Neglected tropical diseases

Bangladesh poised to defeat kala-azar with responsive health system

Technical expertise, political commitment and community mobilization contribute to historic drop in number of new cases
13 June 2014 | Geneva
Patients receiving treatment for kala-azar using single-dose AmBisome infusion in Suryakanta hospital, Mymensingh, April 2014

Dismissed as insurmountable a decade ago, elimination of one of the most complex neglected tropical diseases – visceral Leishmaniasis, also known as kala-azar – is on track in Bangladesh.

During the past 5 years, more than 15 000 cases have been diagnosed and treated in a country where detection had until recently been a challenge. In 2013, a total of 1284 cases were reported to WHO compared with 4293 cases in 2009, a reduction of more than 70% in the number of new cases reported annually.

We used every available means to engage the public to help us get down to detecting the maximum number of cases in endemic upazilas (sub-districts),” says Professor Be-Nazir Ahmed, Director of the Directorate General of Health Services in the Ministry of Health and Family Welfare. “We combined active case searches, treatment and vector control strategies, and our strategy is working.

Kala-azar is caused by protozoan parasites transmitted to humans through the bites of infected female sandflies. The disease is fatal if left untreated and affects the poorest populations in endemic countries.

Every year, around 300 000 people develop visceral Leishmaniasis. WHO estimates that 20 000–30 000 people die from the disease worldwide. More than 90% of new cases occur in six countries: Bangladesh, Brazil, Ethiopia, India, South Sudan and Sudan.

To eliminate visceral Leishmaniasis in the Indian subcontinent where the disease is endemic, the Ministers of Health of Bangladesh, India and Nepal have shown unprecedented political commitment by signing a Memorandum of Understanding in 2005 during the World Health Assembly in Geneva, Switzerland.

This document calls for aggressive action to decrease the incidence of the disease to below 1 case per 10 000 inhabitants per year in endemic areas at sub-district level by 2015.

Political commitment, access to improved antileishmanial medicines, a strong national control programme combined with a robust surveillance system and integrated vector control are crucial in achieving this goal.

“WHO encourages countries to implement a combination of measures that include enhanced case detection and prompt treatment with quality-assured and safer medicines,” says Dr Daniel Argaw Dagne, Medical Officer in charge of WHO’s Leishmaniasis programme. “Sustained integrated vector control, effective disease surveillance and community mobilization are absolutely essential to tackle the condition.”

Case management and improved access to safe, quality-assured medicines

Diagnosis of kala-azar in Bangladesh is based on clinical assessment and a recombinant antigen (rk39) rapid diagnostic test. Miltefosine was introduced in 2007 as a first-line oral treatment to replace the pentavalent antimonial (sodium stibogluconate) that had been used for decades in Bangladesh as the sole treatment against kala-azar and post-kala-azar dermal Leishmaniasis.

With WHO support and collaboration from the Ministry of Health and Family Welfare, the International Centre for Diarrhoeal Disease Research of Bangladesh conducted a feasibility study in 2011 and 2012 on the safety and efficacy of single-dose liposomal amphotericin B (AmBisome) at a dose of 10 mg/kg. This led to a revision of the treatment policy and the introduction of single-dose liposomal amphotericin B in the districts of Fulbaria and Trishal.

The study followed a recommendation by a WHO Expert Committee that liposomal amphotericin B can be used as a first-line treatment during the attack phase of the visceral Leishmaniasis elimination programme in South-East Asia.

WHO has since continued to provide overarching technical and financial support to Bangladesh. Funds from the United Kingdom Department for International Development and AmBisome donated from Gilead Sciences have contributed to advancing Bangladesh’s elimination programme.

Integrated vector control

Bangladesh has used two classic vector control tools as part of its integrated vector management: spraying residual insecticides and distributing insecticide-treated nets.

With community support, Bangladesh has used an innovative approach of spraying larvicides in potential breeding sites of sandflies around residential homes. Furthermore, the country has managed regular residual spraying of homes in all of its eight hyper-endemic upazilas since 2011, during pre-monsoon and post-monsoon seasons.

During 2012 and 2013, over 110 moderately endemic upazilas were sprayed and more than 20 000 long-lasting insecticide-treated nets were distributed under close monitoring and supervision.

Social mobilization, community involvement and capacity strengthening

In endemic areas of Bangladesh, health-care personnel and volunteers have conducted active case searches and extensive health awareness campaigns, resulting in improved awareness of conditions associated with the disease, the best methods of prevention and the need to seek medical treatment as early as possible.

To sustain achievements, Bangladesh’s national Leishmaniasis control programme has focused on capacity strengthening as the cornerstone of its elimination strategy.

With the support of WHO and other partners, different categories of health professionals involved in various levels of interventions have been trained.

Reaching the end

Defeating kala-azar is a task that involves challenges. These include early detection of all kala-azar and post-kala-azar dermal Leishmaniasis cases, improved treatment for post-kala-azar dermal Leishmaniasis cases, and presentation for and compliance with treatment.

The most important challenge is to maintain a high level of commitment and motivation of health workers against a disease that is fast disappearing.