Quantitative Methods for the Prioritization of Foods Implicated in the Transmission of Hepatititis E to Humans in Italy

Hepatitis E is considered an emerging foodborne disease in Europe. Several types of foods are implicated in the transmission of the hepatitis E virus (HEV) to humans, in particular, pork and wild boar products. We developed a parametric stochastic model to estimate the risk of foodborne exposure to HEV in the Italian population and to rank the relevance of pork products with and without liver (PL and PNL, respectively), leafy vegetables, shellfish and raw milk in HEV transmission. Original data on HEV prevalence in different foods were obtained from a recent sampling study conducted in Italy at the retail level. Other data were obtained by publicly available sources and published literature. The model output indicated that the consumption of PNL was associated with the highest number of HEV infections in the population. However, the sensitivity analysis showed that slight variations in the consumption of PL led to an increase in the number of HEV infections much higher than PNL, suggesting that PL at an individual level are the top risky food. Uncertainty analysis underlined that further characterization of the pork products preparation and better assessment of consumption data at a regional level is critical information for fine-tuning the most risky implicated food items in Italy.

Risk Analysis of the Transmission Route for the African Swine Fever Virus in Mainland China

African swine fever first broke out in mainland China in August 2018 and has caused a substantial loss to China’s pig industry. Numerous investigations have confirmed that trades and movements of infected pigs and pork products, feeding pigs with contaminative swills, employees, and vehicles carrying the virus are the main transmission routes of the African swine fever virus (ASFV) in mainland China. However, which transmission route is more risky and what is the specific transmission map are still not clear enough. In this study, we crawl the data related to pig farms and slaughterhouses from Baidu Map by writing the Python language and then construct the pig transport network. Following this, we establish an ASFV transmission model over the network based on probabilistic discrete-time Markov chains. Furthermore, we propose spatiotemporal backward detection and forward transmission algorithms in semi-directed weighted networks. Through the simulation and calculation, the risk of transmission routes is analyzed, and the results reveal that the infection risk for employees and vehicles with the virus is the highest, followed by contaminative swills, and the transportation of pigs and pork products is the lowest; the most likely transmission map is deduced, and it is found that ASFV spreads from northeast China to southwest China and then to west; in addition, the infection risk in each province at different times is assessed, which can provide effective suggestions for the prevention and control of ASFV.

Deriving “potential target values” of PCDD/F in animal feed: the role of livestock at the interface between feed and food chain

Linking derivation of potential target values of PCDD/Fs in animal feed with risk assessment for consumer protection is a challenge when tolerable weekly intake (TWI) and transfer factors from feed to food are considered. Generally, maximum values for feed and food are set separately without considering the feed and the food producing animal as an important factor along the food chain from farm to fork. Levels of contaminants in feed can accumulate in animals and their products effect consumers at the end of the food chain. Hence, the process of setting legal maximum levels of contaminants should account for transfer from feed consumed by food producing animals into animal products for human consumption. Here, we calculated potential target values of PCDD/F in feed to ensure that animal products such as milk from dairy cows, eggs from laying hens and pork and pork products from fattening pigs are safe for human consumption. In our approach, we calculated potential target values of PCDD/Fs in animal feed using transfer factors for PCDD/F-TEQs from feed to milk fat, eggs fat, and fat in pork and pork products, taking into account the tolerable weekly intake derived by European Food Safety Authority. We assumed equal proportions of WHO-PCDD/F-TEQ and WHO-PCB-TEQ in feed. Potential target values of PCDD/F in feed are expressed as the quantity of toxicologically evaluated PCDD/Fs, expressed in WHO toxic equivalents (WHO2005-PCDD/F-TEQ) per kg feed with 12% moisture. In the current approach, derived values would be 10–54 times lower than the current legal maximum level of 0.75 ng WHO2005-PCDD/F-TEQ per kg feed (12% moisture), according to Directive 2002/32/EC as amended.

African Swine Fever Virus (ASFV): Biology, Genomics and Genotypes Circulating in Sub-Saharan Africa

African swine fever (ASF) is a highly infectious and fatal haemorrhagic disease of pigs that is caused by a complex DNA virus of the genus Asfivirus and Asfarviridae African suids family. The disease is among the most devastating pig diseases worldwide including Africa. Although the disease was first reported in the 19th century, it has continued to spread in Africa and other parts of the world. Globally, the rising demand for pork and concomitant increase in transboundary movements of pigs and pork products is likely to increase the risk of transmission and spread of ASF and pose a major challenge to the pig industry. Different genotypes of the ASF virus (ASFV) with varying virulence have been associated with different outbreaks in several countries in sub-Saharan Africa (SSA) and worldwide, and understanding genotype circulation will be important for ASF prevention and control strategies. ASFV genotypes unique to Africa have also been reported in SSA. This review briefly recounts the biology, genomics and genotyping of ASFV and provides an account of the different genotypes circulating in SSA. The review also highlights prevention, control and progress on vaccine development and identifies gaps in knowledge of ASFV genotype circulation in SSA that need to be addressed.

