How Metabolic Diseases Impact the Use of Antimicrobials: A Formal Demonstration in the Field of Veterinary Medicine

Decreasing the use of antimicrobials has become a primary objective for both human and veterinary medicine in many countries. Medical prevention and good nutrition are seen as key parameters for reducing antimicrobial use. However, little consideration has been given to how metabolic diseases may influence the use of antimicrobials in humans and animals through limiting the prevalence and severity of infectious diseases. To quantify this relationship using the example of a common metabolic disease in dairy cows (subclinical ketosis, SCK), we constructed a stochastic model reporting the total quantity of curative antimicrobials for a given population with the prevalence of cows at risk for SCK. We considered the prevalence of SCK, the relative risk of the disease in cases of SCK compared to no SCK and the use of antimicrobials to treat SCK-induced infectious diseases. Reducing the percentage of cows at risk for SCK from 80% to 10% was associated with an average decrease in the use of antimicrobials of 11% (prevalence of SCK from 34% to 17%, respectively) or 25% (prevalence of SCK from 68% to 22%, respectively), depending on the relative risk to contract SCK if risk was present. For a large percentage of the cows at risk for SCK, using a preventive bolus of monensin reduced the use of curative antimicrobials to the same level that was observed when the percentage of cows at risk for SCK was low. The present work suggests similar approaches for obesity and diabetes.

减少抗菌药物使用已成为多国人类医学与兽医学的核心目标。医疗预防与优质营养被视作减少抗菌药物使用的关键影响因素，然而目前鲜有研究关注代谢疾病可通过抑制传染病的流行与严重程度，进而对人类与动物的抗菌药物使用产生何种影响。为以奶牛常见代谢疾病——亚临床酮病（subclinical ketosis, SCK）——为例量化这一关联，我们构建了一款随机模型，可针对特定奶牛群体，基于该群体中存在亚临床酮病风险的奶牛占比，输出其治疗用抗菌药物总使用量；该模型纳入了亚临床酮病的流行率、亚临床酮病患病组相较于无病组的相对发病风险，以及用于治疗亚临床酮病引发的传染性疾病的抗菌药物使用量三项核心变量。将存在亚临床酮病风险的奶牛占比从80%降至10%，可使抗菌药物使用量平均减少11%（对应亚临床酮病流行率分别从34%降至17%）或25%（对应亚临床酮病流行率分别从68%降至22%），具体降幅取决于存在风险时个体感染亚临床酮病的相对风险水平。当存在亚临床酮病风险的奶牛占比较高时，使用莫能菌素（monensin）预防性给药可使治疗用抗菌药物使用量降至与低风险奶牛占比场景下相当的水平。本研究提示，类似的研究思路可推广至肥胖症与糖尿病领域。