Public toilets with insufficient ventilation present high cross infection risk.

Due to insufficient ventilation, public toilets present high risks for cross-infection. The study investigated 61 public toilets to identify the causes and locations of biological contaminated sources. Airborne and surface bacterial contamination, carbon dioxide concentration, and surface ammonia levels were measured. Both bacterial contamination and CO2 are higher in non-ventilated toilets compared to their ventilated counterparts. Bacteria colony forming units (CFUs) in a public toilet with poor ventilation can reach 5 times the number of CFUs outside of the toilet. This suggests that non-ventilated public toilets present a higher risk of cross-infection. Areas near all kinds of sanitary equipment (toilet bowls, squat toilets and urinals) were highly contaminated, indicating that enhanced cleaning regimes are necessary. Further, lidless trash bins present a higher risk as contaminated matter within the trash bins is not inhibited from being released into the environment. Ventilation and cleaning need to be improved to mitigate the risk of cross-infection in public toilets.

Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets.

UNLABELLED: The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant. PRACTICAL IMPLICATIONS: The results from this study show that an advanced air distribution system such as personalized ventilation reduces exposure to cough-released droplets better than commonly applied overhead mixing ventilation. This work can inform HVAC engineers about different aspects of air distribution systems' performance and can serve as an aid in making critical design decisions.

Human convection flow in spaces with and without ventilation: personal exposure to floor-released particles and cough-released droplets.

UNLABELLED: The effects of the human convective boundary layer (CBL), room airflow patterns, and their velocities on personal exposure are examined. Two pollutants are studied which simulate particles released from the feet and generated at distances of 2 and 3 m by a human cough. A thermal manikin whose body shape, size, and surface temperatures correspond to those of an average person is used to simulate the CBL. The findings of the study reveal that for accurate predictions of personal exposure, the CBL needs to be considered, as it can transport the pollution around the human body. The best way to control and reduce personal exposure when the pollution originates at the feet is to employ transverse flow from in front and from the side, relative to the exposed occupant. The flow from the above opposing the CBL create the most unfavorable velocity field that can increase personal exposure by 85%, which demonstrates a nonlinear dependence between the supplied flow rate and personal exposure. In the current ventilation design, it is commonly accepted that an increased amount of air supplied to the rooms reduces the exposure. The results of this study suggest that the understanding of air patterns should be prioritized. PRACTICAL IMPLICATIONS: A human convective boundary layer plays an important role in pollution transport around the human body. It interacts with the surrounding airflows which modifies air movement around the human body and personal exposure. Understanding the influence of this interaction on the pollution spread around the human can be used to control and reduce personal exposure and improve HVAC design.

Human convective boundary layer and its interaction with room ventilation flow.

This study investigates the interaction between the human convective boundary layer (CBL) and uniform airflow with different velocity and from different directions. Human body is resembled by a thermal manikin with complex body shape and surface temperature distribution as the skin temperature of an average person. Particle image velocimetry (PIV) and pseudocolor visualization (PCV) are applied to identify the flow around the manikin's body. The findings show that the direction and magnitude of the surrounding airflows considerably influence the airflow distribution around the human body. Downward flow with velocity of 0.175 m/s does not influence the convective flow in the breathing zone, while flow at 0.30 m/s collides with the CBL at the nose level reducing the peak velocity from 0.185 to 0.10 m/s. Transverse horizontal flow disturbs the CBL at the breathing zone even at 0.175 m/s. A sitting manikin exposed to airflow from below with velocity of 0.30 and 0.425 m/s assisting the CBL reduces the peak velocity in the breathing zone and changes the flow pattern around the body, compared to the assisting flow of 0.175 m/s or quiescent conditions. In this case, the airflow interaction is strongly affected by the presence of the chair.

Impact of asthma, exposure period, and filters on human responses during exposures to ozone and its initiated chemistry products.

