Microbial Risk Analysis最新文献

Background

We aimed to determine risk factors associated with rates of contaminated blood cultures in the emergency department (ED).

Methods

This single-center, cohort study of 1098 consecutive patients ≥ 20 years of age was performed in the ED of university hospital over a 26-month period.

Results

We analyzed 2096 pairs of blood cultures. Potential contamination was identified in 172 (8.2%) of the 2096 pairs of blood cultures. Multivariate analysis revealed more frequent contamination when puncture sites were disinfected with povidone-iodine (PVI) than with alcohol/chlorhexidine gluconate (adjusted odds ratio, 7.13; 95% confidence interval [CI], 4.8–10.7; P < 0.001). Femoral and central venous catheters showed more frequent contamination than peripheral venous sites. Blood collection by first- or second-year residents did not show an increase in contaminated blood cultures.

Conclusions

Rates of contaminated blood cultures were significantly associated with PVI and specific sites, but were not significantly associated with blood collection by residents.

From the perspectives of molecular biology, genetics and biothermodynamics, SARS-CoV-2 is the among the best characterized viruses. Research on SARS-CoV-2 has shed a new light onto driving forces and molecular mechanisms of viral evolution. This paper reports results on empirical formulas, biosynthesis reactions and thermodynamic properties of biosynthesis (multiplication) for the Zeta P.2, Eta B.1.525, Theta P.3, Kappa B.1.617.1, Iota B.1.526, Lambda C.37 and Mu B.1.621 variants of SARS-CoV-2. Thermodynamic analysis has shown that the physical driving forces for evolution of SARS-CoV-2 are Gibbs energy of biosynthesis and Gibbs energy of binding. The driving forces have led SARS-CoV-2 through the evolution process from the original Hu-1 to the newest variants in accordance with the expectations of the evolution theory.

SARS-CoV-2 has during the last 3 years mutated several dozen times. Most mutations in the newly formed variants have been chemically and thermodynamically characterized. New variants have been declared as variants under monitoring. The European Centre for Disease Prevention and Control has suggested the hypothesis that the new BN.1, CH.1.1 and XBC variants could have properties similar to those of VOC. Thermodynamic properties of new variants have been reported in this manuscript for the first time. Gibbs energy of biosynthesis, as the driving force for viral multiplication, is less negative for the new variants than for the earlier variants. This indicates that the virus has evolved towards decrease in pathogenicity, which leads to less severe forms of COVID-19.

Wastewater treatment is essential for preventing infectious diseases and water pollution. To perform this process, workers operate and maintain wastewater treatment plants (WWTPs); thus, they are exposed to the many pathogens in domestic wastewater. Consequently, it is necessary assess occupational exposure to pathogens in WWTPs. Quantitative microbial risk assessment (QMRA) is an approach for estimating the risk posed by a specific pathogen which can be useful for occupational hygiene assessments of biological risk. In this study, we applied QMRA, informed by occupational field surveillance, to estimate the potential risk for WWTP workers. Furthermore, we used simulations to test additional control strategies such as personal protective equipment (PPE). The QMRA was conducted for three WWTPs in Costa Rica with data collected between May 2020 and May 2021. Observation in each workplace showed a need for more consistent application of risk reduction strategies in the work environment, especially in behavior, infrastructure, and use of appropriate PPE. Cryptosporidium sp., Giardia sp., norovirus, and enterovirus genus were measured and detected in the WWTPs, and the treatment performance was unsatisfactory. As a result, the total health disease burden was higher than the benchmark for drinking water recommended by WHO (1.00 × 10⁻⁶ DALY per person per year) by between one and three magnitudes orders in all WWTPs for the three exposure scenarios (operation, maintenance, and visitors). The simulation demonstrated that using PPE could reduce the estimated disease burden by nearly two orders of magnitude. Still, this control measure did not reach a level below the benchmark risk (less than 1.00 × 10⁻⁶ DALY per person per year) for the WWTP workers. This study highlights the importance of using PPE with other control measures, such as automation or barriers, to isolate exposure sources. However, this study employed an uncommon approach in occupational health and hygiene, which combined field inspections, survival analysis, and QMRA, using field surveillance to understand the occupational environment and potential exposure routes, which is crucial for hazard identification and risk assessment. In addition, exposure modeling and QMRA were used to simulate different control scenarios, providing a robust estimate of potential risks associated with occupational exposure.

