Visceral leishmaniasis elimination: intensifying surveillance to overcome last-mile challenges in Nepal
29 May 2019 | Kathmandu | Geneva −− Nepal has revised its national guidelines and intensified national surveillance in a concerted effort to overcome last-mile challenges to eliminate visceral leishmaniasis (also known as kala-azar) as a public health problem.1 Although decades-long control and prevention activities have yielded huge gains against this lethal form of the disease, new cases have recently emerged in the hilly areas and districts of the Kathmandu valley.
“We have intensified our surveillance in these areas and in geographical regions where these cases have emerged and, although very few cases have been reported, we view it a challenge that needs to be addressed effectively and promptly,” said Dr Bibek Kumar Lal, Director, Epidemiology and Disease Control Division, Department of Health Services.
Nepal, once highly endemic for visceral leishmaniasis, tackled the disease through intensive control and prevention and with strong political commitment and unflinching support of a highly motivated healthcare workforce. Antileishmanial medicines, easy-to-use diagnostic tests and efficient vector control methods reduced the incidence of the disease to a historic low.
In 2018, only 218 new cases of visceral leishmaniasis were reported from Nepal’s 48 districts of the 77 districts, compared with more than 2200 cases reported annually a decade ago.
“Nepal was the first country in the South-East Asia Region to reach the elimination threshold at its implementation level in 2013,” said Dr Lungten Wangchuk, Scientist, Communicable Disease Unit, WHO Country Office, Nepal. “However, its emergence in other districts serves as a good lesson to sustain robust surveillance in order to consolidate gains. We are strongly committed to eliminating this disease as a public health problem in Nepal.”
With the support of the three levels of WHO (headquarters and regional and country offices), Nepal’s Epidemiology and Disease Control Division (EDCD) recently organized a workshop to train physicians, medical doctors, laboratory personnel and medical recorders from Province 1 on the revised national guidelines and the introduction of an online tracking surveillance system which uses the DHIS 2 platform.
The revised guidelines align with WHO’s latest recommendation and contain a dedicated chapter on outbreak investigations and response focused on expanding diagnostics and treatment sites, case-based surveillance in all districts and reporting of cases.
The WHO Country Office and WHO headquarters technically supported the development and roll out of the surveillance system and the guidelines. Medical doctors and medical recorders from kala-azar treatment centres also benefitted from practical training on the web tracking system, which will be phased out and expanded to all districts.
“I feel extremely privileged to be a part of this kala-azar guideline launching and training programme in Province 1,” said Dr Laxman Khadka, Medical Officer from Sankhuwasabha District Hospital. “With this timely dissemination of the guidelines and the training we can surely achieve the elimination target set by the national programme.”
“Doctors are now updated on the new recommendation for early case diagnosis and proper management of kala-azar cases along with the updated surveillance system. This will enable the country to accelerate its elimination efforts and sustain the gains made so far,” added Ghanashyam Pokharel, Section Chief, NTD and Vector Borne Disease Control Section, EDCD.
“Nepal is the second country in the region to roll out case-based surveillance for kala-azar, and the country’s commitment and dedication of local staff to implementation is exemplary,” said Dr Lise Grout, Epidemiologist, WHO Department of Control of Neglected Tropical Diseases. WHO supported national efforts to design, field test and pilot the surveillance system.
In 2005, EDCD formulated a national plan to eliminate kala azar in Nepal.2 National guidelines, revised in 2010, 2014 and now in 2019, recommends single-dose liposomal amphotericin B for first-line treatment of primary kala-azar in line with the global WHO recommendation.
To support the efforts of the national programme, WHO has ensured a stable supply of liposomal amphotericin B, which is donated by Gilead until 2021.
“This collaborative approach with EDCD is one of the best examples in the region and can be replicated in other countries with a similar context” said Dr Jos Vandelaer, WHO Representative to Nepal.”
Leishmaniasis is caused by protozoan parasites from more than 20 Leishmania species and is transmitted to humans by the bite of infected female sandflies. There are three main forms of the disease: visceral, cutaneous and mucocutaneous.
Visceral leishmaniasis, the most serious form of the disease, is endemic in more than 80 countries. It is characterized by irregular bouts of fever, weight loss, enlargement of the spleen and liver, and anaemia. The disease is highly endemic in the Indian subcontinent and in East Africa, where an estimated 200 000–400 000 new cases occur each year. Some 90% of all new cases are reported from six countries: Brazil, Ethiopia, India, Somalia, South Sudan and Sudan.
Left untreated, visceral leishmaniasis is fatal in more than 95% of cases within 2 years after the onset of the disease.
Leishmaniasis owes its name to Sir William Leishman, a British army medical officer, who discovered the disease in 1901 and published his findings in 1903.
1Defined as less than 1 case per 10 000 population at district level in Nepal and at sub-district level in Bangladesh and in India.
2In 2005, the governments of Bangladesh, India and Nepal – supported by WHO – launched a regional kala-azar elimination initiative to reduce the number of cases to a level where the infection no longer represents a public health problem.