The impact of asthma, exposure period, and filter condition downstream of the mixing box of air-conditioning system on building occupants' perceptual response, work performance, and salivary α-amylase secretion during exposures to ozone and its initiated chemistry products is studied. The experiments were conducted in a field environmental chamber (FEC) (240 m(3)) simulating an office environment. Experiments were conducted during periods when the air-handling system operated with new or used pleated panel filters at constant recirculation (7/h) and ventilation (1/h) rates. Average ozone and secondary organic aerosols (ozone-initiated chemistry products) measured during non-asthmatic and asthmatic subjects' 3-h exposures in the FEC were in the ranges approximately 20-37 ppb and approximately 1.6-3 µg/m(3), respectively. Asthmatic subjects' perceived odor intensity and sensory (eye, nose, and throat) irritation ratings were generally lower than those of non-asthmatic subjects, possibly explaining why asthmatic subjects accept perceived air quality more than non-asthmatic subjects. However, asthmatic subjects' perceived physiological-like symptom ratings (flu, chest tightness, and headache) and concentrations of secreted salivary α-amylase were generally higher than those of non-asthmatic subjects. Asthmatic subjects had significantly lower accuracy than non-asthmatic subjects in a task that required higher concentration although they had higher work speed. Filter condition did not make any significant difference for subjects' responses.

Laparoscopic sleeve gastrectomy: a novel procedure for weight loss.

INTRODUCTION: Morbid obesity is associated with increased morbidity and mortality. Bariatric surgery offers morbidly obese individuals substantial and sustainable weight loss and reduction in obesity-related comorbidities. Laparoscopic sleeve gastrectomy (LSG) is a new restrictive procedure in bariatric surgery. We aimed to evaluate our experience with LSG with regard to its safety and feasibility and early weight loss. METHODS: The surgical outcome, complications and early clinical results of all patients who underwent LSG at Singapore General Hospital were studied. RESULTS: 30 patients underwent LSG between December 2008 and October 2010. The mean preoperative weight of the patients was 113.4 (range 91.0-170.0) kg, while the mean body mass index (BMI) was 42.6 (range 33.0-60.0) kg/m². Diabetes mellitus was present in 39 percent of the patients, hypertension in 43 percent, hyperlipidaemia in 35 percent, obstructive sleep apnoea in 30 percent and osteoarthritis in 22 percent. The majority of patients had two or more obesity-related comorbidities (52 percent). Mean operative time was 142 (range 80-220) minutes and median duration of postoperative stay was three days. At two weeks, one, three and six months post operation, the mean BMI was 38.6 kg/m², 37.8 kg/m², 34.5 kg/m² and 30.8 kg/m², the mean percentage of excess weight loss was 17.7 percent, 23.3 percent, 40.9 percent and 56.7 percent, and absolute weight loss was 8.00 kg, 11.52 kg, 18.77 kg and 26.85 kg, respectively. CONCLUSION: LSG is a promising procedure for surgical treatment of obesity, with good early weight loss and low morbidity.

Life support course for nurses in Singapore.

Nurses are usually the first caregivers for cardiac arrest patients in an in-hospital environment, and subsequently partner with doctors in the further resuscitation of patients. The skills of basic life support are crucial for their practice. The Advanced Cardiac Life Support programme is traditionally geared toward training of medical staff in advanced resuscitation skills. The need for a bridging course that focuses on the knowledge and skills required by nurses to become effective members of the resuscitation team has resulted in the creation of the Life Support Course for Nurses (LSCN) in Singapore. The components of the LSCN programme have evolved over the years, taking into consideration the modifications to resuscitation guidelines. The LSCN programme is gradually including a larger proportion of nurses in the emergency and critical care environments as well as those in the general ward.

An outbreak of haemolytic anaemia associated with infection of Theileria orientalis in naive cattle.

