Fig. 1.
Boxplots for the number of Trichinella spp. larvae per gram (lpg) of three types different muscle tissues from 43 infected grey wolves. The line inside the box is the median. The top and bottom lines of the box are the 25th and 75th quartiles, respectively. The top and bottom whiskers mark the 5th and 95th quartiles, respectively. The dots represent outliers. Statistically significant differences with P-value < 0.05 are marked with asterisks
Fig. 2.
Boxplots for the number of Trichinella spp. larvae per gram (lpg) of three types different muscle tissues divided into T. britovi and T. spiralis from 23 and 20 infected grey wolves, respectively. The line inside the box is the median. The top and bottom lines of the box are the 25th and 75th quartiles, respectively. The top and bottom whiskers mark the 5th and 95th quartiles, respectively. The dots represent outliers. Statistically significant differences with P < 0.05 are marked with asterisks
Table 1.
Sensitivities of the detection two species of Trichinella and the larvae burden (number larvae per gram - lpg) in three muscle tissues collected from 43 infected grey wolves
| Type of muscle | Trichinella britovi cases | Trichinella spiralis cases | ||||
|---|---|---|---|---|---|---|
| n/N (%)a | Mean number of larvae per g (95% CIb) | χ2 (P)c | n/N (%) | Mean number of larvae per g (95% CI) | χ2 (P)c | |
| Forelimb | 21/23 (91.3) | 0.48 (0.24–0.86) | 19/20 (95.0) | 0.42 (0.18–0.83) | ||
| Diaphragm | 19/23 (82.6) | 0.26 (0.1–0.57) | 4.9 (0.08) | 15/20 (75.0) | 0.2 (0.05–0.51) | 8.3 (0.02) |
| Tongue | 13/17d (76.5) | 0.53 (0.24–1.0) | 12/16e (75.0) | 0.71 (0.36–1.23) | ||
Fig. 3.
Distribution of wolves included in the study. Red dot – T. spiralis-positive grey wolf; green dot – T. britovi-positive grey wolf; yellow square – Trichinella-negative grey wolf
Fig. 4.
Boxplots for the number of Trichinella spp. larvae per gram (lpg) of three types different muscle tissues in relation to the age of wolves. The line inside the box is the median. The top and bottom lines of the box are the 25th and 75th quartiles, respectively. The top and bottom whiskers mark 5th and 95th quartiles, respectively. The dots represent data outliers. No statistically significant differences with P-value < 0.05 were found
Table 2.
Descriptive statistics of Trichinella prevalence among grey wolves in the study
| Variable | Trichinella spp. prevalence | T. britovi prevalence | T. spiralis prevalence | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/Na | % (95% CI)b | χ2 (P)c | n/Na | % (95% CI)b,d | χ2 (P)c | n/Na | % (95% CI)b,d | χ2 (P-value)c | |
| Origin (province) | 30.6 (0.002) | 23.9 (0.02) | 31.7 (0.002) | ||||||
| Lubelskie | 0/3 | 0 (0–70.8) | 0/3 | - | 0/3 | - | |||
| Lubuskie | 2/2 | 100 (15.8–100) | 1/2 | 50 (1.2–98.7) | 1/2 | 50 (1.2–98.7) | |||
| Łódzkie | 0/2 | 0 (0–84.2) | 0/1 | - | 0/1 | - | |||
| Małopolskie | 1/2 | 50.0 (12.6–98.7) | 1/2 | 50 (1.2–98.7) | 0/2 | - | |||
| Mazowieckie | 0/1 | 0 (0–97.5) | 0/1 | - | 0/1 | - | |||
| Podkarpackie | 4/5 | 80.0 (28.3–99.5) | 4/5 | 80.0 (28.3–99.5) | 0/5 | - | |||
| Podlaskie | 8/17 | 47.0 (23.0–72.2) | 9/17 | 47.0 (23.0–72.2) | 0/17 | - | |||
| Pomorskie | 13/21 | 62.0 (38.4–81.9) | 4/21 | 14.3 (3.0–36.3) | 9/21 | 47.6 (25.7–70.2) | |||
| Śląskie | 1/4 | 25.0 (0.6–80.6) | 1/4 | 25.0 (0.6–80.6) | 0/4 | - | |||
| Świętokrzyskie | 2/8 | 25.0 (3.2–65.1) | 1/8 | 12.5 (0.3–52.6) | 1/8 | 12.5 (0.3–52.6) | |||
| Warmińsko-mazurskie | 1/2 | 50.0 (1.2–98.7) | 1/2 | 50 (1.2–98.7) | 0/2 | - | |||
| Wielkopolskie | 0/14 | 0 (0.0–23.2) | 0/14 | - | 0/14 | - | |||
| Zachodnio-pomorskie | 11/15 | 73.3 (44.9–92.2) | 2/15 | 13.3 (4.3–48.0) | 8/15 | 53.3 (26.6–78.7) | |||
| Sex | 1.9 (0.2) | 0.01 (0.9) | 0.2 (0.7) | ||||||
| Female | 20/46 | 43.5 (29.9–58.9) | 11/46 | 23.9 (12.6–38.8) | 9/46 | 19.6 (9.3–33.9) | |||
| Male | 23/48 | 47.9 (33.3–62.8) | 12/48 | 25.0 (13.6–39.6) | 11/48 | 22.9 (12.0–37.3) | |||
| Age group | 4.5 (0.2) | 1.8 (0.6) | 4.7 (0.2) | ||||||
| Pups | 1/5 | 20.0 (0.5–71.6) | 0/5 | 0 (0.0-52.2) | 1/5 | 20.0 (0.5-71.6) | |||
| Yearlings | 4/10 | 40.0 (12.1–73.8) | 3/10 | 30.0 (6.7–65.2) | 1/10 | 10.0 (0.2–44.5) | |||
| Younger adults | 19/46 | 41.3 (27.0–56.8) | 10/46 | 21.7 (10.9–36.4) | 9/46 | 19.6 (9.3–33.9) | |||
| Older adults | 6/8 | 75.0 (34.9–96.8) | 2/8 | 25.0 (3.2–65.1) | 4/8 | 50.0 (15.7–84.3) | |||
| Body mass class | 1.9 (0.4) | 0.9 (0.8) | 1.6 (0.4) | ||||||
| Lower (14–25 kg) | 7/22 | 31.8 (13.8–54.9) | 5/22 | 22.7 (7.8–45.4) | 2/22 | 9.1 (1.1–29.2) | |||
| Medium (26–41 kg) | 19/43 | 44.2 (29.1–60.1) | 10/43 | 23.2 (11.8–38.6) | 9/43 | 20.9 (10.0–36.0) | |||
| Higher (42–57 kg) | 10/19 | 52.6 (28.9–75.5) | 6/19 | 31.6 (12.6–56.6) | 4/19 | 21.0 (6.0–45.6) | |||
Table 3.
