An Integrated Approach for Malaria Control in Africa*
Daniel M. N. Okenu1, 2
1. Department of Infectious & Tropical Diseases,
London School of Hygiene &
Tropical Medicine, Keppel Street, London WC1E 7HT, UNITED KINGDOM
2. National Institute for Medical Research, PMB 2013 Yaba, Lagos, NIGERIA
*Abstract in English and French in: Malaria and Infectious Diseases in Africa 10: 4-13, December, 1999
"In recent times, there has been a strong advocacy for an integrated approach for malaria control. This involves the use of drugs, prompt diagnosis, insecticide sprays and insecticide-treated bednets, improved community-based systems, proper case management, improved health information systems, and proper environmental management geared towards vector control, plus a continuous search for an effective vaccine. This article highlights these components of a multilateral approach to malaria control, and is particularly aimed at drawing the attention of healthcare providers and indeed the policy-makers in Africa where the disease has had a devastating effect"
Despite several years of research and concerted efforts at control, the realisation of a malaria-free world remains a dream. The prevalence of the disease continues to increase in many parts of the world. An estimated two billion people (more than 40% of the world population) live in areas with malaria risk. The global annual incidence ranges between three to five hundred million clinical cases, with a death toll of between two to three million. Malaria accounts for 10% of Africas disease burden, causing the greatest suffering and impoverishment among poor people, with pregnant women and children under five years of age, being the most vulnerable. Approximately one million deaths among children under five years are attributable to malaria, with sub-Saharan Africa having more than 90% of the total malaria incidence and mortality. The economic loss due to malaria in Africa is in excess of two billion US dollars per year. This situation calls for a global concerted effort towards management and control of the disease.
Attempts at curtailing the devastating effect of malaria in Africa have been punctuated with many obstacles. The major obstacles are the rapid development and spread of vector resistance to residual insecticides and parasite resistance to clinically useful drugs. Other obstacles include lack of adequate and effective alternative antimalarial drugs that are acceptable, safe, affordable and easily available. Poorly managed health services in most African countries have also limited the effort to combat the disease. The people of sub-Saharan Africa need a strong political will and adequate financial backing, to ease the severe effect of the disease on the continent.
Rapid and prompt diagnosis of malaria infection, followed by adequate drug treatment is a major tool in malaria control. The classical method for diagnosis is the examination of a blood smear under the light microscope. This technique is sensitive and specific, but labour intensive, and requires a good microscope and skilled personnel. The facilities and expertise may be lacking in most rural health centres and private urban clinics in Africa. The need for a simple, sensitive, fast and accurate method of diagnosis has prompted the development of various diagnostic kits. The kits marketed under different brand names include ParaSight F®, MalaQuick®, ICT malaria Pf/Pv test, QBC®, Makro-Mal rapid finger prick test, OptiMal® assay, among others. Although PCR/ELISA technique is fast, highly sensitive and reliable, the high cost and expertise needed, makes the technique more of a research tool than for routine diagnosis in Africa. Because childhood deaths often occur within the first few days of developing symptoms, provision of rapid diagnostic kits especially at community health centres is recommended, and should be addressed as a matter of urgency.
Use of Anti-malarial Drugs:
Inspite of widespread problem of antimalarial drug resistance, use of drug remains the most effective option for malaria treatment. Chloroquine, historically the first-line drug for the treatment of malaria, is readily available and usually affordable in most African countries. However, lately, the malaria parasite, Plasmodium falciparum, has developed ways of avoiding the effect of this drug. Thus, people infected with these drug resistant parasites remain sick even after taking the adequate dose of chloroquine that would have "cured" them. Current efforts to improve malaria treatment are directed towards developing new antimalarials, new drug combinations and making better use of currently available drugs. A suitable replacement must not only be effective but also affordable and with relatively less or no side effects. The biggest effort in this direction is currently in the development of artemisinin and its derivatives. Artemisinin is clinically effective against both chloroquine sensitive and resistant parasites and is being used against severe and uncomplicated forms of malaria. However, this drug is characterised with recrudescence, that parasites in the liver, which are normally not affected by the drug, could reappear shortly after those in the bloodstream have been cleared. Efforts are being made to combine this drug with other antimalarials to enhance its antiparasite activity, and also reduce the chances of developing resistance. Other suitable drug combinations are being looked into. WHO is collaborating with industry to develop a novel combination of two old drugs, chlorproguanil and dapsone. A triple dose of this combination, given at 24 hours interval, was found promising in trials conducted in Africa. The drugs short elimination half-life is an advantage, as it reduces the chances for development of resistance. Another promising drug combination is Malarone, comprising atovaquone and proguanil.