CASE HISTORY: An outbreak of haemolytic anaemia occurred when 87 cattle were introduced from a presumed non-infected herd from south Otago to a herd in Northland (n=580 cows), New Zealand, where theileriosis is endemic. CLINICAL FINDINGS: Clinical signs associated with Theileria spp. infection included lethargy, anorexia, inappetance, pale mucous membranes, and varying severity of anaemia. In the naive imported cattle, 11/29 (38%) of those tested showed haematological signs of anaemia (haematocrit (HCT) <0.25 L/L). A negative association was present between the HCT and the number of Theileria spp. organisms counted using light microscopy (correlation coefficient=-0.4; p<0.05). Haemoparasites consistent with Theileria spp. were observed on examination of a blood smear. Theileria orientalis group (Theileria buffeli/orientalis) species was confirmed using PCR and DNA sequencing, and other causes for anaemia were excluded in the most clinically severely affected cow. The 18S sequence data and phylogenetic analysis of the CoxIII sequences showed samples had the greatest similarity to T. orientalis Chitose from Japan. DIAGNOSIS: Haemolytic anaemia associated with infection of T. orientalis. CLINICAL RELEVANCE: Previous reports have suggested that T. orientalis group species may be non-pathogenic in healthy cattle, and an incidental finding in blood samples. However, this investigation provided evidence that in New Zealand, this pathogen is capable of causing clinical disease in cattle not necessarily debilitated by another disease. The potential for disease should be considered when naive cattle are brought in from non-endemic to endemic regions, for instance cattle from the South Island moved to regions where the vector for T. orientalis group species, Haemaphysalis longicornis, is active, and T. orientalis is present.

Investigation of a pig herd with animals seropositive for classical swine fever and where porcine circovirus-associated disease had been diagnosed.

AIM: To investigate the cause of classical swine fever (CSF) virus-seropositive animals in a nucleus pig-breeding herd in New Zealand, where porcine circovirus-associated disease had been diagnosed. CASE HISTORY AND CLINICAL FINDINGS: An exotic disease investigation was undertaken to exclude CSF and porcine reproductive and respiratory syndrome (PRRS) on a nucleus pig-breeding herd comprising approximately 300 breeding sows, 1,000 weaners, and 650 grower pigs. The herd was experiencing poor reproductive performance in sows, and breeding records showed a declining farrowing rate attributable to a single manager. The growing pigs (10-15 weeks old) were experiencing respiratory disease and wasting, and the mortality rate by pen varied between 9 and 20%. Post-mortem changes in affected grower pigs were consistent with circovirus-associated diseases. DIAGNOSTIC TESTING: Serological screening using an IDEXX-ELISA gave negative results for PRRS virus antibodies, but two grower pigs and one sow tested positive for CSF virus antibodies. These three seropositive animals remained positive to CSF virus, using three commercial ELISA test kits, over 27 weeks. A newly developed virus neutralisation test (VNT), using a New Zealand isolate of border disease (BD) virus, demonstrated that the seropositive pig sera had higher antibody titres to BD virus than to bovine viral diarrhoea (BVD) virus and CSF virus. PCR performed on tonsil, kidney, ileum and spleen gave negative results for CSF virus, and histopathology on lymph nodes, intestine, lung, kidney, liver and brain showed no evidence of the disease. Virus isolation performed on a number of samples was negative. CLINICAL RELEVANCE: The seropositive samples for CSF virus found in this investigation were likely to be a cross reaction to a pestivirus other than CSF virus. The finding of a possible endemic pestivirus capable of being transmitted between sheep and pigs on this farm may explain findings from previous serological survey work in New Zealand, and supports experience elsewhere, where BD virus was found to be the predominant ruminant pestivirus infecting pigs. The results show that pestivirus cross reactivity can result in unexpectedly high titres, and that testing with a full set of (local) pestiviruses is necessary to reach the correct conclusion. The investigation has direct relevance where pig herds with a low seroprevalence are encountered during surveillance for CSF.

Support in everyday activities with a home-based electronic memory aid for persons with memory impairments.

