The role of the home environment in the transmission of infectious diseases

Evaluating infection risks and importance of hand hygiene during the household laundry process using a quantitative microbial risk assessment approach

BACKGROUND

Contaminated laundry contributes to infectious disease spread in residential and home health care settings. The objectives were to (1) evaluate pathogen transmission risks for individuals doing laundry, and (2) compare hand hygiene timing to reduce risks.

METHODS

A quantitative microbial risk assessment using experimental data from a laundry washing effectiveness study was applied to estimate infection risks from SARS-CoV-2, rotavirus, norovirus, nontyphoidal Salmonella, and Escherichia coli in 4 laundry scenarios: 1 baseline scenario (no hand hygiene event) and 3 hand hygiene scenarios (scenario 1: after moving dirty clothes to the washing machine, scenario 2: after moving washed clothes to the dryer, and scenario 3: hand hygiene events following scenario 1 and 2).

RESULTS

The average infection risks for the baseline scenario were all greater than 2 common risk thresholds (1.0×10-6and 1.0×10-4). For all organisms, scenario 1 yielded greater risk reductions (39.95%-99.86%) than scenario 2 (1.35%-55.25%). Scenario 3 further reduced risk, achieving 1.0×10-6(SARS-CoV-2) and 1.0×10-4risk thresholds (norovirus and E. coli).

CONCLUSIONS

The modeled results suggest individuals should reduce hand-to-facial orifice (eyes, nose, and mouth) contacts and conduct proper hand hygiene when handling contaminated garments. More empirical data are needed to confirm the estimated risks.

DATA AVAILABILITY STATEMENT

The data and code that support the findings of this study can be retrieved via a Creative Commons Zero v1.0 Universal license in GitHub at https://github.com/yhjung1231/Laundry-QMRAproject-2022.git DOI: http://doi.org/10.5281/zenodo.7122065.

Bacteriophages from faecal contamination are an important reservoir for AMR in aquatic environments

Bacteriophages have been shown to play an important role in harbouring and propagating antibiotic resistance genes (ARGs). Faecal matter contains high levels of phages, suggesting that faecal contamination of water bodies may lead to increased antimicrobial resistance (AMR) levels due to increased phage loading in aquatic environments. In this study, we assessed whether faecal pollution of three rivers (Rivers Liffey, Tolka, and Dodder) was responsible for increased levels of ARGs in phage particles using established phage-faecal markers, focusing on four ARGs (blaTEM, tet(O), qnrS, and sul1). We observed all four ARGs in phage fractions in all three rivers, with ARGs more frequently observed in agricultural and urban sampling sites compared to their source. These findings highlight the role of faecal pollution in environmental AMR and the impact of agricultural and urban activities on water quality. Furthermore, our results suggest the importance of including phages as indicators when assessing environmental AMR, as they serve as significant reservoirs of resistance genes in aquatic environments. This study provides important insights into the role of faecal pollution and phages in the prevalence of AMR in the environment and the need for their inclusion in future studies to provide a comprehensive understanding of environmental AMR.

Effect of neighborhood deprivation index on breast cancer survival in the United States

PURPOSE

To analyze the association between the Neighborhood Deprivation Index (NDI) and clinical outcomes of locoregional breast cancer (BC).

METHODS

Surveillance, Epidemiology and End Results (SEER) database is queried to evaluate overall survival (OS) and disease-specific survival (DSS) of early- stage BC patients diagnosed between 2010 and 2016. Cox multivariate regression was performed to measure the association between NDI (Quintiles corresponding to most deprivation (Q1), above average deprivation (Q2), average deprivation (Q3), below average deprivation (Q4), least deprivation (Q5)) and OS/DSS.

RESULTS

Of the 88,572 locoregional BC patients, 27.4% (n = 24,307) were in the Q1 quintile, 26.5% (n = 23,447) were in the Q3 quintile, 17% (n = 15,035) were in the Q2 quintile, 13.5% (n = 11,945) were in the Q4 quintile, and 15.6% (n = 13,838) were in the Q5 quintile. There was a predominance of racial minorities in the Q1 and Q2 quintiles with Black women being 13-15% and Hispanic women being 15% compared to only 8% Black women and 6% Hispanic women in the Q5 quintile (p < 0.001). In multivariate analysis, in the overall cohort, those who live in Q2 and Q1 quintile have inferior OS and DSS compared to those who live in Q5 quintile (OS:- Q2: Hazard Ratio (HR) 1.28, Q1: HR 1.2; DSS:- Q2: HR 1.33, Q1: HR 1.25, all p < 0.001).

CONCLUSION

Locoregional BC patients from areas with worse NDI have poor OS and DSS. Investments to improve the socioeconomic status of areas with high deprivation may help to reduce healthcare disparities and improve breast cancer outcomes.

Effect of Neighborhood Deprivation Index on Breast Cancer Survival in the United States

Purpose To analyze the association between the Neighborhood Deprivation Index (NDI) and clinical outcomes of early-stage breast cancer (BC). Methods Surveillance, Epidemiology and End Results (SEER) database is queried to evaluate overall survival (OS) and disease-specific survival (DSS) of early- stage BC patients diagnosed between 2010-2016. Cox multivariate regression was performed to measure the association between NDI (Quintiles corresponding to most deprivation (Q1), above average deprivation (Q2), average deprivation (Q3), below average deprivation (Q4), least deprivation (Q5)) and OS/DSS. Results Of the 88,572 early-stage BC patients, 27.4% (n = 24,307) were in the Q1 quintile, 26.5% (n = 23,447) were in the Q3 quintile, 17% (n = 15,035) were in the Q2 quintile, 13.5% (n = 11,945) were in the Q4 quintile, and 15.6% (n = 13,838) were in the Q5 quintile. There was a predominance of racial minorities in the Q1 and Q2 quintiles with Black women being 13-15% and Hispanic women being 15% compared to only 8% Black women and 6% Hispanic women in the Q5 quintile (p < 0.001). In multivariate analysis, in the overall cohort, those who live in Q2 and Q1 quintile have inferior OS and DSS compared to those who live in Q5 quintile (OS:- Q2: Hazard Ratio (HR) 1.28, Q1: HR 1.2; DSS:- Q2: HR 1.33, Q1: HR 1.25, all p < 0.001). Conclusion Early-stage BC patients from areas with worse NDI have poor OS and DSS. Investments to improve the socioeconomic status of areas with high deprivation may help to reduce healthcare disparities and improve breast cancer outcomes.

