have kala-azar before.

How do humans contract kala-azar?

  1. Kala-azar is caused by a single-celled parasite – Leishmania donovani — in India and is transmitted by sandflies. Humans are the only known reservoir of Leishmania donovaniin India.
  2. The sandfly picks up the parasite from a person suffering from kala-azar or PKDL. The parasite then grows and multiplies inside the sandfly for more than a week.
  3. The parasite enters the body when a sandfly containing the parasite bites another person.
  4. The parasite multiplies in the spleen, liver and bone marrow of the affected person to large numbers and causes a steady deterioration in the health of the person.

Why is kala-azar dangerous?

  1. If untreated, kala-azar kills the infected person.
  2. Kala-azar causes severe debility, malnutrition and loss of ability to work.
  3. Most infected individuals do not realize that they have kala-azar which delays treatment. Thus, they act as source of infection that continues to spread the disease.
  4. Kala-azar is an opportunistic infection in people living with HIV/AIDS.[1] HIV co-infected VL or PKDL patients play a major role in transmission because of the high parasite load in the skin, the viscera and the blood.[2] Relapses of the disease is also very common in HIV co-infected VL and PKDL patients



Symptoms of kala-azar and PKDL

  • Kala-azar is characterized by irregular bouts of high-fever, significant weight loss, enlargement of the spleen and liver, anaemia and darkening of skin.
  • PKDL causes different forms of skin lesions, either pale patches or small or large nodules that do not itch nor lose sensation.
  • Certain kinds of skin lesions of PKDL contain large numbers of parasites, which are likely sources for the spread of the disease.

Where are sandflies found?[3]

  • Sandflies are prevalent in almost all parts of the country with a maximum abundance during monsoon and pre-monsoon months.
  • Dark and damp places, with cracks and crevices in the walls of cattle sheds and homes provide the perfect breeding place for sandflies.

Which population groups are the most vulnerable to kala-azar?

  • The disease affects some of the poorest and most marginalized people and is associated with malnutrition, population displacement, poor housing, weak immune system and lack of financial resources. Sandflies areprevalent in almost all parts of the country with a maximumabundance during monsoon and pre-monsoon months.
  • Dark and damp places, with cracks and crevices in thewalls of cattle sheds and homes provide the perfectbreeding place for sandflies.
  • 13 crore people in India are at risk of contracting the disease in 54 endemic districts (633 endemic blocks) across 4 states.[4] It is estimated the Indian subcontinent (India, Bangladesh, and Nepal) contributes to nearly 28% of the global disease burden.[5]


West Bengal

11 districts (120 bocks)

Cases in 2020: 57 kala-azar cases & 39 PKDL cases


(Source: National Vector Borne Disease Control Programme)


What is being done to accelerate the elimination of kala-azar in India?

The National Kala-azar Elimination Programme aims to achieve elimination of kala-azar as a ‘Public Health Problem’. Elimination is defined as the occurrence of less than one new case of kala-azar per ten thousand population in a block per year. Key elements of the elimination strategy include:


  • Reducing sandfly density in villages where there are known cases, to mitigate spread of disease
  • Villages having cases are identified and sprayed with insecticide twice a year before breeding season until 3 years after the last case in the village.
  • The inside of every room in every house including poojaghars, toilets and cattle sheds are sprayed in these villages. This is called Indoor Residual Spraying (IRS). The effect of the spray is expected to last for 3 months.
  • Typically, spraying is carried out once in February-March, and then again in June-July.
  • Due to increasing resistance to DDT in sand-flies, currently synthetic pyrethroids are used during IRS.


