A scoping review of Coxiella burnetii transmission models in ruminants

Coxiella burnetii is a highly infectious zoonotic bacterium that causes Q fever in humans and coxiellosis in animals. C. burnetii is mainly transmitted from infectious ruminants, particularly during parturition or abortions, to susceptible hosts through the inhalation of contaminated aerosols from the environment. Transmission models have the potential to aid the understanding of transmission dynamics and allow for various control measures to be evaluated. The objective of this PRISMA-ScR guided scoping review was to summarise the key characteristics of C. burnetii transmission models in ruminants and inform development of new or refined C. burnetii transmission models. Electronic databases searched included Web of Science, Scopus, PubMed and Google Scholar with pre-determined search terms. Data extracted from eligible records included the model context, type, structure and input parameters. Of 411 records identified, 14 models from 12 records published from 2010 through 2022 were eligible for data extraction. Models were predominately simulating transmission in cattle herds in France (n = 9), followed by goat herds in The Netherlands (n = 4), and a cattle herd from the UK (n = 1). The models that used field data mainly relied on a three-month observational study in French dairy cattle conducted in 2006. Variations in model structure and parameterisation existed due to the purpose of the study, model assumptions in the absence of observational and experimental data, and gaps in epidemiological knowledge of C. burnetii transmission dynamics in ruminants. Additional observational and experimental studies addressing these gaps in knowledge can help further inform and validate the design and parameterisation of C. burnetii models.