Economic aspects of food borne disease surveillance

The presence of food-borne disease in food systems creates direct and indirect economic impacts. These include the losses caused by the negative effects of disease itself when people are ill or die leading to reduced productivity, loss of income, and human suffering. In animal populations, similar losses occur when animals are ill or die leading to production losses and/or animal welfare issues. To avoid such losses, efforts to prevent, control or eradicate disease can be undertaken but in return also generate economic costs. Economic analyses in this context investigate how resources are allocated to activities and how to balance direct losses against expenditure to reduce the impact of disease

Impacto da pre-extração no processo de desconstrução de casca de E. globulus visando a produção de polissacarídeos

Mestrado em Engenharia QuímicaA biomassa florestal, como a casca de Eucalyptus globulus, é um sub-produto da indústria da pasta de papel cuja única utilização atual é a produção de energia. No entanto, devido à sua abundância e composição química que inclui maioritariamente polissacarídeos (essencialmente celulose e hemiceluloses) e lenhina, a casca tem vindo a ser estudada para a obtenção de frações ricas em polissacarídeos que têm diversas finalidades, como a sua conversão em soluções de açúcares simples. Contudo é necessário submeter os materiais lenhocelulósicos a pré-tratamentos ou desconstrução para melhorar o acesso dos polissacarídeos às enzimas, na hidrólise enzimática. A casca de E. globulus difere da madeira da mesma espécie essencialmente no seu elevado teor de extratáveis polares, nomeadamente compostos fenólicos, e material inorgânico. Estudos anteriores indicam que o cozimento kraft da casca requer condições de operação mais severas para atingir um grau de deslenhificação semelhante ao do cozimento da madeira. Verificaram-se também limitações à hidrólise enzimática da pasta de casca que não se encontram no caso da pasta de madeira da mesma espécie. O objetivo deste trabalho foi estudar o impacto da pré-extração da casca de E. globulus, segundo duas abordagens diferentes (uma com mistura etanol/água e outra com água), na desconstrução deste material lenhocelulósico por cozimento kraft e na hidrólise enzimática da pasta resultante, favorecendo a sua conversão em açúcares simples. Na pré-extração com etanol/água 81,5% dos extratáveis em etanol/tolueno presentes na casca foram removidos, enquanto que na abordagem com água removeram-se apenas 14,3%. Verificou-se que a pré-extração, em ambos os meios, não afetou significativamente o impacto do cozimento kraft nos polissacarídeos. No entanto, em termos da produção de açúcares simples, a hidrólise enzimática da pasta de casca previamente extraída com etanol/água produziu a solução final de açúcares mais concentrada, com 47,7 mg/mL, bem como a maior quantidade de açúcares redutores, 39,1 g, de entre as sequências de valorização estudadas. Esta pasta também apresentou a maior percentagem de conversão de polissacarídeos em açúcares, 71,7%, seguida da pasta de casca previamente extraída com água, 62,3%, relativamente à pasta de casca tal e qual, 50,8%, indicando que a pré-extração beneficia o processo de sacarificação. O balanço de massa global a cada sequência de valorização, permitiu concluir que a pré-extração com etanol/água, a 83ºC durante 264 minutos, seguida de cozimento kraft, com fator H 1114 e alcalinidade de 22%, apresenta o maior potencial de produção de açúcares, de cerca de 33 000 ton/ano considerando uma produção anual de casca de 100 000 ton numa fábrica de média dimensãoForest biomass, like Eucalyptus globulus bark, is a by-product of the pulp and paper industry whose current singular use is energy production. However, due to its availability and chemical composition, which includes mostly polysaccharides (essentially hemicelluloses and cellulose) and lignin, bark has been the subject of many studies regarding the production of polysaccharides enriched fractions that have many applications, like its conversion into simple sugar solutions. However, it’s necessary that the lignocellulosic materials undergo pre-treatments or deconstruction processes to improve the polysaccharides access towards the enzymes, in enzymatic hydrolysis. The E. globulus bark differs from wood due to its high content of polar extractives, mainly phenolic compounds, and inorganic material. Previous studies show that bark’s kraft pulping requires more severe pulping conditions in order to achieve the same degree of delignification as the E. globulus wood kraft pulping. There were also reported limitations in bark’s enzymatic hydrolysis that weren’t found in wood. The purpose of this work was to study the impact of E. globulus bark pre-extraction, with two different approaches (with the mixture of ethanol/water and with water), in its deconstruction by kraft pulping and in the enzymatic hydrolysis of the resulting pulp, benefitting its conversing into simple sugars. Regarding the removal of extractives during the pre-extraction, using ethanol/water 81,5% of the ethanol/toluene extractives in E. globulus bark were removed, while using water the removal of extractives was only 14,3%. In relation to kraft pulping it was noticed that the pre-extraction, in both approaches, didn’t have a significant impact on the removal of polysaccharides during pulping. However, regarding the production of simple sugars, the enzymatic hydrolysis of ethanol/water extracted bark pulp produced the most concentrated sugar solution, with 47,7 mg/mL, as well as the biggest quantity of reducing sugars, 39,1 mg, from among the studied valorisation sequences. In this way, the ethanol/water extracted bark pulp had the highest conversion of polysaccharides into sugars, 71,7%, followed by the water extracted bark pulp, 62,3%, in relation to the initial bark pulp, 50,8%, indicating that the pre-extraction benefits the scarification process. Through the global mass balance of each process sequence it was concluded that the ethanol/water pre-extraction, at 83ºC for 264 minutes, followed by kraft pulping, with an H factor of 1114 and 22% active alkali, presents the highest sugar production, of about 33 000 tons/year, assuming an annual production of 100 000 tons of bark by a medium-sized industr