Summary of Trichinella spp. prevalence reports in wolves in North America, Asia and Europe by country, period, parasite species assigned and sample type
| Country (region) | Source (Reference) | Sampling period | Sample size | Trichinella spp. prevalence (%) | Trichinella speciesa | Tissueb |
|---|---|---|---|---|---|---|
| Finland | (1) | 1995–2005 | 102 | 39.2 | Tn (Tb, Ts) | m/d/fl |
| Finland | (53) | 2011–2013 | 85 | 34.1 | Tn (Tb, Ts) | no data |
| Finland | (52) | 1996–1998 | 18 | 33.0 | Tn, Tb | no data |
| Sweden | (40) | 2014–2019 | 197 | 5.6 | Tn, Tb | no data |
| Latvia | (22) | 2010–2014 | 23 | 100.0 | Tb | fl |
| Latvia | (6) | 2003–2008 | no data | 69.0 | no data | no data |
| Latvia | (7) | 2010–2012 | 8 | 69.7 | no data | m |
| Estonia | (29) | 1992–1999 | 34 | 79.4 | Tn, Tb | m |
| Romania (Carpathians) | (16) | 2000–2005 | 35 | 31.0 | Tb | m |
| Romania (Central) | (25) | 1991 | 399 | 30.5 | Tb | no data |
| Romania (Transylvania) | (25) | 1999–2002 | 7 | 71.4 | Tb | no data |
| Romania (Transylvania) | (25) | 2014–2015 | 3 | 66.7 | Tb | no data |
| USA and Canada | (37) | 2001–2013 | 244 | 51.0 | T6, Tn | tg |
| Canada (North) and USA | (54) | 2022 | no data | 13–52 | T6, Tn | no data |
| Greenland | (54) | no data | no data | 50.0 | T6, Tn | no data |
| Estonia | (54) | 1992–1996 | no data | 75–79 | T6, Tn | no data |
| Estonia | (54) | 1999 | no data | 63.20 | T6, Tn | no data |
| Finland, Norway, Russia (Kola Peninsula), Sweden | (54) | no data | no data | 32–39 | T6, Tn | no data |
| Russia | (54) | no data | no data | 10–65 | T6, Tn | no data |
| Russia | (60) | 1998–2000 | 82 | 97.50 | Tn, Tb | fl |
| Russia | (20) | 1998–2000 | 75 | 97.30 | Tn, Tbc | fl |
| Serbia | (81) | 2009–2010 | 116 | 46.50 | Tb, Ts | m |
| Serbia, Bosnia and Herzegovina, Macedonia | (74) | 2006–2013 | 116 | 46.5 | Tb | tg |
| Serbia | (74) | 2011–2022 | 49.50 | Tb | no data | |
| Bosnia and Herzegovina | (55) | 2013–2023 | 36 | 38.89 | Tb | m |
| Canada (Alberta) | (27) | 1975–1977 | 217 | 5.50 | no data | tg, m, d |
| Canada (North) | (38) | 2001–2015 | 81 | 62.00 | no data | m, tg |
| Kazakhstan | (75) | 2020–2023 | 83 | 20.50 | Tn | m, d |
| Kazakhstan | (2) | 2013–2023 | 98 | 20.40 | no data | m |
| Poland | (51) | 1999–2007 | 10 | 40.0 | Tb | no data |
| Poland | (10) | 1999–2015 | 21 | 54.50 | Tb | m, d, fl |
| Poland (Carpathians) | (18) | 1996–2004 | 6 | 50.00 | Tb | no data |
| Italy | (24) | 2008–2012 | 67 | 8.9 | Tb | m |
| Italy | (4) | 2004–2014 | 218 | 27.1 | Tb | m |
| Italy | (71) | 1987–1993 | 48 | 19.0 | Tb | d |
| Italy | (69) | 1991–1993 | 25 | 28.0 | Tb | d, fl |
| Italy | (61) | 1985–1995 | 81 | 31.0 | Tb | m |
| Italy | (3) | 2015–2020 | 213 | 28.0 | Tb | d, fl |
| Italy (Western Alps) | (43) | 2017–2022 | 130 | 11.53 | Tb | d |
| Slovakia (Tatras) | (28) | 2005–2006 | 4 | 0 | no data | d, fl |
| Spain | (67) | 1996–1999 | 47 | 12.8 | Tb | m |
| Croatia | (8) | 1996–2007 | 67 | 31.0 | Tb, Ts | m |
| Germany | (39) | 2007–2014 | 53 | 3.70 | Tb, Ts | d |
| Germany | (30) | 2013–2023 | 545 | 4.04 | Tb, Ts | d |