Background: In cattle, many serotypes of Salmonella enterica are responsible for a wide variety of clinical manifestations, which can cause considerable economic loss. Some serotypes can cause cows to abort sporadically, such as the Dublin serotype. This study was carried out on different cattle farms in the Algiers region to determine the prevalence of Salmonella Dublin using bacteriological and immunological methods.Methodology: The prevalence of Salmonella was determined by bacteriological analysis in accordance with the reference method AFNOR NF U 47-100 on faecal samples collected from 184 cattle belonging to 19 different farms, and serotyping for S. Dublin. Immunological analysis by enzyme-linked immunosorbent assay (ELISA) for S. Dublin was carried out on milk samples collected from 91 cattle. A survey of case (n=5) and control (n=14) farms for comparative analysis was performed to demonstrate a link between abortion in cows and prevalence of S. Dublin with both bacteriological and immunological methods. Sensitivity, specificity, Cohen Kappa coefficient, McNemar test odds ratios, and confidence intervals were calculated using Winepiscope 2.0 and StatA 9.1 software,and p<0.05 was considered as statistically significant.Results: The bacteriological results showed a prevalence of 7.6% (95%CI: 3-10), for Salmonella and serotyping revealed a prevalence for S. Dublin of 2.7%. The immunological analysis of milk by the ELISA technique revealed a prevalence of 13.2% (95%CI: 5-20) for S. Dublin. The comparative study between immunological results from milk and bacteriological results from faeces for detecting S. Dublin  showed poor agreement between the two tests (k=0.25), with enzyme immunoassay being significantly more sensitive than the bacteriological test (p<0.05). The results of the survey did not demonstrate a clear association between bacteriological detection of S. Dublin in faeces and abortion in cows (OR=8.66, 95%CI: 0.58-130.12). However, with the immunological analysis of milk for S. Dublin, there was a significant positive association (OR=62.33, 95%CI: 2.13-18.22) between a positive antibody response to S. Dublin in milk and the presence of abortions on the farm.Conclusion: In view of these results, we can conclude that Salmonella infections should systematically feature in the differential diagnosis of abortions in dairy cattle in Algeria. Keywords: S. Dublin, cattle, faeces, milk, abortion, immunology, bacteriology, Algiers

Salmonella Dublin is a causative agent of a gastrointestinal bacterial infection prevalent in many cattle herds worldwide. Hence, the goal of this research was to evaluate the prevalence of Salmonella Dublin carriage in fecal and milk samples from dairy cattle from Algeria, and to investigate potential risk factors associated with the presence of S. Dublin antibodies. A total of 307 cows from 39 farms were analyzed in this study. Bacteriological and immunological methods were used to isolate and detect S. Dublin antibodies in feces and cow’s milk. Antimicrobial susceptibility testing was performed using the disc diffusion method. Logistic regression was used to study risk factors associated with S. Dublin antibodies. The bacteriological results showed the absence of S. Dublin and a prevalence of 0.97 % (3/307) (IC 95% 0 - 2.08)for S. Mbandaka. The immunological analysis of milk by the ELISA technique showed a prevalence of 36.33% (95% CI 30.44 - 42.22) for S. Dublin. Final multivariate regression models showed that the breed, the region and introduction of purchased cattle were associated with the presence of S. Dublin antibodies. This study is the first that reports the seroprevalence and risk factors associated with S. Dublin infection in Algeria and could be considered as a comparison point for further studies in Algeria.

Estimating the occurrence and distribution of infection and identification of risk factors remain key components in understanding the epizootiology and monitoring of peste des petits ruminants (PPR). This study was performed from 1997 to 2017, and included details of flocks with emergent infections, within-flock prevalence and risk association between PPR incidence and various flock management factors worldwide. In assessing the impact of PPR on livestock, outbreak incidence per country was used as an effective indicator of the intensity of the infection process. To decode the spatial and temporal dynamics of PPR outbreaks and clarify their relationship with geographical factors, systematic review and logistic regression analyses were conducted. The impact of climatic and socio-economic conditions on PPR was moderate and high, respectively. In the PPR risk analysis, infected PPR zones were 1.68 times more likely to spread the infection to goat farms than to sheep farms (relative risk: 1.69; odds ratio: 3.26). Moreover, during PPR occurrence, goats are more susceptible to infection than sheep. Through a regression model of outbreaks, a value of 960.67 outbreaks was calculated as the expected mean in 2018. The polynomial regression of PPR cases was followed by extrapolation (medium-sized smoothing of the three following points) to define the expected value in 2018. The probability of PPR could be effectively reduced by coordinating the work in disadvantaged countries with low-income farmers, and disease control must be prioritised to support alleviation of poverty, which has a negative impact on livestock production.