ABSTRACT BACKGROUND. There have been few studies conducted in hospitalized patients in Viet nam on the epidemiology of surgical site infections (SSIs) and the impact of hand hygiene practices. This study aimed to assess the impact of a bedside hand sanitizer program on SSIs in orthopaedic and neurosurgical patients. DESIGN. A prospective quasi-experimental study was conducted with an untreated control group design in neurosurgical patients and before-after design in orthopaedic patients. A cost analysis based on data derived from the results of this study was also performed. SETTING. Cho Ray Hospital, a tertiary university hospital in Ho Chi Minh City, Viet nam. PATIENTS. All patients admitted for operation between 11 July and 15 August 2000 (Before), and 14 July and 18 August 2001 (After) were included, except those who had undergone another operation within one month prior to admission or were admitted because of SSIs. INTERVENTION. Bedside hand sanitizers were introduced into the Orthopaedic ward and one Neurosurgical ward (Ward A) from September 2000. Training on proper use was also provided to ward staff. Another Neurosurgical ward (Ward B) was used as a control group with no intervention conducted. RESULTS. A total of 1368 patients were recruited into the study. After intervention, in Ward A of the neurosurgical department, the SSI rate between the two periods was reduced by 54% (8.3% to 3.8%; p=0.09). Superficial SSIs were eliminated after the intervention (p=0.007). Comparison between Ward A (intervention) and Ward B (control) showed that, before the intervention, there was no difference in incidence of SSI between the two wards (Ward A: 8.3%, Ward B: 7.2%, p=0.7); however, after intervention, the incidence of SSI in Ward A was significantly lower than Ward B (3.8% and 9.2%, p=0.04). For orthopaedic patients, the SSI rate between the two periods was reduced by 34% (14.8% to 9.8%; p=0.07). SSI patients had a median post-operative length of stay of 19 days longer than patients without SSI (p&lt0.001). Costs were 2.5 times higher in patients with in-hospital SSI compared to uninfected patients (p&lt0.001). Mean SSI-attributable costs were conservatively estimated at US$368 in neurosurgical patients and US$207 in the orthopaedic patients in the before period. SSIs were responsible for at least 14 percent of the annual budget before intervention. The savings per SSI prevented were estimated at US$332 in neurosurgical patients and US$157 in orthopaedic patients. Annual cost savings arising from the intervention were estimated at US$11,112 in orthopaedic patients and US$19,320 in neurosurgical patients. CONCLUSIONS. The incidence of SSI in the hospital was high. The use of hand sanitizers reduced SSI rates, particularly impacting on the incidence of superficial SSIs. The hand sanitization program was found to be a dominant intervention being both more effective and cost saving as compared with no intervention in both study departments. The use of bedside hand sanitizers should be encouraged in the hospitals in Viet nam, where there often is a lack of other hand-washing facilities. / PhD Doctorate

System programming languages such as C and C++ are designed to give the programmer full control over the underlying hardware. However, this freedom comes at the cost of type and memory safety violations which may allow an attacker to compromise applications. In particular, type safety violation, also known as type confusion, is one of the major attack vectors to corrupt modern C++ applications. In the past years, several type confusion detectors have been proposed, but they are severely limited by high performance overhead, low detection coverage, and high false positive rates. To address these issues, we propose HexType and V-Type. First, we propose HexType, a tool that provides low-overhead disjoint metadata structures, compiler optimizations, and handles specific object allocation patterns. Thus, compared to prior work, HexType significantly improves detection coverage and reduces performance overhead. In addition, HexType discovers new type confusion bugs in real world programs such as Qt and Apache Xerces-C++. However, HexType still has considerable overhead from managing the disjoint metadata structure and tracking individual objects, and has false positives from imprecise object tracking, although HexType significantly reduces performance overhead and detection coverage. To address these issues, we propose a further advanced mechanism V-Type, which forcibly changes non-polymorphic types into polymorphic types to make sure all objects maintain type information. By doing this, V-Type removes the burden of tracking object allocation and deallocation and of managing a disjoint metadata structure, which reduces performance overhead and improves detection precision. Another major attack vector is memory safety violations, which attackers can take advantage of by accessing out of bound or deleted memory. For memory safety violation detection, combining a fuzzer with sanitizers is a popular and effective approach. However, we find that heavy metadata structure of current sanitizers hinders fuzzing effectiveness. Thus, we introduce FuZZan to optimize sanitizer metadata structures for fuzzing. Consequently, FuZZan improves fuzzing throughput, and this helps the tester to discover more unique paths given the same amount of time and to find bugs faster. In conclusion, my research aims to eliminate critical and common C/C++ memory and type safety violations through practical programming analysis techniques. For this goal, through these three projects, I contribute to our community to effectively detect type and memory safety violations.

