Transmission modes of severe acute respiratory syndrome coronavirus 2 and implications for infection control: a review

The complete picture regarding transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. This review summarises the available evidence on its transmission modes, our preliminary research findings and implications for infection control policy, and outlines future research directions. Environmental contamination has been reported in hospital settings occupied by infected patients, and is higher in the first week of illness. Transmission via environmental surfaces or fomites is likely, but decontamination protocols are effective in minimising this risk. The extent of airborne transmission is also unclear. While several studies have detected SARS-CoV-2 ribonucleic acid in air samples, none has isolated viable virus in culture. Transmission likely lies on a spectrum between droplet and airborne transmission, depending on the patient, disease and environmental factors. Singapore's current personal protective equipment and isolation protocols are sufficient to manage this risk.

Insulin Therapy in Type 2 Diabetes Mellitus

@#Initiation of insulin therapy is challenging in the primary care setting without nursing support. Doctors have to prepare their practices to deal with these challenges in order not to delay insulin therapy when needed.

Insulin Therapy in Type 2 Diabetes Mellitus

@#Initiation of insulin therapy is challenging in the primary care setting without nursing support. Doctors have to prepare their practices to deal with these challenges in order not to delay insulin therapy when needed.

Intensifying Lifestyle Management in Type 2 Diabetes Mellitus

@#Lifestyle management (LSM) is a fundamental aspect of Type 2 diabetes mellitus (T2DM) management. Intensifying LSM beyond basic nutritional and exercise advice has been challenging for most doctors as LSM in diabetes is complex. To help navigate through the complexity of LSM in diabetes care, this article introduces an acronym DESMM as an easy-to-remember guide that encompasses most if not all the components of diabetes LSM. DESMM stands for Diet, Exercise, Support/Stress, Monitoring and Medicine. DESMM offers a structured guidance to enable consistent evaluation of the lifestyle of the patient with the intention of intensifying LSM.

Germline gene testing of the RET, VHL, SDHD and SDHB genes in patients with pheochromocytoma/paraganglioma / 北京大学学报(医学版)

OBJECTIVE@#To analyze the germline variations of genes RET, VHL, SDHD and SDHB in patients with pheochromocytoma and/or paraganglioma and to evaluate variations of these genes in Chinese patients.@*METHODS@#Patients who were treated in Peking University First Hospital from September 2012 to March 2014 and diagnosed with pheochromocytoma and/or paraganglioma by pathologists were included in this study. Twelve patients were included in total, of whom 11 had pheochromocytoma, and 1 had paraganglioma. Deoxyribonucleic acid (DNA) was extracted from the leukocytes of peripheral blood of the patients. The exons 10, 11, 13-16 of the RET gene, and all exons of VHL, SDHB and SDHD genes and their nearby introns (±20 bp) were amplified with polymerase chain reactions, and the products were sent to a biotechnology company for sequencing. The sequencing results were compared with wildtype sequences of these genes to identify variations. One of the patients was diagnosed with multiple endocrine neoplasia type 2A. A family analysis was performed in his kindred, and his family members received genetic tests for the related variations.@*RESULTS@#Three patients were found to have germline gene variations. A c.136C>T (p.R46X) variation of the SDHB gene was found in a patient with malignant pheochromocytoma. A c.1901G>A (C634Y) variation, as well as c.2071G>A (p.G691S) and c.2712C>G (p.S904S) variations of the RET gene were found in a patient with multiple endocrine neoplasia type 2A. After a family analysis, five family members of this patient were found to have the same variations. c.2071G>A (p.G691S) and c.2712C>G (p.S904S) variations of the RET gene were also found in a clinical sporadic patient without evidence of malignancy. A patient with congenital single ventricle malformation and pheochromocytoma was included in this study, and no variation with clinical significance was found in the four genes of this patient.@*CONCLUSION@#25% (3/12) patients with pheochromocytoma or paraganglioma were found to have missense or nonsense germline gene variations in this study, including the c.136C>T (p.R46X) variation of the SDHB gene, the c.1901G>A (C634Y) variation of the RET gene, and c.2071G>A (p.G691S) and c.2712C>G (p.S904S) variations of the RET gene. The former two variations have already been confirmed to be pathogenic. The existence of these variations in Chinese patients with pheochromocytoma and/or paraganglioma was validated in this study, which supports the conclusion that genetic testing is necessary to be generally performed in patients with pheochromocytoma and/or paraganglioma.

Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

An experimental study of comparing digital tomosynthesis and multi-slice CT scanning for the detection of pulmonary nodules using the anthropomorphic chest phantom / 中华放射学杂志