Economics of One Health: Costs and benefits of integrated West Nile virus surveillance in Emilia-Romagna

Since 2013 in Emilia-Romagna, Italy, surveillance information generated in the public health and in the animal health sectors has been shared and used to guide public health interventions to mitigate the risk of West Nile virus (WNV) transmission via blood transfusion. The objective of the current study was to identify and estimate the costs and benefits associated with this One Health surveillance approach, and to compare it to an approach that does not integrate animal health information in blood donations safety policy (uni-sectoral scenario). Costs of human, animal, and entomological surveillance, sharing of information, and triggered interventions were estimated. Benefits were quantified as the averted costs of potential human cases of WNV neuroinvasive disease associated to infected blood transfusion. In the 2009–2015 period, the One Health approach was estimated to represent a cost saving of €160,921 compared to the uni-sectoral scenario. Blood donation screening was the main cost for both scenarios. The One Health approach further allowed savings of €1.21 million in terms of avoided tests on blood units. Benefits of the One Health approach due to short-term costs of hospitalization and compensation for transfusion-associated disease potentially avoided, were estimated to range from €0 to €2.98 million according to the probability of developing WNV neuroinvasive disease after receiving an infected blood transfusion

Maternal antibody uptake, duration and influence on survival and growth rate in a cohort of indigenous calves in a smallholder farming system in western Kenya

AbstractThe passive transfer of antibodies from dams to offspring via colostrum is believed to play an important role in protecting neonatal mammals from infectious disease. The study presented here investigates the uptake of colostrum by 548 calves in western Kenya maintained under smallholder farming, an important agricultural system in eastern Africa. Serum samples collected from the calves and dams at recruitment (within the first week of life) were analysed for the presence of antibodies to four tick-borne haemoparasites: Anaplasma marginale, Babesia bigemina, Theileria mutans and Theileria parva. The analysis showed that at least 89.33% of dams were seropositive for at least one of the parasites, and that 93.08% of calves for which unequivocal results were available showed evidence of having received colostrum. The maternal antibody was detected up until 21 weeks of age in the calves. Surprisingly, there was no discernible difference in mortality or growth rate between calves that had taken colostrum and those that had not. The results are also important for interpretation of serosurveys of young calves following natural infection or vaccination

Factors affecting the cost-effectiveness of on-farm culture prior to the treatment of clinical mastitis in dairy cows

