Mechanical transmission of African swine fever virus (ASFV) has been investigated on few occasions, with Stomoxys calcitrans experimentally shown to transmit ASFV which was detected in various body parts for 3 days after infection. However, up to date, there is no field evidence demonstrating the presence of viral DNA in blood-feeding arthropods. For this purpose, 30 pig farms from Romania where ASF was confirmed were selected for sampling according to a risk scoring system. In 9 farms, pigs were still present at the time of sampling, whereas on the other outbreak farms pigs were culled maximum 24h before. Trapping of vectors was done using standard entomological methods and mainly Culicoides spp. and S. calcitrans were collected. After the morphological identification of insects, they were pooled and tested for the presence of ASFV DNA using PCR tests. A total of 200 pools (119 from 20 farms with Culicoides and 81 from 15 farms with S. calcitrans) were prepared. 50.5% of the pools were positive for ASFV DNA. The prevalence of infected pools was the highest in commercial farms. The proportion of ASFV DNA positive pools in S. calcitrans (62.96%) was significantly higher than in Culicoides spp. (42.02%). Positive pools were found in 55% of the locations for Culicoides spp. and in 86.7% for S. calcitrans. The prevalence was significantly higher in farms were sampling was done when pigs were still present compared to farms where the pigs were already culled. This study demonstrates that the most common vectors found around pig farms are Culicoides spp. and Stomoxys and the ASFV DNA can be detected in both groups with higher probability in commercial farms and if tested when pigs are present at the time of sampling. Despite the positive findings of ASFV DNA, the actual role in ASFV mechanical transmission remains to be clarified.

African swine fever (ASF) is a contagious viral disease of swine that causes significant economic damage. The summer peaks and river courses have triggered the hypothesis that vectors may be involved in the transmission of the virus. In temperate climates, insect numbers increase in the late summer. Low temperatures and frosts decrease the number of active insects. Their presence is strongly associated with the nearby wetlands or swamps around the farms. The aim of our study was to evaluate the risk factors associated with the presence of ASFV DNA in hematophagous dipterans and to analyze the relevance of Ct values obtained following RT-PCR analysis of the positive samples in ASF outbreaks in Romania, as an indication for the viral load. The current study included 99 pools of stable flies (Stomoxys calcitrans) and 296 pools of biting midges (Culicoides spp.), collected in June-September 2020, from 30 outbreaks of ASF in domestic swine from backyard farms (BF), type A farms (TAF), and commercial farms (CF). All extracted DNA was tested for the presence of the ASFV genome using a real-time PCR protocol. Ct values of 39.53 and below were considered as positive (min: 18.19; median: 31.41; max: 39.53). The blood meal source was identified in the hematophagous insects by using a PCR protocol targeting the mitochondrial gene cytochrome c oxidase subunit 1. Data were analyzed using R software v. 4.0.5. In total, 3,158 insects (S. calcitrans n = 198 and Culicoides n = 2960) were collected in 23 farms of the 30 outbreak farms. Ten species of biting midges were identified. The total number of insect pools showed significant differences according to the month of sampling, with a higher number of pools collected in August and September. Overall, 137 pools out of the 395 examined were positive for the presence of ASFV DNA. There was a higher viral DNA load in farms where pigs were present at the moment of sampling compared to farms where pigs were already culled, in S. calcitrans compared to Culicoides spp. and in CF and TAF compared to BF.

Identifying potentially carcinogenic substances in the environment represents the primary action step that should be taken in order for us to claim to have a healthy and safe agriculture. Unfortunately, this is not always the case and our foods and waters may not be as safe as we believe them to be. The present elaborate had the purpose of identifying possible carcinogenic contaminants, in a direct correlation with the culture environment -water source and soil, in Ilfov county, Romania. Water: 14 samples were collected from household wells, targeted for the analysis of various chemical and physical parameters, including nitrates, nitrites, pesticides, dioxins, furans, etc. The results have shown a scattered level of pollution with nitrates of the groundwater aquifers, due to the incorrect administration of fertilizers that has especially affected the individual wells from the investigated areas. Soil: 32 crop soil samples were harvested from the upper level (0-20cm, belonging to the same areas as the water samples. Various quantities of mineral nitrogen were determined, either as nitrates or as nitrites. No carcinogens, from the groundwater aquifers investigated, with sufficient levels to contaminate the soil and affect the agricultural products were identified. The analysed water is fit for agricultural irrigations, but is not to be used for human consumption. For soils, the extremely spread distribution of the nitrogen proves that the nitrogen based fertilizers are being used in an irrational manner, thus the danger for environment pollution and for the alteration of animal and human health. The presence of potentially toxic metals was also investigated, elements that, except for arsenic, turned out to be within normal limits.The investigated elements from the Berceni, Glina, Popeşti-Leordeni and Ulmi areas do not present any significant dangerous quantities which proved the fact that the local agricultural technology is functioning normally, producing vegetal and animal foods free of elements with a potentially carcinogenic effect. The rest of the investigated areas, respectively Buda, Bragadiru, Măgurele, Vidra and Copăceni, have shown the presence of potentially carcinogenic elements that exceed the normal limit, most likely based on an improperly implemented agricultural technology.

The finding of the most appropriate way to assess precisely the antivenom efficacy represents one of the major issues for antivenom standardization and success increasing of antivenom therapy. The efficacy of experimental Vipera ammodytes antivenom raised in sheep was determined using in vivo mouse lethality test, respectively, L-aminoacid oxidase, total proteinase and phospholipase A 2 antienzymatic effectiveness. The values gained for the antivenom potency depend on the method of measure. So, some of the most toxic venom proteins own phospholipase A 2 activity and provide the highest antivenom potency (lowest effective dose) values by antienzymatic assay method. This value is similar with total antiproteolytic antivenom potency value, but almost three times higher than value obtained by L-aminoacid oxidase (low toxic viper venom protein) antienzymatic assay method. KeywordsMedian effective dose, L-aminoacid oxidase, phospholipase A2History