Master of Public Health / Department of Diagnostic Medicine and Pathobiology / Katherine S. KuKanich / Hand hygiene by healthcare workers is an effective means of preventing healthcare-acquired infections. However, hand hygiene compliance can be low among healthcare workers. This study used introduction of a gel sanitizer and informational poster as interventional tools in attempt to improve hand hygiene in two outpatient healthcare clinics. Healthcare workers at two outpatient clinics were observed for frequency of hand hygiene (attempts vs. opportunities). Gel sanitizer and informational posters were introduced together as an intervention. Direct observation of hand hygiene frequency was performed during baseline, intervention, and follow-up. A post-study survey of healthcare workers was collected. In both clinics, baseline hand hygiene was poor (11% and 21%) but significantly improved (p[less than or equal to]0.0001) after interventions (36 and 54%), and was maintained (p>0.05) through the follow-up period (32 and 51%). Throughout the study, post-contact hygiene was statistically observed more than pre-contact hygiene. In both clinics, healthcare workers self-reported a preference for soap and water, yet observations showed that sanitizer use predominated over soap and water use when sanitizer was available after the intervention. Fifty per cent of the surveyed healthcare workers considered the introduction of gel sanitizer to be an effective motivating tool for improving hand hygiene. Hand hygiene performance by healthcare workers in outpatient clinics may benefit from promoting gel sanitizer and using informational posters. Direct observation by trained observers may provide more accurate information of hand hygiene tool preference compared with survey results.

Com o aumento gradativo da tecnologia e da necessidade de consumo humana, a cada dia são desenvolvidos novos produtos e novas substâncias. Além dos benefícios desta modernização, surgem as preocupações relacionadas com o uso excessivo de produtos químicos. Muitos produtos químicos possuem potencial de causar efeitos adversos à saúde humana e ao meio ambiente e, por isso, de uns anos pra cá, passou a ser essencial e obrigatória a comunicação dos riscos advindos desses produtos dentro do ambiente de trabalho. O GHS, um sistema globalmente harmonizado de classificação e rotulagem de produtos químicos foi criado pela ONU para trazer critérios e elementos harmonizados para a comunicação desses perigos. A identificação dos perígos do GHS é um procedimento complexo e muito difícil para as empresas, com destaque para aquelas de menor porte, como é o exemplo do setor de saneantes, que é, em sua maioria, constituido por micro e pequenas empresas. Além de terem a obrigação de seguir os requisitos estabelecidos pelo GHS, os fabricantes de saneantes seguem as exigências da Anivsa para comercialização de seus produtos. Combinando os requisitos da Anvisa com os do GHS, percebe-se que algumas classes e categorias de perigo do GHS não se aplicam para saneantes. Com isso, o propósito desse trabalho foi desenvolver um roteiro para classificação do GHS destinado especificamente ao setor de saneantes. Para o desenvolvimento do roteiro foram elaborados fluxogramas de decisões lógicas com requisitos do GHS e exigências da Anvisa. O trabalho atingiu o seu objetivo como um todo, criando um modelo de roteiro para aplicação do GHS para o setor de saneantes. Após a aplicação do roteiro em um produto exemplo e após as discussões levantadas, percebeu-se que alguns detalhes poderiam ser melhor incorporados no roteiro. Apesar do roteiro possuir suas limitações e algumas imperfeições, acredita-se que possa contribuir de alguma forma para o setor. Ao invés dos profissionais consultarem o GHS como um todo, um guia simplificado, resumido e com particularidades do setor, pode fazer com que as indústrias tenham uma maneira mais fácil de aplicar o GHS e, assim, contribuir para que as classificações sejam realizadas de uma maneira correta. / With the technology gradual increase and the need of human consumption every day new products and new substances are developed. In addition to the benefits of this modernization, there are concerns about the excessive use of chemicals. Many chemicals have potential to cause adverse effects on human health and the environment and, therefore, a few years ago the risk communication of these products in a workplace became essential and mandatory. The GHS, a globally harmonized system of classification and labeling of chemicals was created by the UN to bring harmonized criteria and elements to communicate these dangers. The GHS hazard identification is a complex and difficult procedure for the industries, especially those ones that are small, as sanitizer sector for example, which is mostly composed of micro and small companies. In addition to have the GHS obligation the sanitizer manufacturers follow the Anvisa regulation as well. Combining the Anvisa requirements with GHS ones, it is clear that some GHS hazard classes and categories do not apply for cleaning products. Thus, the purpose of this study was to develop a GHS classification guide intended specifically for sanitizer industry. To build the guide flowcharts were developed with logical decisions with GHS and Anvisa requirements. This study reached its goal as a whole, creating a guide model for GHS implementation in sanitizer industries. After the guide application in a product sample and the discussions, it was noted that some details could be better incorporated into the script of the guide. Although the guide has some limitations and imperfections, it can contribute in some way to the industry. Instead of a professional consulting GHS as a whole, a simplified, summarized and with the sanitizer particularities guide may give to the industries an easier way to apply the GHS contributing to the correct classifications.

