Crisis in snake antivenom supply for Africa

Abstract

In Africa, snake bites cause hundreds of deaths each year and thousands of cases of permanent physical disability.1Warrell DA Arnett C The importance of bites by the saw-scaled or carpet viper (Echis carinatus): epidemiological studies in Nigeria and a review of the world literature.Acta Trop. 1976; 33: 307-341PubMed Google Scholar In all the affected countries, there is an increasing shortage of antivenom, the only effective specific treatment. Formerly, the main antivenom producers for Africa were the South African Institute for Medical Research (SAIMR), Aventis Pasteur in France, and Behringwerke in Germany. These companies produced barely enough effective antivenom for Africa. In the past few years, however, Behringwerke has stopped producing antivenom; Aventis Pasteur has produced no antivenom for use in Africa for the past 2 years, and the SAIMR is being privatised, which probably means that the unprofitable antivenom production will cease. As a result of these changes, the burden of snake-bite morbidity and mortality in the continent is already rising. In Africa, at present, the choice is between imported non-specific and ineffective antivenoms manufactured in Asia, using inappropriate venoms, and unproven and frequently dangerous traditional treatments. In Nigeria, fake antivenoms are now flooding the market. Some years ago, hopes were raised by the establishment of an Anglo-American pharmaceutical company, Therapeutic Antibodies UK Ltd, whose aim was to produce antivenoms for use in less-developed and more-developed countries. Production of a new antivenom for use in west Africa was strongly supported, politically and financially, by the Nigerian Federal Ministry of Health, with advice and practical help from experts at the Centre for Tropical Medicine at the University of Oxford, and the Liverpool School of Tropical Medicine. As a result, Welsh sheep were immunised with venom obtained from Nigerian snakes. The new antivenom was assessed pre-clinically in Liverpool2Laing GD Lee L Smith DC Landon J Theakston RDG Experimental assessment of a new, low-cost antivenom for treatment of carpet viper (Echis ocellatus) envenoming.Toxicon. 1995; 33: 307-313Crossref PubMed Scopus (47) Google Scholar and compared clinically with the available Pasteur-Merieux antivenom in snake-bitten patients in northeastern Nigeria.3Meyer WP Habib AG Onayade AA et al.First clinical experience with a new ovine Fab Echis ocellatus snake bite antivenom in Nigeria: randomized comparative trial with Institute Pasteur serum (Ipser) African antivenom.Am J Trop Med Hyg. 1997; 56: 291-300PubMed Google Scholar In that region, in the sowing and harvesting seasons, up to 70% of hospital beds are occupied by victims of snake bite. Therapeutic Antibodies UK Ltd merged with another company to form Protherics Plc in 1999. The company's new rattlesnake antivenom, recently approved by the US Food and Drug Administration, costs £6000 per treatment. This company has shed any commitment to producing antivenoms for less-developed countries for commercial reasons. However, an offshoot, Micropharm Ltd, plans a new collaboration with the Nigerian Federal Ministry of Health to continue antivenom production and to assist with the transfer of appropriate technology to Nigeria. This initiative is funded by a 3-year grant from two UK Research Councils, the Federal Government of Nigeria, and, if successful, might provide a model for other African countries. In the mean-time, surviving antivenom producers, especially those in less-developed countries that have excess production capability, should be encouraged to manufacture geographically relevant antivenoms. In less-developed countries, even treatment costing as little as £3 per vial might be unaffordable.