Successful trials with second-line therapies involving the combination of an antimalarial drug and antibiotics have been reported. A 93% prophylactic efficacy was obtained in a Kenyan population with a combination of mefloquine and doxycycline. A combination of quinine and tetracycline was effective, but showed side effects. Attempts to reverse chloroquine resistance have also been successful. Reversal drugs like chlorpheniramine which have a two-fold effect of being antimalarial as well as antihistamine would be useful for individuals who get allergic chloroquine-associated "itching" reactions. Pyronaridine, another promising alternative to chloroquine, has been found to be 100% effective among children, with uncomplicated form of malaria, in an area of high chloroquine resistance in Cameroon. Mefloquine, another useful drug in the treatment of both chloroquine sensitive and resistant infections has a major draw back. It has a tendency of precipitating mental confusion, even in non-predisposed individuals. Although the drug is said to be safe after the first trimester (three months of pregnancy), its toxic effect on the developing child is not fully understood. Further studies are underway to ensure that the drug is relatively safe.
At the end of the day, antimalarial drug policy, formulations or alterations should be based on sound scientific findings. A carefully planned and well-executed drug surveillance will provide useful information and guidelines, especially on the time-point at which a switch from a failing first-line drug to a second-line drug should be made. To make antimalarial drugs easily available and affordable in Africa, the Malarone drug donation programme was established. This will ensure that good and effective drug combinations reach the people at subsidised rates. However, because of the limited health budget in Africa, the possibility of acquiring cheap and sub-standard drugs is anticipated. To curtail this problem, antimalarial drug policy should carefully monitor drug importation.
The problem with easy availability of drugs is that it allows for improper use such as erratic and inadequate dosages. This subsequently results in unnecessary drug pressure, which may lead to the selection of resistant parasites. Thus, to avoid such situation, there may be a need to train potential drug shopkeepers on how to give advice to their customers on correct dosages and if possible to monitor the drug intake by patients. This approach of using Direct Observed Therapy (DOT) has been implemented successfully by the Global Tuberculosis Control Programme in the management and control of drug resistant tuberculosis. Alternatively, potential drugs should be classified and withdrawn from the shelf, so that instead of being sold across the counter, are distributed by community health centres in correct doses to the patients. Measures to ensure transparency and avoid corruption should also be instituted.
Information on the use of natural plant products for antimalarial activity has not been fully explored and utilised. While the search for effective modern drugs continues, there is need for proper detailed studies on natural plant products like the West African liana, Triphylophyllum peltatum or the Chinese licochalcone and the Nigerian "dogo-yaro" (Neem; Azadiracata indica) for their anti-malarial activities. The development of new and effective drugs is a challenge. To achieve this, the interaction between the public sector and the pharmaceutical industry must be strengthened with improved mutual collaboration and adequate funding.