Evaluating food safety knowledge and practices among Saudi women in Al-Ahsa Region, Saudi Arabia

Foodborne illnesses are responsible for about half a million deaths annually, of which 30% occur among kids. This study aimed to assess the current food safety knowledge and practice level of Saudi women in Al-Ahsa region, Saudi Arabia. A cross-sectional study was conducted through personal interviews among 239 Saudi women. The questionnaire consisted of close-ended questions covering different aspects of food safety knowledge and practices at home and during shopping. Descriptive analyses were used to identify the level of participant's awareness, and the scores were shown in three categories (good - fair - poor) based on their food safety knowledge and practice awareness. The effect of socio-demographic characteristics and their correlation to food safety knowledge and practices was conducted using Chisquare analysis. The results about food safety knowledge showed that around 50% of participants achieved a good score, and 37.5% achieved a fair score, while 12.5% achieved a poor score. In comparison, the participants achieved 75% good score, whereas 12.5% achieved both fair and poor in food safety practices. The results also highlighted a significant correlation (P<0.05) between level of food safety knowledge, practices of participants and their age, marital status, work status, and educational level, while there's no correlation with their family size and total income. Although, the overall result showed good level in food safety knowledge and slightly less in food safety practices among Saudi women living in Al-Ahsa region, continuous education, training, awareness, and motivation are highly recommended to improve women's knowledge and practices to higher levels.

Antimicrobial Performance of Innovative Functionalized Surfaces Based on Enamel Coatings: The Effect of Silver-Based Additives on the Antibacterial and Antifungal Activity

Frequently touched surfaces (FTS) that are contaminated with pathogens are one of the main sources of nosocomial infections, which commonly include hospital-acquired and healthcare-associated infections (HAIs). HAIs are considered the most common adverse event that has a significant burden on the public's health worldwide currently. The persistence of pathogens on contaminated surfaces and the transmission of multi-drug resistant (MDR) pathogens by way of healthcare surfaces, which are frequently touched by healthcare workers, visitors, and patients increase the risk of acquiring infectious agents in hospital environments. Moreover, not only in hospitals but also in high-traffic public places, FTS play a major role in the spreading of pathogens. Consequently, attention has been devoted to developing novel and alternative methods to tackle this problem. This study planned to produce and characterize innovative functionalized enameled coated surfaces supplemented with 1% AgNO₃ and 2% AgNO₃. Thus, the antimicrobial properties of the enamels against relevant nosocomial pathogens including the Gram-positive Staphylococcus aureus and the Gram-negative Escherichia coli and the yeast Candida albicans were assessed using the ISO:22196:2011 norm.

Impoverishment Effect of Hydatid Disease and Precision Medical Assistance Pattern of Government: Evidence from Yushu in China

Hydatid disease is one of the 17 neglected tropical diseases recognized by WHO and causes a huge global disease burden. Hydatid disease poses a great threat to local medical poverty alleviation. In efforts to break the vicious circle of poverty, Hydatid disease has been widely concerned and discussed. In the practice of poverty alleviation in China, medical poverty alleviation is regarded as the double goal of getting rid of poverty and promoting the construction of a healthy China. On the basis of on-the-spot investigation in Yushu Prefecture, this paper conducts a follow up study on the poverty-causing effect of Hydatid disease and the precision medical assistance pattern of government using a field investigation method. The results show that Hydatid disease led to the increase of poverty in the population in Yushu Prefecture, precision medical assistance played an obvious role in treating Hydatid disease and poverty alleviation, the health service in the study area continues to improve and the medical backbone team further expanded. The main conclusion is that the three-level diagnosis and treatment framework can effectively reduce local poverty and improve people's living environment.

WASH and Health in Sindhupalchowk District of Nepal after the Gorkha Earthquake

An earthquake of magnitude 7.8 MW and 6.8 MW struck Nepal on 25 April and 12 May, 2015, respectively, which caused massive damage. In such crises, understanding the water, sanitation, and hygiene (WASH) situation is of paramount importance. Therefore, we aimed to assess the WASH situation and its impact on health, particularly in the Sindhupalchowk district. A questionnaire survey and microbial analysis of water samples were conducted. Descriptive statistics and parametric and non-parametric statistical tests were employed. The results revealed that 97.1% of water samples from the source during the pre-monsoon season and 98.5% during the monsoon season had fecal contamination. Similarly, 92.8% of water samples during the pre-monsoon season and 96.7% during the monsoon season at point of use (PoU) had fecal contamination. Furthermore, water consumption was comparatively less during the pre-monsoon season. The increase in water consumption improved hygiene behavior and lowered the prevalence of waterborne diseases. Similarly, less water consumption affected water handling behavior; for example, the cleaning interval of storage vessels was less frequent. An increase in cleaning interval resulted in fecal contamination of water at PoU. The findings of this study can be useful in the review of existing WASH policy and plans and integration with the disaster management plan for disaster risk reduction.

International ring trial to validate a new method for testing the antimicrobial efficacy of domestic laundry products

Due to greater environmental awareness, domestic laundry habits are changing, and antimicrobial control by chemical methods has become an essential factor to compensate for the use of lower temperatures during washing machine cycles. Disinfectants added to laundry detergents are a preventive strategy to reduce the transmission of bacteria, fungi, and viruses in the home, correct aesthetic damage (e.g., spotting, discolouration, and staining), and control the microbial contamination that leads to malodour. In Europe, disinfectants are regulated by the EU Biocidal Products Regulation (No. 528/2012), which stipulates that antimicrobial efficacy must be evaluated according to standardized methods. Current European standards for laundry sanitization only apply to clinical settings (EN 16616: 2015) and are restricted to the main wash cycle. Therefore, there is a gap in the EU standards regarding the testing of product efficacy in household laundering. With the aim of addressing this gap, an international ring trial was organized to evaluate the robustness of a new method (prEN 17658) designed to test the efficacy of antimicrobial laundry products in a domestic setting. The seven participating laboratories were equipped with 5 different laboratory-scale devices to simulate the washing process, and they evaluated 7 microbial parameters for 2 experimental conditions and 3 levels of active substance. The analysis of data according to ISO 5725–2 and ISO 13528 demonstrated that the method was robust. All reproducibility standard deviation values were between 0.00 and 1.40 and the relative standard deviation indicates satisfactory reproducibility. Values of logarithmic reduction ranged from less than 2 log₁₀ for tests with water to more than 5 log₁₀ when disinfectants were added. The evidence generated by the ring trial was presented in a proposal for a standardized method under CEN/TC 216, in which the SOP used in the ring trial is referred to as the prEN 17658 phase 2 step 2 test method covering chemothermal textile disinfection in domestic settings.