ObjectiveTo compare detection rate of pulmonary nodules and the radiation doses of digital tomosynthesis (DTS) and MSCT chest scanning by using the anthropomorphic chest phantom which containsthermoluminescent dosimeters( TLD ) and simulated pulmonary nodules.Methods The radiation doses of DTS and MSCT scanning were measured by using the anthropomorphic chest phantom which contains 45 TLD and simulated pulmonary nodules.The radiation doses of najor organs were converted into effective dose ( ED ). Three radiologists of different clinical experiences independently reviewed and recorded the density,diameter and position of pulmonary nodules.The sensitivity of nodule detection by DTS and MSCT were compared by Fisher exact test and Chi-square test. The paired t test was conducted to analyze the dose levels of DTS and MSCT.ResultsThe sensitivity of detection nodule by DTS and MSCT were 66.7％ (30/45) and 91.1％ (41/45) respectively.Statistically significant difference between the two examinations existed ( x2 =8.073,P ＜ 0.05).The sensitivity of detection - 650 HU ground glass opacity pulmonary nodule by MSCT and DTS were 93.3％ (14/15) and 73.3％ (11/15) respectively.There was no significant difference between DTS and MSCT ( P ＞ 0.05 ).The sensitivity of detection - 800 HU ground glass opacity nodule and ground glass opacity nodule (d ＜ 8 mm) by DTS were 33.3％ (5/15) and 16.7％ (2/12) respectively,which were lower than those by CT[80.0％ (12/15) and 66.7％ (8/12)].The radiation doses of DTS for various organs in the chest were lower than those of CT. Statistical significant difference between DTS and MSCT existed ( lung t =19.69,thoracic vertebral t =30.01,heart t =16.33,liver t =5.06,breast t =9.43,thyroid gland t =8.05 ;P ＜ 0.05).The effective doses of the DTS and MSCT were 0.65 and 7.71 mSv respectively.ConclusionsThere is no difference between the DTS and MSCT in the detection rate of -650 HU ground glass opacity nodule.For detecting the ground glass opacity nodule ( - 800 HU) and ground glass opacity nodule (d ＜ 8 mm),MSCT is superior to DTS. However,the radiation dosage of DTS is 8.41％ of the MSCT scanning.

Correlation between the tube current and image noise in low-dose chest CT scean / 中华放射医学与防护杂志

Objective To analyze the distribution of image noise in low-dose chest CT scan and optimize the relative scanning parameters.Methods The CT images of the Chinese anthropomorphic chest phantom( CDP-1 C) were simulated into six groups of low-dose images with different noise indexs by using an image noise addition tool.The difference between the preset noise index and analog noise value was compared.The CT images of 20 volunteers were also simulated into nine groups of low dose scans with the tube currents of 10,30,50,80,100,120,150,180 and 240 mA.The noise values of images were recorded and analyzed.Results There was no statistical difference between the analog noise value and the noise index.The image noise of low-dose chest scan was increased with the decrease of tube current.The noise was increased quickly when the current was decreased from 50 to 30 mA ( F =24.09 - 40.79,P ＜ 0.05),but the noise increased slowly when the current decreased from 240 to 80 mA.There was no statistical difference between the noise of 80 mA group and that of 120 mA(P ＞ 0.05).Conclusions The noise addition tool can be used to evaluate the image noise of low-dose chest CT scan.Adoption of 80 mA in chest CT scan would result in low radiation dose without adding image noise.

Outbreak of acute norovirus gastroenteritis in a military facility in Singapore: a public health perspective

<p><b>INTRODUCTION</b>Norovirus gastrointestinal disease (GID) outbreaks occur frequently in closed settings, with high attack rates. On October 16, 2008, a norovirus GID outbreak occurred at a Singapore military camp. This study describes the epidemiological investigations conducted to determine the cause of outbreak and the efficacy of the public health measures implemented.</p><p><b>METHODS</b>Epidemiologic investigations included a case-control study of exposure to different food items and an environmental exposure survey. Stool samplings of patients and food handlers for common pathogens, and microbiologic testing of food and water samples were performed. Inspection of dining facilities and health screening of all food-handlers were also conducted.</p><p><b>RESULTS</b>A total of 156 GID cases were reported on October 15-31, 2008. 24 (15.4%) personnel were positive for norovirus. The predominant symptoms were diarrhoea (76.3%) and abdominal pain (69.2%). There was no clinical correlation between any food item and the affected personnel. Testing of food and water samples, dining facility inspections and health screening of food handlers showed satisfactory results. The environmental exposure survey indicated possible transmission due to environmental contamination by vomitus in common areas. Comprehensive environmental decontamination was performed with hypochlorite solution, and personal hygiene measures were enforced. The outbreak lasted 17 days, with a decline in cases post intervention.</p><p><b>CONCLUSION</b>Timely notification and prompt response can curtail disease transmission. Swift implementation of public health measures, such as emphasis on personal hygiene, isolation of affected cases and comprehensive disinfection of the environment, effectively stopped norovirus transmission and may be adapted for future GID outbreaks.</p>

Antiviral drugs for the control of pandemic influenza virus

In the advent of an influenza virus pandemic it is likely that the administration of antiviral drugs will be an important first line of defence against the virus. The drugs currently in use are effective against seasonal influenza virus infection, and some cases have been used in the treatment of patients infected with the avian H5N1 influenza virus. However, it is becoming clear that the emergence of drug-resistant viruses will potentially be a major problem in the future efforts to control influenza virus infection. In addition, during a new pandemic, sufficient quantities of these agents will need to be distributed to many different parts of the world, possibly at short notice. In this review we provide an overview of some of the drugs that are currently available for the treatment and prevention of influenza virus infection. In addition, basic research on influenza virus is providing a much better understanding of the biology of the virus, which is offering the possibility of new anti-influenza virus drugs. We therefore also review some new antiviral strategies that are being reported in the scientific literature, which may form the basis of the next generation of antiviral strategies during a future influenza virus pandemic.