Malaria Fact Sheet

WHO Press Release, Malaria Fact Sheet

Malaria is by far the world's most important tropical parasitic disease, and kills more people than any other communicable disease except tuberculosis. In many developing countries, and in Africa especially, malaria exacts an enormous toll in lives, in medical costs, and in days of labour lost. The causative agents in humans are four species of Plasmodium protozoa

• P.falciparum,
• P.vivax,
• P.ovale,
• P.malariae.

Of these, P.falciparum accounts for the majority of infections and is the most lethal. Malaria is a curable disease if promptly and adequately treated.

Prevalence

The geographical area affected by malaria has shrunk considerably over the past 50 years, but control is becoming more difficult and gains are being eroded. The spread of the disease is linked with activities like road building, mining, logging and new agricultural and irrigation projects, particularly in "frontier" areas like the Amazon. Elsewhere, disintegration of health services, armed conflicts and mass movements of refugees worsen the malaria situation.

The current global picture:

Malaria is a public health problem today in more than 90 countries, inhabited by a total of some 2400 million people or 40% of the world's population.

Worldwide prevalence of the disease is estimated to be on the order of 300-500 million clinical cases each year.

More than 90% of all malaria cases are in sub-Saharan Africa. Two-thirds of the remainder are concentrated in six countries in decreasing order of prevalence:

• India,
• Brazil,
• Sri Lanka,
• Viet Nam,
• Colombia and
• Solomon Islands, .

Mortality due to malaria is estimated to be in the range of 1.5 to 2.7 million deaths each year. The vast majority of deaths occur among young children in Africa, especially in remote rural areas with poor access to health services.

Other high-risk groups are women during pregnancy, and non-immune travellers, refugees, displaced persons and labourers entering endemic areas.

Malaria epidemics related to political upheavals, economic difficulties and environmental problems also contribute in the most dramatic way to death tolls and human suffering.

The Malaria Control Strategy
The four basic technical elements of WHO's Global Malaria Control Strategy are:

• provision of early diagnosis and prompt treatment for the disease;
• planning and implementation of selective and sustainable preventive measures, including vector control;
• early detection for the prevention or containment of epidemics; and,
• strengthening of local research capacities to promote regular assessment of countries' malaria situations, in particular the ecological, social and economic determinants of the disease.

Implementation of the Strategy: the Malaria Control Action Plan

The Global Malaria Control Strategy emphasizes the strengthening of local and national capabilities to analyse the malaria situation, to plan, implement and evaluate control interventions, and to contribute to health development in the context of primary health care. Training is the main instrument for capacity building. The Action Plan emphasizes partnership among all UN organizations and other agencies involved in malaria control; planning region by region towards country specific action plans that are realistic, affordable and respond to national needs; rapid application of technical developments and guidelines; and integration of malaria control activities with the general health services and other health programmes.

Achievements and Support to the Implementation of National Plans for Malaria Control

What has been achieved to date is a political commitment to malaria control and a progressive strengthening of national and local capacities for assessing malaria situations and selecting appropriate measures aimed at reducing or preventing the disease in the community according to the Global Control Strategy. National plans of action have also been developed in more than 80% of malaria endemic countries. This now needs to be followed by a deeper commitment for the effective implementation and continuous evaluation of these plans. This requires not only the commitment of the health sector, but also other governmental sectors and the private sector where activities may directly or indirectly affect the malaria situation and the community itself. Only when these partnerships are reinforced and activities coordinated will future reports be able to indicate reductions in malaria disease and deaths.

Technical cooperation and the mobilisation of bilateral/multilateral funding for national programme implementation is of the highest importance. By the end of 1995, 38 malaria endemic countries in Africa (out of 46) had completed the preparation of plans for malaria control in accordance with the principles of the Global Control Strategy. These are at initial stages of implementation in terms of disease management, selective preventive measures, including insecticide impregnated bednets, and epidemic preparedness. Outside Africa, 20 countries in the WHO Eastern Mediterranean region (EMRO), 17 countries in the Americas (AMRO) and 18 countries in the WHO South-East Asia region (SEARO) and the WHO Western Pacific (WPRO) region have reoriented their malaria control programmes in line with the Global Control Strategy principles and have commenced implementation. Many countries, especially in Africa, that have not completed their action plans have been hampered by problems of political instability, civil war and natural disasters.