Development and validation of questionnaire to assess exposure of children to enteric infections in the rural northwest Ethiopia

In areas where children have multiple environmental exposures to enteric pathogens, identifying the sources of exposure by measuring external and internal exposures to enteric pathogens and complementing by questionnaire and observational checklist to capture behaviors resulting risk of exposure is critical. Accordingly, this study was conducted to design valid and reliable questionnaire to assess behaviors and environmental conditions resulting exposure to enteric pathogens in the rural northwest Ethiopia. We began with a thorough exploration of relevant literature to understand the theoretical framework on the research objectives to identify variables to highlight what the questionnaire is measuring. We then generated items in each domain that can effectively address the study objectives and we refined and organized the items in a suitable format. Then after, we conducted face and content validity by involving experts on the research subject. After pre-testing a pre-final version of the instrument generated in the content validity study, we conducted a pilot study in 150 randomly selected rural households to test the internal consistency reliability. We used content validity ratio (CVR), item-level content validity index (I-CVIs), scale-level content validity index (S-CVI/UA), and modified kappa statistics to measure content validity of items. Moreover, we used agreement and consistency indices (i.e., Cronbach's alpha) to assess the internal consistency of items. The content validity test result showed that the value of CVR was 0.95, I-CVIs was 0.97, and modified kappa was 0.97 for the whole items, indicating all the items are appropriate. The scale-level content validity index (S-CVI/UA) was 0.95 for the whole items indicating the agreement among judges to each items is higher. The internal consistency reliability test result indicated that Cronbach's alpha for the pre-final version of the pre-final tool was 0.85, indicating the strong reliability of the tool. The final version of the questionnaire was, therefore, prepared with 8 dimensions and 80 items. In this study, we designed valid and reliable questionnaire to assess behaviors and environmental conditions that result high risk of exposure to enteric infections in rural settings. The questionnaire can be used as a tool in the rural settings of developing countries with some amendments to account local contexts. However, this questionnaire alone does not measure exposure of children to enteric infections. It only complements external and internal exposure assessments.

Fecal indicator bacteria along multiple environmental exposure pathways (water, food, and soil) and intestinal parasites among children in the rural northwest Ethiopia

Background

Children in low-resource settings are exposed to multiple risk factors for enteropathogens. However, the probability of exposures may be different across exposure pathways. Accordingly, this study was conducted to assess environmental exposures of children to intestinal parasites in the east Dembiya district of Ethiopia.

Methods

A cross-sectional study was conducted for 372 households with children aged 24–59 months. The potential for external exposure of children to intestinal parasites was assessed by determining the presence of fecal indicator organism (Escherichia coli (E. coli)) in drinking water at point of use, ready-to-eat foods, and courtyard soil from children’s outdoor play areas. For internal exposure assessment, ova of parasites in stool samples was detected using wet mount and Kato-Katz techniques to estimate exposure to intestinal parasites. The external and internal exposure assessments were also complemented using questionnaire and spot-check observations to assess behaviors that result in high risk of exposure. Individual and community-level predictors of intestinal parasites were identified using a multilevel logistic regression model. Statistically significant variables were identified on the basis of adjusted odds ratio (AOR) with 95% confidence interval (CI) and p-value < 0.05.

Results

Ova of one or more intestinal parasites was detected among 178 (47.8%) (95% CI 42.8, 52.6%) of the children. The most common intestinal parasites were A. lumbricoides (20.7%) and S. mansoni (19.1%). Furthermore, E. coli was detected in 69.1% of drinking water samples at point of use, 67.5% of ready-to-eat food samples, and 83.1% of courtyard soil samples from children’s outdoor play areas. Exposure of children to intestinal parasites among children in the studied region was associated with poor hand hygiene of mothers (AOR 1.98, 95% CI (1.07, 3.66), poor hand hygiene of children (AOR 3.20, 95% CI (1.77, 5.77), mouthing of soil contaminated materials (AOR 2.31, 95% CI (1.26, 4.24), open defecation practices (AOR 2.22, 95% CI (1.20, 4.10), limited access to water (AOR 2.38, 95% CI (1.13, 5.01), water contamination (AOR 2.51, 95% CI (1.31, 4.80), food contamination (AOR 3.21, 95% CI (1.69, 6.09), and soil contamination (AOR 2.56, 95% CI (1.34, 4.90).

Conclusion

An extensive E. coli contamination of water, foods, and courtyard soil was found in the studied region and the potential sources of contamination were open defecation practices, unhygienic disposal of wastes, poor animal husbandry and keeping practices, and poor water and food safety measures at household level. Moreover, fecal contamination of water, foods, and soil linked to exposure of children to intestinal parasites in the studied region. Thus, it is critical to implement individual-level interventions (such as latrine utilization, hand hygiene promotion, food safety, home-based water treatment, and containment of domestic animals), plus community-level interventions (such as protecting water sources from contamination, source-based water treatment, and community-driven sanitation).

