BackgroundAntimicrobial resistance (AMR) poses a colossal threat to global health and incurs high economic costs to society. Economic evaluations of antimicrobials and interventions such as diagnostics and vaccines that affect their consumption rarely include the costs of AMR, resulting in sub-optimal policy recommendations. We estimate the economic cost of AMR per antibiotic consumed, stratified by drug class and national income level.MethodsThe model is comprised of three components: correlation coefficients between human antibiotic consumption and subsequent resistance; the economic costs of AMR for five key pathogens; and consumption data for antibiotic classes driving resistance in these organisms. These were used to calculate the economic cost of AMR per antibiotic consumed for different drug classes, using data from Thailand and the United States (US) to represent low/middle and high-income countries.ResultsThe correlation coefficients between consumption of antibiotics that drive resistance in S. aureus, E. coli, K. pneumoniae, A. baumanii, and P. aeruginosa and resistance rates were 0.37, 0.27, 0.35, 0.45, and 0.52, respectively. The total economic cost of AMR due to resistance in these five pathogens was $0.5 billion and $2.9 billion in Thailand and the US, respectively. The cost of AMR associated with the consumption of one standard unit (SU) of antibiotics ranged from $0.1 for macrolides to $0.7 for quinolones, cephalosporins and broad-spectrum penicillins in the Thai context. In the US context, the cost of AMR per SU of antibiotic consumed ranged from $0.1 for carbapenems to $0.6 for quinolones, cephalosporins and broad spectrum penicillins.ConclusionThe economic costs of AMR per antibiotic consumed were considerable, often exceeding their purchase cost. Differences between Thailand and the US were apparent, corresponding with variation in the overall burden of AMR and relative prevalence of different pathogens. Notwithstanding their limitations, use of these estimates in economic evaluations can make better-informed policy recommendations regarding interventions that affect antimicrobial consumption and those aimed specifically at reducing the burden of AMR.Electronic supplementary materialThe online version of this article (10.1186/s13756-018-0384-3) contains supplementary material, which is available to authorized users.

Vietnam is an important producer of aquaculture products, and aquatic products are essential to the Vietnamese diet. However, Vietnam also has very little enforced regulation pertaining to antibiotic usage in domestic aquaculture, which raises concerns for antibiotic resistance in pathogenic bacteria. In this study, analysis was conducted on the presence of antibiotic residues in domestically sold fish and shrimp raised in freshwater farms in Vietnam, and an assessment of farmers’ knowledge of proper antibiotics usage was performed. The results indicated that a quarter of tested aquaculture products were antibiotic screening test positive, and there is a general lack of knowledge about the purpose and proper usage of antibiotics by aquaculture producers. Farmers’ decision-making processes about antimicrobial use are influenced by biased sources of information, such as drug manufacturers and sellers, and by financial incentives.Electronic supplementary materialThe online version of this article (doi:10.1007/s10393-014-1006-z) contains supplementary material, which is available to authorized users.

If the acquisition of virulence genes (VGs) for pathogenicity were not solely acquired through horizontal gene transfers of pathogenicity islands, transposons, and phages, then clonal clusters of enterotoxigenic Escherichia coli (ETEC) would contain few or even none of the VGs found in strains responsible for extraintestinal infections. To evaluate this possibility, 47 postweaning diarrhea (PWD) ETEC strains from different geographical origins and 158 commensal E. coli isolates from the gastrointestinal tracts of eight group-housed healthy pigs were screened for 36 extraintestinal and 18 enteric VGs using multiplex PCR assays. Of 36 extraintestinal VGs, only 8 were detected (fimH, traT, fyuA, hlyA, kpsMtII, k5, iha, and ompT) in the ETEC collection. Among these, hlyA (␣-hemolysin) and iha (nonhemagglutinating adhesin) occurred significantly more frequently among the ETEC isolates than in the commensal isolates. Clustering analysis based on the VG profiles separated commensal and ETEC isolates and even differentiated serogroup O141 from O149. On the other hand, pulsed-field gel electrophoresis (PFGE) successfully clustered ETEC isolates according to both serotype and geographical origin. In contrast, the commensal isolates were heterogeneous with respect to both serotype and DNA fingerprint. This study has validated the use of VG profiling to examine pathogenic relationships between porcine ETEC isolates. The clonal relationships of these isolates can be further clarified by PFGE fingerprinting. The presence of extraintestinal VGs in porcine ETEC confirmed the hypothesis that individual virulence gene acquisitions can occur concurrently against a background of horizontal gene transfers of pathogenicity islands. Over time, this could enable specific clonotypes to respond to host selection pressure and to evolve into new strains with increased virulence.Enterotoxigenic Escherichia coli (ETEC) is the major cause of postweaning diarrhea (PWD) in weaned pigs. ETEC strains colonize the small intestine with the aid of adhesion factors (e.g., F4 or F18 fimbriae). Once attached, the release of either heat-labile or heat-stable (STa or STb) enterotoxins induces diarrhea by affecting the electrolyte balance of the small intestine. The presence of virulence genes (VGs) encoding these determinants is a key requirement for pathogenicity in ETEC and is generally used to distinguish these pathogens from the nonpathogenic or commensal E. coli normally carried in the intestine (37).Characterization of isolates from outbreaks of PWD has shown that ETEC strains lacking recognized fimbriae, such as F4 and F18, are becoming more common (19,26,44). This may be related to the widespread use of vaccines incorporating fimbriated strains, providing selection pressure for the acquisition and carriage of novel, unrecognized VGs. For example, Noamani et al. (37) found that most of the PWD isolates recovered in the period 1998 to 2001 in Ontario, Canada, were associated with a new type of O149 ETEC, which possessed VGs for STa and an enteroag...

Objectives To review community-level consumption of antibiotics in rural Vietnam, according to the WHO Access, Watch, Reserve (AWaRe) classification of 2019, and identify factors associated with the choice of these antibiotics. Methods In this cross-sectional study, data on antibiotic purchases were collected through a customer exit survey of 20 community antibiotic suppliers in Ba Vi District, Hanoi, between September 2017 and July 2018. Antibiotic consumption was estimated through the number of antibiotic encounters, the number of DDDs supplied and the number of treatment days (DOTs) with antibiotics, and analysed according to the AWaRe classification. The factors associated with watch-group antibiotic supply were identified through multivariable logistic regression analysis. Results In total, there were 1342 antibiotic encounters, with access-group antibiotics supplied in 792 encounters (59.0%), watch-group antibiotics supplied in 527 encounters (39.3%) and not-recommended antibiotics supplied in 23 encounters (1.7%). No reserve-group antibiotics were supplied. In children, the consumption of watch-group antibiotics dominated in all three measures (54.8% of encounters, 53.0% of DOTs and 53.6% of DDDs). Factors associated with a higher likelihood of watch-group antibiotic supply were: private pharmacy (OR, 4.23; 95% CI, 2.8–6.38; P < 0.001), non-prescription antibiotic sale (OR, 2.62; 95% CI, 1.78–3.87; P < 0.001) and children (OR, 2.56; 95% CI, 1.84–3.55; P < 0.001). Conclusions High consumption of watch-group antibiotics was observed, especially for use in children. The frequent supply of watch-group antibiotics at private pharmacies reconfirms the need for implementing pharmacy-targeted interventions in Vietnam.