High Contamination Rate Research Articles

Bacterial contamination on used face masks in healthcare personnel

Background: Face masks have been worn universally and for long periods of time by healthcare personnel during the COVID-19 pandemic. They are frequently touched or adjusted with the hands and may come in contact with various surfaces and high-touch sites when taken off and on even briefly. These activities present opportunities for face masks to become contaminated with microorganisms. Nursing homes have high rates of multidrug-resistant bacteria and low PPE compliance; therefore, contamination of face masks in this setting may be of great interest. We investigated bacterial colonization status on used face masks in healthcare personnel, including assessing the presence of clinically important and multidrug-resistant bacteria. Methods: At a nursing home serving mostly post–acute-care patients, we collected 69 face masks from personnel at the end of the user’s work shift. Information about the mask and the user was also collected via a self-reported survey. Face masks were incubated in BHI broth overnight at 36°C and 10 μL was then plated on selective and differential plates. Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and gram-negative bacteria (GNB) resistant to several antibiotic classes were identified using standard microbiological methods. Resistance testing for cefoxitin (S. aureus), ciprofloxacin, meropenem, tetracycline, erythromycin, gentamicin, trimethoprim–sulfamethoxazole, and ceftazidime with and without clavulanic acid (gram-negative bacteria) was performed using the disc diffusion technique on Mueller-Hinton plates (Kirby Bauer). Results: The job categories of face mask users were competency-evaluated nursing assistant or nursing assistant (22.73%), nurse (12.12%), and other or administrative (37.88%). Overall face mask contamination rates for MRSA (0%) and VRE (3.3%) were low; however, methicillin-susceptible S. aureus was found on 11 masks (15.9%). High contamination and resistance rates were found for gram-negative bacteria, with 113 isolates. Among them, 69 (60.9%) were resistant to at least 1 antibiotic, most commonly was erythromycin (59.4%). Additionally, higher rates of clinically important pathogenic gram-negative bacteria were identified: 14.3% of masks were contaminated with Klebsiella pneumoniae, 13.0% were contaminated with Enterobacter spp, and 4.2% were contaminated with Escherichia coli. Importantly, there were no significant differences in the total number of isolates of potential clinical significance recovered from masks worn >6 hours versus those worn <6 hours. Conclusions: Among nursing-home healthcare workers, face masks were often contaminated with multiple organisms, including potentially pathogenic bacteria and antibiotic-resistant gram-negative organisms. This contamination may pose a risk for transmission if face masks are not properly used and/or disposed of after wearing. Prolonged duration of face-mask wearing, however, was not associated with increased contamination rates.Funding: NoneDisclosures: None

Goalpara and bacterial water contamination

The current world is fighting with several issues like Covid- 19, Poverty, Malnutrition and many more. But there are some other issues which are still ignored by considering as less important. Among these least concern issues death due to drinking of contaminated water or ingestion of food come in contact with polluted water holds a major percentage. The study was conducted to determine the quality of water contamination trend in Goalpara district of Assam. The presence of fecal and total coliform were tested by Most Probable Number as well as Membrane filtration tests (MF) to rule out any chance of missing out any positive sample. During the study we identified the causative agent which contaminates the water in the targeted district of Assam, India. Water samples were collected from drinking water supplies and from routine household chores. During the study, evidence of microorganisms such as Escherichia coli, Streptococci, Staphylococci and Klebsiella were found. Escherichia coli were isolated from most numbers of samples, whereas Shigella spp. has the lowest contamination rate. The water with highest contamination rate was from Rangjuli development block and Lakhipur development block gave the lowest water contamination rate. The most prevalent bacteria were Escherichia coli.

Differences in levels of E. coli contamination of point of use drinking water in Bangladesh.

This study aimed to quantify the inequalities and identify the associated factors of the UN sustainable development goal (SDG) targets in relation to safe drinking water. The concentration of the gut bacterium Escherichia coli in drinking water at the point of use (POU) and other information were extracted from the latest wave of the nationally representative Bangladesh Multiple Indicator Cluster Survey (MICS 2019). Bivariate and multivariable multinomial logistic regression models were used to identify potential predictors of contamination, whereas, classification trees were used to determine specific combinations of background characteristics with significantly higher rates of contamination. A higher risk of contamination from drinking water was observed for households categorized as middle or low wealth who collected water from sources with higher concentrations of E. coli. Treatment of drinking water significantly reduced the risk of higher levels of contamination, whereas owning a pet was significantly associated with recontamination. Regional differences in the concentrations of E. coli present in drinking water were also observed. Interventions in relation to water sources should emphasize reducing the level of E. coli contamination. Our results may help in developing effective policies for reducing diarrheal diseases by reducing water contamination risks.