An assessment of the health risks associated with shared sanitation: a case study of the community ablution blocks in Durban, South Africa

Shared sanitation facilities have been hailed as an innovative approach to solve the challenge with sanitation access. However, these facilities may act as hotspots for disease transmission due to unhygienic conditions. In this study we used quantitative (based on Escherichia coli contamination) techniques to assess the health risks associated with the use of community ablution blocks (CABs). The most contaminated surfaces were the cistern handle (5.7 Log₁₀ cfu/cm²) and internal pull latch (5.8 Log₁₀ cfu/cm²). Based on the E. coli contamination, at least two people out of 100 CAB users might be potentially infected when they touch "hot" surfaces. These risks were modelled assuming transfer of potentially pathogenic E. coli from these surfaces to the mouth. The incorporation of risk-reduction measures, such as wiping of these surfaces or washing of hands, could potentially result in significant reduction of infection risks. The most significant risk-reduction intervention was determined to be wiping of the contact surfaces, especially twice prior to contact. A combination of risk-reduction interventions could further reduce the risks. This study shows that contamination of contact surfaces within shared CABs could lead to increased risks of infections, requiring measures aimed at reducing the associated risks. The risk assessment framework used in this study could therefore be applied in similar settings to estimate associated health risks with the use of such facilities.

All alone: A qualitative study of home health aides' experiences during the COVID-19 pandemic in New York

BACKGROUND

Despite their integral role, Home Health Aides (HHAs) are largely unrecognized as essential to implementing effective infection prevention and control practices in the home healthcare setting. We sought to understand the infection prevention and control needs and challenges associated with caring for patients during the pandemic from the perspective of HHAs.

METHODS

From June to August 2020, data were collected from HHAs in the New York metropolitan area using semi-structured qualitative interviews by telephone; 12 HHAs were interviewed in Spanish. Audio-recorded interviews were transcribed, translated and analyzed using conventional content analysis.

RESULTS

In total, 25 HHAs employed by 4 unique home care agencies participated. HHAs had a mean age of 49.8 (± 9.1), 24 (97%) female, 11 (44%) Black, 12 (48%) Hispanic. Three major themes related to the experience of HHA's working during the COVID-19 pandemic emerged: (1) all alone, (2) limited access to information and resources, and (3) dilemmas related to enhanced COVID-19 precautions. Hispanic HHAs with limited English proficiency faced additional difficulties related to communication.

CONCLUSIONS

We found that HHA communication with nursing staff, plays a key role in infection control efforts in home care. Efforts to manage COVID-19 in home care should include improving communication between HHAs and nursing staff.

Effect of extremely low-concentration gaseous chlorine dioxide against surface Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii in wet conditions on glass dishes

Objective

Healthcare-associated infections due to Gram-negative bacteria (GNB) are a major cause of mortality and morbidity throughout the world. The purpose of the research described here was to evaluate the possibility of using an extremely low-concentration gaseous chlorine dioxide (ClO₂, 0.01 ppmv, 0.028 mg/m³) as a technique to reduce the risk of environmental infection by GNB. In this study we set up an exposure chamber (1 m³) and used three types of GNB, namely Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii.

Results

The extremely low-concentration gaseous ClO₂ inactivated E. coli (> 2 log₁₀ reductions, within 2 h), P. aeruginosa (> 4 log₁₀ reductions, within 2 h) and A. baumannii (> 2 log₁₀ reductions, within 3 h) in wet conditions on glass dishes. Treatment of moist environments with extremely low-concentration gaseous ClO₂ may help to reduce the risk of environmental infection by GNB without harmful effects.

The Effectiveness of a Poster Intervention on Hand Hygiene Practice and Compliance When Using Public Restrooms in a University Setting

Background: Most research on hand hygiene compliance in community settings indicates that compliance is poor. It is not conclusive as to whether poster interventions are effective at improving compliance. Methods: An independent, self-designed poster intervention was installed in one set of male and female public restrooms in a university campus in the UK. The hand hygiene practice and compliance of the university population was measured via indirect observation over a 60 day period. Results: During the pre-intervention observation period, 51.09% of the university population practiced basic hand hygiene compliance (washed hands with water, soap and dried afterwards), and 7.88% practiced adequate hand hygiene compliance (washed hands with water and soap for 20 s or more and dried afterwards for 20 s or more). During the post-intervention observation period, 55.39% of the university population were observed practicing basic hand hygiene compliance, and 7.97% practicing adequate hand hygiene compliance. Gender differences revealed that more females practiced basic hand hygiene in the post-intervention observation period (62.81%) than during the pre-intervention period (49.23%) and this was statistically significant (χ² = 13.49, p = < 0.01). Discussion: The poster intervention had a limited effect on improving the basic and adequate hand hygiene compliance of the general population when using public restrooms. The use of independent, self-designed posters to improve hand hygiene practice and compliance is largely ineffective in the short term and should be used with caution in future intervention strategies.

Avoiding bites and scratches? Understanding the public health implication of human-bat interactions in Ghana

Zoonotic pathogens cause an estimated 70% of emerging and re-emerging infectious diseases in humans, affecting various aspects of human development on a global scale. The significance of bats as a source of emerging infectious diseases is being progressively appreciated. This study was undertaken post-Ebola virus disease in West Africa and assessed the public health implications of human-bat interactions by exploring the reasons for contact between humans and bats, as well as reported actions taken upon experiencing bat bites or scratches. The paper highlights the nuances of human-bat interactions, stressing zoonotic disease risk awareness as well as the sources of information. The study used questionnaires to solicit information from 788 respondents in five communities with significant bat populations. We show that bat consumption was one of the main reasons for human-bat interactions. More men across the various communities ate bat meat. Only a small number of respondents (4.4%) reported being bitten by a bat, and 6.1% had been scratched by a bat. More than 21% had come into direct contact with bat blood. An even lower number went to the hospital after been bitten or scratched by bats. There was little knowledge on post-exposure management. The most common places human-bat interactions occurred were at home and on farms. Seventy-three per cent of the respondents believed that bats carried diseases, with Ebola virus disease being the most mentioned. Respondents indicated that the way they interacted with bats had not changed, even though they believed bats carried diseases and 46% stated that they had not changed the way they interacted with bats over the last two years. Apart from providing information on avoiding bites and scratches, a more holistic framework is needed to reduce human-bat interactions. The paper recommends a comprehensive and coordinated approach to optimizing an effective response to a potential bat-borne zoonotic disease spillover.

