Efficacy of cleaning and sanitizing procedures to reduce Listeria monocytogenes on food contact surfaces commonly found in fresh produce operations

Cleaning and/or sanitizing methods were evaluated to reduce Listeria monocytogenes (Lm) on coupons of porous (PS; polyester-nylon with coating conveyor belt [PNCB], plywood [PW]) and non-porous (NPS; high density polyethylene, stainless steel) surfaces. Coupons (2.5 cm diameter) were inoculated with six-strain cocktail with cabbage juice, inverted and incubated on tryptic soy agar with yeast extract (TSAYE; 37 °C, 24 h). Coupons (n = 4; ∼9 log CFU/coupon) were rinsed only (RO), multi-step cleaned (MSC), sanitized only (SO; peroxyacetic acid [PAA], bleach, quaternary ammonium compounds [QAC]), or cleaned and sanitized (MSC + S), transferred to Dey/Engley broth (DEB) with glass beads (1 g), vortexed and enumerated on Harlequin-TSAYE. Half of the coupons were dried prior to transfer to DEB. MSC resulted in ave. 2 log CFU/coupon reductions on NPS, and 0.6-1.1 log on PS. MSC + S led to >5-log reduction on NPS (81%; n = 48). On PS, MSC + S-PAA resulted in 1.8 and 1.9 log reductions on PW and PNCB, respectively. RO and SO reduced Lm on all surfaces, although less effectively than MSC and MSC + S. On PS, MSC + S-PAA was most effective, followed by bleach and QAC (p < 0.05). Drying after sanitizing increased Lm reduction by ∼0.4 log (p < 0.05). Partial cleaning and/or sanitizing leads to minimal reduction of Lm, while multi-step cleaning with sanitizing is highly effective.

E-commerce readiness and training needs of small-scale dairy processors in Serbia: Understanding barriers and knowledge gaps

The objective of this study was to identify the requirements needed for selling dairy products through e-commerce, as well as current gaps and challenges that exist for small scale dairy processors (SSDPs), and need to be addressed in order to comply with those requirements. A mixed method research design was used for training needs assessment. Qualitative (in-depth interview with 7 online platform representatives (OPRs)) and quantitative approach (survey questionnaire with 58 SSDPs) were conducted. Interview transcripts were coded and codes were grouped into seven themes. Hierarchical cluster analysis was applied to 146 answers from 58 SSDPs. They were divided into 4 clusters. Mean sums of responses between clusters were compared by Mann-Whitney U test. OPRs suggested that SSDPs should be provided with tools and resources to help them achieve food safety and quality targets, as well as practical knowledge and skills. They reported that it is crucial to find a solution for the cold chain transportation, for maintaining consistent product quality. Survey results showed that SSDPs use kitchen equipment (79.3%) and kitchen cleaning products (81.0%) for dairy processing. In total, 43.1% process raw milk and only 24.1% have product label on the package. Only members of cluster 3 and 4 sell their products online (73.7% and 90.0%, respectively), mostly using their own social media platforms (57.9% and 60.0%, respectively), transporting products to end buyers by themselves in hand refrigerators (47.4% and 70.0%, respectively). By analyzing the differences among clusters of SSDPs, trainings can be tailored to the characteristics and knowledge gaps of each group.

Genomic characterization of Listeria monocytogenes recovered from dairy facilities in British Columbia, Canada from 2007 to 2017

Listeria monocytogenes is a foodborne pathogen of concern in dairy processing facilities, with the potential to cause human illness and trigger regulatory actions if found in the product. Monitoring for Listeria spp. through environmental sampling is recommended to prevent establishment of these microorganisms in dairy processing environments, thereby reducing the risk of product contamination. To inform on L. monocytogenes diversity and transmission, we analyzed genome sequences of L. monocytogenes strains (n = 88) obtained through the British Columbia Dairy Inspection Program. Strains were recovered from five different dairy processing facilities over a 10 year period (2007-2017). Analysis of whole genome sequences (WGS) grouped the isolates into nine sequence types and 11 cgMLST types (CT). The majority of isolates (93%) belonged to lineage II. Within each CT, single nucleotide polymorphism (SNP) differences ranged from 0 to 237 between isolates. A highly similar (0-16 SNPs) cluster of over 60 isolates, collected over 9 years within one facility (#71), was identified suggesting a possible persistent population. Analyses of genome content revealed a low frequency of genes associated with stress tolerance, with the exception of widely disseminated cadmium resistance genes cadA1 and cadA2. The distribution of virulence genes and mutations within internalin genes varied across the isolates and facilities. Further studies are needed to elucidate their phenotypic effect on pathogenicity and stress response. These findings demonstrate the diversity of L. monocytogenes isolates across dairy facilities in the same region. Findings also showed the utility of using WGS to discern potential persistence events within a single facility over time.