Effect of time, temperature and pH on Mycobacterium tuberculosis culture positivity of gastric aspirate: An experimental study

BackgroundThe culture of gastric aspirate (GA) has been used for bacteriological confirmation of pulmonary tuberculosis in children and patients who are unable to expectorate. Sodium bicarbonate neutralization of gastric aspirates is commonly recommended to increase culture positivity. We aim to study Mycobacterium tuberculosis (MTB) culture positivity of GA collected from confirmed case of pulmonary tuberculosis after storing it at different temperature, pH & time. MethodsGA specimens from 865 patients of either sex predominately non-expectorating children/adults with suspected pulmonary TB were collected. Gastric lavage was performed in the morning after an overnight fasting (at least 6hrs fasting). The GA specimens were tested by CBNAAT (GeneXpert) and AFB microscopy & those who were positive on CBNAAT were further processed with MTB culture on Growth Indicator Tube (MGIT™) culture. pH neutralized and non-neutralized CBNAAT positive GA specimens were culture within 2 hours of collection and 24 hours after storage at 4 °C & room temperature. ResultsMTB was detected in 6.8% of collected GA specimens by CBNAAT. Culture positivity of neutralized GA specimens when processed within 2 hours of collection, was higher compared to paired non-neutralized GA specimens. Neutralized GA specimens had higher contamination rate than non-neutralized GA specimens. Storage of GA specimens at $Deg C had better culture yield than those stored at room temperature. ConclusionEarly neutralization of acid in Gastric aspirate (GA) is essential for better culture positivity of M. tuberculosis (MTB). If there is a delay in processing GA, it should be kept at 4 °C after neutralization; however, positivity decreases with time.

Statistical Investigation of High Culture Contamination Rates in Mycobacteriology Laboratory.

BackgroundCulture of Mycobacterium tuberculosis remains the gold standard in mycobacteriology laboratories, constrained by the very high risk of contamination; therefore, contamination rate is an important key performance indicator (KPI) for laboratory monitoring and evaluation processes.AimThis study aimed to investigate the factors that contribute to elevated contamination rates in the Sudan National Tuberculosis Reference Laboratory.MethodA laboratory-based retrospective study was applied; a TB culture register-book was carefully reviewed and data from 2 January 2019 to 31 December 2019 were entered, cleaned, and analyzed using IBM SPSS 20. A multivariate logistic regression model was performed to examine two dependent variables, the massive contamination, and the single tube contamination against predictors of reason for cultivation, type of specimen, experiment team, and the quarter of cultivation.ResultsIt has been found that in 2019 contamination rates were frequently higher; the highest rates were recorded in January and November, 28.2 and 25.2%, respectively. August is an exception with an accepted contamination rate of 4.6%. Of 1,149 specimens requested for culture, 945 (82.2%) samples were eligible to be included in multivariate logistic regression analysis. The team conducting the experiment was significantly associated with a high single tube contamination p value 0.007; adjusted odds ratio AOR 3.570 (1.415–9.005). The correlation between the single tube contamination and the massive contamination is significant; p value 0.01.ConclusionThe study concludes that high culture contamination is the greatest risk to the quality of laboratory service and can end in either the loss of specimens or delay in the decisions of initiating patient treatment. In addition, the low quality or incompleteness of data increases the uncertainty and undermines the measurement of key performance indicators.

Plant Regeneration Protocol for Recalcitrant Passionflower (Passiflora quadrangularis L.)

This research was designed to provide the first protocol to establish an efficient solution for direct organogenesis regeneration in Passiflora quadrangularis using nodal explants from young shoots. Passifloraceae tissue culture has been associated with problems such as recalcitrance, sensitivity to ethylene accumulation and browning of explants due to the presence of phenols in the tissues. Due to the high rate of endogenous contamination of the explants, a preliminary experiment was performed. The best results of surface sterilization were obtained using the pretreatment with 70% EtOH, 1 min and 50% NaOCl, 10 min along with the treatment of Rifampicin 15 µg/mL and Benomyl 2 g/L. The effects of plant growth regulators on the induction of direct organogenesis, multiplication of shoots in subcultures and in vitro rooting were evaluated. Additional compounds such as AgNO3 and Pluronic F-68 were added to the culture media in order to reduce the effects of phenols and the sudden browning of the explants. Shoot proliferation increased to the sixth subculture after which it decreased. A maximum of 7.17 shoots were obtained from one shoot on Murashige and Skoog (MS) medium supplemented with 2 mg/L 6-benzylaminopurine and 1 mg/L thidiazuron. Supplementation of ½ MS medium with 1 mg/L 1-naphthaleneacetic acid was conducing to root formation in 61.11% of shoots. After acclimatization, the plants showed vigorous growth, green leaves, and well-developed roots. Although this species has previously shown difficulty in in vitro propagation, this protocol established based on the results proved to be efficient and reproducible.

