112 research outputs found

    Overview of Hybrid Ventilation Control System and Full Scale Monitoring

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    Mix-mode or hybrid ventilation systems have been previously shown to reduce cooling and ventilation energy consumption. This paper presents a case study of a new ten story 83,700 ft² (7,780 m²) office building in downtown Tokyo with a hybrid ventilation system that uses only 1.7% of the building footprint for ventilation shafts. The control system design is presented as an example of balancing the comfort expectations of multiple tenants in a mix-mode system. On-site measurements are presented from a three week commissioning project to show: modest temperature differences within the occupied zone with a maximum difference of 1.5 °F (0.83 °C), large differences of up to 6.1 °F (3.4 °C) between the measured outdoor temperature in the control system and the actual inlet temperature for the natural ventilation system, the importance of smooth integration of various design teams, and the use of low-power fans, 1.2-0.60 hp (900-450 W), that leverage the low pressure drop through the building when natural driving forces are insufficient for pure natural ventilation. Practical lessons learned from the design and commissioning of the building are also shared.Hulic Co., Ltd

    25 years after Vi typhoid vaccine efficacy study, typhoid affects significant number of population in Nepal

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    Salmonella Typhi, first isolated in 1884, results in infection of the intestines and can end in death and disability. Due to serious adverse events post vaccination, whole cell killed vaccines have been replaced with new generation vaccines. The efficacy of Vi polysaccharide (ViPS) vaccine, a new generation, single-dose intramuscular typhoid vaccine was assessed in Nepal in 1987. However, despite the availability of ViPS vaccine for more than 25 years, Nepal has one of the highest incidence of typhoid fever. Therefore we collected information from hospitals in the Kathmandu Valley from over the past five years. There were 9901 enteric fever cases between January 2008 and July 2012. 1,881 of these were confirmed typhoid cases from five hospitals in the Kathmandu district. Approximately 70% of the cases involved children under 15 years old. 1281 cases were confirmed as S. Paratyphi. Vaccines should be prioritized for control of typhoid in conjunction with improved water and sanitation conditions in Nepal and in endemic countries of Asia and Africa

    Burden of typhoid fever in low-income and middle-income countries: a systematic, literature-based update with risk-factor adjustment

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    Background No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk. Methods We estimated the typhoid disease burden from studies done in LMICs based on blood-culture-confi rmed incidence rates applied to the 2010 population, after correcting for operational issues related to surveillance, limitations of diagnostic tests, and water-related risk. We derived incidence estimates, correction factors, and mortality estimates from systematic literature reviews. We did scenario analyses for risk factors, diagnostic sensitivity, and case fatality rates, accounting for the uncertainty in these estimates and we compared them with previous disease burden estimates. Findings The estimated number of typhoid fever cases in LMICs in 2010 after adjusting for water-related risk was 11·9 million (95% CI 9·9–14·7) cases with 129 000 (75 000–208 000) deaths. By comparison, the estimated riskunadjusted burden was 20·6 million (17·5–24·2) cases and 223 000 (131 000–344 000) deaths. Scenario analyses indicated that the risk-factor adjustment and updated diagnostic test correction factor derived from systematic literature reviews were the drivers of diff erences between the current estimate and past estimates. Interpretation The risk-adjusted typhoid fever burden estimate was more conservative than previous estimates. However, by distinguishing the risk diff erences, it will allow assessment of the eff ect at the population level and will facilitate cost-eff ectiveness calculations for risk-based vaccination strategies for future typhoid conjugate vaccine

    Community Participation in Two Vaccination Trials in Slums of Kolkata, India: A Multi-level Analysis

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    This study aims at understanding the individual and community-level characteristics that influenced participation in two consecutive vaccine trials (typhoid and cholera) in urban slums of Kolkata, India. The study area was divided into 80 geographic clusters (communities), with 59,533 subjects aged ≥2 years for analysis. A multi-level model was employed in which the individuals were seen nested within the cluster. Rates of participation in both the trials were nearly the same; those who participated in the initial trial were likely to participate in the subsequent cholera vaccine trial. Communities with predominantly Hindu population, lower percentage of households with an educated household head, or lower percentage of households owning a motorbike had higher participation than their counterparts. At individual scale, higher participation was observed among younger subjects, females, and individuals from households with a household head who had no or minimal education. Geographic patterns were also observed in participation in the trials. The results illustrated that participation in the trial was mostly influenced by various individual and community-level factors, which need to be addressed for a successful vaccination campaign

