Year : 2012 | Volume
: 136 | Issue : 3 | Page : 504--506
Control of leishmaniasis - Report of a meeting of the WHO Expert Committee on the control of leishmaniasis
Department of Parasitology, Postgraduate Institute of Medical Education & Research, Chandigarh 160 012, India
Department of Parasitology, Postgraduate Institute of Medical Education & Research, Chandigarh 160 012
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Malla N. Control of leishmaniasis - Report of a meeting of the WHO Expert Committee on the control of leishmaniasis.Indian J Med Res 2012;136:504-506
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Malla N. Control of leishmaniasis - Report of a meeting of the WHO Expert Committee on the control of leishmaniasis. Indian J Med Res [serial online] 2012 [cited 2019 Oct 14 ];136:504-506
Available from: http://www.ijmr.org.in/text.asp?2012/136/3/504/102020
Control of leishmaniasis - Report of a meeting of the WHO Expert Committee on the control of leishmaniasis, WHO Technical Report Series 949 (World Health Organization, Geneva). 2010. 186 pages.
Price: CHF/US$ 25.00; in developing countries:CHF/US$ 17.50
Leishmaniasis is one of the major public health problems in many endemic areas both in the old and new world. Visceral leishmaniasis (VL) is one of the ten neglected tropical diseases listed for control by the end of this decade. A strategic milestone was achieved in 2007, when the World Health Assembly approved Resolution 60.13 on the control of leishmaniasis. This resolution calls for the creation of conditions to enable WHO to take a leading role in providing technical assistance for the initiation, maintenance and expansion of lesihmaniasis control programmes. One of the recommendations was to draft guidelines on the prevention and management of leishmaniasis and to update the WHO technical report on the control of leishmaniasis prepared by the WHO Expert Committee in 1990. For this purpose, the Expert Committee reconvened in Geneva in 2010 to review the 1990 guidelines.
WHO Technical Report Series 949 is an outcome of meeting of the WHO Expert Committee on the Control of Leishmaniasis held at Geneva, Switzerland on March 22-26, 2010. This report is revised, updated edition and a significant contribution to the knowledge pertaining not only to the control but leishmaniasis as a whole clinical entity. The members of the Expert Committee, members on the Advisory Board and eminent scientists worldwide with considerable experience in the field have captured most of the research studies and put forward their views based on decades of intense research.
The text is divided into chapters and annexures are provided at the end of the document. Chapter one signifying the history is comprehensive and well compiled. A few milestones were achieved in India, e.g. Bramachari described post Kala-azar dermal leishmaniasis (PKDL) in 1922 and introduced urea stibamine for treatment which has remained the mainstay of treatment of all forms of VL. Further, in the early 1940s, Swaminath, Shortt and Anderson demonstrated the transmission by sandflies.
Chapter two on 'Leishmaniasis in humans' aptly describes reservoir hosts, vectors, epidemiologic features of both old and new world leishmaniasis, PKDL, Leishmania and HIV co-infection. The list of reference strains is an additional information often required for diagnosis and research purposes. Geographical information system is used for mapping of important species of sandflies, incidence of VL in Sudan and Brazil and cutaneous leishmaniasis (CL) in Columbia and Tunisia. This technology may help further in understanding the epidemiology of this infection. It is suggested that application of highly specific techniques like Western blot and PCR may be the most practical approach to detect asymptomatic infection in epidemiologic surveys. Therapeutic vaccines may be achievable. The success achieved in experimental studies and the present day status of vaccines leads to hope for developing an effective vaccine for humans.
Chapter three on 'Control' covers in detail the diagnosis, recommended diagnostic policy at different levels of the health system, treatment, prophylactic leishmaniasis vaccines, active and passive case detection, control of reservoir hosts and vectors. The additional information on epidemic response, socio-economic aspects of controls, cost-effectiveness of control measures and public-private partnerships adds value to the document.
Chapter four details country/ territory-wise burden of leishmaniasis with information on clinical forms, proven or suspected vectors, and animal reservoir hosts. The co-infection with HIV, geographical clustering of anthroponotic L.donovani infected cases, widely dispersed CL cases and epidemics of visceral form in previously unaffected areas in Sudan is described under the section on estimated burden.