Before and After: Evaluation of Microbial and Organic Loads in Produce Handling and Packing Operations with Diverse Cleaning and Sanitizing Procedures

Inadequate cleaning and/or sanitation (C/S) of food contact surfaces (FCSs) has been frequently reported during Produce Safety Rule inspections; however, limited data are available evaluating the effectiveness of C/S processes in produce operations. Different C/S practices were evaluated in four fresh produce operations for their efficacy in reducing microbial and organic loads on various FCSs. Microbial (aerobic plate counts; APC) and organic (ATP) loads were quantified during production, after cleaning, and after sanitizing, if applicable. Operations included: a berry packinghouse (BerryPK; wet cleaning), a blueberry harvest contractor (BerryHC; cleaning + sanitizing, C+S), and two mixed vegetable packinghouses (MixedV1; C+S, and MixedV2; rinsing + sanitizing, R+S). Following wet cleaning, significant reductions in APCs (p < 0.05) were seen on high-density polyethylene (HDPE) storage trays (n = 50) in BerryPK (3.1 ± 0.9 to 2.5 ± 0.7 log CFU/100 cm2). In BerryHC, a greater reduction in APCs was seen on HDPE harvest buckets (n = 25) following C+S (3.8 ± 0.5 to 1.1 ± 0.4 log CFU/100 cm2), compared to wet cleaning only in BerryPK. Stainless steel and conveyor belt FCSs (n = 16) in MixedV1 were sampled, and a significant reduction in APCs (p < 0.05) was observed when comparing in-use (4.8 ± 1.3 log CFU/100 cm2) to post-C+S (3.9 ± 0.7 log CFU/100 cm2). When similar FCSs (n = 17) were sampled in MixedV2, R+S also led to significant reduction in APCs (3.3 ± 0.6 to 1.9 ± 0.6 log CFU/100 cm2) (p < 0.05). ATP testing in fresh produce settings yielded inconsistent results, with no correlation between organic and bacterial loads detected during production (R2 = 0.00) across four operations, and weak correlations observed after cleaning (R2 = 0.18) and after sanitation (R2 = 0.33). The results from this study provide the foundational basis for future research on practical and effective C/S methods tailored to the produce industry.

Combined Infection Control Interventions Protect Essential Food Workers from Occupational Exposures to SARS-CoV-2 in the Agricultural Environment

Essential food workers experience elevated risks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection due to prolonged occupational exposures in food production and processing areas, shared transportation (car or bus), and employer-provided shared housing. Our goal was to quantify the daily cumulative risk of SARS-CoV-2 infection for healthy susceptible produce workers and to evaluate the relative reduction in risk attributable to food industry interventions and vaccination. We simulated daily SARS-CoV-2 exposures of indoor and outdoor produce workers through six linked quantitative microbial risk assessment (QMRA) model scenarios. For each scenario, the infectious viral dose emitted by a symptomatic worker was calculated across aerosol, droplet, and fomite-mediated transmission pathways. Standard industry interventions (2-m physical distancing, handwashing, surface disinfection, universal masking, ventilation) were simulated to assess relative risk reductions from baseline risk (no interventions, 1-m distance). Implementation of industry interventions reduced an indoor worker's relative infection risk by 98.0% (0.020; 95% uncertainty interval [UI], 0.005 to 0.104) from baseline risk (1.00; 95% UI, 0.995 to 1.00) and an outdoor worker's relative infection risk by 94.5% (0.027; 95% UI, 0.013 to 0.055) from baseline risk (0.487; 95% UI, 0.257 to 0.825). Integrating these interventions with two-dose mRNA vaccinations (86 to 99% efficacy), representing a worker's protective immunity to infection, reduced the relative infection risk from baseline for indoor workers by 99.9% (0.001; 95% UI, 0.0002 to 0.005) and outdoor workers by 99.6% (0.002; 95% UI, 0.0003 to 0.005). Consistent implementation of combined industry interventions, paired with vaccination, effectively mitigates the elevated risks from occupationally acquired SARS-CoV-2 infection faced by produce workers. IMPORTANCE This is the first study to estimate the daily risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across a variety of indoor and outdoor environmental settings relevant to food workers (e.g., shared transportation [car or bus], enclosed produce processing facility and accompanying breakroom, outdoor produce harvesting field, shared housing facility) through a linked quantitative microbial risk assessment framework. Our model has demonstrated that the elevated daily SARS-CoV-2 infection risk experienced by indoor and outdoor produce workers can be reduced below 1% when vaccinations (optimal vaccine efficacy, 86 to 99%) are implemented with recommended infection control strategies (e.g., handwashing, surface disinfection, universal masking, physical distancing, and increased ventilation). Our novel findings provide scenario-specific infection risk estimates that can be utilized by food industry managers to target high-risk scenarios with effective infection mitigation strategies, which was informed through more realistic and context-driven modeling estimates of the infection risk faced by essential food workers daily. Bundled interventions, particularly if they include vaccination, yield significant reductions (>99%) in daily SARS-CoV-2 infection risk for essential food workers in enclosed and open-air environments.