The objective of this study was to use probabilistic sensitivity analysis to evaluate the cost-effectiveness of using an on-farm culture (OFC) approach to the treatment of clinical mastitis in dairy cows and compare this to a ‘standard’ treatment approach. A specific aim was to identify the herd circumstances under which an OFC approach would be most likely to be cost-effective. A stochastic Monte Carlo model was developed to simulate 5000 cases of clinical mastitis at the cow level and to calculate the associated costs simultaneously when treated according to 2 different treatment protocols; i) a 'conventional' approach (3 tubes of intramammary antibiotic) and ii) an OFC programme, whereby cows are treated according to the results of OFC. Model parameters were taken from recent peer reviewed literature on the use of OFC prior to treatment of clinical mastitis. Spearman rank correlation coefficients were used to evaluate the relationships between model input values and the estimated difference in cost between the standard and OFC treatment protocols. The simulation analyses revealed that both the difference in the bacteriological cure rate due to a delay in treatment when using OFC and the proportion of Gram-positive cases that occur on a dairy unit would have a fundamental impact on whether OFC would be cost-effective. The results of this study illustrated that an OFC approach for the treatment of clinical mastitis would probably not be cost-effective in many circumstances, in particular, not those in which Gram-positive pathogens were responsible for more than 20% of all clinical cases. The results highlight an ethical dilemma surrounding reduced use of antimicrobials for clinical mastitis since it may be associated with financial losses and poorer cow welfare in many instances

One Health in Action:Operational Aspects of an Integrated Surveillance System for Zoonoses in Western Kenya

Surveillance of diseases in Kenya and elsewhere in East Africa is currently carried out by both human and animal health sectors. However, a recent evaluation highlighted the lack of integration between these sectors, leading to disease under-reporting and inefficiencies. This project aimed to develop an integrated and cost-effective surveillance and reporting system for 15 zoonotic diseases piloted in the counties of Bungoma, Busia, and Kakamega in western Kenya. Specifically, in this paper we describe the operational aspects of such a surveillance system. Interviews were carried out with key informants, and this was followed by field visits to identify sentinel sites and liaise with relevant stakeholders. Based on this information, a sampling strategy comprising 12 sentinel sites, 4 in each county, was developed. Each sentinel site comprised of a livestock market, 1–2 neighboring slaughter houses/slabs, and a hospital in the vicinity; each of the 12 sites, comprising 12 × 3 = 36 sampling locations, was visited every 4 weeks for 20 cycles. At each site, animal or patient sampling included a clinical examination and collection of blood, feces, and nasal swabs; in slaughtered animals, mesenteric lymph nodes, hydatid cysts, and flukes were also collected. At the end of each field visit, data on staff involved and challenges encountered were recorded, while biological samples were processed and tested for 15 zoonotic diseases in the field laboratory in Busia, Kenya. Public engagement sessions were held at each sentinel site to share preliminary results and provide feedback to both stakeholders and study participants. A livestock market visit lasted just over 3 h, and the most common challenge was the frequent refusals of animal owners to participate in the study. At the slaughterhouses, visits lasted just under 4 h, and challenges included poorly engaged meat inspectors or slaughter processes that were too quick for sampling. Finally, the hospital visits lasted around 4 h, and the most frequent challenges included low patients turn-out, frequent staff turn-over leading to poor institutional memory, and difficulty in obtaining patient stool samples. Our experiences have highlighted the importance of engaging with local stakeholders in the field, while also providing timely feedback through public engagement sessions, to ensure on-going compliance

Afferent cardiac signals modulate attentional engagement to low spatial frequency fearful faces

Despite the growing consensus that the continuous dynamic cortical representations of internal bodily states shape the subjective experience of emotions, physiological arousal is typically considered only a consequence and rarely a determinant of the emotional experience. Recent experimental approaches study how afferent autonomic signals from the heart modulate the processing of sensory information by focussing on the phasic properties of arterial baroreceptor firing that is active during cardiac systole and quiescent during cardiac diastole. For example, baroreceptor activation has been shown to enhance the processing of threat-signalling stimuli. Here, we investigate the role of cardiac afferent signals in the rapid engagement and disengagement of attention to fear stimuli. In an adapted version of the emotional attentional cueing paradigm, we timed the presentation of cues, either fearful or neutral faces, to coincide with the different phases of the cardiac cycle. Moreover, we presented cues with different spatial frequency ranges to investigate how these interoceptive signals influence the processing of visual information. Results revealed a selective enhancement of attentional engagement to low spatial frequency fearful faces presented during cardiac systole relative to diastole. No cardiac cycle effects were observed to high spatial frequency nor broad spatial frequency cues. These findings expand our mechanistic understanding of how body–brain interactions may impact the visual processing of fearful stimuli and contribute to the increased attentional capture of threat signals