Quantitative risk assessment of hepatitis E virus: modelling the occurrence of viraemic pigs and the presence of the virus in organs of food safety interest

Hepatitis E virus (HEV) is a zoonotic pathogen with consumption of pork and derived products identified in different countries as a risk factor for human exposure to HEV. Great efforts have been made to understand the dynamics of virus transmission within domestic swine populations through modelling. However, from a food safety prospective, it is critical to integrate the parameters involved in the transmission dynamics with those governing the actual presence of HEV in the bloodstream, the liver, gallbladder or faeces. To date, several aspects related to the pathogenesis of the disease are still unknown or characterized by significant levels of uncertainty, making this conjunction challenging. We used published serological data obtained from pigs in a farrow-to-finish farm to implement an Immune-Susceptible-Infected-Recovered (MSIR) model reproducing the on-farm dynamics that lead to the occurrence of viraemic pigs at slaughter. Expert opinion on the length of time infectious HEV can be detected in liver, gallbladder/bile and faeces after recovery from viraemic status were used to inform a stochastic model aimed at estimating the expected proportion of viraemic pigs, pigs with infectious HEV in liver, gallbladder/bile and faeces entering the slaughterhouse. To simulate the potential effect of on-farm mitigation strategies, we estimated the changes in outcomes of interest as a function of variations in the baseline transmission parameters. The model predicted a proportion of viraemic pigs entering the slaughterhouse of 13.8% while the proportions of, and ranged from 13.8% to 94.4%, 13.8% to 94.7% and from 25.3% to 30.8% respectively, due to the uncertainty surrounding the experts’ opinions. Variations in MSIR model’s parameters alert of the need to carefully consider the application of mitigation strategies aimed at delaying the decay of maternal immunity or the peak of the within herd transmission. When the rate of decay of maternal immunity and the transmission rate were decreased between 80% and 5% and 40% and 5% from the baseline values respectively, adverse effects on were observed. The model highlights the relevance of specific aspects in the pathogenesis of the disease from a food safety prospective and it was developed to be easily reproducible and updatable as soon as accurate data becomes available. As presented, the model can be directly connected to existing or future pig-related models to estimate the significance of the identified parameters on the risk of human exposure to HEV through consumption of pork products

Overview of Evidence of Antimicrobial Use and Antimicrobial Resistance in the Food Chain

Antimicrobial resistance (AMR) is a global health problem. Bacteria carrying resistance genes can be transmitted between humans, animals and the environment. There are concerns that the widespread use of antimicrobials in the food chain constitutes an important source of AMR in humans, but the extent of this transmission is not well understood. The aim of this review is to examine published evidence on the links between antimicrobial use (AMU) in the food chain and AMR in people and animals. The evidence showed a link between AMU in animals and the occurrence of resistance in these animals. However, evidence of the benefits of a reduction in AMU in animals on the prevalence of resistant bacteria in humans is scarce. The presence of resistant bacteria is documented in the human food supply chain, which presents a potential exposure route and risk to public health. Microbial genome sequencing has enabled the establishment of some links between the presence of resistant bacteria in humans and animals but, for some antimicrobials, no link could be established. Research and monitoring of AMU and AMR in an integrated manner is essential for a better understanding of the biology and the dynamics of antimicrobial resistance

Fatores ambientais que afetam a taxa se secagem no grão de milho (Zea mays L.) após a maturidade fisiológica.

Avaliou-se a influencia dos fatores ambientais na perda de agua pelo grao de milho (Zea mays L.), apos a maturidade fisiologica, em duas safras (1995/96 e 1997/98), em Botucatu, SP. O delineamento experimental utilizado foi o de blocos casualizados, com cinco e quatro repeticoes, nas respectivas safras. A avaliacao da perda de agua do grao, em nove cultivares (AG 122, AG 1051, AG 9012, AG 8012, C 901, XL 370, Z 8392, Z 8452 e Z 8501), iniciou-se apos todas as cultivares terem atingido a maturidade fisiologica. Posteriormente, a perda de agua pelos graos foi correlacionada com as medias dos elementos meteorologicos no periodo amostrado. Os resultados indicaram que graus-dia, radiacao solar global, insolacao e evaporacao do tanque classe A foram os elementos que mais se relacionaram com a perda de agua nos graos, com efeito quadratico e que ate aproximadamente 16% de teor de agua no grao estes fatores apresentaram efeito bem marcante

Crescimento e desenvolvimento da cultura do milho (Zea mays, L.) em semeadura tardia e sua relação com graus-dia e radiação solar global.

