A Survey of Antibiotics Use and the Awareness of Antibiotics Resistance Among Farmers of Broiler Farms at Sylhet Sadar Upazilla in Bangladesh

Md. Saiful Islam Siddiqui1*, Sharmin Akter2 and Mohd. Riajul Islam2

1Department of Anatomy and Histology, Faculty of Veterinary, Animal and Biomedical Sciences, Sylhet Agricultural University, Sylhet-3100, Bangladesh; 2International Centre for Diarrhoeal Disease Research (ICDDR, B) 68, Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka-1212.

Editor | Muhammad Abubakar, National Veterinary Laboratories, Park Road, Islamabad, Pakistan.

Received | April 01, 2023; Accepted | May 03, 2023; Published | May 19, 2023

*Correspondence | Md. Saiful Islam Siddiqui, Department of Anatomy and Histology, Faculty of Veterinary, Animal and Biomedical Sciences, Sylhet Agricultural University, Sylhet-3100, Bangladesh; Email: msisiddiqui2000@yahoo.com

Citation | Siddiqui, M.S.I., S. Akter and M.R. Islam. 2023. A survey of antibiotics use and the awareness of antibiotics resistance among farmers of broiler farms at Sylhet Sadar Upazilla in Bangladesh. Veterinary Sciences: Research and Reviews, 9(1): 57-64.

DOI | https://dx.doi.org/10.17582/journal.vsrr/2023/9.1.57.64

Keywords | Antibiotic, Misuse or haphazard use, Broiler farm, Antibiotic resistance

Copyright: 2023 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Introduction

Antibiotic resistance (ABR) is an emanate problem globally, and antibiotic usage (ABU) in poultry production is thought to be a subsidize factor (Marshal and Levy, 2011). The matter has created much argumentation, the recent resistance against antimicrobials such as colistin from animal production (Liu et al., 2016) has substantiated the case that ABU in food animal and poultry production is a momentous patron to the universal drift of ABR in humans. ABU in poultry production is likely to accord propagation and sustainment of ABR bacteria on farms. Resistant bacteria, ABR antecedent, or the antibiotics themselves may be dispersed to the environment through farm waste, and may outreach humans because of direct contact with poultry, the depletion of polluted foods of animal and poultry origin, water, and vegetables (Costa et al., 2013). Antibiotics used in poultry production and in human medicine are very similar (FAO, 2007) and therefore resistance against antibiotics is off importance for human medicine (WHO, 2014). The high quantities of antibiotics currently used in animal and poultry production are expected to further increase due to increased demand, particularly in emerging economies (Van Boeckel et al., 2015). Southeast Asia (SEA) is a bloc of rapidly developing and linked economies (Richter et al., 2015; Walther et al., 2014) and can be considered a hotspot of ABR (Cocker et al., 2011; Von Wintersdorff et al., 2016; WHO, 2014). In Indian subcontinent, particularly in Bangladesh poultry sector is raising day by day. This may promote further risk of dissipation of ABR organisms and genes to consumers nationally and globally. The Center for Veterinary Medicine (CVM) of the US Food and Drug Administration (FDA) have banned the use of the fluoroquinolone antimicrobial enrofloxacin in poultry (OIE, 2001).

The actual quantity of antibiotics used in poultry production globally is unknown and important to valuation. In the US, for instance, more than 70 percent of medically important antibiotics are used in animals (O’Neill, 2015). It’s a common trend to use antibiotics in poultry without a prescription of a registered veterinarian, even the feature is almost the same in human medicine also. No or least scientific report available in regard to random and haphazard or misuse of antibiotics in agriculture, livestock including poultry farming in Bangladesh. As it’s now established that antibiotic use for food production is now increasing the risk of ABR, resistant bacteria transferring to humans and producing health threats, That’swhy, it is essential to know the real scenario of using antibiotics at poultry farms level in an area. Therefore, this study was undertaken as a basic study with following aims:

1. To investigate the commonly used antibiotics in broiler production in a study area of Bangladesh
2. To evaluate the factors govern farmers “selection of antibiotics” for use on their farms in Bangladesh perspectives.
3. To assess the status of poultry farmers’ knowledge about antibiotic resistant.