PURPOSE: The purposes of this study was to examine the possibilities of a home-based electronic memory aid with sensors for persons with memory impairments, as support to carry out everyday activities in their own home environments. METHOD: The method involved a single-subject study with a multiple baseline AB design. Five participants identified three activities each that they usually forget to carry out. An electronic memory aid with individually spoken reminders was installed in the participant's home. There were automatic computer registrations of completed activities during the study phase of 12 weeks. Assessments of functioning and quality of life (QoL) were conducted before and after the intervention and at follow-up after 2 months. RESULTS: Four participants improved in completing most of the self-chosen activities when the electronic memory aid was used. Performance and satisfaction with performance and QoL improved, but there was no memory function improvement. There were technical problems with the aid, which had a negative effect for users. CONCLUSIONS: Electronic memory aids have a large potential for supporting persons with cognitive impairments. It is important to conduct follow-up afterwards, because the use of an aid and the need of support change over time and put high demands on technical reliability of the electronic memory aid.

Fetal corticotrophin-releasing hormone mRNA, but not phosphatidylserine-exposing microparticles, in maternal plasma are associated with factor VII activity in pre-eclampsia.

BACKGROUND: Pre-eclampsia is associated with increased placental debris circulating in maternal plasma. OBJECTIVES: This study related placental debris to maternal markers of coagulation and endothelial activation in pre-eclampsia. PATIENTS/METHODS: Circulating fetal corticotrophin-releasing hormone (CRH) mRNA and phosphatidylserine (PS)-exposing microparticles were assayed in third trimester plasma from women with pre-eclampsia (n = 32) and controls (n = 32) matched for age, body mass index, parity, and gestational age at sampling. Markers of maternal hemostasis and endothelial function were assessed. RESULTS: Fetal CRH mRNA levels were higher in pre-eclampsia [mean 0.75 (SD 2.77) CRH/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA ratio] than in control pregnancies [0.20 (0.74), P = 0.014]. PS-exposing microparticle levels were not different between the groups. Women with pre-eclampsia had higher levels of tissue factor pathway inhibitor (TFPI), prothrombin F(1+2) fragment (F(1+2)), factor XIIa, soluble vascular cell adhesion molecule 1, von Willebrand factor and plasminogen activator inhibitor 1 than controls. Fetal CRH mRNA correlated with TFPI in pre-eclampsia and control groups (r = 0.38, P = 0.031, and r = 0.37, P = 0.039, respectively). Fetal CRH mRNA correlated with FVII activity (r = 0.43, P = 0.017) and PS-exposing microparticles correlated inversely with F(1+2) (r = -0.64, P < 0.001) in pre-eclampsia. CONCLUSIONS: Placental debris, assessed by fetal CRH mRNA levels in maternal blood, is related to coagulation potential, i.e. FVII activity, but not to markers of coagulation or endothelial activation in pre-eclampsia.

Home exposures to environmental tobacco smoke and allergic symptoms among young children in Singapore.

BACKGROUND: Research relating environmental tobacco smoke (ETS) exposures have focused on childhood asthma. There have been fewer studies with conflicting results performed on associations of ETS exposures with allergic symptoms. We are interested to see if ETS exposures in the homes are associated with allergic symptoms among preschool children in Singapore where public smoking is banned. METHODS: A cross-sectional study adopting an expanded and modified ISAAC (International Study on Asthma and Allergies in Childhood) questionnaire for the evaluation of asthma and allergies was conducted on 6,794 children attending 120 randomly selected child care centers. Specific information on demographics and ETS exposures was obtained. Adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) were determined using Poisson multivariate regression with a log-link function and robust variance estimates as recommended for cross-sectional studies. RESULTS: The response proportion was 70.0%, and 4,759 children from 97 centers participated. After adjusting for covariates, it was found that home ETS exposure was associated with increased risks of current symptoms of rhinitis (PR 1.23; 95% CI 1.01-1.50) and rhinoconjunctivitis (PR 1.79; 95% CI 1.26-2.54). These associations followed dose-response trends with respect to number of cigarettes smoked or smokers in the homes. Home ETS exposures were also associated with higher PRs of wheeze, nocturnal cough and doctor-diagnosed asthma. Compared with paternal smoking, higher risks of the above outcomes were found for maternal smoking. CONCLUSION: Home ETS exposure is a risk factor associated with rhinitis and asthma among preschool children.

