|Gutema, Fanta - Addis Ababa University|
|Abdi, Reta - University Of Tennessee|
|De Zeutter, Lieven - Ghent University|
|Duchateau, Luc - Ghent University|
|Gabriël, Sarah - Ghent University|
Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2019
Publication Date: 4/9/2019
Citation: Gutema, F.D., Agga, G.E., Abdi, R.D., De Zeutter, L., Duchateau, L., Gabriël, S. 2019. Prevalence and serotype diversity of Salmonella in apparently healthy cattle: Systematic review and meta-analysis of published studies, 2000–2017. Frontiers in Veterinary Science. 6:102. https://doi.org/10.3389/fvets.2019.00102.
DOI: https://doi.org/10.3389/fvets.2019.00102 Interpretive Summary: Salmonellosis is a foodborne infection that is caused by bacteria belonging to genus Salmonella. Salmonellosis usually causes a self-limiting gastrointestinal disturbances in healthy people. However, in children and the immunosuppressed individuals it can cause a life threatening infection if left untreated. Cattle are carriers of Salmonella that can be shed through feces which can lead to carcass and milk contamination. People can acquire the infection through consumption of undercooked beef and milk. We estimated the global burden of Salmonella, and the diversity of its serotypes in cattle from 75 independently published studies representing 29 countries from six continents. Overall Salmonella detection was 9% with significant variation by continent. The level of Salmonella detection in cattle was 2% (Europe), 4% (Asia and Australia), 9% (Africa), 14% (South America) and 16% (North America). The observed variation by continent is possibly due to differences in the number of studies included in the analysis rather than actual differences. Among the top 10 serotypes identified, Salmonella Montevideo, Typhimurium, Anatum, Mbandaka and Newport belong to the World Health Organization’s list of the top 20 serotypes associated with human salmonellosis. The results indicate variations in the level of Salmonella carriage in cattle across the world, and the presence of diverse number of Salmonella serotypes associated with cattle production which can potentially cause infection in people if preventive and control measures are not implemented to ensure the safety of beef and milk.
Technical Abstract: Salmonellosis is a leading cause of foodborne illnesses in humans with cattle being one of the reservoirs for Salmonella. We estimated a pooled prevalence of Salmonella in apparently healthy cattle and examined serotype diversity through systematic review and meta-analysis of studies published between 2000 and 2017. Peer reviewed publications reporting the prevalence of Salmonella in cattle were searched through five electronic databases (PubMed, Google scholar, Agricola, Scopus, CAB direct) and through manual search. We obtained 71 publications with 75 datasets consisting a total of 52,766 animals examined and 5,010 Salmonella positive cattle from 29 countries in six continents (except from Antarctica). Pooled prevalence of Salmonella in cattle was 9% (95% confidence interval: 7–11%). Significantly high heterogeneity (I2 = 98.7%, P < 0.01) was observed among all studies as well as within continents. Prevalence varied from 2% (Europe) to 16% (North America). Overall, 143 different serotypes were reported with the most diverse serotypes being reported from Africa (76 different serotypes) followed by North America (49 serotypes). The 10 most frequently reported serotypes (Montevideo, Typhimurium, Kentucky,Meleagridis, Anatum, Cerro,Mbandaka, Muenster, Newport, and Senftenberg) accounted for 65% of the isolates for which specific serotype information was reported. Salmonella Montevideo and S. Dublin are the most frequently reported serotypes in North America and Europe, respectively, while S. Typhimurium was the most frequent in Africa, Asia and Australasia. Our results indicated variability both in the prevalence and serotype diversity of Salmonella in cattle across continents. Although all Salmonella serotypes are potentially pathogenic to humans, five (Montevideo, Typhimurium, Anatum, Mbandaka, and Newport) of the top 10 serotypes identified in this study are among the serotypes most commonly associated with clinical illnesses in humans.