Materials and Methods

Study area

Sadar Upazilla of Sylhet District in Bangladesh.

Target poultry farms and farmers

Probability proportional to size sampling was employed to select the farms 50 poultry (broiler) farms of remote area with at least 300 chickens/farm and farmers under the geographic arena of Sadar Upazilla of Sylhet District in Bangladesh were randomly selected for this study.

Study period

The study was conducted for a period of around one year between 01, July 2018 to 31, May 2019.

Survey design

In 2018, a cross-sectional study was conducted on 50 farms out of 64 following multi-stage sampling technique. Small to medium sized rural broiler farms of remote area were visited and conversation with farms owners recorded as a part of survey at Sylhet Sadar Upazilla of Syhlet district of Bangladesh. The owner of each surveyed farm was asked as per questionnaire formulated for this purpose.

Questionnaire preparation

A structured questionnaire was compiled and used for poultry farm level survey to obtain information relating to commonly used antibiotics in broiler production, factors govern farmers “selection of antibiotics” for use on their farms and perceptions and knowledge about antibiotic resistance and its impact on public health. To accomplish these objectives, the questionnaire was divided into following subsection, namely: (1) The category and magnitude of antibiotics use: includes commonly used antibiotics for both prophylactic and therapeutic purposes and its types, dosages, duration etc. (2) Factors govern farmers “selection of antibiotics” – includes socio-economic and educational status of the poultry farmers, experience and training on farm management, status of Veterinary services, role of agro-vet companies or chick and feed supplier, farmers knowledge about poultry diseases and antibiotics, drug efficacy, and withdrawal period etc. (3) poultry farmers knowledge of and attitudes to antibiotic use includes farmers knowledge about haphazard or misuse of antibiotics, marketing authorization of antibiotics drug, antibiotics resistant and publicity about ABR by any government or non-government organization. The questionnaire were structured to reproduce information covering the extensive usages of antibiotics, antibiotics resistance, and dissipation of resistance factors.

Data collection

Data were collected by asking questions to poultry farmers as per formulated questionnaires during farm visit.

Data analysis

Descriptive statistics were used to examine characteristics of the study farms and farmers and no statistical tests were performed.

Results and Discussion

The survey revealed that, the poultry farmers use antibiotics for both therapeutic and prophylactic purposes. Subtherapeutic use of antibiotics was found common phenomena in broiler farming. Almost all (98%) farmers are involved with sub-therapeutic use of antibiotics. Enrofloxacin, Ciprofloxacin, Levofloxacin, Azithromycin, Cephalexin, Erythromycin, Neomycin, Amoxicillin and Collistin were found most commonly used and effective (as per farmer opinion and observation) antibiotics. Farmers were found influenced by different factors to choice antibiotics for their farm (Table 3). Mostly marginal farmers were found involved with broiler farming as a part-time occupation or in some cases full time. Data revealed that poultry farming is the co-income source of 70% farm personnel and main income source of 30% personnel. Most farmers (cent percent) trust on personal cognizance and practicality during antibiotic administration instead of seeking experts advice, even 22% farmers furnished treatment depending on their own decision, 10% and 68% farmers follow registered veterinarian and agro-vet companies/ poultry feed and chick supplier suggestion respectively (Tables 1, 2). 74% poultry farmers found habituated to use antibiotics as preventive tools, so that their birds don’t get sick, even they are habituated to use antibiotics before clinical outbreak of disease or before confirmative diagnosis of disease is made. 82% farmers use antibiotics in their poultry flock to reduce any stress, particularly after vaccination (Table 3).

 

Table 1: Percentage of Farms or farmers under supervision of agro-vet companies.

Factors	%
Supervision of Agrovet companies (direct or indirect)	100
Under direct supervision/ suggestion of Agrovet companies	68

 

Table 2: Farmers educational status, training and knowledge about farm management.

Factors	%
Educational status under secondary school level	91
No training on poultry rearing or farm management	90
Poor knowledge about farm management	50

 

Table 3: Category/ factors govern farmer to select antibiotics.