Com o aumento gradativo da tecnologia e da necessidade de consumo humana, a cada dia são desenvolvidos novos produtos e novas substâncias. Além dos benefícios desta modernização, surgem as preocupações relacionadas com o uso excessivo de produtos químicos. Muitos produtos químicos possuem potencial de causar efeitos adversos à saúde humana e ao meio ambiente e, por isso, de uns anos pra cá, passou a ser essencial e obrigatória a comunicação dos riscos advindos desses produtos dentro do ambiente de trabalho. O GHS, um sistema globalmente harmonizado de classificação e rotulagem de produtos químicos foi criado pela ONU para trazer critérios e elementos harmonizados para a comunicação desses perigos. A identificação dos perígos do GHS é um procedimento complexo e muito difícil para as empresas, com destaque para aquelas de menor porte, como é o exemplo do setor de saneantes, que é, em sua maioria, constituido por micro e pequenas empresas. Além de terem a obrigação de seguir os requisitos estabelecidos pelo GHS, os fabricantes de saneantes seguem as exigências da Anivsa para comercialização de seus produtos. Combinando os requisitos da Anvisa com os do GHS, percebe-se que algumas classes e categorias de perigo do GHS não se aplicam para saneantes. Com isso, o propósito desse trabalho foi desenvolver um roteiro para classificação do GHS destinado especificamente ao setor de saneantes. Para o desenvolvimento do roteiro foram elaborados fluxogramas de decisões lógicas com requisitos do GHS e exigências da Anvisa. O trabalho atingiu o seu objetivo como um todo, criando um modelo de roteiro para aplicação do GHS para o setor de saneantes. Após a aplicação do roteiro em um produto exemplo e após as discussões levantadas, percebeu-se que alguns detalhes poderiam ser melhor incorporados no roteiro. Apesar do roteiro possuir suas limitações e algumas imperfeições, acredita-se que possa contribuir de alguma forma para o setor. Ao invés dos profissionais consultarem o GHS como um todo, um guia simplificado, resumido e com particularidades do setor, pode fazer com que as indústrias tenham uma maneira mais fácil de aplicar o GHS e, assim, contribuir para que as classificações sejam realizadas de uma maneira correta. / With the technology gradual increase and the need of human consumption every day new products and new substances are developed. In addition to the benefits of this modernization, there are concerns about the excessive use of chemicals. Many chemicals have potential to cause adverse effects on human health and the environment and, therefore, a few years ago the risk communication of these products in a workplace became essential and mandatory. The GHS, a globally harmonized system of classification and labeling of chemicals was created by the UN to bring harmonized criteria and elements to communicate these dangers. The GHS hazard identification is a complex and difficult procedure for the industries, especially those ones that are small, as sanitizer sector for example, which is mostly composed of micro and small companies. In addition to have the GHS obligation the sanitizer manufacturers follow the Anvisa regulation as well. Combining the Anvisa requirements with GHS ones, it is clear that some GHS hazard classes and categories do not apply for cleaning products. Thus, the purpose of this study was to develop a GHS classification guide intended specifically for sanitizer industry. To build the guide flowcharts were developed with logical decisions with GHS and Anvisa requirements. This study reached its goal as a whole, creating a guide model for GHS implementation in sanitizer industries. After the guide application in a product sample and the discussions, it was noted that some details could be better incorporated into the script of the guide. Although the guide has some limitations and imperfections, it can contribute in some way to the industry. Instead of a professional consulting GHS as a whole, a simplified, summarized and with the sanitizer particularities guide may give to the industries an easier way to apply the GHS contributing to the correct classifications.

