Comparative efficacy of antimicrobials for treatment of clinical mastitis in lactating dairy cattle: a systematic review and network meta-analysis

Abstract

A systematic review and network meta-analysis were conducted to assess the relative efficacy of antimicrobial therapy for clinical mastitis in lactating dairy cattle. Controlled trials in lactating dairy cattle with natural disease exposure were eligible if they compared an antimicrobial treatment to a non-treated control, placebo, or a different antimicrobial, for the treatment of clinical mastitis, and assessed clinical or bacteriologic cure. Potential for bias was assessed using a modified Cochrane Risk of Bias 2.0 tool. From 14775 initially identified records, 54 trials were assessed as eligible. Networks were established for bacteriologic cure by bacterial species group, and clinical cure. Disparate networks among bacteriologic cures precluded meta-analysis. Network meta-analysis was conducted for trials assessing clinical cure, but lack of precision of point estimates resulted in wide credibility intervals for all treatments, with no definitive conclusions regarding relative efficacy. Consideration of network geometry can inform future research to increase the utility of current and previous work. Replication of intervention arms and consideration of connection to existing networks would improve the future ability to determine relative efficacy. Challenges in the evaluation of bias in primary research stemmed from a lack of reporting. Consideration of reporting guidelines would also improve the utility of future research.

What Is Success? A Narrative Review of Research Evaluating Outcomes of Antibiotics Used for Treatment of Clinical Mastitis

“…While a systematic review or meta-analysis is the ideal method to summarize and compare studies, the wide diversity of study designs, variation in outcomes, differences in pathogens and treatment protocols included in mastitis trials creates a challenging situation relative to use of this method. The limited number of trials evaluating antimicrobial therapy used for treatment of bovine mastitis has been previously noted by authors of a systematic review who were unable to identify sufficient papers to establish networks to evaluate bacteriological cure and were unable to reach a conclusion about clinical efficacy of antimicrobials (59). Studies included in this review were conducted in the U.S. or Canada (n = 9), European Union (n = 8), New Zealand (n = 6), Brazil (n = 2) and Mexico (n = 1).…”

Antibiotikaresistenz von E. coli aus Rinderpopulationen in Deutschland

“…Dies überrascht wenig, da die häufigste antibiotische Behandlung bei Milchkühen die der Mastitis ist. Die meisten eingesetzten Mastitispräparate enthalten β-Laktam-Antibiotika, also Penizilline und Cephalosporine 20 , 21 . Der häufige Einsatz von Cephalosporinen in der Mastitistherapie und als Trockensteller 20 , 22 könnte auch zu den relativ hohen RR der Isolate aus Mastitisproben gegenüber Cefotaxim beigetragen haben, die von anderen Studien aus Deutschland bestätigt werden 23 .…”

Editorial: Systematic reviews reveal a need for more, better data to inform antimicrobial stewardship practices in animal agriculture

“…Articles in this special issue include scoping reviews of systematic reviews in animal health (Vriezen et al, 2019a) and of non-antibiotic approaches to reduce the need for antibiotic treatments in beef and veal production (Wisener et al, 2019). The systematic reviews with meta-analyses or network meta-analyses include an assessment of the efficacy of vaccines and injectable antibiotics administered on arrival to control respiratory disease in feedlot cattle (O'Connor et al, 2019a(O'Connor et al, , 2019b; the efficacy of teat sealants, antibiotics at dry off, selective dry cow treatment to reduce the incidence of mastitis and intra-mammary infection in early lactation, and the efficacy of antibiotics to treat clinical mastitis in dairy cattle (Winder et al, 2019a(Winder et al, , 2019b(Winder et al, , 2019c(Winder et al, , 2019d; the comparative efficacy of litter type for preventing illness in broiler chickens (Sargeant et al, 2019a); the efficacy of antibiotics to prevent colibacillosis in broiler chickens (Sargeant et al, 2019b); and the efficacy of bacterial vaccines and of preventive antibiotics to prevent respiratory disease in swine (Sargeant et al, 2019c(Sargeant et al, , 2019d. Finally, an evaluation of the methodological quality of systematic reviews and meta-analyses evaluating preventive antibiotics or management to reduce disease in livestock species is included (Vriezen et al, 2019b).…”

“…In some instances, intervention comparisons were only evaluated in a single trial, without a common intervention connecting that trial to another in the literature. The mastitis treatment review (Winder et al ., 2019 d ), beef vaccine review (O'Connor et al ., 2019 a ), and poultry litter review (Sargeant et al ., 2019 a ) provide good examples of these disparate networks. The value of connected networks of evidence can be seen by contrasting the ability to reach conclusions for those reviews compared to the beef feedlot antibiotic review (O'Connor et al ., 2019 b ), where the interventions were very well connected.…”