Forty-three malaria endemic countries in the WHO Africa Region (AFRO) and 22 in other WHO Regions have received financial support from WHO for developing their programmes. WHO is currently collaborating with UNICEF to strengthen the malaria programmes in Eritrea, Namibia, Uganda and United Republic of Tanzania; with UNDP in Myanmar; with the World Bank in Bangladesh, Madagascar, Lao People's Democratic Republic and Viet Nam; and with the European Commission in the development of a programme for malaria control for Cambodia, Laos and Viet Nam.

In 1995, WHO helped prepare project proposals, based on action plans in 14 African countries, for submission to different donors. Seven of these are already being supported. In 1996 WHO, is providing technical cooperation and financial support to malaria control activities in 18 countries in Africa (Angola, Benin, Burkina Faso, Burundi, Chad, Eritrea, Ethiopia, Gambia, Guinea, Mozambique, Niger, Nigeria, Rwanda, Togo, Uganda, United Republic of Tanzania, Zambia and Zimbabwe).

WHO continues to provide support to countries facing epidemic/emergency situations (including those in Europe). Such support is provided in close cooperation with bilateral, international organisations and nongovernmental organisations (NGOs). Recently WHO provided technical support for malaria prevention and control in refugee camps in Azerbaijan, Burundi, Rwanda, Tanzania and Zaire and in countries affected by epidemics (Azerbaijan, Bangladesh, Botswana, India, Iraq, Sudan, Swaziland and Tajikistan, Turkey, Yemen and Zimbabwe).

Capacity Building

Capacity building is first and foremost concerned with establishing the presence of a core group of health professionals in each malaria endemic country for the planning, implementation and evaluation of national control programmes. The international training courses organized by WHO target decision-makers at ministerial level, programme managers, provincial and district medical officers, planners in governmental and non-governmental organizations, trainers and professionals in the private sector. To date 437 participants from all WHO regions have participated in one of these courses (AFRO - 231, AMRO - 8, EMRO - 48, EURO- 35, SEARO - 76, WPRO - 39).

Over 150 trainers have been trained in Africa; they now have the responsibility for the country level training of district health officers and their teams in malaria disease management and control. Nearly 16,000 trainees have been trained in malaria in courses that have been organised primarily at district and community levels with priority being given to the development of national drug policies, monitoring of drug efficacy, and the management of severe malaria. Courses have been organized for the private sector providers of health care. The use of selective vector control, particularly that of insecticide-treated bednets and other materials, has also been the subject of training courses. Seminars have been organized in a total of 15 African countries concerning the training of staff of district health teams in disease management. Training of District Health Team personnel in epidemic preparedness and control of malaria epidemics was initiated in a few countries of the WHO/South-East Asia Region

In order to have a clearer picture of future training requirements, preliminary global estimations have been made. These indicate that more than 800 programme managers, 1,500 specialists, 13,000 assistants, 55,000 workers at the district level and more than 120,000 community health workers are in need of training or retraining. To date a total of 43 countries have provided information concerning their needs.

Research Developments

Significant progress has been made in the research and development of new tools for use in malaria control activities.