Use of Insecticide-treated Bednets:
The use of insecticide-treated nets (ITN) and house spraying represent a quantum leap on the use of physical barriers and chemicals in malaria control. Mosquito nets treated with pyrethroid insecticides provide a remarkable degree of protection against malaria in Africa. Excellent results were obtained from field trials in Ghana, the Gambia, Kenya and Tanzania. Chris Curtis showed that both methods reduced the prevalence of anaemia and the number of malaria-infective mosquitoes biting each night by 90%. ITN was however found more cost-effective, and households preferred the treated bednets to house spraying. ITN reduces child mortality and the incidence of mild and severe malaria. The significant positive impact on malaria control, the acceptance and cost-effectiveness of ITN should be good indicators for decision-makers to consider re-directing policies on this very important control tool. Currently, the use of treated bednets is not as widespread as it ought to be. Implementation of ITN programmes should be encouraged and supported as widely as possible in Africa. Emphasis should be placed on the effective development and marketing of simple and affordable treatment kits for self-use in homes. This would be more user-friendly, avoiding the cumbersome community-based treatment, and encourage more people to use ITN. Until an effective vaccine becomes available, malaria control will rely predominantly on ITNs to reduce human-mosquito contact. National ITN programmes should therefore be set up in all African countries to pursue this option vigorously. Local private sector initiatives in bednet production at subsidised prices, and free distribution of insecticides should be encouraged. This would make ITN available to the most impoverished members in our rural communities, where malaria is prevalent. There is an argument that long term use of ITN may lead to loss of partial protection in African adults. This is underscored by the success of ITN in reducing mortality due to malaria, especially in children. The claim however, need to be further investigated, in areas of high transmission. More studies are also required to clearly define the benefits of ITN to pregnant women
Proper Case Management:
Proper management of the sick child is a cost-effective health intervention strategy, which according to WHO, has been estimated to have a large positive impact on the global burden of disease in the developing world. An initiative known as the integrated management of childhood illness (IMCI) was launched by WHO and UNICEF, to address case management of the clinically ill child in developing countries, with emphasis on malaria and pneumonia. The initiative hopes to train and support health workers, conduct in-patient training and drug supply management courses, monitoring and reinforcement of skills after training, and develop a guide to improve household management of childhood diseases. These are aimed at improving the standard of case management in developing countries. The knowledge and expertise of the rural clinical health workers in patient history taking, physical examination, diagnosis, treatment, and patient education have direct relevance on the quality of care received by the sick child at the community level. Good clinical decisions can only be taken by properly trained and well-informed clinical health workers. For instance, a study in the Gambia and Tanzania showed that the best clinical intervention for children with severe malaria anaemia and signs of respiratory distress must be blood transfusion, to save their lives. Strict observation of good clinical practice, re-training and updating the knowledge of clinical health workers in case management, provision of essential drugs, supplies and equipment in rural health centres should therefore be addressed.
Improved Community-based System:
Malaria control would also benefit from improved community-based systems. The family is the first hospital for any child with high fever in Africa. Improved home management of malaria will therefore have a positive impact on treatment and control. Proper pre-packaged drugs with trained shopkeepers may bring about drug dosage compliance, and improve malaria treatment in the communities. Adequate health education on how to reduce human-vector contact, proper use and treatment of bednets with insecticides, correcting myths that surround many diseases at the community level, would be a boost to malaria control in Africa.
Proper Environmental Management:
Most African countries are involved in one developmental project or the other. Some of these projects include World Bank-assisted water schemes, construction of dams and bridges, oil drilling and mining activities, urban planning and development, logging activities, road and railway constructions, building of new airports, etc. These projects have been known to inadvertedly lead to increase in mosquito breeding sites, thereby increasing human-mosquito contact, and indeed transmission. It is suggested that such projects should include health personnel for proper evaluation of the health risks associated with the projects in their immediate communities. Good drainage systems will reduce mosquito-breeding sites and improve the sanitary condition of urban centres. Proper environmental management will not only lead to sustainable economic resources, but also reduces the creation of new breeding sites for disease vectors. This would be an added responsibility to the various national vector control programmes in Africa.