Recall of discharge advice given to patients with minor head injury presenting to a Singapore emergency department.

INTRODUCTION: Most patients presenting to the emergency department (ED) with minor head injury (HI) can be discharged, provided a caregiver is present and careful discharge instructions are given. The study ED uses an advice leaflet with verbal reinforcement to patients and caregivers detailing post-discharge instructions and warning symptoms of worsening HI. We aim to evaluate local patients' and caregivers' compliance to discharge instructions and their ability to recall HI advice. METHODS: A prospective study was conducted in an adult ED between April 10, 2006 and May 1, 2006. All patients with minor HI discharged from the ED or its 24-hour observation ward were included in the study. A telephone survey was conducted within 48 hours of discharge using a standardised questionnaire. RESULTS: During the study period, 292 patients had HI, of which 182 were eligible for the study. 71 were uncontactable and one refused to participate, leaving 110 patients in the study. Patients' age ranged between 7 and 109 years (median 41 years). 100 confirmed receiving HI advice (57 percent received by patients, 26 percent caregivers, 16 percent both patients and caregivers). 29 percent of respondents reported non-compliance to discharge advice. Mean HI-symptom recall score was 1.9 (SD 1.6) (total 9 symptoms). 30 percent cited other symptoms not part of the HI advice, which they believed necessitated a return to the ED. Recall scores were not statistically different, regardless of mode of instruction (verbal or printed) or the recipient (patient, caregiver or both). CONCLUSION: Our study raises concerns about the reliability of discharge advice for minor HI patients.

The effect of ventilation strategies of child care centers on indoor air quality and respiratory health of children in Singapore.

UNLABELLED: This paper reports the effects of ventilation strategies on indoor air quality (IAQ) and respiratory health of children within 104 child care centers (CCCs) in a hot and humid climate. The CCCs were categorized by ventilation strategies: natural (NV), air-conditioned and mechanically ventilated (ACMV), air-conditioned using split units (AC), and hybrid (NV and AC operated intermittently). The concentration levels of IAQ parameters in NV CCCs are characterized by the influence of the outdoors and good dilution of indoor pollutants. The lower ventilation rates in air-conditioned CCCs result in higher concentrations of occupant-related pollutants but lower outdoor pollutant ingress. This study also revealed lower prevalence for most asthma and allergy, and respiratory symptoms in children attending NV CCCs. In multivariate analyses controlled for the effects of confounders, the risk of current rhinitis among children is significantly higher if they attend mechanically ventilated CCCs compared to NV CCCs. Air-conditioned CCCs were also associated with higher adjusted prevalence ratio of severe phlegm and cough symptoms and lower respiratory illness. Finally, children attending CCCs with hybrid ventilation are at high risk for almost all the respiratory symptoms studied. PRACTICAL IMPLICATIONS: This large field study indicates that different ventilation strategies employed by child care centers can cause significant variations in the indoor air quality and prevalence of asthma, allergies and respiratory symptoms of attending children. The higher prevalence rates of allergic and respiratory symptoms among young children, whose immune system is still under-developed, in child care centers, whether fully or partially air-conditioned, suggest that ventilation and plausible growth and propagation mechanisms of allergens and infectious agents be further investigated.

Using electronic aids to daily living after acquired brain injury: a study of the learning process and the usability.

PURPOSE: The purpose was to study the ability of persons with memory impairments after acquired brain injury to learn how to and use electronic aids to daily living (EADL) and to describe changes in function and quality of life. METHOD: Eight participants stayed in two apartments equipped with a set of basic and advanced EADL for either 4 or 6 months during an intervention time of 2 years. The teaching and learning method was influenced by certain principles of errorless learning. Ability to learn to use EADL was measured by structured observations. Function and quality of life were assessed with self-rating questionnaires. RESULTS: Results indicate that the participants learned to use EADL in their everyday activities. They perceived that EADL were very useful and easy to learn. Occupational performance and satisfaction with occupational performance and quality of life was improved. CONCLUSION: The results indicate that EADL may play an important role in facilitating everyday activities and improve satisfaction with occupational performance and quality of life for people with memory impairments. The study indicates the importance of adjusting technology to the user's needs and calls for more consideration for human-technology interaction factors.