Knowledge about HPV vaccination among Croatian university students

Background

Studies have shown the low uptake of the human papillomavirus (HPV) vaccine among university students. Knowledge about the HPV virus and the vaccine can be a factor that may sway an individual’s decision to receive the vaccine. This study aimed to investigate HPV vaccine uptake and knowledge about HPV vaccination among Croatian university students.

Methods

This cross-sectional questionnaire study was conducted from February to May 2021 period. A validated, anonymous questionnaire that contained questions regarding demographic data, data about HPV vaccine uptake, and data regarding knowledge about the HPV virus and the vaccination was self-administered to a cross-faculty representative student sample of the University of Osijek in Eastern Croatia.

Results

The study sample included 840 subjects with, median age of 20 years (interquartile range 20-21), 45.8% males, and 54.2% females. The prevalence of vaccination uptake in the studied population was 20.8%. The study revealed that there were 25.6% of students with a low level of knowledge and 74.4% of students with satisfactory levels of knowledge about the HPV virus and the vaccination. The excellent knowledge about the HPV virus and the vaccination was more frequently shown by students who studied in biomedicine and health area of science (p &lt; 0.001) and students with an excellent average grade of study (p &lt; 0.001). HPV vaccination uptake was higher among females (p &lt; 0.001), students who studied within biomedicine and health area of science (p &lt; 0.001), students with an excellent average grade of study (p &lt; 0.001), and students who showed excellent knowledge about the HPV virus and the vaccination (p &lt; 0.001).

Conclusions

The majority of Croatian university students had a satisfactory level of knowledge about the HPV virus and the vaccination but the vaccination uptake is still very modest. Additional efforts are needed to organize more appropriate education and promotion of vaccine uptake in the studied population.

Key messages

• The HPV vaccination uptake among Croatian university students is very modest although the majority of students have a satisfactory level of knowledge about the HPV virus and the vaccination.

• Continuous examination of HPV knowledge gaps and identification of factors influencing vaccine uptake is key to increasing vaccination rates in the Croatian university student population.

Risk factors for internet addiction among Croatian university students during the COVID-19 pandemic

Background

Following the increased internet use due to the COVID-19 pandemic there have been concerns regarding an elevated risk of developing internet addiction (IA). University students are especially prone to develop IA and risk factors for its development in this population during pandemics are not fully investigated nor understood. This study aimed to identify possible risk factors of IA in the studied population during the ongoing pandemic and to compare it with risk factors in pre-pandemic time.

Methods

In April 2016 and April 2022 a validated, anonymous questionnaire that contained questions regarding demographic data, as well as Young's Internet Addiction Test, was self-administered to a cross-faculty representative student sample of the University of Osijek, Croatia.

Results

The study included 1602 university students median age of 21 years (interquartile range 20-22), 34.5% males, and 65.5% females. There was no statistically significant difference in the median age between the two student samples (p = 0.234). The main reason for internet use (social networking and entertainment and online gaming) was considered the significant risk factor for IA in a studied population in pre-pandemic time (the year 2016) and pandemic time (the year 2022) (p < 0.001). In pre-pandemic time the IA was more frequent in males (p = 0.046) while the difference in IA prevalence between sexes did not exist during pandemics (p = 0.160). During pandemics, the students who did not work during their study had higher proportions of IA (p = 0.021) while there was no difference in IA prevalence among students regarding their working status during the study in pre-pandemic time (p = 0.251).

Conclusions

During the COVID-19 pandemic working status of students has been recognized as the new risk factor for IA in the Croatian university students population. Further studies are needed to identify other possible risk factors for IA in the studied population during pandemics.

Key messages

Probing antimicrobial resistance and sanitizer tolerance themes and their implications for the food industry through the Listeria monocytogenes lens

The development of antibiotic resistance is a serious public health crisis, reducing our ability to effectively combat infectious bacterial diseases. The parallel study of reduced susceptibility to sanitizers is growing, particularly for environmental foodborne pathogens, such as Listeria monocytogenes. As regulations demand a seek-and-destroy approach for L. monocytogenes, understanding sanitizer efficacy and its uses are critical for the food industry. Studies have reported the ability of L. monocytogenes to survive in sanitizer concentrations 10-1000 times lower than the manufacturer-recommended concentration (MRC). Notably, data show that at MRC and when applied according to the label instructions, sanitizers remain largely effective. Studies also report that variables such as the presence of organic material, application time/temperature, and bacterial attachment to surfaces can impact sanitizer effectiveness. Due to the lack of standardization in the methodology and definitions of sanitizer resistance, tolerance, and susceptibility, different messages are conveyed in different studies. In this review, we examine the diversity of definitions, terminology, and methodologies used in studies examining L. monocytogenes resistance and susceptibility to antimicrobials. Research available to date fails to demonstrate "resistance" of L. monocytogenes to recommended sanitizer treatments as prescribed by the label. As such, sanitizer tolerance would be a more accurate description of L. monocytogenes response to low sanitizer concentrations (i.e., sub-MRC). Conservative use of word "resistance" will reduce confusion and allow for concise messaging as sanitizer research findings are communicated to industry and regulators.

