Table 1. Study areas (geographical units A-E) and their characteristics.
| Unit | Wild boar density a | Density of outdoor piggeries b | Predominant Climate | Prevalence of Mhyop d | Predominantly detected DNA target e | Outbreaks of enzootic pneumonia (year of last outbreak) f | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air temperature | Humidity | |||||||||||
| min.-max. (°C) | OD c | Precipitation (mm) | Relative humidity (%) | OD c | % | 95% CI | Target | Detection frequency(%) | ||||
| A | very high | very low | 6.2–15.2 | warm | 100.1 | 73 | dry | 54.6 | 46.0–63.1 | ABC/REP | 71.0 | 0 (2007) |
| B | medium | low | 3.9–13.9 | cold | 966–1118 | 76–79 | humid to equilibrate | 35.4 | 29.1–42.1 | ABC/REP | 53.8 | 5 (2013) |
| C | low | high | 4.7–14.1 | mild to cold | 983–1123 | 76.5–77 | equilibrated | 20.3 | 11.2–32.2 | ABC/REP | 53.8 | 4 (2011) |
| D | medium | medium | 4.1–12.4 | mild | 1085 | 78.5 | equilibrated | 35.6 | 24.7–47.6 | ABC/REP | 46.1 | 7 (2012) |
| E | medium | very low | 6.7–24.5 | warm | 1542 | 69.6 | disequilibrated (dry and humid seasons and or areas) | 8.4 | 5.8–11.9 | ABC only | 63.3 | 0 |
a Wild boar density index categories correspond to the following estimations: very high = 1.65 dead individuals/km2 per year, medium = 0.40–0.54 and low = 0.04.
b Density of outdoor piggeries correspond to the following estimations: high = 0.31 outdoor piggeries/km2, medium = 0.19, low = 0.08 and very low = 0.01.
c OD = Official definition. The climatic characteristics of the five geographical units are based on measurements of the Swiss Federal Office of the Environment, Transport, Energy and Communication, Federal Meteorology and Climatology Department, Federal Agronomy Office.
d Prevalence (%) and 95% confidence interval (95% CI) of Mycoplasma hyopneumoniae in wild boar nasal swabs (PCR analysis) in 2011–2013 (this study).
e predominant M. hyopneumoniae type (ABC only, REP only, ABC/REP).
f Number of recorded outbreaks of enzootic pneumonia in domestic pigs in 2010–2013.