1,106 research outputs found
A novel technology for disinfecting surfaces infested with Candida auris: the UVC chip
Background
The fungal pathogen Candida Auris is increasingly associated with multidrug-resistant infections that are highly expensive for the Health Care System. The spreading of this pathogen can occur, among others, through contact with infected surfaces or medical instruments. This study evaluated the efficacy of a novel UVC chip, novel alternative to UVC LEDs and lamps, in inactivating Candida auris strain.
Methods
This experimental study was carried out between July and September 2020 at the University of Siena. Candida auris (ATCC 12372) at two known concentrations (1.5X107 and 1.5x106 CFU/ml) at a fixed distance (7,5 cm) from the chip (5.1mW radiant power) was tested, in triplicates, with three exposure times (5, 10 and 15 minutes). Potato Dextrose Agar (PDA) plates without the plate lid and containing Candida auris were exposed to UVC light. Subsequently, the plates were incubated at 36 °C for 48 h. Log reduction between treated and positive control (not exposed to UVC light) samples was calculated.
Results
At 15 minutes, we had the highest inactivation result, mean 4.43 log10, starting from a 1.5x106 CFU/mL concentration. At a higher concentration, 1.5X107 CFU/mL, the reduction had a mean of 3.51 log10.
Conclusions
The results of the experiments showed a significant microbial reduction in relation to the exposure time. The highest level of reduction was reached after 15 minutes of exposure. UVC chip had a relevant biocidal effect on Candida auris and may represent a valuable tool in the prevention of infections caused by this pathogen, which is becoming increasingly prevalent and persistent globally.
Key messages
• The use of UVC Chip decreases surface contamination.
• New technology against healthcare-associated infections
A time-varying SIRD model for dynamic vaccination strategies against COVID-19
The COVID-19 pandemic has demonstrated how the optimal allocation of the limited doses of vaccine available represents one of the main useful measures to mitigate the transmission of the infection and reduce the mortality associated with it, especially at an early stage of the pandemic. The use of a compartmental model allows us to understand which population groups to vaccinate and to what extent to act depending on the type of health or social objective to be achieved
Wind of change: Better air for microbial environmental control
Background: The COVID19 epidemic highlighted the importance of air in the transmission of pathogens. Air
disinfection is one of the key points to reduce the risk of transmission both in the health sector and in public, civil
and industrial environments. All bacteria and viruses tested to date can be inactivated by UV-C rays. Laboratory
tested UV-C systems are increasingly popular and proposed as effective technologies for air purification; few
studies have evaluated their performance in populated indoor environments. The aim of this investigation was to
evaluate the effectiveness of a UV-C disinfection system for air in a real working context.
Methods: This experimental study was conducted between December 2020 and February 2021 in an office of the
Department of Molecular and Developmental Medicine of the University of Siena, Italy. A pre-final version air
purifier (Cleaning Air T12), capable of treating 210 m3/h of air, was first tested for its ability to filter particulates
and reduce microbial air contamination in the absence of people. Subsequently, the experiments were conducted
in the presence of 3–5 subjects who worked for several hours in an office. During the tests, microbiological
samples of air were collected in real time, switching the system on and off periodically. Air samples were
collected and incubated on Petri dishes at 36 â—¦C and 22 â—¦C. Statistical analysis was performed with Stata 16
software assuming a significance level of 95%. An interpolating model was identified to describe the dynamics of
contamination reduction when the device operates.
Results: Preliminary tests showed a significant 62.5% reduction in Colony-Forming Units (CFUs) with 36 â—¦C
incubation. Reductions in the particulate component were also observed. In the main test, comparison of CFU
data, between the device-on phase (90 min) and the subsequent device-off phase (60 min), showed statistically
significant increase (p = 0.001) of environmental contamination passing from a mean of 86.6 (65.8–107.4) to
171.1 (143.9–198.3) CFU/m3, that is a rise of about 100%. The interpolating model exhibited a good fit of CFU
reduction trend with the device on.