Covid-19 Dissemination: Late Contact in Local Centers in Southeastern Tocantins

In 2020, the world was overwhelmed by COVID-19, which produced a severe pathology with high mortality rates. National policies to control the pandemic clashed with Brazil’s precarious health structure. While the Brazilian state of Tocantins, along with the rest of the world, saw its main cities suffer from high contamination rates, certain other localities remained free from these dynamics for a much longer period. Thus, this study set out to investigate five municipalities, all located in the southeastern corner of the state, and which were the last to be affected by the pandemic. The aim was to reflect upon the factors that delayed the arrival of the virus. A descriptive analysis was conducted, with a bibliographical review and the use of secondary data from the Instituto Brasileiro de Geografia e Estatística (IBGE) database, the State Department of Planning and Budget, epidemiological bulletins from the Department of Health, indices from the agribusiness production chain and the industrial profile, produced by the Tocantins State Federation of Industries. It was concluded that certain factors contributed to this process, such as a low level of influence from urban centers, a lack of major highways and the low purchasing power of the population, which avoided greater flows resulting from the low economic attractiveness.

Clostridioides difficile positivity rate and PCR ribotype distribution on retail potatoes in 12 European countries, January to June 2018.

BackgroundWhile human-to-human transmission of Clostridioides difficile occurs often, other infection sources, including food, animals and environment, are under investigation.AimWe present a large study on C. difficile in a food item in Europe, encompassing 12 European countries (Austria, France, Greece, Ireland, Italy, the Netherlands, Poland, Slovakia, Spain, Sweden, Romania and the United Kingdom).MethodsPotato was selected because of availability, ease of sampling and high C. difficile positivity rates. Identical protocols for sampling and isolation were used, enabling a direct comparison of the C. difficile positivity rate.ResultsFrom C. difficile-positive potato samples (33/147; 22.4%), we obtained 504 isolates, grouped into 38 PCR ribotypes. Positivity rates per country varied (0–100%) and were at least 10% in 9/12 countries. No geographical clustering of samples with high positivity rates or in PCR ribotype distribution was observed. The most frequently detected PCR ribotypes (014/020, 078/126, 010 and 023) are also commonly reported in Europe among human clinically relevant isolates, in animal isolates and in the environment. Whole genome sequencing revealed several genetically related strain pairs (Spain/RT126, France/RT010, Austria and Sweden/RT276) and a cluster of very similar strains in RT078/126.ConclusionOur results suggest, the high potato contamination rates could have public health relevance. They indicate potatoes can serve as a vector for introducing C. difficile spores in the household environment, where the bacterium can then multiply in sensitive hosts with disrupted or unmature microbiota. Potato contamination with PCR ribotypes shared between humans, animals and soil is supportive of this view.

Organ Donation in the 21st Century a Call for Social Care

This study analyses the current state of a serious and persistent social emergency, the shortage of organs, and discusses possible alternatives for a solution. It should be mentioned in this regard that society is currently experiencing a terrible epidemic with high rates of contamination and critical mortality, COVID 19. This serious situation has generated changes in the medical-social approaches and in the therapeutically resources of habitual solution. Of course organ and tissue transplantation has had to undergo this health crisis. The persistent presence of “organ shortage” before the pandemic showed unsatisfactory statistical results of organ transplants worldwide. Based on the results, the following key factors have been suggested as potentially responsible for this reality, and ideas and conclusions

Machine learning (ML) algorithms and artificial neural network for optimizing in vitro germination and growth indices of industrial hemp (Cannabis sativa L.)