    Replacing paper data collection forms with electronic data entry in the field: findings from a study of community-acquired bloodstream infections in Pemba Zanzibar

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    BackgroundEntering data on case report forms and subsequently digitizing them in electronic media is the traditional way to maintain a record keeping system in field studies. Direct data entry using an electronic device avoids this two-step process. It is gaining in popularity and has replaced the paper-based data entry system in many studies. We report our experiences with paper- and PDA-based data collection during a fever surveillance study in Pemba Island, Zanzibar, Tanzania.MethodsData were collected on a 14-page case report paper form in the first period of the study. The case report paper forms were then replaced with handheld computers (personal digital assistants or PDAs). The PDAs were used for screening and clinical data collection, including a rapid assessment of patient eligibility, real time errors, and inconsistency checking.ResultsA comparison of paper-based data collection with PDA data collection showed that direct data entry via PDA was faster and 25% cheaper. Data was more accurate (7% versus 1% erroneous data) and omission did not occur with electronic data collection. Delayed data turnaround times and late error detections in the paper-based system which made error corrections difficult were avoided using electronic data collection.ConclusionsElectronic data collection offers direct data entry at the initial point of contact. It has numerous advantages and has the potential to replace paper-based data collection in the field. The availability of information and communication technologies for direct data transfer has the potential to improve the conduct of public health research in resource-poor settings

    Adults\u27 perceived prevalence of enteric fever predicts laboratory-validated incidence of typhoid fever in children

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    This study was undertaken to develop a model to predict the incidence of typhoid in children based on adults’ perception of prevalence of enteric fever in the wider community. Typhoid cases among children, aged 5-15 years, from epidemic regions in five Asian countries were confirmed with a positive Salmonella Typhi culture of the blood sample. Estimates of the prevalence of enteric fever were obtained from random samples of adults in the same study sites. Regression models were used for establishing the prediction equation. The percentages of enteric fever reported by adults and cases of typhoid incidence per 100,000, detected through blood culture were 4.7 and 24.18 for Viet Nam, 3.8 and 29.20 for China, 26.3 and 180.33 for Indonesia, 66.0 and 454.15 for India, and 52.7 and 407.18 for Pakistan respectively. An established prediction equation was: incidence of typhoid (1/100,000= −2.6946 + 7.2296 × reported prevalence of enteric fever (%) (F=31.7, p2=0.992). Using adults’ perception of prevalence of disease as the basis for estimating its incidence in children provides a cost-effective behavioural epidemiologic method to facilitate prevention and control of the disease

    Immune responses to Vi capsular polysaccharide typhoid vaccine in children 2 to 16 years old in Karachi, Pakistan, and Kolkata, India

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    The geometric mean concentration (GMC) and the proportion maintaining a protective level (150 enzyme-linked immunosorbent assay (ELISA) units [ELU]/ml) 2 years following a single dose of 25 μg of injectable Vi capsular polysaccharide typhoid vaccine was measured against that of the control hepatitis A vaccine in children 2 to 16 years old in cluster randomized trials in Karachi and Kolkata. The GMC for the Vi group (1,428 ELU/ml) was statistically significantly different from the GMC of the control hepatitis A vaccine group (86 ELU/ml) after 6 weeks. A total of 117 children (95.1%) in the Vi group and 9 (7.5%) in the hepatitis A group showed a 4-fold rise in Vi IgG antibody concentrations at 6 weeks (P \u3c 0.01). Protective antibody levels remained significantly different between the two groups at 2 years (38% in the Vi vaccine groups and 6% in the hepatitis A group [P \u3c 0.01]). A very small proportion of younger children (2 to 5 years old) maintained protective Vi IgG antibody levels at 2 years, a result that was not statistically significantly different compared to that for the hepatitis A group (38.1% versus 10.5%). The GMCs of the Vi IgG antibody after 2 years were 133 ELU/ml for children 2 t