Evaluation of Growth Performance, Carcass Characteristics and Meat Quality of Shaziling Pigs and its Hybrids Crossbred with Berkshire Pigs

Background: The Chinese Shaziling pig is representative of good meat quality but has been scarcely utilized on commercial farms because of the unpleasing growth and carcass traits. Methods: The growth performance, carcass characteristics, meat quality and fatty acids profile were analyzed among (Berkshire × Shaziling) × (Berkshire × Shaziling) (BS × BS), BS × S, Shaziling (S × S) and S × BS pigs. Result: BS × BS pigs exhibited higher growth rate and superior carcass performance. Each breed possessed desirable meat quality, as evidenced by moderate pH, color score, IMF content and shear force value, among which the performance of S × BS pigs was prominent. Take account of the contents of SFAs, MUFAs, PUFAs and PUFAs/SFAs value, the eating quality of S × BS pigs was favorable and the meat of BS × BS pigs, by contrast, was helpful for human health with advanced nutritional value. In summary, BS × BS pigs is more effective for commercial development of Shaziling pigs and providing healthy pork products.

Prevalence, Molecular Characterization and Antimicrobial Susceptibility of Clostridioides difficile Isolated from Pig Carcasses and Pork Products in Central Italy

In the last decade, the incidence and severity of Clostridioides difficile infections (CDIs) in humans have been increasing and community-associated infections have been described. For these reasons, the interest in C. difficile in food and in food animals has increased, suggesting other possible sources of C. difficile acquisition. This study evaluated the presence of C. difficile on pig carcasses at the slaughterhouse and in pork products in Central Italy. The contamination rate on pig carcasses was 4/179 (2.3%). Regarding food samples, a total of 216 pork products were tested (74 raw meat preparations and 142 ready-to-eat food samples made by cured raw meat). The real-time PCR screening was positive for 1/74 raw meat preparation (1.35%) and for 1/142 ready-to-eat food samples (0.7%) C. difficile was isolated only from the raw meat preparation (pork sausage). All the isolated strains were toxigenic and susceptible to all the tested antibiotics. Strains isolated from carcass samples displayed A+B+CDTa+CDTb+ profile, were toxinotype IV and belonged to the same ribotype arbitrary named TV93, while the one isolated from food samples displayed A+B+CDTa-CDTb- profile and it was not possible to determine ribotype and toxinotype, because it was lost after freeze storage. It was concluded that the prevalence of C. difficile in the pork supply chain is very low.

PSX-A-27 Late-Breaking: The sulfatase mediated regeneration of androstenone from androstenone sulfate in boar fat

Boar taint is an off-odour or off-flavour that develops in heated pork products from entire male pigs, which is caused by the accumulation of androstenone, a sex pheromone, in the fat. However, we have previously demonstrated that a significant amount of androstenone undergoes sulfoconjugation upon synthesis in the Leydig cells and circulates in the plasma primarily as a polar steroid sulfate. Therefore, the purpose of this study was to determine if androstenone sulfate can be deconjugated within the adipose tissue by the sulfatase enzyme to return free androstenone and indirectly contribute to the development of boar taint. Backfat was obtained from 6-month-old terminal cross [Duroc x (Landrace x Yorkshire)] boars that had high (n=4) or low (n=4) sulfatase expression as determined by RT-PCR. Sulfatase activity in the fat was measured by quantifying the conversion of androstenone sulfate to free androstenone. Backfat was homogenized and the supernatant was incubated with [3H]-androstenone sulfate for 24-hours. Androstenone was extracted from the incubation using ether and steroid conversion was quantified using high-performance liquid chromatography (HPLC). Additionally, fat androstenone concentrations were quantified using an established HPLC procedure. Statistical analysis was conducted using a Student’s t-test. There was a significant difference (p=0.04) in the expression of sulfatase between the high (2.99 ± 0.67) and low (1.21 ± 0.19) sulfatase boars and the percentage of androstenone sulfate that was converted to free androstenone was proportional to the expression of sulfatase. Interestingly, the expression of sulfatase was positively related to the concentration of androstenone in the fat in boars with high sulfatase expression; however, this relation was not as strong in animals with low sulfatase expression. These preliminary results suggest that the development of boar taint may occur indirectly through the deconjugation of androstenone sulfate in boars with high expression of sulfatase in the fat.

Bilateral Sensorineural Hearing Loss and Septic Arthritis in Streptococcus suis Meningitis Patient: A Case Report

Background/aim: Bacterial meningitis is inflammation of the lining of the brain due to bacterial invasion of the CNS, especially in the cerebrospinal fluid in the subarachnoid and ventricles. Transmission of S. suis to humans occurs through direct contact with pigs and their processed products and consuming raw pork products. This case report reports a case of meningitis S. Suis with symptoms of decreased consciousness, bilateral sensorineural deafness and arthritis. Case: with a gradual loss of consciousness accompanied by headache and fever. The patient works in a pig slaughterhouse, and often consumes processed pork. The patient has decreased consciousness, fever, stiff neck, headache and septic arthritis. The patient found S.Suis type I in the blood, joint fluid culture (+), and CSF culture (+). The patient was treated with ceftriaxone according to CSF sensitivity culture test, dexamethasone and antipyretic/ analgesic as adjuvants. Patient recovered with improved genu arthritis and bilateral sensorineural hearing loss. Conclusion: Transmission of S. suis to humans occurs through direct contact with pork and its raw processed products. Clinical manifestations such as headache, fever, nausea and vomiting accompanied by signs of meningeal stimulation. The most prominent and frequently reported symptom is hearing loss. Definitive diagnosis is highly dependent on clinical examination, CSF culture and blood culture. Antibiotic therapy for 14 days, corticosteroids are the treatment of choice in bacterial meningitis. A frequently reported complication with sensorineural loss. Death is frequently reported in cases with systemic infection. Keywords: Bacterial meningitis, Streptococcus Suis, sensorineural hearing loss, arthritis septic, infected pigs and pork products.