Category/ factors governs farmer to select antibiotics
Prophylectic use	74 (100)
Use after vaccination	82(100)
Rely on personal knowledge and experience	100 (100)
Treatment by farmers own decision	22 (100)
Follow registered Veterinarian suggestion	10(100)
Follow agro-vet companies suggestion	68 (100)

 

84% farmers normally use antibiotics as therapeutic or prophylactic purpose immediately prior to sell the broiler for meat purposes or even before completion of withdrawal period of drug residue. 50% farmers were found bears poor knowledge about farm management. 90% poultry farmers found lack of experience of attending any training on poultry farm management from any government or non-government organization. It also found that 91% farmers have the educational status under secondary school certificate level (Table 2). The study also revealed that 100% farmers are very unaware about antibiotics resistance and its impact on public health. No monitoring or surveillance concerning antibiotic resistance (ABR) and haphazard and misuse of antibiotics from any government or non –government organization were observed in study area during study period.

In this study, it is found that farmers are habituated and got good results from therapeutic use of Enrofloxacin, Ciprofloxacin, Levofloxacin, Azithromycin and Cephalexin. This finding also supports the findings of study conducted by Xu et al. (2020) in China. It also found that, this is the main reason behind gradual decreasement of therapeutic use of penicillin’s group of antibiotics. However, in this study, we did not perform any Antimicrobial Sensitivity Test but our findings were found almost in support of the results obtained in Antimicrobial Sensitivity Test performed in Bangladesh by Advance Laboratories, Advance Animal Science Co. Ltd., 2005 that was stated by Chowdhury et al. (2009). The findings are also in accordance with the findings stated by (Diarrassouba et al., 2007; Forgetta et al., 2012; Diarra et al. 2014; Diarra and Malouin, 2014). It is also found that, therapeutic use of Ampicillin, Amoxicillin, Doxycycline, Oxytetracycline and Tetracycline singly are very less frequent than quinolones groups of antibiotics such as Enrofloxacin and Ciprofloxacin, though sometimes used combinedly, but could not full fill farmer’s expectation. Amoxicillin, Doxycycline, Oxytetracycline, Tilmicosin and Colistin were used routinely, for prophylaxis, in different surveyed farms. Amoxicillin and Colistin is a critically important and Doxycycline and Oxytetracycline are highly important antimicrobials (WHO, 2011; George et al., 2012). Although Tilmicosin is not used in humans but considered analogous to macrolide group, therefore, could drive resistance (George et al., 2012). The United States Food and Drug Administration (FDA) has approved the use of Amoxycillin, Doxycycline, Oxytetracycline and Tilmicosin in food-producing animals (Wellcome Trust, 2015; Seventh ESVAC Report, 2017; WHO, 2017). Colistin did not used in animals in the United States of America (EMA, 2016) by 2016. Colistin is currently considered to be the last defense against multidrug resistant bacteria (Walsh et al., 2016). In China, use of Colistin in food animal production have resulted Colistin-resistance mcr-1 gene by Escherichia coli (Liu et al., 2016; Lancet, 2016). As a result, very recently, China banned the use of Colistin in animals (Walsh et al., 2016). Therefore, it is certain that, in Bangladesh perspective frequent use of Colistin in raising broiler meat may be attributed to the Colistin-resistance mcr-1 gene by Escherichia coli. In 2019, the drug administration of Bangladesh has banned single use of Colistin in poultry production. It is found that, therapeutic use of macrolide is common in poultry (broiler) farms of the study area though the Dutch government has restricted macrolide use in Dutch farms that raise chickens for meat between 2014 and 2015, British farmers reduced antibiotic use by 27% when raising chickens for meat (Welcome Trust, 2015). Most farmers (cent percent) have faith on personal knowledge and experience during antibiotic administration instead of seeking Veterinarian advice, even 22% farmers furnished treatment depending on their own decision. These finding are almost similar to the findings stated by Boamah et al. (2016). 