Will "no blood" kill Jehovah Witnesses?

A 46-year-old Indonesian woman presented with signs and symptoms suggestive of an ovarian tumour and was advised to have surgery with exploratory laparotomy and removal of the mass. She agreed but refused blood transfusion any time in the course of her treatment or procedure, as she was a Jehovah Witness. As there was a high risk of intraoperative haemorrhage, steps were taken to reduce any consequent complications due to the surgery. The ethical conflict is between respecting patient autonomy and compromising standards of care, arising from the refusal of a standard therapy. The latest developments in the blood transfusion doctrine policy for the Jehovah Witnesses are also discussed in this case study.

Lessons from SARS in an age of emerging infections.

SARS, the first pandemic of this century, commanded the world's attention and required public health actions at the national and international levels. In an age of emerging infections, the lessons learnt from combating SARS can be used to improve our preparedness capabilities in three key areas to effectively tackle a public health emergency of international concern. The first area is in outbreak alert, which encompasses use of surveillance to detect, assess, notify and report events involving death or disease, and share information widely to enable proper risk assessment. The system must able to build up a comprehensive picture with appropriate warning for zoonotic diseases, environmental health and food safety. The second area is in public health response. In the event of an outbreak alert, the authorities must be able to quickly investigate cases/deaths and institute comprehensive control measures to break the chain of transmission. Protection of healthcare workers and reducing the opportunities for spread of infection through contact tracing and quarantine are important. The third area is in international health. This comprises health requirements for inbound and outbound travellers at the border checkpoints and global information exchange to mitigate the risks of travel abroad. Extrapolating these lessons to a wider public health context, our rapidly changing global infectious diseases situation mandates that we evaluate all available public health tools and build institutional capacity to effectively manage emerging infections.

Helmet use and bicycle-related trauma in patients presenting to an acute hospital in Singapore.

INTRODUCTION: To describe the relationship between bicycle helmet use and injury pattern sustained by patients presenting to an emergency department (ED) in Singapore for bicycle-related trauma. METHODS: Data was collected from all individuals treated for bicycle-related trauma between September 1, 2004 and May 31, 2005 using a closed-ended questionnaire. RESULTS: 160 bicyclists with mean age of 34.4 years (range 10 to 89 years) were surveyed. Among them, 80 percent were male and 30.6 percent were non-residents. Helmets were worn by 10.6 percent of the patients. Alcohol was clinically detected in 11.3 percent of bicyclists. There was no difference in bicycle helmet use between Singaporeans and non-residents (p-value is 0.275). However, compared to younger bicyclists, bicyclists aged 30 years or older (p-value is less than 0.05), and compared to recreational or sport bicyclists, those who commute by bicycle, tended not to wear helmets (p-value is less than 0.01). Compared to Singaporeans (p-value is less than 0.05), non-residents and bicyclists aged 30 years or older (p-value is 0.011) believed that helmets did not protect against head injury. Comparing the helmeted group with the non-helmeted group, injury patterns by body region were: head injury 5.9 percent versus 40.0 percent (p-value is less than 0.01); facial injury 5.9 percent versus 37.1 percent (p-value is less than 0.05). Not wearing a helmet, being hit by a motor vehicle and age were significantly associated with higher injury severity scores, after adjusting for several potential confounding factors. CONCLUSION: Bicycle helmet use was low in our sample of injured patients. When worn, protection against injury was demonstrated. A campaign to promote use of bicycle helmets should be targeted at non-residents and older bicyclists. Authorities should consider compulsory helmet laws for bicyclists and expanding anti-drunk driving campaigns to target alcohol-intoxicated bicyclists.