India has revised its target for eliminating Kala-azar from 2015 to 2017. Elimination would mean bringing down the number of cases so that it no longer poses a threat to public health and keeping it low. The target is to eliminate Kala azar from all the blocks by the end of this year. India accounts for about 50% of the global Kala-azar burden with 4,632 cases reported till August last year. Bihar is home to over 77% of the national burden of Kala-azar, reporting 3,563 cases until August 2016. Bihar and Jharkhand together account for over 90% of Kala-azar cases in the country.
Visceral Leishmaniasis (VL) or Kala-azar (KA) as it is called in South Asia, is a relatively rare communicable disease, usually affecting the poorest, that is characterized by prolonged fever and debility, and that usually kills unless treated.
Other than the Indian subcontinent, it is also found in Brazil in South America, Ethiopia, Somalia, Sudan and South Sudan in Africa in sizeable numbers. It is considered one of the neglected tropical diseases (NTDs), in the sense that for a long time, there was little attention paid to the disease, and it remained poorly understood and addressed. Ever since a global effort began to eliminate it since 2005, it is receiving more attention.
Kalaazar is caused by a tiny, one-celled parasite called Leishmaniadonovani- examples of similar parasites are malarial parasite and ameba. The parasite multiplies in the spleen, liver and bones of the affected person to large numbers and causes a steady deterioration in the health of the person. The parasite enters the body when a sand fly containing the parasite comes looking for a blood meal and bites a person.
The sand fly picks up the parasite from a person suffering from Kala azar, the parasite grows and multiplies inside the sand fly for more than a week, and then the parasites get accidentally injected into the blood of the next person who gets bitten. If left untreated, it usually kills the infected person. Even before killing, the disease causes severe debility, loss of ability to work and malnutrition. It spreads slowly but silently from person to person, and even after years of efforts to control it, thousands of cases still occur every year in India. Since it is rare, people take a long time to realize that they may have Kala azar, and in the meanwhile they themselves suffer, and continue to spread the disease
The disease is regularly found in the Indian subcontinent in 54 districts in India, 11 districts (Zila) in Bangladesh and 16 districts in Nepal. In India 33 districts in Bihar, 4 districts in Jharkhand, 11districts in West Bengal, and 6 districts in Uttar Pradesh are consistently affected. Additionally, Bhutan has sporadic cases, and occasional cases turn up in different states of India, usually in people traveling out of the affected areas.
Kala azar symptoms include fever that does not respond to usual treatment for malaria, typhoid, viral infections for two weeks or more, enlargement of the abdomen due to the spleen and liver becoming large. It is associated with tiredness, loss of appetite and loss of weight; and darkening of the skin. The disease is seen more among people living in villages in kutcha homes, sleeping on the floor and living close to cattle. These often belong to the economically weaker and vulnerable sections of society.
The sandfly is often found in places that have heavy annual rainfall, a mean humidity of above70%, a temperature range of 15-38Â°C, abundant vegetation, high subsoil water and alluvial soil. It is found in dark, damp places. Treatment of Kala azar is free of cost in government facilities and Accredited Social Health Activists are given an incentive for identifying a patient, bringing him/her to the health facility and ensuring that the patient completes the course. This is important since there have been reports of patients developing resistance to Kala azar medicines which is becoming a serious.
In addition to free treatment in Bihar, patients are given a compensation of Rs.6,600 to make up for the loss of wages they may have suffered because of their illness and associated expenses. This is provided from the Chief Ministerâ€™s Relief Fund.
The Government of India provides Rs 500 to every patient of Kala azar and Rs 2000 to every patient of Post Kala-azar Dermal Leishmaniasis (PKDL). This is a complication of the disease which primarily affects the skin that develops lesionsâ€”mostly small, pale lesions that do not itch or lose sensation. This results in cosmetic disfigurement. Though curable, it takes several years.
Certain kinds of skin lesions of PKDL contain a large number of parasites, and thus these cases are likely to be source of spread of the disease.
Researchers Piero L. Olliaro, Tushar A.K.M. Shamsuzzaman, Baburam Marasini, A.C.Dhariwal and others in a latest scientific paper “Investments in Research and Surveillance Are Needed to Go Beyond Elimination and Stop Transmission of Leishmania in the Indian Subcontinent,â€™â€™ have said that to maintain this target and stop transmission, it is necessary to re-evaluate whether the appropriate interventions are in place for surveillance, diagnosis, treatment, and vector control. In particular, it is important to decide whether current approaches should be reconsidered and whether new or modified interventions are required.
“”The current strategy in the Indian subcontinent is built around the early detection of symptomatic cases so that morbidity and mortality can be reduced and the source of infection is removed from the community,”” the paper points out.
Regardless of what treatments are available now and in the future, the paper says, perhaps the most important consideration is to ensure that treatments and diagnostic tests are available at all of the Primary Health Centres in endemic communities. This will require a greater number of PHCs with sufficient expertise to deliver the first-line treatment. Access to treatment locally, combined with increased knowledge in the community, will reduce the time from symptoms to treatment and, consequently, reduce the rate of transmission. This can be achieved immediately with the necessary commitment.
Finally, a vaccine to stop transmission would represent the best intervention. People who are cured of visceral leishmaniasis following treatment are immune against re-infection for life, which implies that a vaccine for leishmaniasis is possible. Due to the relatively low numbers of cases and high population, it would be necessary in the first instance to combine a vaccination programme with the elimination programme to deploy the vaccine in highly endemic areas and areas with new outbreaks during the maintenance phase. Any vaccine would need to be effective on both immunologically naive people and asymptomatic infected people if it is to be deployed in highly endemic areas, the paper says.”