Conclusions and recommendations

CONCLUSIONS AND RECOMMENDATIONS CONCLUSIONS AND RECOMMENDATIONS The participants in the WHO/CDC Symposium on Malaria Research noted the significant advances that have been made recently in biomedical science related to malaria, especially as regards the means for controlling or eradicating this disease. Never- theless, there are still many gaps in the knowledge of malaria, and technical means of control or eradi- cation need further improvement. While noting with appreciation the international assistance in stimulating, coordinating, and support- ing malaria research in many parts of the world, the participants learned with great concern of the restrictions on funds devoted to research in malaria. The following recommendations were made: (1) Malaria research should continue to be stimu- lated, coordinated, and supported in international centres, in national institutes, and in the field. (2) New ways should be explored of obtaining adequate funds for malaria research from national governments or from other governments in the form of bilateral assistance, or from industrial concerns, as part of the effort to control malaria. (3) The increased incidence of imported and acci- dentally induced malaria is related to the rising speed and volume of human travel. In order to improve the system of notification of cases of malaria in countries where this imported disease creates a prob- lem, special reference centres should be set up to assist with the diagnosis of malaria and to advise the medical profession and the public on adequate protective measures. (4) For the final testing of new antimalarial drugs and new immunological methods of prevention and cure of malaria, no animal model can be a sub- stitute for tests in man; without such decisive tests no progress in this field will be possible. In view of this and in the interests of eliminating malaria, there is need for international effort to support and facili- tate the continuation of the activity of human malaria research centres existing in some countries, in which this scientific work is carried out under stringent ethical and professional conditions. (5) Because of the importance of owl monkeys for both immunological and chemotherapeutic re- search, further investigation into the natural history, conservation, breeding, and limits of exploitation of this species should be encouraged. Furthermore, research workers should cooperate, both nationally and internationally, in the multidisciplinary use of these monkeys, including their breeding. (6) Further research related to the control and eradication of malaria within national health plans will be increasingly the responsibility of the govern- ments of countries where this disease is prevalent. In view of this and in order to train many more national research workers, especially from malarious areas, as well as international scientists, international or bilateral organizations should stimulate the estab- lishment or strengthening of national research and training institutions for the preparation ofnew cadres of scientists in the field of malaria, prevail on the countries concerned to widen the opportunities for the employment of these scientists, and pursue with undiminished vigour the successful policy of fellow- ships and research grants. (7) The threat of resistance of plasmodia to some currently used drugs is growing. The search for alternative antimalarial compounds should therefore be continued, and compounds that have undergone satisfactory final screening in human malaria should be assessed in well-conducted field trials. (8) In spite of the high therapeutic value of the combination of sulfonamide compounds with anti- folates in areas where resistance of P. falciparum to 4-aminoquinolines is apparent, the use of these drugs should be reserved for the treatment and prophylaxis of malaria only in areas where resistance to 4-aminoquinolines has been confirmed. (9) The present conventional control measures directed against the vector are insufficient in a number of geographical areas. As some of these failures depend on behavioural patterns of Ano- pheles, which appear to be genetically determined, wider use of cytogenetic studies as a complement to entomological surveys should be made, to permit the selection of the best control methods and to predict their effect. (10) The development and study of new insecti- cides should be pursued. New techniques for the application of insecticides, particularly ULV, should be more intensively investigated under different con- ditions; biological control methods should take their proper place in integrated vector control and the cost of each method of vector control should be - 3713201 CONCLUSIONS AND RECOMMENDATIONS comparatively assessed in different situations from the point of view of effectiveness. (11) Immunological studies in malaria, and espe- cially the encouraging preliminary reports of malaria vaccination in man, are highly significant. Very high priority should therefore be given to: (a) the expan- sion of vaccination studies with sporozoites and blood stages of malaria parasites; (b) improving methods of in vitro cultivation of plasmodia; and (c) developing practical methods for measuring protective immunity. This will also call for further studies on the isolation and purification of malarial antigens associated with protective immunity. (12) Seroepidemiological studies have indicated the value of new methods for assessing the response of individuals and of communities to malaria infec- tion. The usefulness of the main methods now avail- able should be investigated in longitudinal studies and in late phases of malaria eradication, as well as for various other epidemiological purposes-e.g., to determine malarious areas in which hypoendemic conditions exist. Furthermore, modem serological methods should be used for a more precise and meaningful classifi- cation of malaria endemicity. In this connexion, the participants in the symposium endorsed the recom- mendations made in the memorandum entitled " Serological testing in malaria" (Bulletin of the World Health Organization, in press). (13) More knowledge is required on the distri- bution and degree of resistance of plasmodia to various antimalarial compounds. There is therefore a need for the improved flow of critical information from the field on this subject, for confirmation or otherwise of collected data and for communication of these data. (14) Several aspects of malaria research deserve particular attention and support and encouragement should be given to studies on: (a) the genetics of plasmodia and the definition of human genes that affect the susceptibility of man to infection with plasmodia; (b) the epidemiological importance of G6PD deficiency in areas with both P. vivax and P. falciparum infection; (c) the bionomics and geo- graphical distribution of some important malaria vectors following the major man-made environmental changes affecting water management; (d) the suscep- tibility of various strains of Anopheles to isolates of P. falciparum and P. vivax of various geographical origins; and (e) the new rodent malarial model (P. berghei yoelii-A. stephensi) for the screening of causal prophylactic activity of antimalarial drugs. This model has shown much promise and should be more widely assessed and used for appropriate chemotherapeutic studies. 372