    Community participation in two vaccination trials in slums of Kolkata, India: A multi-level analysis

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    This study aims at understanding the individual and community-level characteristics that influenced par-ticipation in two consecutive vaccine trials (typhoid and cholera) in urban slums of Kolkata, India. The study area was divided into 80 geographic clusters (communities), with 59, 533 subjects aged 65 2 years for analysis. A multi-level model was employed in which the individuals were seen nested within the cluster. Rates of participation in both the trials were nearly the same; those who participated in the initial trial were likely to participate in the subsequent cholera vaccine trial. Communities with predominantly Hindu population, lower percentage of households with an educated household head, or lower percentage of households owning a motorbike had higher participation than their counterparts. At individual scale, higher participation was observed among younger subjects, females, and individuals from households with a household head who had no or minimal education. Geographic patterns were also observed in participa-tion in the trials. The results illustrated that participation in the trial was mostly influenced by various indi-vidual and community-level factors, which need to be addressed for a successful vaccination campaign

    The Burden of Invasive Bacterial Infections in Pemba, Zanzibar

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    BACKGROUND: We conducted a surveillance study to determine the leading causes of bloodstream infection in febrile patients seeking treatment at three district hospitals in Pemba Island, Zanzibar, Tanzania, an area with low malaria transmission. METHODS: All patients above two months of age presenting to hospital with fever were screened, and blood was collected for microbiologic culture and malaria testing. Bacterial sepsis and malaria crude incidence rates were calculated for a one-year period and were adjusted for study participation and diagnostic sensitivity of blood culture. RESULTS: Blood culture was performed on 2,209 patients. Among them, 166 (8%) samples yielded bacterial growth; 87 (4%) were considered as likely contaminants; and 79 (4%) as pathogenic bacteria. The most frequent pathogenic bacteria isolated were Salmonella Typhi (n = 46; 58%), followed by Streptococcus pneumoniae (n = 12; 15%). The crude bacteremia rate was 6/100,000 but when adjusted for potentially missed cases the rate may be as high as 163/100,000. Crude and adjusted rates for S. Typhi infections and malaria were 4 and 110/100,000 and 4 and 47/100,000, respectively. Twenty three (51%), 22 (49%) and 22 (49%) of the S. Typhi isolates were found to be resistant toward ampicillin, chloramphenicol and cotrimoxazole, respectively. Multidrug resistance (MDR) against the three antimicrobials was detected in 42% of the isolates. CONCLUSIONS: In the presence of very low malaria incidence we found high rates of S. Typhi and S. pneumoniae infections on Pemba Island, Zanzibar. Preventive measures such as vaccination could reduce the febrile disease burden

    The Role of Epidemiology in the Introduction of Vi Polysaccharide Typhoid Fever Vaccines in Asia

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    Despite the availability of at least two licensed typhoid fever vaccines-injectable sub-unit Vi polysaccharide vaccine and live, oral Ty21a vaccine-for the last decade, these vaccines have not been widely introduced in public-health programmes in countries endemic for typhoid fever. The goal of the multidisciplinary DOMI (Diseases of the Most Impoverished) typhoid fever programme is to generate policy-relevant data to support public decision-making regarding the introduction of Vi polysaccharide typhoid fever immunization programmes in China, Viet Nam, Pakistan, India, Bangladesh, and Indonesia. Through epidemiological studies, the DOMI Programme is generating these data and is offering a model for the accelerated, rational introduction of new vaccines into health programmes in low-income countries. Practical and specific examples of the role of epidemiology are described in this paper. These examples cover: (a) selection of available typhoid fever vaccines to be introduced in the programme, (b) generation of policy-relevant data, (c) providing the 'backbone' for the implementation of other multidisciplinary projects, and (d) generation of unexpected but useful information relevant for the introduction of vaccines. Epidemiological studies contribute to all stages of development of vaccine evaluation and introduction
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