Adequate Health Information Management:
Access to relevant health information is the key to early detection and prevention of infectious diseases. One basic problem however with Health Information System (HIS), is that it tends to be data-driven, rather than policy or action-driven, to translate into real practical management issues in real life situations. In Africa, we need a systems approach to the management of health information. To develop HIS that is relevant to Africa, it should be taken into account that ours is a poor society, with widespread illiteracy, and predominantly state-run health care services. There is need for an indigenous systematic approach in using all the parameters, with proper regard to our health management structure, to provide specific information-based evidence for the decision making process. This would obviously eliminate the "fire-brigade" approach to management of epidemic outbreaks in Africa. A MALSAT study in Namibia, Kenya and Zimbabwe has demonstrated that early warning of epidemics is crucial in the fight against malaria. The current MARA project of mapping malaria risk in Africa is an excellent example of information-based approach to disease control. Decision-makers in Africa need such reliable information well in advance, spelt out in a simple language, devoid of technical jargons or unprocessed satellite data. The present orientation of HIS needs to be restructured for effective information management at the three levels of healthcare delivery, tertiary, secondary and primary. This would enable the end users of health information, namely, clinicians, nurses, midwives, traditional birth attendants and other health workers, to translate them into improved quality care delivered to the patient.
Malaria Vaccine Development:
The development of an effective vaccine for use in Africa and other malaria endemic areas, remains the ultimate quest for malaria control and perhaps, eradication. About eight potential vaccines for malaria are currently in different stages of development. The recent establishment of the African Malaria Vaccine Testing Network (AMVTN) is very timely. Its overall objective is to provide a forum for interaction by scientists and policy makers involved in the planning, coordination, and execution of malaria vaccine trials in Africa. Considering the duration of the different phases of vaccine trial, it may take another 20 years before a malaria vaccine is in the market. Until then, the integration of the various methods outlined above, would remain the only practical option for malaria control in Africa.
Application of Economics to Malaria Control:
To answer questions of efficacy, affordability, acceptability and sustainability of control programmes within a particular community, an economic consideration in the evaluation and implementation of disease control interventions is of utmost importance. These are important points that influence the decision of policy-makers towards the choice of which control measure to adapt. Taking ITN as an example, Anne Mills noted that there are three key policy questions that need to be addressed. These include, how much does it cost? Is it affordable? Finally, is it an efficient use of scarce resources? The willingness of the people to pay for ITN varies in different communities, with different socio-economic characteristics. This willingness however, does not translate to actual purchase of treated bednets in these communities. The people are faced with serious economic reality, between buying a bednet or food for the family. It is evident therefore that subsidised distribution of bednets through community health centres and free distribution of insecticides should be an integral part of any successful national ITN programme. On drug therapy, the overall cost depends on both the cost of treatment and of getting the patient to seek treatment. At present, this cost is very high, patients therefore resort to self-medication, self-diagnosis, and across the counter services from drug shopkeepers in their communities. The high cost of effective drugs should be addressed, either through a drug donation programme or outright subsidies on antimalarial drugs.
Role of the Sector-wide Initiatives:
The logistics of application of these control measures, and the realisation of the projected impact on malaria burden in Africa make the newly established sector-wide initiatives on malaria relevant. The major ones include the Roll Back Malaria (RBM) and the Multilateral Initiative on Malaria (MIM) in Africa. Others include the new Medicines for Malaria Ventures (MMV), the Malaria Foundation International (MFI), the Drive Against Malaria (DAM), plus the different Malaria Centres and Consortia with field sites in Africa, established by the various Schools of Tropical Medicine in Europe and the United States. RBMs strategy is to strengthen health services and health systems, and reduce the burden due to malaria by half within the next ten years. It is hoped that major gains would be made through better application of current knowledge and good practices. MIM is an international campaign sponsored by thirteen funding bodies, aimed at research capacity building for malaria control in Africa. MIMs immediate goal is to facilitate collaboration between scientists, governments, control programmes and supporting agencies in malaria research and control. MIM hopes to act as a global forum for malaria-related discussions, to create the political awareness needed for a concerted action against malaria by all the stakeholders. MMV is a public-private sector partnership aimed at developing new and effective drugs against malaria. MFI and DAM are committed to creating international awareness on the burden of malaria. They support, educate and assist in malaria-related activities, stimulate discussions, secure funds, and encourage the most effective use of available resources for malaria research and control. Proper implementation of disease control programmes will depend largely on the availability of well-trained personnel. Emphasis should therefore be placed on training health professionals, technicians and malariologists including vector biologists, molecular biologists, epidemiologists, health economists and sociologists, among others. African governments, NGOs and international funding agencies are encouraged to participate in providing the needed critical mass of well-trained Africans for proper implementation of disease control programmes in the continent.
