Global prevalence of Porcine Astrovirus: A systematic review and meta-analysis

Porcine astrovirus (PAstV) is a widespread enteric virus in pigs, often co-infecting with other enteric viruses and contributing to diarrhea, leading to significant economic losses in the global swine industry. This study aims to identify the factors influencing PAstV prevalence by conducting a statistical meta-analysis of global data and evaluating heterogeneity across various subgroups. A systematic literature search was performed across PubMed, Web of Science, CNKI, Wanfang, and VIP databases, covering studies from the inception of the databases up to December 2023. A random-effects model was employed to estimate the global pooled prevalence of PAstV infection, and subgroup analyses were performed to evaluate the impact of different continents, years, detection methods, and sample types on the prevalence. Publication bias was assessed using a funnel plot and Egger's test. A total of 45 studies from 10 countries across three continents, involving 376 articles, were included in the meta-analysis. The global pooled prevalence of PAstV infection was found to be 28.19 % (95 % CI, 21.94 %-34.89 %). Subgroup analysis indicated significant differences in PAstV prevalence across continents, with Asia at 26.25 % (95 % CI, 25.41 %-27.09 %), Europe at 36.19 % (95 % CI, 34.09 %-38.33 %), and North America at 63.24 %. The prevalence of PAstV was highest between 2012 and 2014 (49.86 %, 95 % CI, 47.21 %-52.51 %), followed by a decreasing trend that stabilized below 30 % from 2015 to 2023. The analysis showed no significant influence of detection methods on PAstV prevalence. However, the prevalence in non-fecal samples (43.09 %, 95 % CI: 41.05 %-45.15 %) was significantly higher than in fecal samples (22.92 %, 95 % CI: 21.87 %-23.99 %). Additionally, the prevalence of PAstV in asymptomatic pigs (36.71 %, 95 % CI, 34.97 %-38.48 %) exceeded that in diarrheic pigs (28.18 %, 95 % CI, 26.94 %-29.44 %). Among different age groups, nursery pigs(6-10 weeks) exhibited the highest infection rate (63.19 %, 95 % CI, 58.45 %-67.75 %), followed by weaning pigs(3-6 weeks) (60.00 %, 95 % CI, 56.48 %-63.45 %), finisher pigs(>10 weeks) (49.89 %, 95 % CI, 46.59 %-53.19 %), sows (35.33 %, 95 % CI, 31.45 %-39.37 %), with suckling pigs(0-3 weeks) showing the lowest rate (31.93 %, 95 % CI, 30.23 %-33.68 %). This study highlights the widespread nature of PAstV infection in pig populations globally, with notable variations in prevalence across regions, years, and sample types. The high prevalence of asymptomatic infections underscores the need for enhanced PAstV surveillance and control measures.