Adaptation to a Commercial Quaternary Ammonium Compound Sanitizer Leads to Cross-Resistance to Select Antibiotics in Listeria monocytogenes Isolated From Fresh Produce Environments

The effective elimination of Listeria monocytogenes through cleaning and sanitation is of great importance to the food processing industry. Specifically in fresh produce operations, the lack of a kill step requires effective cleaning and sanitation to mitigate the risk of cross-contamination from the environment. As facilities rely on sanitizers to control L. monocytogenes, reports of the development of tolerance to sanitizers and other antimicrobials through cross-resistance is of particular concern. We investigated the potential for six L. monocytogenes isolates from fresh produce handling and processing facilities and packinghouses to develop cross-resistance between a commercial sanitizer and antibiotics. Experimental adaptation of isolates belonging to hypervirulent clonal complexes (CC2, CC4, and CC6) to a commercial quaternary ammonium compound sanitizer (cQAC) resulted in elevated minimum inhibitory concentrations (2–3 ppm) and minimum bactericidal concentrations (3–4 ppm). Susceptibility to cQAC was restored for all adapted (qAD) isolates in the presence of reserpine, a known efflux pump inhibitor. Reduced sensitivity to 7/17 tested antibiotics (chloramphenicol, ciprofloxacin, clindamycin, kanamycin, novobiocin, penicillin, and streptomycin) was observed in all tested isolates. qAD isolates remained susceptible to antibiotics commonly used in the treatment of listeriosis (i.e., ampicillin and gentamicin). The whole genome sequencing of qAD strains, followed by comparative genomic analysis, revealed several mutations in fepR, the regulator for FepA fluoroquinolone efflux pump. The results suggest that mutations in fepR play a role in the reduction in antibiotic susceptibility following low level adaptation to cQAC. Further investigation into the cross-resistance mechanisms and pressures leading to the development of this phenomenon among L. monocytogenes isolates recovered from different sources is needed to better understand the likelihood of cross-resistance development in food chain isolates and the implications for the food industry.

Knowledge about vaccination in Croatian high school population

Background

Knowledge about vaccination is one of the key determinants of vaccination uptake and it is shaped by different information sources. Future of the vaccination coverage depends on vaccination knowledge and uptake in young generations. The aim of this study was to investigate knowledge about vaccination and information sources of this knowledge among Croatian high school students.

Methods

This online cross-sectional questionnaire study was conducted during the January 2021 to April 2021 in convenient sample of high school students from north-western part of Croatia.

Results

The study sample consisted of 1012 subjects (29.2% males and 70.8% females). The median age of all subjects was 17.0 (interquartile range (IQR) 17.0 - 18.0) years. According to the knowledge there were 29.5% of students with poor, 53.9% of students with average and 16.6% of students with good knowledge about vaccination. Male students more frequently had poor knowledge about vaccination (P = 0.028). Information source of knowledge about vaccination in study population were internet (39.2%), family and friends (35.2%) and formal education (25.6%). Students who displayed poor knowledge about vaccination more frequently stated internet as dominant source of knowledge about vaccination while students who displayed good knowledge about vaccination more frequently stated formal education as dominant source (P = 0.002).

Conclusions

The study showed that large proportion of Croatian high school students has poor knowledge about vaccination. Furthermore, study revealed that internet was dominant source of information regarding vaccination in study population. Additional education is needed to improve observed situation regarding vaccination knowledge and its sources among Croatian high school students.

Key messages

Improvement of general knowledge regarding vaccination in younger population subgroups is necessary precondition for insuring adequate vaccination coverage in future. Enhancement of the formal education about vaccination in younger population subgroups is crucial element of successful vaccination programs.

Attitudes towards vaccination among Croatian high school students

Background

Due to the success of immunization, most of young people have little experience with vaccine preventable diseases. This inexperience may increase vaccine hesitancy in this population subgroup which can potentially jeopardize population vaccination coverage. Understanding young peoples' attitudes towards vaccination is important for vaccination uptake. The aim of this study was to evaluate attitudes towards vaccination among Croatian high school students.

Methods

This online cross-sectional questionnaire study was conducted during the January 2021 to April 2021 in convenient sample of high school students from north-western part of Croatia. Vaccination Attitudes Examination scale (VAX) was used to assess antivaccination attitudes in study population.

Results

The study included 1012 high school students; 29.2% males and 70.8% females; median age 17.0 (interquartile range (IQR) 17.0 - 18.0) years. Overall value of the VAX score in study sample was 50.4±11.1. Female students had more negative attitudes towards vaccination in comparison to male students (P = 0.001). When analysing differences between female and male students according to the VAX scale subcategories the study revealed that female students demonstrated more worries over unforeseen future effects of the vaccination (P &lt; 0.001) while there were no differences between females and males according to the mistrust of vaccine benefits, concerns about commercial profit and preference for natural immunity (P = 0.155, P = 0.157 and P = 0.142, respectively).