Chapter five details the control strategies, keeping in view the existing reservoir hosts and vectors in different geographical areas. It is suggested that in India control activities should be accompanied by adequate surveillance and reporting. Susceptibility to insecticides and sandfly vector density in India should be monitored periodically.
In East Africa and South-West Arabian peninsula, the annual incidence should be assessed by active detection and serological surveys. In areas with known or assumed canine reservoir hosts, the passive case detection, reporting and treatment alone may not reduce the incidence. The control measures should be focused on animal reservoir host. The effect of all control measures can be assessed by changes in the annual incidence of VL in a population. Similarly, for anthroponotic and zoonotic CL appropriate control measures are essential. Organization of control programme at national level needs to be well planned.
Chapter six covers the distribution tasks at different levels in the national health system. Budget framework for national programme needs to be detailed out. Need to assess progress and regularly evaluating the programme is suggested.
Chapter seven emphasizes the need for international co-ordination. Co-ordinated efforts between endemic countries is desired for exchange of technical data and biological material. Development of inter-country programmes and implementation of international standards will certainly help to achieve the goal together in all the countries.
Chapter eight discusses the need of health education and training programmes for health staff, laboratory technicians, social scientists and community health workers. Health education is the most essential component of control for infectious diseases.
Chapter nine covers the recommendations for future research strategies, as applicable to study the epidemiology, clinical aspects, basic research, development of new drugs and vaccines. It is divided into sections covering field research, laboratory research, drug and vaccine research. The field research on risk factors, studies on new foci and outbreaks, annual fluctuations in vector population and clinical part involving evaluation of new drugs and drug combinations are suggested. Laboratory research should be focused on studies to determine the role of asymptomatic and PKDL subjects as reservoir hosts, molecular typing of Leishmania parasites and sandfly vectors. Development of rapid diagnostic tests, effective newer drugs and vaccines remains a high research priority.
Chapter ten highlights the recommendations of Expert Committee members. The main recommen-dations are establishment of control programmes with mobilization of financial and technical support in the affected areas, efforts to improve the living conditions of population in endemic areas to reduce transmission, implementation of effective diagnostic measures, adoption of integrated vector management for vector control, regional training programmes for concerned health officials to reduce cost of medicines and diagnostics, multicentric appropriate drug trials and development of prophylactic as well as therapeutic vaccines and immunomodulators. The recommendations, if implemented, probably will go a long way in controlling the infection.
Annexure I details out the Generic codes for labelling of Leishmania isolates according to the International code. The list of centres to which Leishmania isolates can be sent for identification is useful for all the concerned diagnostic and research laboratories.
Annexure 2 covers the methods for isolation and cryopreservation of Leishmania, which is highly beneficial to the interested technical persons.
Annexure 3 covers the WHO recommended case definitions pertaining to leishmaniasis. Annexure 4 describes the procedures for splenic aspiration and grading of parasites. Annexure 5 details the test procedure, interpretation, advantages and disadvantages of rK39 rapid diagnostic test. Annexure 6 provides the cost of medicines in current use for the treatment of leishmaniasis.
The document is a ready reckoner and provides up-to-date information for health care policy makers, quality managers, clinicians, epidemiologists and researchers interested in the subject. This Report highlights the global burden of leishmaniasis, its neglect and provides guidance on implementation of control measures. The contents are relevant to the topics and text is compiled in a lucid manner. There is a need for comprehensive National Leishmania Control Programme involving all the functionaries including health system, environmental analysts, epidemiologists, along with emphasis on control of animal reservoirs (wherever applicable) and integrated vector control. The Report justifies the purpose of establishing national control programme in endemic countries that do not have one, by presenting a well researched knowledge. The notification of infected cases should be mandatory not only in endemic areas but also in non-endemic areas due to frequent travel and migration. If amendments are to be done in future documents, the addition of host genetic factors, strain variation (genetic speciation) in Leishmania parasites, its effect on control measures including vaccine trials and WHO proposal for Integrated Neglected Tropical Diseases Control (2012-16) which includes VL, would be an additional welcome. The text supported by references may be helpful to new entrants in the field.