Foram avaliados a relação dos graus-dia e da radiação solar global com a altura da planta e com o aparecimento e comprimento das folhas em duas cultivares de milho (Zea mays L.), BR 206 (ciclo normal) e XL212 (ciclo superprecoce). O experimento foi conduzido, em condições de campo, com irrigação, na área experimental da EMBRAPA - Milho e Sorgo, em Sete Lagoas, MG. O delineamento experimental utilizado foi de blocos casualizados com 3 repetições. A semeadura foi feita na primeira quinzena de fevereiro de 1994. Diariamente, foram registrados numa estação meteorologica portátil eletrônica, as temperaturas máxima e mínima do ar e a radiação solar global. As mensurações de altura da planta, da qualidade de folhas com bainha (FCB) e sem bainha (FSB) expostas e do comprimento de folhas (CFB) foram feitas sempre nas mesmas plantas. O número total de folhas foi obtido por meio da soma de FCB + FSB. Utilizou-se 8oC como temperatura base para cálculo dos graus-dia. Os resultados mostraram que os graus-dia e a radiação solar global influenciam o desenvolvimento vegetativo do milho com a mesma magnitude, portanto, a utilização da regressão múltipla considerando os dois fatores, pode expressar de forma mais adequada o desenvolvimento vegetativo, sendo a equação polinomial de quarta ordem a que melhor representa o crescimento da cultura do milho

Cell genesis and dendritic plasticity: a neuroplastic pas de deux in the onset and remission from depression

Brain neuroplasticity is increasingly considered to be an important component of both the pathology and treatment of depressive spectrum disorders. Recent studies shed light on the relevance of hippocampal cell genesis and cortico-limbic dendritic plasticity for the development and remission from depressive-like behavior. However, the neurobiological significance of neuroplastic phenomena in this context is still controversial. Here we summarize recent developments in this topic and propose an integrative interpretation of data gathered so far

Doença Hepática Crónica Agudizada: Revisão da Experiência de um Centro Português de Referenciação

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by an acute deterioration of a patient with cirrhosis, frequently associated with multi-organ failure and a high short-term mortality rate. We present a retrospective study that aims to characterize the presentation, evolution, and outcome of patients diagnosed with ACLF at our center over the last 3 years, with a comparative analysis between the group of patients that had ACLF precipitated by infectious insults of bacterial origin and the group of those with ACLF triggered by a nonbacterial infectious insult; the incidence of acute kidney injury and its impact on the prognosis of ACLF was also analyzed. Twenty-nine patients were enrolled, the majority of them being male (89.6%), and the mean age was 53 years. Fourteen patients (48.3%) developed ACLF due to a bacterial infectious event, and 9 of them died (64.2%, overall mortality rate 31%); however, no statistical significance was found (p < 0.7). Of the remaining 15 patients (51.7%) with noninfectious triggers, 11 died (73.3%, overall mortality rate 37.9%); again there was no statistical significance (p < 0.7). Twenty-four patients (83%) developed acute kidney injury (overall mortality rate 65.5%; p < 0.022) at the 28-day and 90-day follow-up. Twelve patients had acute kidney injury requiring renal replacement therapy (41.37%; overall mortality rate 37.9%; p < 0.043). Hepatic transplant was performed in 3 patients, with a 100% survival at the 28-day and 90-day follow-up (p < 0.023). Higher grades of ACLF were associated with increased mortality (p < 0.02; overall mortality 69%). CONCLUSIONS: ACLF is a heterogeneous syndrome with a variety of precipitant factors and different grades of extrahepatic involvement. Most cases will have some degree of renal dysfunction, with an increased risk of mortality. Hepatic transplant is an efficient form of therapy for this syndrome.info:eu-repo/semantics/publishedVersio