Conclusions

The study revealed rather high antivaccination attitudes among Croatian high school students as measured by VAX score. Further studies are needed to better understand factors that influence such attitudes in study population because programs directed towards changing antivaccination attitudes in order to be efficient need to successfully tackle all of those factors.

Key messages

Public health interventions directed towards suppression of antivaccination movement should more involve younger population subgroups, such as elementary and high school students. Positive attitudes towards vaccination in younger population subgroups are one of the crucial preconditions for adequate vaccination coverage.

Performance-enhancing drugs attitudes among young amateur Croatian athletes

Background

Recent studies revealed that amateur athletes, especially young ones, have an increasing tendency of performance-enhancing drugs (PEDs) usage. The aim of this study was to explore PEDs attitudes among young, amateur Croatian athletes.

Methods

This cross-sectional questionnaire study was done in convenient sample of young amateur Croatian athletes during the August 2019 to January 2020 at the occupational and sports medicine office in Eastern Croatia. Performance Enhancement Attitudes Scale (PEAS) was used for evaluation of athletes' attitudes towards doping.

Results

There were 306 athletes median age 18.0 (interquartile range (IR) 15.0 - 21.0) years; 62.7% females and 37.3% males. According to the age there were 52.9% of adolescents (aged 13 to 18 years) and 47.1% of young adults (aged 19 to 24 years). Regarding the type of sport there were 19.6% of subjects who played individual sports and 80.4% of them who played team sports. Considering the length of sport engagement 49.7% of subjects were engaged in their sport for 1 to 5 years and 50.3% of them were engaged in their sport for 6 or more years. The prevalence of current PEDs usage was 1.3%, while past PEDs usage prevalence was 3.3%. Current PEDs usage was more frequent among young adults (P = 0.048) and athletes playing individual sports (P = 0.001). Athletes who were engaged in sports for 1 to 5 years had more permissive attitudes toward PEDs (P &lt; 0.001) as measured by the PEAS. The study did not establish any correlation between current or past PEDs usage and attitudes toward PEDs.

Conclusions

PEDs usage is present among young Croatian amateur athletes. There is a need for interventions directed toward the prevention of PEDs usage in an observed subgroup of athletes.

Key messages

In order to be more effective doping prevention strategies should take into account athletes’ attitudes towards doping. Public awareness and knowledge about doping in sports should be increased in order to achieve more efficient anti-doping programs.

Application of Whole Genome Sequencing to Understand Diversity and Presence of Genes Associated with Sanitizer Tolerance in Listeria monocytogenes from Produce Handling Sources

Recent listeriosis outbreaks linked to fresh produce suggest the need to better understand and mitigate L. monocytogenes contamination in packing and processing environments. Using whole genome sequencing (WGS) and phenotype screening assays for sanitizer tolerance, we characterized 48 L. monocytogenes isolates previously recovered from environmental samples in five produce handling facilities. Within the studied population there were 10 sequence types (STs) and 16 cgMLST types (CTs). Pairwise single nucleotide polymorphisms (SNPs) ranged from 0 to 3047 SNPs within a CT, revealing closely and distantly related isolates indicative of both sporadic and continuous contamination events within the facility. Within Facility 1, we identified a closely related cluster (0-2 SNPs) of isolates belonging to clonal complex 37 (CC37; CT9492), with isolates recovered during sampling events 1-year apart and in various locations inside and outside the facility. The accessory genome of these CC37 isolates varied from 94 to 210 genes. Notable genetic elements and mutations amongst the isolates included the bcrABC cassette (2/48), associated with QAC tolerance; mutations in the actA gene on the Listeria pathogenicity island (LIPI) 1 (20/48); presence of LIPI-3 (21/48) and LIPI-4 (23/48). This work highlights the potential use of WGS in tracing the pathogen within a facility and understanding properties of L. monocytogenes in produce settings.

Relative performance of commercial citric acid and quaternary ammonium sanitizers against Listeria monocytogenes under conditions relevant to food industry

Growth of Listeria monocytogenes in cold temperatures coupled with its tolerance of antimicrobials can promote its survival and persistence in food processing environments. The food industry relies heavily on cleaning and sanitation to control L. monocytogenes; therefore, it is important to understand the environmental context (i.e., temperature) on the efficacy of antimicrobials used in food industry. The minimum bactericidal concentrations (MBCs) of an "eco-friendly" citric acid-based (CAB) sanitizer and a conventional quaternary ammonium compound (CQAC) sanitizer were determined against 14 L. monocytogenes isolates at 4-30 °C. A subset of isolates (n = 3) was also exposed to sub-lethal concentrations of sanitizers to assess differences in growth behavior. CAB and CQAC were effective at manufacturer recommended concentrations in liquid assays. The MBC of CAB was significantly lower at 4 °C compared to 23 °C (p < 0.05), whereas the MBC of CQAC was unchanged between 4 °C and 23 °C. Manufacturers' recommendations for dose and duration of CAB and CQAC were unable to consistently achieve a >5-log reduction of L. monocytogenes attached to surfaces. Findings from this study demonstrate the importance of sanitizer evaluation under conditions representative of their use in the food industry.

