Consumers' behavior in quantitative microbial risk assessment for pathogens in raw milk: Incorporation of the likelihood of consumption as a function of storage time and temperature

Foodborne disease as a result of raw milk consumption is an increasing concern in Western countries. Quantitative microbial risk assessment models have been used to estimate the risk of illness due to different pathogens in raw milk. In these models, the duration and temperature of storage before consumption have a critical influence in the final outcome of the simulations and are usually described and modeled as independent distributions in the consumer phase module. We hypothesize that this assumption can result in the computation, during simulations, of extreme scenarios that ultimately lead to an overestimation of the risk. In this study, a sensorial analysis was conducted to replicate consumers' behavior. The results of the analysis were used to establish, by means of a logistic model, the relationship between time\u2013temperature combinations and the probability that a serving of raw milk is actually consumed. To assess our hypothesis, 2 recently published quantitative microbial risk assessment models quantifying the risks of listeriosis and salmonellosis related to the consumption of raw milk were implemented. First, the default settings described in the publications were kept; second, the likelihood of consumption as a function of the length and temperature of storage was included. When results were compared, the density of computed extreme scenarios decreased significantly in the modified model; consequently, the probability of illness and the expected number of cases per year also decreased. Reductions of 11.6 and 12.7% in the proportion of computed scenarios in which a contaminated milk serving was consumed were observed for the first and the second study, respectively. Our results confirm that overlooking the time\u2013temperature dependency may yield to an important overestimation of the risk. Furthermore, we provide estimates of this dependency that could easily be implemented in future quantitative microbial risk assessment models of raw milk pathogens

Los robledales galaico-septentrionales

The oakwoods of northern Galicia, included in the association Blechno spicantis-Quercetum roboris are studied; the pulmonarietosum longifoliae subassociation has been described. Several data on these particular woods are also reported, including the vegetation serie and the relationships with other similar vegetation types.Se estudian los robledales galaico-septentrionales que se incluyen en la asociación Blechno spicantis-Quercetum roboris Tx.& Oberd. 1958, describiéndose la nueva subasociación pulmonarietosum longifoliae. Se aportan datos sobre su serie de vegetación y sus relaciones con otros robledales afines

A probabilistic approach to the interpretation of milk antibody results for diagnosis of Johne’s disease in dairy cattle

Johne’s disease is a serious wasting disease of ruminants that is of high economic importance for the dairy sector in particular. The chronic nature of the disease, the fluctuations in antibody levels and the limited ability of diagnostic tests to identify cows at early stages of infection are huge challenges for the control of the disease. In the United Kingdom, the latter is commonly based on repeated milk ELISA testing of lactating cows, followed by selected culling and improved management practices around calving. In this paper, the dataset built through a large quarterly screening programme conducted in the United Kingdom since 2010 is used to investigate the use of milk ELISA testing for Johne’s disease management. Over the study period, 13,509 out of 281,558 cows were identified as high-risk of being infected and shedding mycobacteria in the faeces, based on a case definition of at least two consecutive positive milk ELISA results. Around a third of them were kept in the dairy herd a year or more after being classified as high-risk. However, 16% of these cows did not have any further positive test, suggesting that they might be uninfected animals. The mean specificity and sensitivity of the milk ELISA test were estimated at 99.5% and 61.8%, respectively. The cows in the dataset are categorised in different result groups according to the number of positive test results and whether they are classified as high-risk according to the programme’s case definition. The posterior probability of infection is calculated after each test in order to investigate the impact of repeated testing on the belief in a cow’s infection status. The interpretation of the results show that most cows classified as high-risk are very likely to be infected, while some other groups that do not match the case definition could reasonably be considered as infected too. Our results show that there is considerable potential for more targeted use of serological testing, including adjusting the testing frequency and implementing the posterior probability approach

Knowledge, Attitudes, and Practices Associated with Brucellosis in Livestock Owners in Jordan

We evaluated livestock owners' knowledge, attitudes, and practices regarding brucellosis in Jordan. A questionnaire was administered and biological samples were examined to verify the serological status of animals. Seroprevalence estimates indicated that 18.1% (95% CI: 11–25.3) of cattle herds and 34.3% (95% CI: 28.4–40.4) of small ruminant flocks were seropositive. The results showed that 100% of the interviewed livestock keepers were aware of brucellosis: 87% indicated a high risk of infection if unpasteurized milk is consumed and 75% indicated a high risk if unpasteurized dairy products are consumed. Awareness of the risk of infection through direct contact with fetal membranes or via physical contact with infected livestock is considerably lower, 19% and 13%, respectively. These knowledge gaps manifest in a high frequency of high-risk practices such as assisting in animal parturition (62%), disposing aborted fetuses without protective gloves (71.2%) or masks (65%), and not boiling milk before preparation of dairy products (60%). When brucellosis is suspected, basic hygiene practices are often disregarded and suspect animals are freely traded. Public health education should be enhanced as the disease is likely to remain endemic in the ruminant reservoir as long as a suitable compensation program is not established and trust on available vaccines is regained

Unravelling transmission of Mycobacterium avium subspecies paratuberculosis to dairy calves: results of a lifelong longitudinal study

Johne's disease (JD) is a chronic disease of ruminants endemic in the UK and other countries and responsible for large economic losses for the dairy sector. JD is caused by Mycobacterium avium subspecies paratuberculosis (MAP), which typically infects calves that remain latently infected during a long period, making early detection of infection challenging. Cow to calf transmission can occur in-utero, via milk/colostrum or faecal-orally. Understanding of the different transmission routes to calves is important in informing control recommendations. Our aim in this longitudinal study was to measure the association between the transmission routes via the dam and the environment on a calf subsequently testing serologically positive for MAP. The study population comprised of 439 UK dairy calves from 6 herds enrolled between 2012 and 2013. These calves were followed up from birth until 2023. At birth individual calf data was captured. During follow-up, individuals entering the milking herd were quarterly tested for the presence of MAP antibodies using milk ELISA. Cox regression models were used to measure the association between exposure from the dam (in-utero and/or colostrum) or from the environment (long time in dirty yard) and time to first detection of MAP infection. An association between calves born to positive dams and probability of having a MAP positive test result remained after excluding potential MAP transmission via colostrum (Hazard ratio: 2.24; 95% CI: 1.14 - 4.41). Calves unlikely to be infected with MAP via the in-utero or colostrum route, had 3.68 (95% CI: 3.68 1.45-9.33) higher hazard of a positive test result when they stayed longer in a dirty calving area. The effect of the dam infection status on transmission to calves precedes the dam's seroconversion and persists after excluding the potential role of transmission via colostrum. The association between time spent in a dirty calving area and probability of a MAP positive test result highlights the role of environmental contamination as a source of infection in addition to the dam. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.