Bakgrund: Vårdrelaterade infektioner är ett problem som tar upp resurser och vårdplatser. Ett av huvudproblemen är brister i handhygienen. Handhygienen ska utföras korrekt för att bedriva en god och säker vård. Det sistnämnda är en kärnkompetens hos den utbildade sjuksköterskor. Händerna utgör en smittväg mellan vårdpersonal och patienter. För att förhindra detta används skyddsutrustning men även handtvätt och handdesinfektion. Trots kunskap om handhygienens betydelse ses bristande tillämpning bland vårdpersonal.Syfte: Syftet är att identifiera faktorer som kan associeras med följsamheten till handhygien hos vårdpersonal inom somatisk slutenvård.Metod: I detta arbete har en litteraturstudie gjorts. Metoden som valts för att svara på syftet  är en kvantitativ metod. Observationsstudier (7) samt kombinerad observation och enkätstudier (3). Databaserna som användes var PubMed och Cinahl för att få fram relevanta artiklar.Resultat: Tio artiklar har sammanställts för att besvara syftet. Resultatet visade att handtvätt görs för sällan och ersätts med desinfektionsmedel. Arbetsbelastning och utbrändhet leder till sämre följsamhet till handhygien. Att handhygien spelar roll beroende av vilket typ av moment som ska genomföras. Följsamheten till handhygien var sämre innan kontakt med patientkontakt än efter. Slutsats: Dålig handhygien har setts på grund av olika faktorer, detta minskar patientsäkerheten genom risken för eventuell vårdrelaterade infektioner (VRI). Genom god handhygien minskar risken för smittbara ämnen vilket främjar både samhället och patienten. / Background: Healthcare related infections are a big problem in our society. This takes up unnecessary resources and hospital beds. One of the main problems is deficiencies in hand hygiene. Hand hygiene has to be performed correctly to provide good and safe care. Safe care is one of the nurses core competencies. Our hands transmit bacteria and viruses infections between the patient and healthcare professionals. To prevent this use protective equipment but also hand washing and hand disinfection. Aim: the purpose is to identify factors that can be associated with compliance with hand hygiene among care staff in somatic inpatient care.Method: In this work a literature study has been used. Observation studies (7) but also combined observation and questionnaire studies (3) was applied. Cinahl and PubMed were used as databases.Result: A total of ten articles were included in the result. The result showed that handwashing is not done as often as it should, and getting replaced with hand disinfection, workload and burnout leads to less compliance with hand hygiene. Hand hygiene plays a role depending on the type of procedures that are going to be performed. Adherens to hand hygiene were worse before patient contact than after. Conclusion: Poor hand hygiene has been due to various factors. This reduces patient safety through the risk of possible healthcare related infections (HRI). Good hand hygiene reduces the risk of infectious substances, which promotes both society and the patient.