How clean is your house? A study of house dust mites, allergens and other contents of dust samples collected from households

Household dust contains an array of constituents, including house dust mites (HDM) and the HDM allergen, Der p 1, which can cause sensitivities such as asthma and eczema. Vacuuming can help alleviate symptoms, yet little is understood about cleaning behaviour in different households. This pilot study investigated the contents of dust from four household types (students; over 65 s; and families with and without pets). This was then related to cleaning behaviours and perceptions of cleanliness. Our investigation found that HDMs and Der p 1 were present in all households and sampling locations, including participants' cars. The median Der p 1 was greatest in the living room, though results varied. Demographic group was a determinant for the number of human and pet hairs present in dust. Surprisingly, vacuuming was the most disliked task overall. This information requires consideration when developing cleaning products and advising individuals with dust-related health issues.

Food Safety Knowledge and Practices of Male Adolescents in West of Iran

BACKGROUND:

Every year many people around the world become infected with food-borne infections. Insufficient knowledge and skills related to food safety and hygiene are among the factors affecting the incidence of food-borne diseases, especially in adolescents.

AIM:

The purpose of this study was to determine the knowledge and practices associated with food safety and hygiene in Ilam city male adolescents.

MATERIAL AND METHODS:

Three hundred and eighty of male adolescents aged 13 to 19 were selected randomly and entered the cross-sectional study. Data were collected using a researcher-made questionnaire From December 2016 to February 2017. Descriptive statistics, Pearson correlation, independent t-test and one-way ANOVA were used to analyse the data in SPSS software (version 19.0).

RESULTS:

The findings of the study showed a positive and significant relationship between knowledge and practices related to food safety and hygiene (r = 0.122; p = 0.018). Also, the findings showed that food safety knowledge and practice of adolescents were significantly affected by the level of their education, parental education level, parental employment status and household economic conditions, (p < 0.005). Also, the results showed that the participants generally obtained 57.74% of the knowledge score and 57.63% of practices score. The subjects had the most knowledge about food supply and storage (60%), and the highest practice was related to personal and environmental hygiene, (61.73%).

CONCLUSION:

The inadequacy of knowledge and performance of adolescents about food safety and hygiene shows the need for implementation of health education interventions in this area.

Surveillance of surgical site infections by Pseudomonas aeruginosa and strain characterization in Tanzanian hospitals does not provide proof for a role of hospital water plumbing systems in transmission

Background

The role of hospital water systems in the development of Pseudomonas aeruginosa (P. aeruginosa) surgical site infections (SSIs) in low-income countries is barely studied. This study characterized P. aeruginosa isolates from patients and water in order to establish possible epidemiological links.

Methods

Between December 2014 and September 2015, rectal and wound swabs, and water samples were collected in the frame of active surveillance for SSIs in the two Tanzanian hospitals. Typing of P. aeruginosa was done by multi-locus sequence typing.

Results

Of 930 enrolled patients, 536 were followed up, of whom 78 (14.6%, 95% CI; 11.6–17.5) developed SSIs. P. aeruginosa was found in eight (14%) of 57 investigated wounds. Of the 43 water sampling points, 29 were positive for P. aeruginosa. However, epidemiological links to wound infections were not confirmed. The P. aeruginosa carriage rate on admission was 0.9% (8/930). Of the 363 patients re-screened upon discharge, four (1.1%) possibly acquired P. aeruginosa during hospitalization. Wound infections of the three of the eight P. aeruginosa SSIs were caused by a strain of the same sequence type (ST) as the one from intestinal carriage. Isolates from patients were more resistant to antibiotics than water isolates.

Conclusions

The P. aeruginosa SSI rate was low. There was no evidence for transmission from tap water. Not all P. aeruginosa SSI were proven to be endogenous, pointing to other routes of transmission.

Effectiveness of UV-C light irradiation on disinfection of an eSOS(®) smart toilet evaluated in a temporary settlement in the Philippines

Ultraviolet germicidal (short wavelength UV-C) light was studied as surface disinfectant in an Emergency Sanitation Operation System(®) smart toilet to aid to the work of manual cleaning. The UV-C light was installed and regulated as a self-cleaning feature of the toilet, which automatically irradiate after each toilet use. Two experimental phases were conducted i.e. preparatory phase consists of tests under laboratory conditions and field testing phase. The laboratory UV test indicated that irradiation for 10 min with medium-low intensity of 0.15-0.4 W/m(2) could achieve 6.5 log removal of Escherichia coli. Field testing of the toilet under real usage found that UV-C irradiation was capable to inactivate total coliform at toilet surfaces within 167-cm distance from the UV-C lamp (UV-C dose between 1.88 and 2.74 mW). UV-C irradiation is most effective with the support of effective manual cleaning. Application of UV-C for surface disinfection in emergency toilets could potentially reduce public health risks.

Bactericidal and Fungicidal Activity in the Gas Phase of Sodium Dichloroisocyanurate (NaDCC)

Sodium dichloroisocyanurate (NaDCC) is usually employed as a disinfectant for the treatment of water, environmental surfaces and medical equipment principally for its effectiveness as a microbicide agent. In this study, we explore the possibility of a new use for NaDCC by investigating the microbicidal activity of chlorine, which derives from the hydrolysis of NaDCC mediated by air humidity, and by testing its effect on the neutralization of microbes present in domestic waste. NaDCC was inserted in a plastic garbage can where LB agar plates, with different dilutions of a known title of four different microorganisms (Escherichia coli, Staphylococcus aureus, Debaryomyces hansenii and Aspergillus brasiliensis), were weakly inserted. The molecular chlorine (Cl2) levels present in the garbage can were quantified using an iodometric titration. The gas emitted in the garbage can presented a strong microbicide effect, inhibiting the proliferation of all four microorganisms and for four consecutive weeks, thus showing that NaDCC hydrolysis, mediated by air humidity, is able to ensure the decontamination of restricted environments, avoiding the proliferation of both Gram-positive and Gram-negative bacteria as well as fungi.