Conclusions: The system, which mainly uses UV-C lamps for disinfection, was able to significantly reduce envi-
ronmental and human contamination in real time. Experimental tests have shown that as soon as the device is
switched off, after at least half an hour of operation, the healthiness of the air decreases drastically within 10
minutes, bringing the airborne microbial contamination (induced by the presence of operators in the environ-
ment) to levels even higher than 150% of the last value with the device on. Re-engineering strategies for system
improvement were also discusse
Recommended from our members
Microfluidic interactions between red blood cells and drug carriers by image analysis techniques
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Blood is a complex biological fluid composed of deformable cells and platelets suspended in
plasma, a protein-rich liquid. The peculiar nature of blood needs to be considered when designing a drug
delivery strategy based on systemically administered carriers. Here, we report on an in vitro fluid dynamic
investigation of the influence of the microcapillary flow of red blood cells (RBCs) on micron sized carriers
by high speed imaging methods. The experiments were carried out in a 50μm diameter glass capillary that
mimicked the hydrodynamic conditions of human microcirculation. Spherical μ particles (μ-Ps), with sizes
ranging between 0.5 and 3μm, were tested. Images of the flowing RBCs and μ-Ps were acquired by a highspeed/ high-magnification microscopy. The transport and distribution of rigid particles in a suspension of
RBCs under shear flow were followed for: i) the migration of RBCs towards the vessel centerline due to
their deformability; ii) the cross-flow migration of μ-Ps towards the vessel wall due to their hydrodynamic
interactions with RBCs; iii) the radial distribution of μ-Ps in the presence of RBCs. This study suggests that
the therapeutic efficacy of μ-Ps could be ultimately affected by their interactions with the flowing RBCs in
the vasculature
Safer school with near-UV technology: novel applications for environmental hygiene
Systems capable of disinfecting air and surfaces could reduce the risk of infectious diseases transmission. Aim: to evalu-ate the effectiveness of near-UV LED ceiling lamps, with a wavelength of 405 nm, in improving environmental hygiene. Between November and December 2020, we conducted an experimental study having a pre-post design in a kindergarten room in Siena where 4 ceiling lamps with 405 nm LED technology were installed. Twice per day, sampling was performed before (T0) and after treatment with near-UV (T1). We used between 8 and 12 pairs of contact plates to sample at various random spots each day. Air samplings were also performed. The plates were incubated at 22 and 36 degrees C. Significance was set at 95% (p < 0.05). The mean level of Colony Forming Unit (CFU) at T(0) was 249 (95% CI 193.1 - 305.0) at 36 degrees C and 535.2 (374.3 - 696.1) at 22 degrees C. The reduction was significant at T(1): by 65% at 36 degrees C and, 72% at 22 degrees C. Also, for air contamination: 95.3% (98.4 & mdash;92.3). A dose threshold of about 5 J/cm2 was identified to have an 80% CFU abatement and remains nearly constant. The advantage of being able to use this technology in the presence of people is very important in the context of controlling environmental contamination. © 2023, The Author(s)
concordance and time estimation of store and forward mobile teledermatology compared to classical face to face consultation
Smartphones have overcome the limitations of image quality seen in older devices and opened a new field of telemedicine called "mobile teledermatology". Technological advances and the need to reduce health service costs will strongly promote the development of telemedicine. For this reason, we evaluated the concordance be tween store-and-forward mobile teledermatology and the classical face-to-face dermatological visit. We also measured the time taken to submit a teleconsultation using a smartphone. Before conventional face-to-face visit, a final-year resident of the 3-year course for general practitioners collected medical history, took digital images of skin diseases with a smartphone and, measuring the time required to complete this operation, transmitted them to an expert teledermatologist. In 391 patients we obtained a concordance between face-to-face and store-and-forward diagnosis of 91.05% (Cohen κ coefficient = 0.906). On average only few minutes needs to be added to a no
An Updated Algorithm Integrated With Patient Data for the Differentiation of Atypical Nevi From Early Melanomas: the idScore 2021
Introduction: It is well known that multiple patient-related risk factors contribute to the development of cutaneous melanoma, including demographic, phenotypic and anamnestic factors. Objectives: We aimed to investigate which MM risk factors were relevant to be incorporated in a risk scoring-classifier based clinico-dermoscopic algorithm. Methods: This retrospective study was performed on a monocentric dataset of 374 atypical melanocytic skin lesions sharing equivocal dermoscopic features, excised in the suspicion of malignancy. Dermoscopic standardized images of 258 atypical nevi (aN) and 116 early melanomas (eMM) were collected along with objective lesional data (i.e., maximum diameter, specific body site and body area) and 7 dermoscopic data. All cases were combined with a series of 10 MM risk factors, including demographic (2), phenotypic (5) and anamnestic (3) ones. Results: The proposed iDScore 2021 algorithm is composed by 9 variables (age, skin phototype I/II, personal/familiar history of MM, maximum diameter, location on the lower extremities (thighs/legs/ ankles/back of the feet) and 4 dermoscopic features (irregular dots and globules, irregular streaks, blue gray peppering, blue white veil). The algorithm assigned to each lesion a score from 0 to 18, reached an area under the ROC curve of 92% and, with a score threshold ≥ 6, a sensitivity (SE) of 98.2% and a specificity (SP) of 50.4%, surpassing the experts in SE (+13%) and SP (+9%).Conclusions: An integrated checklist combining multiple anamnestic data with selected relevant dermoscopic features can be useful in the differential diagnosis and management of eMM and aN exhibiting with equivocal features
Antenatal syphilis serology in pregnant women and follow-up of their infants in northern Italy
ABSTRACTPositive syphilis serology was noted in 119 (0.49%) of the 24 053 pregnant women delivering at St Orsola Hospital in Bologna, Italy, from November 2000 through July 2007. Six presumptive cases of congenital syphilis with IgM western blot positive results were found. Two infants had a positive cerebrospinal fluid (CSF) Venereal Disease Research Laboratory test result (one also had a positive CSF PCR result), another presented long-bone lesions, and the remaining three were preterm. These observations confirmed that antenatal syphilis screening facilitates treatment during pregnancy and offsets vertical transmission; moreover, the use of IgM western blot and careful CSF examination allowed the identification and treatment of high-risk newborns
Italy-Japan agreement and discrepancies in diagnosis of superficial gastric lesions.
The agreement between Italian and Japanese endoscopists and pathologists on endoscopic and histopathological diagnoses of superficial gastric lesions is verified with the use of Paris and Vienna classifications. The correlations between Paris endoscopic types and Vienna histopathological categories is high in both the independent Italian and Japanese evaluations. However, the agreement between Italian and Japanese endoscopists is moderate due to the difficult evaluation of the height of the lesions, in particular when they are mixed. The agreement on the size of the lesions is fairly good. The probability of the same allocation to the Vienna categories of a single case is 87 per cent, disagreements remaining in dysplasia grading, between dysplasia, not only high-grade but also low-grade, and in situ carcinoma, and on cancer invasion of the lamina propria. The results indicate that use of the Paris and Vienna classifications has reduced the discrepancies between Western and Japanese endoscopists and pathologists in the diagnosis of these lesions
- …