Dietary and lifestyle habits of secondary school students in Subotica

Dietary habits, alcohol use and physical activity initiated in childhood and adolescence are often maintained during later life. Study objective was to investigate high school students' behavior patterns and nutritional status.

The cross-sectional study involved 301 students (16 years old) from two secondary schools in Subotica, North Backa Region. Study took place in October 2019. Students anonymously filled out a modified national questionnaire consisting of 27 questions and covering the areas: free time, physical activity, alcohol use, eating habits. Anthropometric measurements (height, weight) were done in schools. Statistical data processing was done in SPSS.

Boys were more physically active than girls, both in regard to competitive sports (36.4% vs. 8.2%) and recreational sports or other physical activity for at least 4 hours per week (15.2% vs. 7.3%). This difference is statistically significant (χ2=40.534; DF = 3; p = 0.001). More than a half of the students (58%) admitted drinking alcohol occasionally in the last 12 months and every fifth student during weekends. Daily consumption of breakfast is present in 44% students, fresh fruits in 28.3% and vegetables in 25.9%. On the contrary, 31.6% of them eat sweets and 30.8% drink sweetened soft drinks daily. There is a statistically significant difference in type of used fats, with boys using more often “bad” fats (χ2=12.884; DF = 3; p = 0.005). Every third student (32.5%) is overweight or obese (&gt;85th percentile).

The high percentage of students with BMI &gt; 85th percentile, poor nutrition habits, lack of physical activity, frequent alcohol use, indicated a need for stronger implementation of interventions aimed at adolescents and younger age groups. Following the study, a comprehensive intervention program was implemented in the period October-December 2019. The program included educational seminars, peer education, demonstrational cooking workshops, stands for parents, preparing an e-cookbook, sports and recreation fair.

Key messages

The results obtained underline a need for youth empowerment and environmental interventions to support their lifestyle change. It is our obligation to help them find a way to enhance their health potential as early as possible.

Mental health outcomes in road traffic accident survivors: prospective cohort study

Background

Mental health outcomes of road traffic accidents (RTAs) are always investigated amongst the injured. The aim of this study was to investigate psychological consequences and associated factors in all RTA survivors irrelevant of their injury status.

Methods

A cohort of 200 Croatian RTA survivors was assessed one month after experiencing a RTA using the posttraumatic stress disorder (PTSD) Checklist for civilians, the Beck Depression Inventory and the Beck Anxiety Inventory. The New Injury Severity Scale was used for the injury severity assessment.

Results

RTA survivors reported substantial rates of PTSD (35.5%) and depression (20.0%) symptoms, and low rates of anxiety (4.5%). Symptoms of depression were associated with under-average self-perceived economic status (SES) (P = 0.001), irreligiousness (P = 0.001), medication use (P &lt; 0.001), injury severity (P &lt; 0.001), self-perceived threat to life (P &lt; 0.022), hospitalization (P = 0.003), hospitalization duration (P = 0.004), surgical treatment of the injury (P &lt; 0.001), unconsciousness in the RTA (P = 0.033) and post-RTA amnesia (0.039). PTSD symptoms were associated with unemployment (P = 0.034), under average SES (P = 0.004), lack of previous RTA experience (P = 0.025), previous psychiatric illness (P = 0.001), medication use (P = 0.001), psychiatric medication use (P &lt; 0.001), injury affliction (P = 0.001), injury severity (P &lt; 0.001), self-perceived threat to life (P &lt; 0.001), pain after RTA (P = 0.009), hospitalization duration (P = 0.017) and claiming compensation (P = 0.008). Anxiety symptoms were associated with previous chronic (P = 0.037) or psychiatric illness (P = 0.010), previous permanent pain (P &lt; 0.001), psychiatric medication use (P = 0.013) and rehabilitation after injury (P = 0.032).

Conclusions

A RTA is a traumatic event that can result in physical injuries, but also with psychological consequences depending on pre-RTA survivor's characteristics. Psychological support to those at risk may prevent psychological disorders after a RTA.

Key messages

Along with evaluation and treatment of road traffic accidents injuries, health care providers should evaluate pre-accident health status of all road traffic accidents victims. Understanding factors that present risk for poor mental health outcomes after the road traffic accidents is the key step in planning and organizing recovery of accidents survivors.

What if we combine Quit and win and individual approach to help smokers quit at the community level?

Issue

Tobacco eventually kills up to a half of its users. Helping smokers who wish to quit is one of the six cost effective interventions listed by World Bank to decrease smoking harm. Tobacco Control Scale in 2016, shows diversity in approaches and coverage to help smokers quit across Europe. Comprehensive interventions are most effective. Combining contest, financial incentives, individual approach and triggers (start of Lent or other) could be implemented in other settings.