Impact of disinfectant wipes on the risk of Campylobacter jejuni infection during raw chicken preparation in domestic kitchens

AIMS

In the present study, we conducted a quantitative microbial risk assessment forecasting the exposure to Campylobacter jejuni contaminated surfaces during preparation of chicken fillets and how using a disinfectant-wipe intervention to clean a contaminated work area decreases the risk of infection following the preparation of raw chicken fillet in a domestic kitchen.

METHODS AND RESULTS

Using a Monte Carlo simulation of the risk of transferring Camp. jejuni strain A3249, from various surfaces to hands and subsequently transferring it to the mouth was forecasted. The use of a disinfectant-wipe intervention to disinfect contaminated surface area was also assessed. Several assumptions were used as input parameters in the classical Beta-Poisson model to determine the risk of infection. The disinfectant-wipe intervention reduced the risk of Camp. jejuni infection by 2-3 orders on all fomites.

CONCLUSIONS

The use of disinfectant wipes after the preparation of raw chicken meat reduces the risk of Camp. jejuni infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

This risk assessment shows that the use of disinfectant wipes to decontaminate surface areas after chicken preparation reduces the annual risk of Camp. jejuni infections up to 99·2%, reducing the risk from 2 : 10 to 2 : 1000.

Pseudomonas aeruginosa in CF and non-CF homes is found predominantly in drains

BACKGROUND

For patients with cystic fibrosis (CF) Pseudomonas aeruginosa infection is a major contributor to progressive lung disease. While colonizing strains are thought to be primarily environmental, which environments are important in lung colonization is unclear.

METHODS

We took 11,674 samples from a broad range of sites over 3-8 visits to homes with (7) and without (8) CF patients.

RESULTS

Twenty-eight percent of sampled drains yielded P. aeruginosa at least once, and a general mixed linear model estimated that 6.3% of samples from drains yield P. aeruginosa. This is more than eight times the estimated recovery from any other type of household environment.

CONCLUSIONS

These findings implicate drains as important potential sources of P. aeruginosa infection. They suggest that maximizing P. aeruginosa control efforts for drains would reduce exposure with minimal extra burden to CF patients and families.

A comparison of the sensitivity of four Staphylococcus aureus isolates to two chlorine-based disinfectants and an eco-friendly commercially available cleaning agent

The aim of this study was to determine the effect of household bleach, a sodium dichloroisocyanurate (NaDCC)-based disinfectant and an eco-friendly cleaning agent (EFCA) on four Staphylococcus aureus strains, including two isolated from community infections. The products were assessed using the suspension (EN 1276) and surface (EN 13697) tests, while biofilm activity was determined using the 96-well plate method. Bleach and NaDCC caused > 5 log reduction in viable counts within 5 min in suspension, whilst on surfaces the reduction was < 3 log. Bleach at 5000 ppm free available chlorine completely eradicated MSSA NCTC 13297 and PVL CA MSSA biofilms within 10 min, but not at 500 and 50 ppm, NaDCC was less effective against biofilms. The EFCA demonstrated no antimicrobial activity. It is of concern that at the recommended "use" dilution, bleach did not eradicate biofilms. Although increasing contact time and/or concentration should improve the activity, this may not be acceptable to the user.

Development and Piloting of a Food Safety Audit Tool for the Domestic Environment

Research suggests that consumers often mishandle food in the home based on survey and observation studies. There is a need for a standardized tool for researchers to objectively evaluate the prevalence and identify the nature of food safety risks in the domestic environment. An audit tool was developed to measure compliance with recommended sanitation, refrigeration and food storage conditions in the domestic kitchen. The tool was piloted by four researchers who independently completed the inspection in 22 homes. Audit tool questions were evaluated for reliability using the κ statistic. Questions that were not sufficiently reliable (κ < 0.5) or did not provide direct evidence of risk were revised or eliminated from the final tool. Piloting the audit tool found good reliability among 18 questions, 6 questions were revised and 28 eliminated, resulting in a final 24 question tool. The audit tool was able to identify potential food safety risks, including evidence of pest infestation (27%), incorrect refrigeration temperature (73%), and lack of hot water (>43 °C, 32%). The audit tool developed here provides an objective measure for researchers to observe and record the most prevalent food safety risks in consumer's kitchens and potentially compare risks among consumers of different demographics.

Increasing quinolone resistance and multidrug resistant isolates among Salmonella enterica in Hong Kong

OBJECTIVES

To study the antimicrobial susceptibility and molecular epidemiology of Salmonella enterica isolates from 2005 to 2010 in Hong Kong.

METHODS

S. enterica isolates from 2005 to 2010 in one of the hospital clusters were serotyped and studied their antimicrobial susceptibility by determining the minimal inhibitory concentration of 17 antimicrobial agents and their relatedness by pulsed-field gel electrophoresis (PFGE).

RESULTS

A total of 60 S. enterica serovars were identified among the 963 strains of Salmonella from 2005 to 2010. Enteritidis (47.3%) and Typhimurium (17.2%) were the two most common serovars. Ciprofloxacin non-susceptibility increased significantly from 39.3% in 2005 to 63% in 2010 (p < 0.05) and the percentage of multidrug resistant strains increased from 17.8% in 2005 to 36.2% in 2010 (p < 0.05). However, resistance to the third generation cephalosporins (1.4%) remained low. More strains of S. Typhimurium than other Salmonella serovars were resistant to the antimicrobial agents tested than S. Enteritidis. PFGE analysis showed there were predominant clones of S. Enteritidis, S. Typhimurium and S. Stanley circulating in the community, and two outbreaks caused by S. Enteritidis and S. Virchow during the study period.

CONCLUSIONS

The study showed both a worrying percentage of Salmonella strains resistant to quinolone and of multidrug resistant strains. PFGE identified two outbreaks in the study period.

Community perceptions of infectious diseases, antibiotic use and antibiotic resistance in context of environmental changes: a study in Odisha, India

BACKGROUND

The public health impact of environmental changes and the faceless threat of antibiotic resistance are currently among the top global health challenges. Community understanding of health, diseases and medicines in relation to the changing environment is necessary to mitigate the impact of these changes on health and for prudent use of antibiotics.

OBJECTIVE

The objective is to explore community perceptions of infectious diseases, antibiotic use and antibiotic resistance in the context of environmental changes.