It is known that Africa is home to various vector-borne diseases other than malaria. These include river blindness, sleeping sickness and leishmaniasis, among others. Certainly, a cost-effective integrated approach will be beneficial also, to the control of these other vector-borne diseases. With the current global concern, it is imperative for scientists, clinicians, policy-makers, health managers and health-care providers in Africa, to act in concert with other players, and reduce the burden of malaria on the continent, using an integrated approach. The active participation of all stakeholders is indispensable, and should be focused towards achieving a 50% reduction of malarial deaths in the next ten years, reduction in poverty and an appreciable human resource development, as earmarked by RBM.
Acknowledgement: I wish to thank Ipemida Adagu and Willie Githui for critically reading the manuscript. The author is a Wellcome Trust-funded Research Fellow at the London School of Hygiene & Tropical Medicine, United Kingdom.
Email: Dr. Daniel M.N. Okenu (email@example.com)
References and further reading:
1. Binka F.N. and Adongo P. (1997), Acceptability and use of insecticide impregnated bednets in northern Ghana.. Tropical Medicine & International Health 2: 499-507
2. Bojang K. A. et al (1997) Predictors of mortality in Gambian children with severe malaria anaemia. Ann Trop Paediatr 17 (4): 355-359
3. Curtis C. F. (1999) Malaria control: bednets or spraying? Background and trial in Tanzania. Unpublished Roy. Soc. Trop. Med. Hyg Meeting on Bednets.
4. Evans D. B. et al (1997) Should governments subsidize the use of insecticide-impregnated mosquito nets in Africa? Implications of a cost-effectiveness analysis. Health Policy & Planning 12: 107-114
5. Heiby J. R. (1998) Quality improvement and the integrated management of childhood illness: lessons from developed countries. Jt Comm J Qual Improv 24 (5): 264-279
6. Holzer B. R. et al (1993) Childhood anaemia in Africa: to transfuse or not transfuse. Acta Trop 55 (1-2): 47-51
7. Malaria Meeting Briefing Packet; Center for International Development,
Harvard University, December 14-15, 1998
8. Maxwell C. A. et al (1999) Comparison of bednets impregnated with different pyrethroids for their impact on mosquitoes and re-infection with malaria after clearance of pre-existing infections with chlorproguanil-dapsone. Trans. Roy. Soc. Trop. Med. Hyg. 93: 4-11
9. Mills A. (1998) Operational research on the economics of insecticide-treated mosquito nets: lessons of experience. Annals of Tropical Medicine & Parasitology 92: 435-447
10. Jo Lines (1996) Mosquito nets and insecticides for net treatment: a discussion of existing and potential distribution systems in Africa. Tropical Medicine & International Health 1: 616-632
11. Lengeler C. (1998) The Cochrane Review. The Cochrane Library, Issue 3, Oxford.
12. Lippeveld T. et al (1997) Health information systems - making them work. World Health Forum 18: 176-184
13. TDR News No 55 February, 1998
14. Ridley R. G. and Hudson A. T. (1998) Chemotherapy of Malaria. Current Opinion in Infectious Diseases 11: 691-705
15. UK-DFID International Health Matters; Malaria, Issue 3, December, 1998
16. World Health Organisation Press Feature Number 191 of March, 1998, p1-3 Increased information key to detection and prevention of infectious diseases.
17. Bulletin World health Organisation 1995; 73 (6): 735-740. Integrated management of the sick child.
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