Fig. 1.
Voivodeship map of Poland. Grey shading indicates the regions of origin of cattle tested for anti–influenza D virus antibodies. The number of cattle tested and corresponding seroprevalence are provided for each region
Fig. 2.
Scatter plots of influenza D virus antibody titres obtained by haemagglutination inhibition (HI) assay and virus neutralisation (VN) test. The positive slope (1.6558) suggests that an increase in HI titre was associated with a corresponding increase in VN titre
Fig. 3.
Box plot diagrams of the distribution of haemagglutinin inhibition (HI) and virus neutralisation (VN) titres in three age groups of cattle (A) and with regard to the origin of the animals tested (B); only positive HI and VN titres were considered. The whiskers are the 25th and 75th quartiles. The lines across the middle of the boxes identify the median values of titres
Table 1.
Analysis of influenza D virus seroprevalence in relation to cattle age, sex and voivodeship of origin
| Variable | Seroprevalence in cattle in haemagglutination inhibition assay | |||
|---|---|---|---|---|
| n/N1 | % (95% CI2) | Chi-squared | P-value | |
| Age group | ||||
| Calves (≤1 year old) | 11/98 | 11.2 (5.7–19.2) | 55.2 | <0.001 |
| young adults 2–4 years old) | 202/381 | 53.0 (47.9–58.1) | ||
| older adults (≥5 years old) | 128/276 | 46.4 (40.4–52.4) | ||
| Sex | ||||
| female | 71/283 | 25.1 (20.1–30.6) | 2.5 | <0.1 |
| male | 4/32 | 12.5 (3.5–29.0) | ||
| missing data | 266/440 | 60.4 (55.7–65.0) | ||
| Voivodeship | ||||
| Dolnośląskie | 30/169 | 17.8 (12.3–24.3) | 123.5 | <0.001 |
| Lubelskie | 44/105 | 41.9 (32.2–51.9) | ||
| Podkarpackie | 1/41 | 2.4 (0.1–12.8) | ||
| Wielkopolskie | 266/440 | 60.4 (55.7–65.0) | ||