METHODS

A qualitative study was conducted among community members with various backgrounds in education, gender, age and occupation of two districts of Odisha, India. Eight focus groups discussions and ten individual interviews were conducted. Data were analysed using content analysis.

RESULTS

Two themes emerged: 'Interpretation of infectious diseases and health hazards in the context of environmental changes', and 'Understanding of antibiotic use and its consequences for resistance development and the environment'. The participants perceived that nowadays there is irregularity in the occurrence of seasons, particularly an increase in average temperature, which is influencing health. Participants' perceptions of infectious diseases, antibiotic use and resistance varied according to their social environment. Furthermore, they perceived that improved sanitation, choice of alternative medicine and awareness and education on prudent use of antibiotics are probably some ways to prevent antibiotic resistance.

CONCLUSIONS

The participants perceived that climate variability is increasing and that this has health consequences for the community. They also hypothesized an interrelationship between the environment, infectious diseases and medicine use, particularly antibiotics. This is helpful for further empirical studies.

A model of the transmission of micro-organisms in a public setting and its correlation to pathogen infection risks

AIM

Gastro-intestinal infections are widespread in the community and have considerable economic consequences. In this study, we followed chains of infection from a public toilet scenario, looking at infection risks by correlating the transmission of bacteria, fungi and viruses to our current knowledge of infectious doses.

METHODS AND RESULTS

Transmission of Escherichia coli, Bacillus atrophaeus spores, Candida albicans and bacteriophage MS2 from hands to surfaces was examined in a transmission model, that is toilet brush, door handle to water tap. The load of viable pathogens was significantly reduced during transfer from hands to objects. Nevertheless, it was shown that pathogens were successfully transferred to other people in contagious doses by contact with contaminated surfaces.

CONCLUSIONS

Our results suggest that infection risks are mainly dependent on current infectious doses of pathogens. For enteritic viruses or bacteria, for example Norovirus or EHEC, only a few particles or cells are sufficient for infection in public lavatories, thus bearing a high risk of infection for other persons. However, there seems to be only a low probability of becoming infected with pathogens that have a high infectious dose whilst sharing the same bathroom.

SIGNIFICANCE AND IMPACT OF THE STUDY

The transmission model for micro-organisms enables a risk assessment of gastro-intestinal infections on the basis of a practical approach.

Effect of low-concentration chlorine dioxide gas against bacteria and viruses on a glass surface in wet environments

Aims:  To evaluate the efficacy of low‐concentration chlorine dioxide (ClO₂) gas against model microbes in the wet state on a glass surface.

Methods and Results:  We set up a test room (39 m³) and the ClO₂ gas was produced by a ClO₂ gas generator that continuously releases a constant low‐concentration ClO₂ gas. Influenza A virus (Flu‐A), feline calicivirus (FCV), Staphylococcus aureus and Escherichia coli were chosen as the model microbes. The low‐concentration ClO₂ gas (mean 0·05 ppmv, 0·14 mg m⁻³) inactivated Flu‐A and E. coli (>5 log₁₀ reductions) and FCV and S. aureus (>2 log₁₀ reductions) in the wet state on glass dishes within 5 h.

Conclusions:  The treatment of wet environments in the presence of human activity such as kitchens and bathrooms with the low‐concentration ClO₂ gas would be useful for reducing the risk of infection by bacteria and viruses residing on the environmental hard surfaces without adverse effects.

Significance and Impact of the Study:  This study demonstrates that the low‐concentration ClO₂ gas (mean 0·05 ppmv) inactivates various kinds of microbes such as Gram‐positive and Gram‐negative bacteria, enveloped and nonenveloped viruses in the wet state.

Food safety at home: knowledge and practices of consumers

Aim

To define food safety and risk perception of foodborne diseases in the private home setting and identify specific behaviours during food purchase, storage and preparation in a large survey study.

Subject and methods

A large sample of individuals (n = 1,000) living in the area of Cassino, Italy, volunteered to participate in the study. All participants were randomly recruited and underwent a questionnaire-based interview at their home regarding food-safety measures. Logistic regression analyses were used to test for correlations between demographic characteristics and knowledge/behaviours of food diseases. Risks of hazardous practices in the home were calculated according to educational, physical, occupational and marital status. All analyses were performed using the EPIINFO 3.5 statistical program.

Results

Our data showed that there was an insufficient amount of knowledge regarding foodborne diseases and pathogens. In most families, we found that there was a lack of correct adherence to food hygiene, mainly due to errors during both food preparation and storage. There was a higher risk for food safety errors in families with children, older persons and pregnant women.

Conclusion

Our findings confirm that the home environment represents an important site for the spread of pathogens responsible for foodborne diseases. In order to adopt good hygiene practices in the home setting, consumers need to be informed about safety procedures of domestic food handling, storage and preparation.

Quantifying school officials' exposure to bacterial pathogens at graduation ceremonies using repeated observational measures

The purpose of this study was to estimate the risk of acquiring pathogenic bacteria as a result of shaking hands at graduation ceremonies. School officials participating in graduation ceremonies at elementary, secondary, and postsecondary schools were recruited. Specimens were collected before and immediately following graduation. Cultures identified any pathogenic bacteria in each specimen. Subjects shook a total of 5,209 hands. Staphylococcus aureus was separately detected on one pregraduation right hand, one postgraduation right hand, and one postgraduation left hand. Nonpathogenic bacteria were collected in 93% of specimens. Pregraduation and postgraduation specimens were of different strains. We measured a risk of one new bacterial acquisition in a sample exposed to 5,209 handshakes yielding an overall estimate of 0.019 pathogens acquired per handshake. We conclude that a single handshake at a graduation offers only a small risk of bacterial pathogen acquisition.

Skin microbiota: microbial community structure and its potential association with health and disease

Skin, the largest human organ, is a complex and dynamic ecosystem inhabited by a multitude of microorganisms. Host demographics and genetics, human behavior, local and regional environmental characteristics, and transmission events may all potentially drive human skin microbiota variability, resulting in an alteration of microbial community structure. This alteration may have important consequences regarding health and disease outcomes among individuals. More specifically, certain diversity patterns of human microbiota may be predictive or diagnostic of disease. The purpose of this review is to briefly describe the skin microbiota, outline the potential determining factors driving its variability, posit the likelihood of an association between the resulting microbial community structure on the skin with disease outcomes among individuals, and finally, to present some challenges and implications for studying the skin microbiota.