  • Diagnosing and treating all cases of kala-azar and PKDL as early as possible
  • Active Case Detection (ACD) drives are conducted periodically wherein trained health workers undertake house-to-house campaign to identify people with suspicion of kala-azar and PKDL and refer them to government hospitals.
  • All cases with symptoms of kala-azar and PKDL are screened with rk39 rapid diagnostic tests (RDT) after clinical assessment of a medical officer.
  • Confirmed cases of kala-azar and PKDL are provided free treatment at government hospitals, monitored until treatment is completed, and early follow-up (six months for kala-azar cases and 12 months for PKDL cases) thereafter to detect relapse, if any. Further, long-term follow-up to the cases is continued up to three to five years to detect relapse, PKDL and ADRs (adverse drug reactions)
  • For each case, neighbours, relatives and nearby houses (at least 200 houses) are actively screened for symptoms of kala-azar, and anyone with symptoms is tested. This is referred to as index case ACD.


  • Communication to raise awareness about the disease
  • Community members are continuously engaged through locally relevant targeted communications and social mobilization activities to improve their awareness, participation and health-seeking behaviour through display of messages through wall writing, hoardings, banners, pamphlets, radio jingles, loudspeaker canvassing, etc.

Most of the kala-azar patients initially seek care through rural/private sector healthcare providers. A major challenge towards the elimination of the disease is the rural/private providers’ inability to suspect kala-azar timely, which leads to a long cascade of care, resulting in delay in initiation of treatment. Another challenge is that most of the PKDL patients do not have any medical problem except cosmetic changes and the treatment involves regular medication for three months leading to low treatment adherence.



Kala-azar elimination programme in West Bengal

  • of endemic districts: 11 districts with 120 endemic blocks[6]Darjeeling, Uttar Dinajpur, Dakshin Dinajpur, Malda, Murshidabad, Nadia, North 24 Paragnas, South 24 Paragnas, Hooghly, Burdwan, Birbhum
  • Of villages in all KA endemic districts[7]: 19993
  • of blocks reported withincidence of > 1case (new andrelapses)/10,000[8]: 0 blocks
  • Kala-azar and Post-Kala-azar Dermal Leishmaniasis (PKDL) situation in India since 2013[9]
Year Kala-azar cases PKDL cases
2013 595 73
2014 668 221
2015 576 255
2016 179 240
2017 156 166
2018 95 87
2019 87 51
2020 57 39
2021 (till Feb) 9 1


[1] Alvar J, Aparicio P, Aseffa A, Den Boer M, Canavate C, et al. (2008) The relationship between leishmaniasis and AIDS: the second 10 years. Clin Microbiol Rev 21(2): 334–59. table of contents. doi:10.1128/CMR.00061-07.

[2]Zijlstra EE. PKDL and other dermal lesions in HIV co-infected patients with Leishmaniasis: review of clinical presentation in relation to immune responses. PLoSNegl Trop Dis. 2014;8(11):e3258. Epub 2014/11/21.

[3] Review Paper on Vector Control Strategy towards Kala-azar Elimination Programme in India – 2019

[4] Eliminating visceral leishmaniasis: India takes decisive steps to overcome last-mile challenges. Available from https://www.who.int/neglected_diseases/news/VL-India-takes-decisive-steps-overcome-last-mile-challenges/en/. Accessed on June 1, 2020

[5]WHO Weekly epidemiological record19 June 2020

[6] Independent Assessment of Kala-Azar Elimination Programme India. Available fromhttps://www.who.int/docs/default-source/searo/evaluation-reports/independent-assessment-of-kala-azar-elimination-programme-in-india.pdf?sfvrsn=fa0d8baa_2

[7]Independent Assessment of Kala-Azar Elimination Programme India. Available from https://www.who.int/docs/default-source/searo/evaluation-reports/independent-assessment-of-kala-azar-elimination-programme-in-india.pdf?sfvrsn=fa0d8baa_2

[8]Independent Assessment of Kala-Azar Elimination Programme India. Available from https://www.who.int/docs/default-source/searo/evaluation-reports/independent-assessment-of-kala-azar-elimination-programme-in-india.pdf?sfvrsn=fa0d8baa_2

[9] National Vector Borne Disease Control Programme. Accessed on November 21, 2020. Available from (https://nvbdcp.gov.in/index4.php?lang=1&level=0&linkid=467&lid=3750)

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