In vitro germination of hemp is challenging due to low germination and high contamination rates. Successful establishment of in vitro sterilization is the prerequisite of plant tissue culture studies. Recent advancements in the field of artificial neural network (ANN) and machine learning (ML) algorithms open new horizons for sustainable and precision agriculture. ANN and ML algorithms are powerful tools to evaluate the results and make more precise and high accuracy predictions in the field of plant tissue culture, especially for industrial purposes. Keeping in view, the study was designed to investigate the possible response of variable concentrations of hydrogen peroxide (H2O2) on germination and morphological traits of in vitro-grown hemp seedlings by using ML algorithms. Five different ML algorithms used in this study to evaluate the prediction of the output variables were: Support Vector Classifier (SVC), Gaussian Process (GP), Extreme Gradient Boosting (XGBoost), Random Forest (RF) models, and Multilayer Perceptron (MLP) neural network utilizing accuracy, F1 score, precision, and recall values. Among the tested models, the RF model exhibited better prediction of output variables with a high F1 score in the range of 0.98–1.00. The F1 scores of the other models ranged between 0.69 and 0.86. Response surface methodology (RSM) used to compute the optimum concentration of H2O2 revealed the statistically significant effect of H2O2 on in vitro germination and seedling growth. The optimum value of H2O2 for the maximum germination and seedling was optimized to about ~2.2% by using RSM. The present work is a case study about the application of different ML and ANN models in plant tissue culture and reveals the possibility of application in many other economic crops.

51 Wireless Electroceutical Dressing for the Treatment of Biofilm Infected Burn Wounds

IntroductionBurn injuries are common to all military conflicts. In combat, eradication and prevention of burn wound infection is complicated by high rates of soft tissue contamination and prolonged delays to definitive stateside care. Furthermore, in the battlefield setting the salvage rate for infected burned extremities is low. Therefore, a simple, easy, non-invasive and rapid method to protect the wound, while also inhibiting infection, would represent a significant advance in the treatment of combat burn wounds. The purpose of this clinical trial was to investigate the efficacy of an FDA approved disposable and easily portable, wireless electroceutical dressing (WED) in the treatment of burn wounds. The hypothesis was that a low electric field generated by the moisture-activated WED will reduce infection load, improve graft survival and take, enhance wound healing and restore skin barrier function of biofilm infected wounds.MethodsA phase I, prospective, randomized, controlled clinical trial was performed to evaluate the efficacy of the WED dressing as compared to the standard of care (SoC) dressing to prevent and disrupt biofilms. Subjects were screened from inpatient admissions for traumatic burns >300cm2 in size. In total 38 subjects were enrolled to the study. Subject burn wounds were divided into two parts and randomized to receive either the SoC dressing or the WED dressing. Dressings were changed on day 4, removed on day 7 and the burns were followed for 30 days. Small biopsies were collected on days 4 and 7 for histology, SEM examination of biofilm and for quantitative bacteriological analysis. In addition, non-invasive wound imaging techniques were utilized to study wound healing. Furthermore, Vancouver scar scale and patient observer scar assessment were used to evaluate quality of healing.ResultsThe results showed that at the time of dressing removal, non-grafted burns that were treated with the WED dressing presented statistically significantly less biofilm in comparison to the SoC treated burns (p < 0.05). The results also demonstrated that the WED dressing was more efficient at eradicating biofilm than the SoC dressing. At the time of the dressing removal, biofilm score [0-3] had decreased in 48% of the WED dressing treated burns in comparison to 28% in the SoC treated burns. In terms of wound healing and quality of healing no significant differences were observed between the WED and the SoC dressings.ConclusionsThis trial demonstrated that the WED dressing was more efficient against biofilm infection than the SoC dressing. In addition, the study concluded that the WED dressing performed equally well as the SoC in terms of burn wound healing.

An Audit of Blood Cultures in an Emergency Department at a Johannesburg Academic Hospital

Background: Blood cultures (BCs) are the standard test for detecting bacteraemia but have come under scrutiny on their usefulness in the Emergency Departments (EDs) as they have a low yield, tend not to alter patient management and may be subject to high contamination rates especially in resource-limited settings. Identifying patients most at risk of bacteraemia may improve BCs’ usefulness. Methods: We conducted a retrospective observational, descriptive and comparative study. Reports from all BCs performed in the ED at Helen Joseph Hospital in 2017 were requested from the National Health Laboratory Service. Data from all positive BCs were used to audit cultured organisms and their sensitivity and resistance patterns. Second, clinical and laboratory data from 206 consecutively selected patients (103 positive and 103 negative BC results) were used to calculate the Shapiro score and the Systemic Inflammatory Response Syndrome (SIRS) criteria as screening tools for sepsis. Results: There was a total of 4011 BCs performed in 2017 of which 715 (17.8%) were positive. Pathogens were cultured in 400 (10.0%) of cases and 315 (7.9%) cultured known contaminants. A positive Shapiro score and SIRS criteria increased the likelihood of a positive BC by 5.6 and 2.3 times, respectively. Positive HIV status, rigors, pulse rate &gt; 115 bpm, deranged mentation, white cells &gt; 18 × 109 cells/L and creatinine &gt; 177 μmol/L were risk factors for positive BCs. Conclusion: There was a low yield of positive BCs from the ED, and using the SIRS criteria or the Shapiro score improves the pre-test probability of positive BC results in patients with suspected sepsis.