Description of the problem

Contest to motivate smokers for a quit attempt and individual help provided, has been conducted yearly since 2015 in a local community in Pozega-Slavonia County in Croatia. Data on all participants from 2015 through 2018 contests were collected by questionnaires and long term smoking status (6 months) evaluated by phone interviewing. Statistical analysis was conducted in SPSS. The objective was to determine how effective in helping smokers quit is a novel combination of evidence-based approaches “Quit and win” and individual support in local setting and to establish certain smokers characteristics as possible predictors of outcome.

Results

Data for 153 participants were collected. There were more (54%) male participants. Participants mean age was 35.8 years (range 18-67). Short term (30 day) abstinence rate was 73.9% (113/153) and out of those 34.1% (31/91) abstained long term (6 months). Long term follow-up was 80.5% (91/113). Overall, long term quit rate was 23.7% (31/131). There were no statistically significant differences in short and long term quit rates depending on age, sex, education, employment or socio-economic status, pack-year measure or personal success estimates.

Lessons

Comprehensive contest approach was found to be effective in helping smokers quit. Interest for implementation was shown by several counties and cities in Croatia. Effectiveness regardless of personal and social characteristics of contestants shows potential in different settings.

Key messages

Comprehensive interventions that include contest, financial incentives, individual approach and triggers in smoking cessation helped one in four involved smokers to quit. This approach has potential for implementation in diverse local communities as no difference in quit rates in different sex, age or socioeconomic groups were detected.

Application of the design of experiments in optimization of drug layering of pellets with an insight into drug polymer interactions

This study consists of two experimental designs. Within the first one, suitable technique for application of model drug onto inactive pellets was evaluated and formulation and process parameters with greatest impact to process efficency and useful yield were determined. Results of experiments showed that formulation characteristics were the ones with the greatest impact on coating efficiency and that suspension layering technique was significantly better for drug application onto inactive pellets in comparison to solution layering during which pronounced agglomeration of pellets occurred. Analysis of drug-polymer interactions by differential scanning calorimetry was performed to explain the results of experiments. The reason for agglomeration of pellets during solution layering was formation of low Tg amorphous form of model drug. The second set of experiments was performed according to central composite design experimental plan in order to optimize level of binder and concentration of solids in the coating liquid which were found to have greatest positive impact on process efficiency and useful yield in the screening study. Statistically significant models were obtained by response surface methodology and it was possible to use them to define optimal levels of excipients in the formulation.

Cold growth behaviour and genetic comparison of Canadian and Swiss Listeria monocytogenes strains associated with the food supply chain and human listeriosis cases

Sixty-two strains of Listeria monocytogenes isolated in Canada and Switzerland were investigated. Comparison based on molecular genotypes confirmed that strains in these two countries are genetically diverse. Interestingly strains from both countries displayed similar range of cold growth phenotypic profiles. Based on cold growth lag phase duration periods displayed in BHI at 4 °C, the strains were similarly divided into groups of fast, intermediate and slow cold adaptors. Overall Swiss strains had faster exponential cold growth rates compared to Canadian strains. However gene expression analysis revealed no significant differences between fast and slow cold adapting strains in the ability to induce nine cold adaptation genes (lmo0501, cspA, cspD, gbuA, lmo0688, pgpH, sigB, sigH and sigL) in response to cold stress exposure. Neither was the presence of Stress survival islet 1 (SSI-1) analysed by PCR associated with enhanced cold adaptation. Phylogeny based on the sigL gene subdivided strains from these two countries into two major and one minor cluster. Fast cold adaptors were more frequently in one of the major clusters (cluster A), whereas slow cold adaptors were mainly in the other (cluster B). Genetic differences between these two major clusters are associated with various amino acid substitutions in the predicted SigL proteins. Compared to the EGDe type strain and most slow cold adaptors, most fast cold adaptors exhibited five identical amino acid substitutions (M90L, S203A/S203T, S304N, S315N, and I383T) in their SigL proteins. We hypothesize that these amino acid changes might be associated with SigL protein structural and functional changes that may promote differences in cold growth behaviour between L. monocytogenes strains.

