Prevalence of bovine paratuberculosis in Chinese cattle populations: a meta-analysis

Abstract

Background: Bovine paratuberculosis is a chronic infectious disease of ruminants primarily caused by Mycobacterium avium subsp. paratuberculosis (MAP). It is essentially a chronic granulomatous enteritis characterized by intractable diarrhea, progressive lethargy, and thickening of the intestinal mucosa with the formation of crumpled pouches. Bovine paratuberculosis not only adversely affects milk production and the quality of dairy products but also poses a significant threat to the economic development of dairy farming and human food security. This systematic review and meta-analysis was conducted to assess the prevalence of MAP infection among cattle herds in mainland China.

Results: A total of 62 studies with data from 102,340 cattle in 24 provinces in China were selected after matching the assessment criteria. In China, the overall estimated prevalence of MAP infection in cattle was 8%(7727/102340). Interestingly, the MAP infection rate in cattle in southern China was estimated to be 2% (6/281), which was significantly lower compared with other regions of China, and the highest infection rate was 12% (1914/16008) in eastern China. MAP infection rates were related to age, average herd size, type of use, season, detection method, and sample type. Moreover, the MAP infection rate in cattle did not correlate with the publication date of the studies.

Conclusion: The analysis identified age, average herd size, type of use, and season as significant potential risk factors associated with PTB pool positivity. In addition, the detection method and sample type can also potentially affect the incidence of detected PTB.

Keywords: China; bovine paratuberculosis; cattle; meta-analysis; prevalence.

Figure 1

Flow diagram showing the selection of eligible studies. A total of 62 articles were obtained by screening the database in four processes: “Identification”, “Screening”, “Eligibility” and “Included”.

Figure 2

Funnel plot with pseudo 95% confidence interval limits for the examination of publication bias. A funnel plot is a scatter plot based on the effect size of each experimental study as the horizontal coordinate and the sample size as the vertical coordinate for each experimental study. At the top of the funnel plot and enriched towards the center are samples with high learning volume and high accuracy; at the bottom and scattered towards the periphery are samples with small learning volumes and low accuracy.

Figure 3

Forest plot of paratuberculosis pooled prevalence in cattle in China. The length of the horizontal line indicates the 95% confidence interval and the diamond indicates the summed effect.

Figure 4

Map of bovine infection with pooled paratuberculosis in China. The pattern of squares in the lower-left corner of the graph is sequentially decreasing in prevalence and data deficient. Data Deficient: Indicates that there were no epidemiological surveys of PTB in the province during the statistical year. The labelled data are: Province [(pooled prevalence) 95% Conf. Interval].