68% of the farmer administered antibiotics as per suggestion of the agro-based companies or feed and chick supplier. It was also observed that farmers who sought veterinary advice from different agro-vet industries are more likely to use higher frequencies of antibiotic-containing agents for treatment and prevention of infections, as they are corporate people. The administration of antibiotics by such individuals could lead to under-dosing or over-dosing of antibiotics in birds (Chowdhury et al., 2009; Maron et al., 2013). In several European countries such as The Netherlands, Denmark, Norway and Sweden, the administration of antibiotics to food animals are strictly under the supervision of a veterinarian (Cogliani et al., 2011). Bangladesh does not have enough Veterinarians to enforce such regulations and rules. Ethics, rules and regulation in regard to use of antibiotic drugs are not strictly followed in Bangladesh. Government has to ensure the appropriate use of antibiotics. Farmers are required to observe a withdrawal period after administration of antibiotics during which products from their farms are not to be sold (Darwish et al., 2013; Mirlohi et al., 2013). This study showed that over 84% of the farmers sold their broiler for meat purposes before withdrawal period of drug residue, in Ghana, which is 60% (Boamah et al., 2016). This gap might be due to differences of socioeconomic status and label of awareness among farmers about antibiotic resistance and its impact on public health, as 91% farmers have the educational status under school secondary level and 100% farmers in our study area are found very unaware about antibiotic resistance (ABR). It is also observed that Veterinarians are influential in the use of antibiotics on farms and improvement in delivery of veterinary services could significantly decrease the use and possible misuse of antibiotics on these farms. Also, monitoring farmers access to antibiotics by instituting surveillance systems may lead to a decline in the use of antibiotic-containing agents on poultry farms. There is the need for policies and stricter regulations that would limit illegal access to antibiotics. Policy makers must also introduce programmes that would monitor the importation, sale, distribution, use and consumption of antibiotics in animal production in Bangladesh. We propose that the extent and nature of antibiotic use in animals and birds should be officially and openly reported by each farm, sector and country. Also, the labels on animal products should contain information on antibiotic footprints. These measures may encourage a reduction in antibiotic use globally and lead to a reduction of drug-resistant bacteria. Misuse and random use of antibiotics is considered as the most important factor for emergence of antibiotic resistance. In this study, it is found that haphazard uses of antibiotics in broiler farming are very common. The misuse of antibiotics in poultry rearing has also been associated with the spread of antibiotic resistance (Carlet et al., 2012) which is in accordance with the findings of this study. Despite the increasing resistance of pathogenic bacterial strains in Bangladesh (WHO, 2017) there are only a few reports on antibiotics used in poultry production particularly in broiler industry, how they are used and possible factors influencing their selection, hence the need for this study but to get complete scenario it is essential to conduct a further study in a great extent.