Microbiological survey of imported produce available at retail across Canada

Increasing consumption and year-round consumer demand for fresh, minimally processed green vegetables have been observed in Canada and other developed countries. However, in the past two decades, produce has been increasingly implicated in outbreaks and correspondingly recognized as a vector for the transmission of pathogenic microorganisms. To this end, we examined the microbiological quality of imported produce available at retail across Canada during a period of limited domestic availability. In total, 106 samples obtained from five Canadian cities were purchased from retail outlets and subjected to microbiological analyses, including aerobic plate (APC) and coliform counts, and enrichments for enterococci, indicator Escherichia coli, E. coli O157:H7 and Salmonella spp. Also, recovered Enterococcus faecalis and Enterococcus faecium were screened for antimicrobial resistance (AMR). Overall, samples included herbs (n=61), leafy greens (n=25), and spinach (n=20) deriving from five countries (Columbia, Dominican Republic, Guatemala, Mexico, and the United States [US]). APCs were consistent across commodities regardless of country, ranging from mean log10 CFU/g of 6.1 to 7.4, with no significant differences observed. Excluding a single leafy green sample from Guatemala, the lowest prevalence of coliforms was for Mexican herbs (22.2%), with a high of 66.7% on US leafy greens. With the exception of spinach, concentrations of coliforms varied widely, ranging from undetectable to too numerous to count (>8.5 log10 CFU/g). Of the commodities assessed, Mexican and US spinach had the lowest coliform concentrations (undetectable to 4.0 log10 CFU/g). Organic herbs and conventional leafy greens possessed significantly lower (p<0.05) prevalence of coliforms compared to conventional herbs and organic leafy greens, respectively. The most frequent recovery of indicator E. coli was observed for herbs, with 11.1, 8.3, and 3.7% prevalence observed in samples from Columbia, US, and Mexico, respectively. For spinach, 0 and 6.7% of Mexican and US samples tested positive, while no leafy green samples from either country were positive. No E. coli O157:H7 or Salmonella spp. were detected. E. faecium and E. faecalis were recovered from 15.1 and 5.7% of samples, respectively. Although no glycopeptide resistance was observed, resistance to other clinically relevant antibiotics was noteworthy in both species. Overall, though microbiological quality indicators were frequently high, E. coli O157:H7 and Salmonella were not detected. However, the presence of resistance and reduced susceptibility to clinically relevant antimicrobials in recovered enterococci demonstrate imported fresh produce may serve as a vehicle for the transmission of antimicrobial resistance across national borders.

Model building and intelligent acquisition with application to protein subcellular location classification

MOTIVATION

We present a framework and algorithms to intelligently acquire movies of protein subcellular location patterns by learning their models as they are being acquired, and simultaneously determining how many cells to acquire as well as how many frames to acquire per cell. This is motivated by the desire to minimize acquisition time and photobleaching, given the need to build such models for all proteins, in all cell types, under all conditions. Our key innovation is to build models during acquisition rather than as a post-processing step, thus allowing us to intelligently and automatically adapt the acquisition process given the model acquired.

RESULTS

We validate our framework on protein subcellular location classification, and show that the combination of model building and intelligent acquisition results in time and storage savings without loss of classification accuracy, or alternatively, higher classification accuracy for the same total acquisition time.

AVAILABILITY AND IMPLEMENTATION

The data and software used for this study will be made available upon publication at http://murphylab.web.cmu.edu/software and http://www.andrew.cmu.edu/user/jelenak/Software.

CONTACT

jelenak@cmu.edu.

Local cosine bases in two dimensions

We construct two-dimensional (2-D) local cosine bases in discrete time. Solutions are offered both for rectangular and nonrectangular lattices. In the case of nonrectangular lattices, the problem is solved by mapping it into a one-dimensional (1-D) equivalent problem.

Deinterlacing by successive approximation

We propose an algorithm for deinterlacing of interlaced video sequences. It successively builds approximations to the deinterlaced sequence by weighting various interpolation methods. A particular example given here uses four interpolation methods, weighted according to the errors each one introduces. Due to weighting, it is an adaptive algorithm. It is also time-recursive, since the motion-compensated part uses the previously interpolated frame. Furthermore, bidirectional motion estimation and compensation allow for better performance in the case of scene changes and covering/uncovering of objects. Experiments are run both on "real-world" and computer generated sequences. Finally, subjective testing is performed to evaluate the quality of the algorithm.

Subband coding systems incorporating quantizer models

A new method for dealing with the effects of quantization in a subband system is proposed. It uses the "gain plus additive noise" linear model for the Lloyd-Max quantizer. Based on this, it is demonstrated how, by an appropriate choice of synthesis filters, one can cancel all signal-dependent errors at the output of the system. The only remaining error is random in nature and not correlated with the input signal. We therefore have a tradeoff between the error being only random or having signal-dependent components as well (since the error variances in both cases are comparable). As a result of having only a random error, it is possible to reduce this error using, for example, a noise removal technique. The result is then extended to the case where the input is a multidimensional signal, and arbitrary sampling lattices are used, as well as to the QMF (alias cancellation) case. To demonstrate the validity of the proposed approach, two types of experiments on images are carried out: In a toy example, it is shown that using noise removal could be beneficial. For a more realistic coding scheme, however, it is demonstrated that even in the case when the model is no longer valid (when some of the subbands are discarded), the output error is still much less correlated with the input signal as opposed to the commonly used subband system, while visually, the reconstructed images look very similar.

FCO sampling of digital video using perfect reconstruction filter banks

Three-dimensional nonseparable perfect reconstruction filter banks using three-dimensional nonseparable sampling by two, FCO, are proposed. Filter structures are derived and applied to digital video. Separation into two bands is obtained, and it is shown to perform better from the perceptual point of view than interlaced sequences resulting from the quincunx sampling of a progressively scanned signal in time-vertical dimensions.