After oral contamination, zearalenone (ZEN) is rapidly absorbed in organisms and can be detected in biological fluids. In this study, we investigated the metabolites of ZEN in the biological fluids of cows (blood, urine, milk). The study was divided into three stages: preparation (the first stage), investigation (the second stage), and final stage (the third stage). Samples of biological fluids were taken 7, 21, and 35 days after the beginning of the study. At the first stage and at the second stage, the cows were fed a total mixed ration (TMR) with naturally contaminated mycotoxin-zearalenone (500 ± 75 µg/kg). In the third stage, the cows were fed a TMR without mycotoxins. This study established that at the second stage, the alpha-zearalenol concentrations in the serum increased by 92% and the beta-zearalanol in the urine decreased by 48% compared to the first stage (p < 0.05). The beta-zearalenol and zearalanone concentrations in the urine were higher compared to that of the alpha-zearalenol. The zearalenone concentration in the milk at the second stage was 35% higher than at the first stage (p < 0.05). A significant negative correlation (r = –0.540) was determined between the beta-zearalenol and beta-zearalanol concentrations in the urine and the positive significant correlation (r = 0.826) between the beta-zearalanol and alpha-zearalenol concentrations in the serum (p < 0.05). During the study, it was determined that feeding cows for two weeks with a TMR without mycotoxins can reduce concentrations of alpha-zearalanol, beta-zearalenol, and beta-zearalanol in the biological fluids and can reduce the concentrations of ZEN in the milk, but does not reduce the concentration of zearalanone.

Background Rabies vaccination of wildlife carnivores is a powerful tool to prevent, control and eliminate rabies. The presence of neutralizing rabies antibodies in blood is considered a reliable indicator of adequate vaccination. The main purpose of the present study was to analyze the seroprevalence of specific antibodies in target populations of Lithuanian red fox (RF) and raccoon dog (RD) during the oral rabies vaccination (ORV) campaigns during the 2010–2019 period. Results Over the ten-year period, 7,261 RF and 2,146 RD sera samples were collected post-mortem in field conditions and tested using a commercial standardized enzyme-linked immunosorbent assay (ELISA) kit in Lithuania. In the ORV spring and autumn vaccination periods, 31.8% (20.3–43.4 95% CI – 95% confidence interval) and 31.7% (21.2–42.1 95% CI) of RF, and 34.1% (22.5–45.7 95% CI) and 34.7% (22.7–46.7 95% CI) of RD sera samples, respectively, were identified as ELISA-positive (seroconversion ≥ 0.5 EU/mL—Equivalent Units per Millilitre). The seroprevalence analysis in adult/ juvenile animal subpopulations indicated that 34.9% (27.2–42.5 95% CI) and 29.2% (20.3–37.9 95% CI) of RF, and 35.6% (25.2–46.0 95% CI) and 30.6% (20.2–40.9 95% CI) of RD sera samples, respectively, were identified as ELISA-positive (seroconversion ≥ 0.5 EU/mL). Statistically strong determinate correlations (r) between the serological results (pos.%) in RF adult/juvenile animal subpopulations (r = 0.937) and between RF and RD positive seroconvert (pos.%) sera samples during the spring vaccinations (r = 0.864) were demonstrated. In different ORV periods, 14–29% of RF and 7–25% of RD sera samples were identified as ELISA-negative (seroconversion < 0.5 EU/mL), but with low (0.125 < 0.49 EU/mL) antibody (Abs) titres. Conclusions The 2010–2019 ORV programme has been an effective tool in both RF and RD populations in Lithuania. The rabies-free status of Lithuania was self-declared in 2015 with only three rabies cases identified in buffer zones since then. The percentage of ELISA-positive serum samples (seroconversion ≥ 0.5 EU/mL) during the different periods of vaccination was similar in RF and RD populations—32% and 34% respectively. The identified seroconversion average of 21.5% in RF and 16% in RD sera samples were officially identified as ELISA-negative (seronversion < 0.5 EU/mL), but with low 0.125 < 0.49 EU/mL Abs titres. That low, but positive seroconversion participated in the formation of populations overall immune status and can influence the interpretation of oral vaccination efficacy.

No abstract

The incidence of rabies and vaccination against this disease in human and animal populations were investigated in Lithuania in 2006-2010. In the last five years, up to 7-10 thousand people in Lithuania suffered from the diseased animals every year. Dogs are the most common domestic animals that humans suffer from (in earlier years, about 70-80% every year); in 2006-2009, 23-30% of human victims were exposed to rabid dogs, whereas in 2010 only 1.92%. The exposed people were vaccinated with inactivated vaccine against rabies Verorab® (Sanofi Pasteur, France) and immunoglobulin Imogam®Rabies (Sanofi Pasteur, France). For about a year (2006)(2007) Favirab immunoglobulin (Sanofi Pasteur, France) has been used. This preventive method is applied to 60-70% of people exposed to potentially rabid animals every year. During the time frame of investigation only in 2007 a case of human rabies was reported in a person who had not been preventively vaccinated. That was a man who travelled in India and was bitten by a stray dog.Dogs, cats and cattle are the most common domestic animals responsible for transmission of human rabies, while red foxes and raccoon dogs are most common in the wild animal group. In the last five years, 9 554 domestic and wild animals were investigated for rabies. Among 2 980 samples taken from domestic animals and 6 574 samples from the wild ones, 16.77% and 35.39%, respectively, were positive. Since 2006 in Lithuania twice a year (in spring and autumn) wild animals are orally vaccinated using "Lysvulpen" vaccine (Bioveta, Czech Republic). In 2006-2010, 3 130 blood serum samples from wild animals were examined for efficiency of rabies oral vaccination (ORV). The greatest number of serologically positive samples was taken from red foxes and raccoon dogs: 57.55% and 50.00%, respectively. Systematic ORV is responsible for the rabies decline in animals. In 2010, rabies was reported in 13 Lithuanian districts: Ignalina, Šalčininkai, Zarasai, Širvintos, Molėtai, Vilnius, Varėna, Utena, Kaunas, Raseiniai, Skuodas, Panevėžys and Pasvalys. Vaccination against rabies is the main immunopreventive measure controlling the disease in animals.