title: Integrating serological and genetic data to quantify cross-species transmission: brucellosis as a case study.
abstract: Epidemiological data are often fragmented, partial, and/or ambiguous and unable to yield the desired level of understanding of infectious disease dynamics to adequately inform control measures. Here, we show how the information contained in widely available serology data can be enhanced by integration with less common type-specific data, to improve the understanding of the transmission dynamics of complex multi-species pathogens and host communities. Using brucellosis in northern Tanzania as a case study, we developed a latent process model based on serology data obtained from the field, to reconstruct Brucella transmission dynamics. We were able to identify sheep and goats as a more likely source of human and animal infection than cattle; however, the highly cross-reactive nature of Brucella spp. meant that it was not possible to determine which Brucella species (B. abortus or B. melitensis) is responsible for human infection. We extended our model to integrate simulated serology and typing data, and show that although serology alone can identify the host source of human infection under certain restrictive conditions, the integration of even small amounts (5%) of typing data can improve understanding of complex epidemiological dynamics. We show that data integration will often be essential when more than one pathogen is present and when the distinction between exposed and infectious individuals is not clear from serology data. With increasing epidemiological complexity, serology data become less informative. However, we show how this weakness can be mitigated by integrating such data with typing data, thereby enhancing the inference from these data and improving understanding of the underlying dynamics.
authors.affiliation: Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Mafalda
authors.initials: M
authors.lastname: Viana
authors.affiliation: Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha, Tanzania.
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Shirima
authors.affiliation: National Institute of Medical Research, PO Box 9653, 11101 Dar es Salaam, Tanzania.
authors.forename: Kunda S
authors.initials: KS
authors.lastname: John
authors.affiliation: Moredun Research Institute, Pentlands Science Park. Penicuik, Midlothian EH26 0PZ, UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Fitzpatrick
authors.affiliation: Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, P.O. Box 3021, Morogoro, Tanzania.
authors.forename: Rudovick R
authors.initials: RR
authors.lastname: Kazwala
authors.affiliation: Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha, Tanzania.
authors.forename: Joram J
authors.initials: JJ
authors.lastname: Buza
authors.affiliation: Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Cleaveland
authors.affiliation: Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Haydon
authors.affiliation: Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: Jo E B
authors.initials: JEB
authors.lastname: Halliday
mesh_terms: D000818:Animals; D002002:Brucella / Q000145:classification / Q000235:genetics*; D002006:Brucellosis / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology / Q000635:transmission; D003198:Computer Simulation; D015511:Goat Diseases / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D006041:Goats; D006801:Humans; D008954:Models, Biological; D065288:Serogroup; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D013636:Tanzania / Q000453:epidemiology; D015047:Zoonoses / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission
keywords: Bayesian modelling; brucellosis; data integration; epidemiological modelling; genetics; serology; state-space models