Antimicrobial usage in animal farming could select for antimicrobial-resistant bacteria that may spread to humans either through direct contact, consumption of meat or indirectly through environmental pathways (Marshall and Levy 2011).
The use of almost all classes of antimicrobials available for humans has been reported in animal production (WHO 2000), and widespread usage of antimicrobials in animal farming was associated to the development of antimicrobial-resistance which potentially decrease treatment choices for infections (WHO 2000 Apata 2009). However, their misuse can lead to the presence of residues in animal products that may have harmful effects on consumers, raison why maximum residue limits for veterinary drugs were defined in edible tissues of animal origin (Crawford 1985). To increase animal production, many chemical compounds are used as veterinary drugs with the aim of treating and preventing animal diseases, as well as improving growth performance (Page and Gautier 2012). It is therefore necessary to implement actions that will prevent the misuse of antimicrobials. High and uncontrolled usage of antimicrobials (sulfonamides, tetracyclines and fluoroquinolones) was noted in chicken farming in Yaoundé, Cameroon, as well as usage of banned substances such as nitrofurans. The ratio of Used Daily Doses (UDD)/Defined Daily Doses (DDD) estimating correctness of dosing showed that enrofloxacin, sulfadimethoxine and trimethoprim were underdosed in most of the administrations whereas ciprofloxacin, doxycycline, erythromycin, flumequine, furaltadone, neomycin, sulfadiazine, sulfadimidin and sulfamerazine were usually overdosed. Fluoroquinolones, sulfonamides, tetracyclines and nitrofurans were the antimicrobials commonly used by most farms (57.1, 53.1, 46.9 and 17.3 % respectively), whereas sulfonamides, tetracyclines, fluoroquinolones and nitrofurans were quantitatively the most used compounds (48.2, 26.5, 16.1 and 7.6 % of the total amount of antimicrobials used). No disease was recorded in 36.7 % of farms during the last 3 months and 42.9 % of farms were not following withdrawal periods. 19.4 % of farms used antimicrobials for therapeutic purpose, 11.2 % for prophylactic purpose and 69.4 % for both therapeutic and prophylactic. Twenty types of drugs containing antimicrobials belonging to 9 classes were recorded. ResultsĪll the farms were using antimicrobials via drinking water administration. A cross-sectional survey was conducted in 98 farms holding 220,262 chickens, from February to May 2015 in six areas of Yaoundé, the capital of Cameroon, to describe and quantify the use of antimicrobials. Antimicrobials are widely used in chicken production in Cameroon, but no quantitative data are available.