SARS-CoV-2 is the virus responsible for the current global pandemic, COVID-19. Because this virus is novel, little is known about its sensitivity to disinfection. In this study, we performed suspension tests against SARS-CoV-2 using three commercially available quaternary ammonium compound (Quat) disinfectants and one laboratory-made 0.2% benzalkonium chloride solution. Three of the four formulations completely inactivated the virus within 15 seconds of contact, even in the presence of a soil load or when diluted in hard water. We conclude that Quats rapidly inactivate SARS-CoV-2, making them potentially useful for controlling SARS-CoV-2 spread in hospitals and the community. In addition to disinfection, little is known about the sensitivity of SARS-CoV-2 to wastewater. A number of researchers have tracked the spread of COVID-19 by using qPCR to look for SARS-CoV-2 RNA in wastewater, but it is unclear how long that RNA lasts or whether that RNA is from intact or inactivated virus. In this study, we added laboratory-grown SARS-CoV-2 to various samples of wastewater and measured its persistence using both qPCR, which detects all viral RNA, and a plaque assay, which detects only infectious virus. The level of infectious virus declined sharply by over 4 log reductions during an 8 day time period, while the level of measurable RNA did not decline significantly. Autoclaving or filtering the wastewater before adding virus attenuated this effect, producing declines of only around 1-3 logs for the infectious virus over 8 days and no significant decline for the RNA.

Background SARS-CoV-2 is the virus responsible for the current global pandemic, COVID-19. Because this virus is novel, little is known about its sensitivity to disinfection. Methods We performed suspension tests against SARS-CoV-2 using three commercially available quaternary ammonium compound (Quat) disinfectants and one laboratory-made 0.2% benzalkonium chloride solution. Findings Three of the four formulations completely inactivated the virus within 15 s of contact, even in the presence of a soil load or when diluted in hard water. Conclusion Quats rapidly inactivate SARS-CoV-2, making them potentially useful for controlling SARS-CoV-2 spread in hospitals and the community.

Background: Hand hygiene is now, more than ever, one of the most important factors to minimize spread of infection. In low income countries like Lesotho between 6% - 19% of patients contract at least one healthcare associated infection. Compared to between 3% - 10% in high income countries. Objective: The aim was to describe how healthcare professionals experience and conduct basic hand hygiene procedures at a hospital in Lesotho. Method: The study was conducted using a qualitative content analysis with a manifest level of abstraction and an inductive approach. Result: The results showed in our final categories; Healthcare professionals perceive different views on the risk for contamination, Healthcare professionals described hand hygiene as important although there are hindrances, and Healthcare professionals stated that basic hand hygiene need support from management for good compliance. That healthcare professionals did not always perform basic hand hygiene the way it was supposed as low budget or lack of knowledge was an obstacle. Conclusions: There are many problem areas, such as cost, availability and knowledge although the personnel are interested, resourceful and willing to make the best of any situation they come across.

The Food Safety Modernization Act (FSMA) has a regulation stating that there can be no detectable generic Escherichia coli in agricultural water. The objective of this study was to optimize the use of peracetic acid (PAA) as a mitigating strategy in postharvest processing. This project began by investigating the impact of storage temperatures on stability of a commercially available PAA sanitizer. Regression analysis showed a quadratic relationship in the concentration of PAA over 12 weeks when storing the product at 4, 20 and 37°C. Stability of the product was also investigated in the presence of organic load over time at 60ppm PAA. PAA significantly decreased at an organic load level of 750COD. From this, the impact of various ratios of hydrogen peroxide (H2O2) and PAA were investigated further to see the efficacy against E. coli O157:H7 over three hours with reinoculation of bacteria after 3 hours. A higher level of PAA in the solution had a greater inactivation efficacy against E. coli O157:H7. The impact of concentration, organic load, temperature and pH on the efficacy against E. coli O157:H7 and stability of PAA over four hours was then investigated. All of the conditions tested showed a significant decrease in H2O2 and PAA concentrations over time, except at concentration of 80ppm, with varying rates of depletion under each condition tested. This study will help to create guidance on optimizing the use of PAA. With this knowledge growers can understand how changes in their post-harvest processing water can affect sanitizer performance.