Press Release WHO/46
9 June 1998
MAJOR GAPS IN RESEARCH ON ANTIBIOTIC RESISTANCE NEED FILLING
Fluoroquinolones are important members of the quinolone group of antibiotics licensed to treat diseases in humans and animals. However, their use in livestock animals can contribute to increased resistance in foodborne bacteria (such as Campylobacter and Salmonella) which may infect humans. Fluoroquinolones are important for the treatment of invasive Salmonella and Campylobacter infections in humans and an increase in the resistance in these bacteria is therefore of concern.
"To date, there has been little documented impact on human health of fluoroquinolone use in livestock, but there is concern over the potential human health consequences if resistance were to increase and spread. Further research and data gathering are thus essential," said Dr David Heymann, Director of the World Health Organization's (WHO) Division of Emerging and other Communicable Diseases Surveillance and Control (EMC).
Consequently, WHO convened a meeting on the medical impact of quinolone use in food animals at WHO headquarters in Geneva from 2 to 5 June. The meeting, in which over 60 experts from both the human and animal health fields participated, agreed that that major emphases of future research should include: determining the full extent of quinolone usage outside human medicine; improving epidemiological evidence on how resistance in both animals and humans develops, persists and spreads between animal species and humans; developing surveillance techniques specifically designed to capture the above data; determining the mechanisms and levels of resistance in important zoonotic pathogens to quinolones and how important these resistance levels are in terms of human health risk; developing strategies for prudent use in animals to maximize therapeutic benefit while minimizing development of resistance; developing alternatives, such as vaccines, to the use of antimicrobials for animal disease prevention.
Following the introduction of fluoroquinolones in several countries, Salmonella with reduced susceptibility to fluoroquinolones have emerged in food animals; resistant Campylobacter have also emerged. Although no human cases have been documented, the experts expressed concern that there could be treatment failures in humans infected with Salmonella with reduced susceptibility. The experts also noted that, with the use of fluoroquinolones in humans, human pathogens have begun to develop resistant strains and there are now several circumstances in which resistance has limited the therapeutic use of this class of antibiotic for important diseases such as for gonorrhoea and typhoid.
While fluoroquinolones are not used as growth promoters, they are currently used for treatment of animal disease in many countries of the world and, in some regions, they are also used for disease prevention in animals. However, the data available so far on their usage are scarce and are often the proprietary information of the drugs' manufacturers. Consequently, correlations between quinolone usage and the emergence of resistance are hard to make. WHO and the meeting's participants welcomed the initiative by COMISA (World Federation of the Animal Health Industry) at the 2-5 June meeting that provided sales and volume data for the major fluoroquinolones in more than 30 countries.
The experts, from 18 countries, requested that WHO, in conjunction with the Food and Agriculture Organization of the United Nations (FAO) and the International Office of Epizootics (OIE), work together to gather data, standardize testing methods and develop a code of practice for the prudent use of antimicrobials in food animals. WHO should also, the participants agreed, ensure that public health safeguards are given prominence in such a code of practice.
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