Impact of prescribed cleaning and disinfectant use on microbial contamination in the home

AIMS

To identify and quantify the presence of Escherichia coli, Staphylococcus aureus, Salmonella, hepatitis A and norovirus in households and to assess the effect of chlorine and quaternary ammonium-based disinfectants following a prescribed use.

METHODS AND RESULTS

Eleven sites distributed in kitchen, bathroom, pet and children's areas of two groups of 30 homes each: (i) a nonprescribed disinfectant user group and (ii) a disinfectant protocol user group. During the 6-week study, samples were collected once a week except for week one when sample collection occurred immediately before and after disinfectant application to evaluate the disinfectant protocol. The concentration and occurrence of bacteria were less in the households with prescribed use of disinfectants. The greatest reductions were for E. coli (99%) and Staph. aureus (99·9999%), respectively. Only two samples were positive for HAV, while norovirus was absent. Disinfection protocols resulted in a significant (P < 0·05) microbial reduction in all areas of the homes tested compared to homes not using a prescribed protocol.

CONCLUSIONS

The study suggests that disinfectant product application under specific protocol is necessary to achieve greater microbial reductions.

SIGNIFICANCE AND IMPACT OF THE STUDY

Prescribed protocols constitute an important tool to reduce the occurrence of potential disease-causing micro-organisms in households.

A critical evaluation of methicillin-resistant Staphylococcus aureus and other bacteria of medical interest on commonly touched household surfaces in relation to household demographics

BACKGROUND

We sought to characterize and quantify bacteria of medical interest on commonly touched household surfaces and to evaluate predictors such as employment, day care attendance, and presence of infants and pets.

METHODS

A convenience sample of 35 homes was recruited from the metro-Boston area, and up to 32 surfaces were sampled in kitchens, bathrooms, and living areas.

RESULTS

Highest bacterial counts were associated with wet sites including hand/skin contact surfaces such as the tub, kitchen sink, and faucet handles. Surfaces were found to be contaminated with the bacteria of medical interest including species of Enterobacteriaceae, Pseudomonas, methicillin-sensitive Staphyloccus aureus (MSSA), and methicillin-resistant Staphyloccus aureus (MRSA).

CONCLUSION

A number of hand/skin contact surfaces were found to be frequently contaminated with one or more of the bacteria of medical interest. The presence of a cat in the home was found to be a strong predictor for the isolation of MRSA. This study provides further insight about microorganisms of medical interest on surfaces in American homes and the impact of factors that can influence bacterial contamination. The study may indicate that cleaning in private homes should be directed to the areas pinpointed by the study as very rich in bacteria of potential medical importance.

Demographic determinants of acute gastrointestinal illness in Canada: a population study

Background

Gastrointestinal illness is an important global public health issue, even in developed countries, where the morbidity and economic impact are significant. Our objective was to evaluate the demographic determinants of acute gastrointestinal illness in Canadians.

Methods

We used data from two population-based studies conducted in select communities between 2001 and 2003. Together, the studies comprised 8,108 randomly selected respondents; proxies were used for all respondents under 12 years and for respondents under 19 years at the discretion of the parent or guardian. Using univariate and multivariate logistic regression, we evaluated the following demographic determinants: age, gender, cultural group, and urban/rural status of the respondent, highest education level of the respondent or proxy, number of people in the household, and total annual household income. Two-way interaction terms were included in the multivariate analyses. The final multivariate model included income, age, gender, and the interaction between income and gender.

Results

After adjusting for income, gender, and their interaction, children under 10 years had the highest risk of acute gastrointestinal illness, followed by young adults aged 20 to 24 years. For males, the risk of acute gastrointestinal illness was similar across all income levels, but for females the risk was much higher in the lowest income category. Specifically, in those with total annual household incomes of less than $20,000, the odds of acute gastrointestinal illness were 2.46 times higher in females than in males.

Conclusion

Understanding the demographic determinants of acute gastrointestinal illness is essential in order to identify vulnerable groups to which intervention and prevention efforts can be targeted.

The burden of acute gastrointestinal illness in Ontario, Canada, 2005-2006

A retrospective, cross-sectional telephone survey (n=2090) was conducted in Ontario, Canada, between May 2005 and April 2006, to determine the burden of acute gastrointestinal illness in the population. The 4-week prevalence was 8.56% (95% CI 7.36-9.76); in households with more than one resident, 35% of cases reported someone else in their household had similar symptoms at the same time. The annual adjusted incidence rate was 1.17 (95% CI 0.99-1.35) episodes per person-year, with higher rates in females, rural residents, and in the winter and spring. Health care was sought by 22% of cases, of which 33% were asked to provide a stool sample. Interestingly, 2.2% of cases who did not visit a health-care provider reported self-administering antibiotics. Overall, acute gastrointestinal illness appears to pose a significant burden in the Ontario population. Further research into the specific aetiologies and risk factors is now needed to better target intervention strategies.

How often do you wash your hands? A review of studies of hand-washing practices in the community during and after the SARS outbreak in 2003

We reviewed evidence of hand-washing compliance in community settings during the 2003 SARS outbreak. Literature was searched through PubMed, Cochrane Library, Wan Fang database and Google. English and Chinese papers were reviewed. Studies containing data on hand-washing, self-reported or directly observed, in community settings were selected. Case-control studies and studies in healthcare settings were excluded. Fourteen studies were reviewed. Self-reported hand-washing compliance increased in the first phase of the SARS outbreak and maintained a high level 22 months after the outbreak. The decline of hand-washing in Hong Kong after SARS was relatively slow. A significant gender difference in hand-washing compliance (female > male) was found in eight studies. The importance of family support and 'significant female others' in hand hygiene promotion are noted. The impact of education is uncertain. Perceived susceptibility to and severity of SARS, and perceived efficacy of hand-washing in preventing SARS, also predicted self-reported hand-washing compliance.