In this situation, government should forward the activities concerning antibiotic resistance, the farms should be brought under direct supervision of government recruited registered veterinarian and farm personnel such as farm owners and caretaker/managers should be adequately trained to perform such responsibilities. The administration of the correct dose of an antibiotic is as important as the completion of the antibiotic course. Incompletion of antibiotic treatment courses exposes the microorganisms to sub-inhibitory concentrations of the antibiotic (Davies and Davies, 2010; Kohanski et al., 2011) which leads to the development of resistance. The fact that only 43% of the selected farms completed the required antibiotic courses. This was also in accordance with the findings of Boamah et al. (2016) conducted a study in Ghana. This might be due to the absence of veterinarians on farms to supervise antibiotic administration or lack of knowledge on the farmers part on the outcome of such practices (Garforth, 2015) as we found by analyzing the socio-economic status of the farmers that 91% farmers have an educational status below secondary school level and 90% of them did not participated any training before coming this occupation. No monitoring or surveillance concerning antibiotic resistance (ABR) and haphazard and misuse of antibiotics from any government and non-government organization are observed. Therefore, regulatory authorities must take rigorous steps to curtail inappropriate use of numerous drugs for animal use in order to provide safe animal origin food to humans.

Conclusions and Recommendations

It is concluded that, Enrofloxacin, Ciprofloxacin, Levofloxacin, Azithromycin, Cephalexin, Erythromycin, Neomycin, Amoxicillin and Collistin were found most commonly used antibiotics. Different factors such as poor educational status and knowledge, trust on personal cognizance and tendency to follow agro-vet companies suggestion are mainly the factors govern farmers to select antibiotics. No programme concerning build mass awareness about antibiotics resistance was found. Therefore, controlling authorities must take rigorous steps to control the uses of antibiotics in broiler industries, to stop the misuse of antibiotics, to ensure proper veterinary service at marginal farmer’s level and building mass awareness about ABR and its impact on public health.

Acknowledgements

We thank the farmers who participated in the study. The study was funded by the Sylhet Agricultural University Research system (SAURES) is supported by University grants commission (UGC), People’s Republic of Bangladesh.

Author’s Contribution

This research was conducted under the direct supervision of the first author- (Md. Saiful Islam Siddiqui). Sharmin Akter and Mohd. Riajul Islam conceived of the presented idea, verified the analytical methods and supervised the findings of this work. All authors discussed the results and contributed to the final manuscript writing.

Funding

The Sylhet Agricultural University Research System (SAURES), via University Grants Commission (UGC), Government of the People’s Republic of Bangladesh, supported this work.

Ethics approval and consent to participate

• All experimental protocols were approved by the institutional organization (Sylhet Agricultural University Research System (SAURES).
• Informed consent was obtained from birds owners before all experiments.
• All methods are reported in accordance with institutional guidelines (Sylhet Agricultural University Research System (SAURES) for the reporting of animal experiments.
• Informed consent was obtained from all subjects and/or their legal guardian(s) in regard to human data.

Availability of data and material

The datasets generated and/or analysed during the current study are not publicly available due to funder/ institutional obligation but are available from the corresponding author (msisiddiqui2000@yahoo.com) on reasonable request.

Code availability

N/A

Consent for publication

Not applicable.

Conflict of interest

The authors have declared no conflict of interest.

References

Annan-Prah, A., Agbemafle, E., Asare, P.T., and Akorli, S.Y., 2012. Antibiotic use, abuse and their public health implication: The contributory role of management flaws in the poultry industry in two Agro-ecological zones in Ghana. J. Vet. Adv., 2: 199-208. https://www.academia.edu/72417773/Antibiotic_use_Abuse_and_their_Public_Health_Implications_The_Contributory_Role_of_Management_Flaws_in_the_Poultry_Industry_in_two_Agro_ecological_Zones_in_Ghana

Boamah, V.E., Agyare, C., Odoi, H., and Dalsgaard, A., 2016. Practices and factors influencing the use of antibiotics in selected poultry farms in Ghana. J. Antimicro. Agents., 2.2 https://doi.org/10.4172/2472-1212.1000120

Carlet, J., Jarlier, V., Harbarth, S., Voss, A., and Goossens, H., 2012. Ready for a world without antibiotics? The pensieres antibiotic resistant call to action. Antimicrob. Resist. Infect. Contr., 1: 11. https://doi.org/10.1186/2047-2994-1-11

Chowdhury, R., Haque, M.N., Islam, K.M.S., and Khaleduzzaman, A.B.M., 2009. A review on antibiotics in an animal feed. Bangladesh J. Anim. Sci., 38(1 and 2): 22–32. https://doi.org/10.3329/bjas.v38i1-2.9909

Cogliani, C., Goossens, H., and Greko, C., 2011. Restricting antimicrobial use in food animals: Lessons from Europe. Microbe, 6: 274-279. https://doi.org/10.1128/microbe.6.274.1

Coker, R.J., Hunter, B.M., Rudge, J.W., Liverani, M., and Hanvoravongchai, P., 2011. Emerging infectious diseases in Southeast Asia: Regional challenges to control. Lancet, 377: 599–609. https://doi.org/10.1016/S0140-6736(10)62004-1

Costa, D.A., Loureiro, P.M., and Matos, L., 2013. Transfer of multidrug-resistant bacteria between intermingled ecological niches: The interface between humans, animals and the environment. Int. J. Environ. Res. Publ. Health, 10: 278–294. https://doi.org/10.3390/ijerph10010278

Darwish, W.S., Eldaly, E., El-Abbasy, M.T., Ikenaka, Y., and Nakayama, S., 2013. Antibiotic residues in food: The African scenario. Jpn. J. Vet. Res., 61: S13-S22.

