Efficacy of bacterial vaccines to prevent respiratory disease in swine: a systematic review and network meta-analysis.

Jan M Sargeant,Mark Reist,Barbara Wilhelm,Annette M O'Connor,Chong Wang,Katheryn Churchill,Bhumika Deb,Dapeng Hu,Charlotte B Winder,Terri L O'Sullivan,Kaitlyn Dawkins,Michele D Bergevin,Jennifer Dunn,Carly Moody

doi:10.1017/s1466252319000173

Jan M Sargeant, Mark Reist + Show 12 more

Open Access

https://doi.org/10.1017/s1466252319000173

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Abstract

A systematic review and network meta-analysis (MA) was conducted to address the question, 'What is the efficacy of bacterial vaccines to prevent respiratory disease in swine?' Four electronic databases and the grey literature were searched to identify clinical trials in healthy swine where at least one intervention arm was a commercially available vaccine for one or more bacterial pathogens associated with respiratory disease in swine, including Mycoplasma hyopneumoniae, Actinobacillus pleuropneumonia, Actinobacillus suis, Bordetella bronchiseptica, Pasteurella multocida, Stretococcus suis, Haemophils parasuis, and Mycoplasma hyorhinis. To be eligible, trials had to measure at least one of the following outcomes: incidence of clinical morbidity, mortality, lung lesions, or total antibiotic use. There were 179 eligible trials identified in 146 publications. Network MA was undertaken for morbidity, mortality, and the presence or absence of non-specific lung lesions. However, there was not a sufficient body of research evaluating the same interventions and outcomes to allow a meaningful synthesis of the comparative efficacy of the vaccines. To build this body of research, additional rigor in trial design and analysis, and detailed reporting of trial methods and results are warranted.

Highlights

Porcine respiratory disease complex (PRDC), which refers to respiratory disease caused by viruses or bacteria in swine, is the leading single cause of death during the nursery stage (47.3%), and is responsible for the majority of swine deaths during the grower–finisher production stage (75.1%) (USDA, 2016a)
Population (P): Healthy swine at any stage of production; Intervention (I): At least one intervention arm was a commercially available vaccine or a commercially produced injectable autogenous vaccine for bacterial pathogens associated with respiratory disease in swine, M. hyopneumoniae, A. pleuropneumonia, A. suis, Bordetella bronchiseptica, Pasteurella multocida, Stretococcus suis, Haemophils parasuis, and Mycoplasma hyorhinis; Comparator (C): Negative control group, sham treatment, saline placebo, or other alternative treatment; Outcomes (O): At least one of the following outcomes was evaluated: morbidity, mortality, or total antibiotic use; and Study design (S): Controlled trials with natural disease exposure
Several factors exacerbated the lack of data: there was little replication of each specific vaccine intervention in the existing literature with only one or two estimates contributing to most estimates; the metrics and measurements used for outcomes varied considerably across trials; and small sample sizes in trials investigating rare outcomes resulted in zero cells, rendering it difficult to calculate effect sizes

Summary

Introduction

Porcine respiratory disease complex (PRDC), which refers to respiratory disease caused by viruses or bacteria in swine, is the leading single cause of death during the nursery stage (47.3%), and is responsible for the majority of swine deaths during the grower–finisher production stage (75.1%) (USDA, 2016a). Swine respiratory disease is multifactorial, involving the interplay between environmental factors, host characteristics, and infectious disease agents (Opriessnig et al, 2011). Bacterial pathogens involved in respiratory disease may induce disease, or act as co-infections, making the animal more susceptible to other disease agents (Opriessnig et al, 2011). In the USA in 2012, the National Animal Health Monitoring System (NAHMS), which is run by the United States Department of Agriculture (USDA), reported that 59.9% of swine farm nursery sites used injectable antibiotics and 41.2% used water-soluble antibiotics to treat respiratory disease. The NAHMS reported that 72.8% of swine farm grower–finisher sites used injectable antibiotics and 64.2% used water-soluble antibiotics to treat respiratory disease (USDA, 2016b)

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