Fig 1.
Flow diagram for article selection.
Fig 2.
Map of the number of included articles by country.
N = 217 articles overall; some articles reported data from several countries.
Fig 3.
Distribution by year, continent and data type of the included articles.
n = number of articles (some articles had data for several categories). N = 217 articles overall.
Fig 4.
Pig-level seroprevalence distribution by health status and subtypes.
N = 164 studies, 271 entries.
Fig 5.
Distribution of the pig-level seroprevalence for avian subtypes.
N = 25 studies, 38 entries.
Table 1.
Number of swine seroprevalence studies and seroprevalence means for the different variables.
Table 2.
Final mixed-effects models for pig seroprevalence for M1, M2 and M3.
Fig 6.
Herd-level seroprevalence distribution by health status and subtypes.
N = 51 articles, 112 studies, 143 entries.
Table 3.
Number of the studies and herd seroprevalence means for the different variables.
Table 4.
Final mixed-effects models for herd seroprevalence for M1, M2 and M3.
Table 5.
Number of studies according to continent and ILI status.
Table 6.
Number of studies and means of detection and isolation rates for different variables (outbreaks are excluded).
Table 7.
Categories of variables significantly associated with influenza circulation.