What Is Black Fever Or ‘Kala-Azar’ Reported In 11 Districts Of West Bengal | Explained

"Kala-azar was practically eradicated from West Bengal. Recent surveillance, however, led to the detection of 65 cases in 11 districts. Now that these cases have been detected, the state will be able to tackle the spread of the disease,” a official said.

Kolkata: In the last couple of weeks, as many as eleven districts of West Bengal, mostly in the northern part of the state, have reported at least 65 cases of black fever, also known as ‘kala-azar’, a senior official of the health department said citing results of state-administered surveillance. Districts where a maximum number of cases were recorded include– Darjeeling, Malda, Uttar Dinajpur, Dakshin Dinajpur, and Kalimpong. The districts of Birbhum, Bankura, Purulia, and Murshidabad have also reported a few cases of black fever, mainly transmitted by bites of sandflies infected with the parasite Leishmania donovani. No case was detected in Kolkata thus far.

What Is Kala-Azar or Black Fever?

Visceral leishmaniasis (VL), also known as kala-azar is a fatal disease, if left untreated in over 95% of cases. According to World Health Organisation (WHO), it is characterized by irregular bouts of fever, weight loss, enlargement of the spleen and liver, and anaemia. Most cases of kala-azar occur in Brazil, East Africa and in India.

VL remains one of the top parasitic diseases with outbreak and mortality potential. It is caused by protozoan parasites which are transmitted by the bite of infected female phlebotomine sandflies. The disease affects some of the poorest people and is associated with malnutrition, population displacement, poor housing, a weak immune system and lack of financial resources.

Leishmaniasis is also linked to environmental changes such as deforestation, building of dams, irrigation schemes and urbanization.

Kala-azar Was Eradicated From West Bengal

Kala-azar was practically eradicated from West Bengal. Recent surveillance, however, led to the detection of 65 cases in 11 districts. “Now that these cases have been detected, the state will be able to tackle the spread of the disease,” the official told news agency PTI.

According to the official, it was found that the disease was most prevalent in people who have spent a considerable amount of time in Bihar, Jharkhand, and Uttar Pradesh. “Some individuals from Bangladesh, too, have been showing symptoms of kala-azar,” the official said, adding that the surveillance process will continue.

West Bengal Govt To Give Free Of Cost Treatment For Kala-azar

A top bureaucrat at the state secretariat said that the government has taken the decision to treat all diagnosed with the disease “free of cost”.

“Even if the infection is detected in a private laboratory or hospital, the doctor should immediately bring the matter to the attention of the district health officer. All expenses of treatment along with meals will be borne by the state health department. The district chief health officer will monitor the whole matter,” the bureaucrat told PTI.

Arrangements are also being made to provide nutritious food to the patients, he added.

Kala-azar: Diagnosis and treatment

In visceral leishmaniasis, diagnosis is made by combining clinical signs with parasitological, or serological tests (such as rapid diagnostic tests), according to WHO’s website.

The treatment of leishmaniasis depends on several factors including type of disease, concomitant pathologies, parasite species and geographic location. Leishmaniasis is a treatable and curable disease, which requires an immunocompetent system because medicines will not get rid of the parasite from the body, thus the risk of relapse if immunosuppression occurs. All patients diagnosed as with visceral leishmaniasis require prompt and complete treatment.

Kala-azar: Prevention and control

as per WHO, prevention and control of leishmaniasis requires a combination of intervention strategies because transmission occurs in a complex biological system involving the human or animal reservoir host, parasite and sandfly vector. Key strategies for prevention are listed below:

• Early diagnosis and effective prompt treatment reduces the prevalence of the disease and prevents disabilities and death. It helps to reduce transmission and to monitor the spread and burden of disease. Currently there are highly effective and safe anti-leishmanial medicines particularly for visceral leishmaniasis, although they can be difficult to use. Access to medicines has significantly improved thanks to a WHO-negotiated price scheme and a medicine donation programme through WHO.
• Vector control helps to reduce or interrupt transmission of disease by decreasing the number of sandflies. Control methods include insecticide spray, use of insecticide–treated nets, environmental management and personal protection.
• Effective disease surveillance is important to promptly monitor and act during epidemics and situations with high case fatality rates under treatment.
• Control of animal reservoir hosts is complex and should be tailored to the local situation.
• Social mobilization and strengthening partnerships – mobilization and education of the community with effective behavioural change interventions must always be locally adapted. Partnership and collaboration with various stakeholders and other vector-borne disease control programmes is critical.