Background

Few studies have examined the outcomes and predisposing risk factors for anaerobic bloodstream infections (BSIs).

Objective

To determine the survival impact of aerobic versus anaerobic BSI, a prospective cohort study was conducted.

Methods

We prospectively enrolled emergency department patients at a tertiary medical center with BSIs determined by laboratory testing between 2015 and 2016. Anaerobic and aerobic BSIs were compared for demographics, comorbidities, and sources of infection. Several independent risk factors were identified in a multivariable logistic regression model. Using propensity score (PS) matched data, an analysis of survival effects associated with anaerobic BSI has been conducted.

Results

Over a 2-year period, there were 1,166 episodes of BSI, of which 61 (5.2%) occurred as anaerobic episodes. Anaerobic BSIs were strongly associated with intra-abdominal infection (odds ratio [OR] 6.03, 95%CI 2.78–13.09), liver abscess (OR 3.92, 95%CI 1.47–10.45), skin and soft-tissue infection (OR 2.65, 95%CI 1.26–5.62), and metastatic cancer (OR 2.40, 95%CI 1.13–5.08) as the main positive predictors. Negative predictors included diabetes mellitus (OR 0.38, 95%CI 0.18–0.78), thrombocytopenia (OR 0.33, 95%CI 0.18–0.60), and urinary tract infection (OR 0.15, 95%CI 0.04–0.62). Anaerobic BSIs were not associated with worse prognosis after PS-matched analysis (hazard ratio [HR] 1.40, 95%CI 0.44–4.41) in our cohort.

Conclusions

A significant percentage of community-onset BSI was due to anaerobic BSI. Anaerobic BSI can have a detrimental outcome if there are underlying comorbidities, high-risk infection sites, and inappropriate antibiotic choices. The findings of our study may contribute to the prescription of empiric anti-anaerobe antibiotics.

The consumer demand for raw milk from dairy cows has increased and local sales via vending machines have been intensified. Therefore, this study aimed to assess the risk associated with the consumption of unboiled raw milk contaminated with Campylobacter by estimating the number of campylobacteriosis cases. For this a stochastic quantitative microbial risk assessment (QMRA) model was developed that covered the whole supply chain. Information and data for model parametrization were obtained from research publications. Different probability distributions were used to represent the data whenever possible and probabilistic risk estimation was performed using Monte Carlo simulations. Simulations for outbreaks from single vending machines were performed using the developed QMRA baseline model. Further, different risk mitigation scenarios along the supply chain were evaluated to support risk managers in controlling Campylobacter. The analysis suggest a role for Campylobacter infections due to fecal contamination of cows’ udder. The model can easily be adapted and extended when additional data become available as it is provides in the harmonized exchange Food Safety Knowledge Exchange (FSKX) format.

Vibrio parahaemolyticus is a halophilic gram-negative bacterium commonly found in marine environments, particularly in warm coastal waters. This pathogen has been reported as a common cause of foodborne illness associated with the consumption of raw or undercooked seafood. The presence and density of this bacterium in seafood are often associated with the climatological conditions of the marine environment. Herein, we developed the quantitative risk assessment model for Vibrio parahaemolyticus in oysters in Taiwan by considering seasonal variations, time periods, climate change scenarios, and post-harvest interventions. This study showed that season, time period, shared socioeconomic pathway (SSP), and post-harvest intervention significantly influenced the risk level of becoming ill from consuming oysters. The mean estimates of risk in winter, spring, summer, and fall were estimated to be 9.1 × 10⁻⁵, 2.0 × 10⁻³, 2.0 × 10⁻², 6.9 × 10⁻³ per serving, respectively. Our models predict that, if global temperatures continue to increase in the coming decades due to climate change, the risk per serving of oysters is likely to increase by 18-145% by 2041-2060 and by 18-718% by 2081-2100, depending on the season and SSP. The application of thermal processing or high hydrostatic pressure processing was found to be the most effective approach in reducing risk, even under the threat of increasing global temperatures.