• Insecticide treated bednets and curtains have emerged in recent years as a promising tool. Recent results from multi-centre randomized, controlled field trials in Africa supported by WHO/TDR suggest that in certain epidemiological situations, overall childhood mortality can be lowered by 15 to 35% through the use of insecticide-impregnated bednets. Further research is required to enhance the effectiveness of bednets or curtains in operational settings and to ensure their use in a sustainable manner.
• Due to the considerable overlap in signs and symptoms of several childhood diseases, a single diagnosis for a sick child is often inappropriate. WHO and UNICEF have responded to this challenge by developing an approach referred to as the "integrated management of childhood illness". Evidence from surveys of health worker performance and of management of illness in the home suggests that improvements are likely to reduce childhood mortality significantly.
• Despite the simple technology and relatively low direct costs, microscope diagnosis is still expensive, requiring an adequate infrastructure to purchase and maintain supplies and equipment, to train health workers and to ensure proper quality assurance of the service. The results of recent evaluations of standardized antigen detection tests suggest that the technique has potential for use in the management of malaria disease, if accuracy can be assured and the test made affordable for those in need.
• In Africa, with increasing levels of chloroquine resistance and fears of toxicity and decreased efficacy for sulfadoxine/pyrimithamine, there is an urgent need for an affordable, effective and safe alternative to chloroquine. In the short-term, amodiaquine could be reconsidered as a first or second line drug in areas of chloroquine resistance. There are also studies on the combination of the short half-life antifolates, chloroproguanil and dapsone. Pyronaridine, a Chinese synthetic compound, is under international development by WHO/TDR.
• At the present time, artemisinin derivatives show no cross-resistance with known antimalarials and as such are important for treating severe malaria in areas of multidrug resistance; however, they require long treatment courses. Additional drugs for multidrug resistant malaria are being developed by the private sector: atovaquone+proguanil and artemether+benflumetol.
• WHO/TDR has conducted randomised multi-centre trials with intramuscular artemether, is currently developing arteether, and artesunate suppositories are being evaluated for control of severe complications in children at the periphery.
• Three main types of vaccine are currently in development:
  • "Anti-sporozoite" vaccines, designed to prevent infection.
  • "Transmission-blocking" vaccines, designed to arrest the development of the parasite in the mosquito, thereby reducing or eliminating transmission of the disease.
  • "Anti-asexual blood stage" vaccines, designed to reduce severe and complicated manifestations of the disease.

  Such vaccines could lower morbidity and mortality among children under 5 years of age in Africa, the main risk group, and their development is given priority by WHO. Several such vaccine candidates are currently undergoing clinical and field testing.

  A cost effective vaccine must be capable of being incorporated into appropriate health delivery programmes, and to provide sufficient duration of immunity. At the present, it is difficult to predict when such a vaccine will become available.

It should be recognised that the success or failure of newly developed and existing malaria control tools will depend on availability of adequate resources, effective implementation, promotion and sustainability over time.

Major Constraints

All malarious countries have expressed a strong willingness to develop their national programmes along the lines of the Global Control Strategy. However, this will has not been translated in all cases into a flow of new resources in support of implementation, neither from national nor international, including bilateral, sources.

Also important is the fact that some national malaria programmes are still slow in demonstrating that their control activities are an integral part of the general health services thereby giving the false impression that they remain a vertical programme. This often contributes to the restraint of some donors to provide financial support.

Insufficient resources at both national and international levels are increasing the demands on WHO, especially those stemming from emergencies such as controlling epidemic outbreaks, protection of highly vulnerable refugee camps, and preventing epidemics in high risk situations. Requests for direct WHO involvement are also increasing in national programme implementation, including the preparation of project proposals, local capacity building, testing of newly developed guidelines, and designing relevant operational research.

Task Force on Malaria Prevention and Control.

In response to the WHA resolution 49.11, the Director-General established a Task Force on Malaria Prevention and Control. The Task Force met in Geneva from 21-24 October 1996, endorsed the Global Malaria Control Strategy and emphasized that the highest priority should be given to control of malaria mortality in Africa south of the Sahara. However, the Members pointed out that it was imperative that the leadership of WHO as a coordinating, high profile and technical advisory agency be reaffirmed and collaboration with the UN system strengthened. Multi-disciplinary malaria operational field research as well as training should be seen as essential components of the Malaria Control activities and need to be effectively integrated into the Malaria Control Programme. The Task Force recommended that national political commitment be objectively demonstrated by ensuring that the necessary resources, including technically competent staff, are made available on a sustainable basis irrespective of external assistance.

All WHO Press Releases, Fact Sheets and Features can be obtained on Internet on the WHO home page http: //www.who.ch/