Davies, J., and Davies, D., 2010. Origins and evolution of antibiotic resistance. Microbial Mol. Biol. Rev., 74: 417-433. https://doi.org/10.1128/MMBR.00016-10

Diarra and Malouin. 2014. Antibiotics in Canadian poultry productions and anticipated alternatives. Front. Microbial., https://doi.org/10.3389/fmicb.2014.00282

Diarra, M.S., Delaquis, P., Rempel, H., Bach, S., Harlton, C., and Aslam, M., 2014. Antibiotic resistance and diversity of Salmonella enterica serovars associated with broiler chickens. J. Food Prot., 77: 40–99. https://doi.org/10.4315/0362-028.JFP-13-251

Diarrassouba, F., Diarra, M.S., Bach, S., Delaquis, P., Pritchard, J., and Topp, E., 2007. Antibiotic resistance and virulence genes in commensal Esherichia coli and Salmonella isolated from commercial broiler chicken farms. J. Food Prot., 70: 1316–1327. https://doi.org/10.4315/0362-028X-70.6.1316

EMA, 2016. Updated advice on the use of colistin products in animals within the European Union: development of resistance and possible impact on human and animal health. London: European Medicines Agency, Available from: http://www.ema.europa.eu/docs/en_GB/document_library/ Scientific _ guideline /2016 /05/ WC 500207233. pdf.

ESVAC, 2015. Sales of veterinary antimicrobial agents in 30 European countries in 2015. Trends from 2010 to 2015. Seventh ESVAC report. London: European Medicines Agency; 2017. Available from: http://www. ema. europa. eu/ docs /en_ GB /document_ library/ Report/ 2017/10/ WC500236750. pdf

FAO, 2007. Food and agriculture organization of the United Nations. Joint FAO/WHO/OIE Expert Meeting on Critically Important Antimicrobials; FAO, WHO and OIE: Rome, Italy.

Forgetta, V., Rempel, H., Malouin, F., Vaillancourt, R.Jr., Topp, E., and Dewar, K., 2012. Pathogenic and multidrug-resistant Escherichia fergusonii from broiler chicken. Poult. Sci., 91: 512–525. https://doi.org/10.3382/ps.2011-01738

Garforth, C., 2015. Livestock keepers reasons for doing and not doing things which governments, vets and scientists would like them to do. Zoo Publ. Health, 62: 29-38. https://doi.org/10.1111/zph.12189

George, D.F., Gbedema, S.Y., Agyare, C., Adu, F., and Boamah, V.E., 2012. Antibiotic resistance patterns of Escherichia coli isolates from hospitals in Kumasi, Ghana. ISRN Microbiol., pp. 1-5. https://doi.org/10.5402/2012/658470

Kohanski, M., Dwyer, D.J., and Collins, J.J., 2010. How antibiotics kill bacteria from targets to networks. Nat. Rev. Microbiol., 8: 423-435. https://doi.org/10.1038/nrmicro2333

Lancet, 2016. Emergence of plasmid-mediated colistin resistance mechanism mcr-1 in animals and human beings in China: A microbiological and molecular biological study. Infect. Dis., 16: 161–168. https://doi.org/10.1016/S1473-3099(15)00424-7

Liu, Y.Y., Wang, Y., Walsh, T.R., Yi, L.X., Zhang, R., and Spencer, J., 2016. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: A microbiological and molecular biological study. Lancet Infect. Dis., 16(2): 161–168. https://doi.org/10.1016/S1473-3099(15)00424-7

Maron, D.F., Smith, T.J.S., and Nachman, K.E., 2013. Restrictions on antimicrobial use in food animal production: An international regulatory and economic survey. Glob. Health, 9: 48. https://doi.org/10.1186/1744-8603-9-48