COVID-19 and SARS-CoV-2 from the perspectives of medicine, biology, molecular biology, chemistry and biothermodynamics represent probably the best studied virus-host interaction until now. Empirical formula of SARS-CoV-2 is the second reported in history, immediately after the poliovirus. Empirical formulas of all SARS-CoV-2 variants have been reported in the literature. This paper reports empirical formulas, biosynthesis reactions and thermodynamic properties (enthalpy, entropy and Gibbs energy) for the XBB.1.9.1, XBF and XBB.1.16 variants of SARS-CoV-2. Since Gibbs energy of biosynthesis represents the driving force for virus multiplication, a conclusion was made that multiplication rate of the new SARS-CoV-2 variants is not significantly different than that of the other Omicron variants. Since multiplication rate determines the damage level to host cells, a conclusion was drawn that there is no increase in the degree of damage to host tissues. Thus, pathogenicity of the new variants did not significantly change. In that case, it can be expected that the number of severe cases should not increase. Therefore, it seems that the health risk for the society should not change.

SARS-CoV-2 resembles the ancient mythical creature Hydra. Just like with the Hydra, when one head is cut, it is followed by appearance of two more heads, suppression of one SARS-CoV-2 variant causes appearance of newer variants. Unlike Hydra that grows identical heads, newer SARS-CoV-2 variants are usually more infective, which can be observed as time evolution of the virus at hand, which occurs through acquisition of mutations during time. The appearance of new variants is followed by appearance of new COVID-19 pandemic waves. With the appearance of new pandemic waves and determining of sequences, in the scientific community and general public the question is always raised of whether the new variant will be more virulent and more pathogenic. The two variants characterized in this paper, BA.5.2 and BF.7, have caused a pandemic wave during the late 2022. This paper gives full chemical and thermodynamic characterization of the BA.5.2 and BF.7 variants of SARS-CoV-2. Having in mind that Gibbs energy of binding and biosynthesis represent the driving forces for the viral life cycle, based on the calculated thermodynamic properties we can conclude that the newer variants are more infective than earlier ones, but that their pathogenicity has not changed.

The risk of human campylobacteriosis due to Danish broiler flocks cross-contaminated (CC) at slaughter with Campylobacter spp. was assessed. National surveillance data (2018) on flock Campylobacter status (called animal level component (AL)) and on contamination of chilled carcasses ready for consumption (food safety component (FS)), were compared. The AL component consisted of PCR testing results on pools of cloacal swabs collected from 3,012 conventional flocks, while the FS component presented culture testing of leg skins from 999 (of the 3,012) randomly sampled flocks. Datasets were integrated on flocks tested in both components, by combinations of farm-ID, house-unit and sampling date. The CC flocks were those entering the slaughterhouse as AL-negative, but resulting FS-positive. All remaining carcass positive flocks were instead classified as Non-CC flocks. The apparent prevalence (AP) of carcass positive flocks and the colony forming units per gram (cfu/g), measured by the FS component, were fed into a published simulation model, to assess under three simulation scenarios: the mean monthly risk per serving during 2018, relative (RR) to that of 2013 (reference year in the current Danish Action Plan). In the baseline scenario, the original AL status and the FS cfu/g were maintained. In the alternative scenarios I and II, the FS cfu/g were set = 0 (i.e. negative) for the Non-CC and for the CC flocks, respectively. Thus, scenario I and the differences between the other two scenarios, provided the contribution of the CC flocks to the AP and to the RR. The (overall) annual median log10 cfu/g was ≈ 2.8 (min. = 1.0; max. = 4.0) for the Non-CC flocks and 1.4 (1.0; 3.9) for the CC flocks. The median monthly difference in AP, between the baseline scenario and scenario II was 7% (min = 2% in January; max = 19% in August), while the difference in risk was 0.04% (0.001%; 0.11%), which was similar to the mean monthly risk under scenario I. If cross-contamination had not occurred (scenario II), the annual AP would have reduced from 24.3% to 16.1% and the RR would have reduced from 0.92 to 0.77. Therefore, ≈16% of the public health risk posed by Danish conventional broiler meat, appeared attributable to CC flocks. Reducing cross-contamination could mitigate the risk of human campylobacteriosis notably. This study illustrates how inter-sectorial surveillance data integration, can be used to optimize National Action Plans against Campylobacter spp. and other similar foodborne pathogens.