Marshall, B.M., and Levy, S.B., 2011. Food animals and antimicrobials: Impacts on human health. Clin. Microbiol. Rev., 24: 718–733. https://doi.org/10.1128/CMR.00002-11

Mirlohi, M., Aalipour, F., and Jalali, M., 2013. Prevalence of antibiotic residues in commercial milk and its variation by season and thermal processing methods. Int. J. Environ. Health Eng., 2: 41. https://doi.org/10.4103/2277-9183.122429

Msoffe, P.L., Aning, K.G., Byarugaba, D.K., Mbuthia, P.G., and Sourou, S., 2009. Handbook of poultry diseases important in Africa. A project of the global livestock CRSP, pp. 83.

O’Neill Jim, 2015. Antimicrobial resistance: Tackling a crisis for the health and wealth of nations. It is Chaired by Jim O’Neill and supported by the welcome trust and the UK Government, but operates and speaks with full independence from both. https://wellcomecollection.org/works/rdpck35v

OIE, 2001. Antibiotic resistance, with special reference to poultry production. Presented by Moritz van Vuuren, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science. University of Pretoria, South Africa Conf. OIE, pp. 135-146

Richter, C.H., Custer, B., Steele, J.A., Wilcox, B.A., and Xu, J., 2015. Intensified food production and correlated risks to human health in the greater mekong subregion: A systematic review. Environ. Health, PMID: 26006733 PMCID: PMC4446077. https://doi.org/10.1186/s12940-015-0033-8

Van Boeckel, T.P., Brower, C., Gilbert, M., Grenfell, B.T., Levin, S.A., Robinson, T.P., Teillant, A., and Laxminarayan, R., 2015. Global trends in antimicrobial use in food animals. Proc. Natl. Acad. Sci., 112: 5649–5654. https://doi.org/10.1073/pnas.1503141112

Von Wintersdorff, C.J., Penders, J., Stobberingh, E.E., Oude Lashof, A.M., Hoebe, C.J., Savelkoul, P.H., and Wolffs, P.F., 2014. High rates of antimicrobial drug resistance gene acquisition after international travel, the Netherlands. Emerg. Infect. Dis., 20: 649–657. https://doi.org/10.3201/eid2004.131718

Walsh, T.R., and Wu, Y., 2016. China bans colistin as a feed additive for animals. Lancet Infect Dis., 16(10):1102–1103. https://doi.org/10.1016/S1473-3099(16)30329-2

Walther, B.A., Boete, C., Binot, A., By, Y., Cappelle, J., Carrique-Mas, J., Chou, M., Furey, N., Kim, S., and Lajaunie, C., 2016. Biodiversity and health: Lessons and recommendations from an interdisciplinary conference to advise Southeast Asian research, society and policy. Infect. Genet. Evol., 40: 29–46. https://doi.org/10.1016/j.meegid.2016.02.003

Welcome Trust, 2015. The review on antimicrobial resistance. Antimicrobials in agriculture and the environment: reducing unnecessary use and waste. London: Available from: https:// amr-review. org/ sites/ default /files/ Antimicrobials in agriculture and the environment - Reducing unnecessary use and waste. Pdf

WHO, 2011. Critically important antimicrobials for human medicine 2011. Available online: http://apps.who.int/iris/bitstream/10665/77376/1/9789241504485_eng.pdf accessed on 30 August 2016.

WHO, 2014. Antimicrobial resistance: Global report on surveillance 2014. Available online: http://www.who.int/drugresistance/documents/surveillancereport/en/ accessed on 23 August 2016.

WHO, 2017. Critically important antimicrobials for human medicine 5th revision. Geneva: World Health Organization; 2017. Available from: http://apps.who.int/iris/bitstream/10665/255027/1/9789241512220-eng.pdf [cited 2017 Oct 17].

Xu, J., Sangthong, R., and McNeil, E., 2020. Antibiotic use in chicken farms in northwestern China. Antimicrob. Resist. Infect. Contr., 9: 10. https://doi.org/10.1186/s13756-019-0672-6