Group B Streptococcus in retail food– beyond ST283 and raw fish

An unprecedented Group B Streptococcus (GBS) outbreak, associated with freshwater fish consumption, occurred in Singapore in 2015. We hypothesized that GBS might be present in food other than freshwater fish, and that there could be potential foodborne transmission of GBS other than the ST283 outbreak strain. As GBS has not been generally recognised as a foodborne pathogen, its presence in food is less commonly tested for. As such, there is a limited number of food isolates available for genomic comparison with animal and human isolates. A study was thus conducted to determine the frequency and distribution of GBS sequence types (STs) in local retail food and to compare their genomic sequences with those from a regional fish (animal) isolate collection and published STs of human isolates. Between October 2016 and June 2018, a total of 238 prepared/ready-to-eat (RTE) seafood samples and 400 unprepared food samples sold at retail were tested for the presence of GBS using molecular and culture methods. Isolates were characterized using whole genome sequencing. GBS was detected in 3.8% (9/238) of the prepared seafood samples and 18% (72/400) of the unprepared food samples by PCR. Among the unprepared food sampled, GBS was most frequently detected in fish (32%, 32/100), followed by meat (22%, 22/100), non-fish seafood (14%, 14/100), and vegetables (4%, 4/100). GBS ST283, which was responsible for the Singapore 2015 outbreak, was detected in an uncooked prepared oyster sample. Seven other known STs (ST1, 3, 7, 10, 23, 24, and 103) and three newly assigned STs (ST 1647, 1648 and 1649) were isolated from food samples. The 146 regional fish (animal) isolates yielded 11 known STs (ST1, 7, 10, 23, 28, 103, 261, 283, 314, 500, and 651) and one newly assigned ST (ST 1650). The prevalence of GBS in non-fish seafood and meat were observed to be significantly higher among wet market samples (28.6–36.5%) than those of the supermarket samples (3.4–6.3%) (p < 0.05). Higher contamination rate is expected in wet market samples as fresh produce in wet markets are generally sold and displayed with little or no primary packaging and are subjected to higher risks of human handling and temperature abuse. Our findings revealed that (i) non-ST283 GBS strains associated with human carriers and invasive disease can be found in food types such as seafood and meat, and (ii) that GBS ST283 can indeed be found in food types beyond freshwater fish. A larger study involving the genomic analysis of human, animal and food isolates collected within the same geographical region and temporal period will be beneficial to understand whether non-ST283 GBS may also cause foodborne infections.

Social dilemmas and poor water quality in household water systems

Abstract. Private water supply systems consisting of a domestic well and septic system are used throughout the world where households lack access to public water supply and sewers. In residential areas with a high housing density, septic contamination of private wells is common and associated with multiple health concerns. This situation can give rise to social dilemmas, where individual costs de-incentivize homeowners from investing in enhanced septic systems that would reduce well contamination and bring communal benefits. We combine a stylized game theoretical model with a probabilistic groundwater model to characterize how economic and hydrogeological conditions interact to produce misaligned incentives conducive to social dilemmas. The occurrence of social dilemmas depends on the relative costs of well contamination versus the cost of installing an enhanced septic treatment system and the relative probabilities of cross-contamination versus self-contamination. The game reveals three types of social dilemmas that occur in such systems, with each calling for distinct policy solutions. We demonstrate how the model can be applied to existing systems, using a case study of St. Joseph County, Indiana, where high nitrate contamination rates have raised public health concerns. This analysis represents a step towards identifying alternative policy solutions for a problem that has remained difficult to address for decades.

Interactions of Co, Cu, and non-metal phthalocyanines with external structures of SARS-CoV-2 using docking and molecular dynamics

The new coronavirus, SARS-CoV-2, caused the COVID-19 pandemic, characterized by its high rate of contamination, propagation capacity, and lethality rate. In this work, we approach the use of phthalocyanines as an inhibitor of SARS-CoV-2, as they present several interactive properties of the phthalocyanines (Pc) of Cobalt (CoPc), Copper (CuPc) and without a metal group (NoPc) can interact with SARS-CoV-2, showing potential be used as filtering by adsorption on paints on walls, masks, clothes, and air conditioning filters. Molecular modeling techniques through Molecular Docking and Molecular Dynamics were used, where the target was the external structures of the virus, but specifically the envelope protein, main protease, and Spike glycoprotein proteases. Using the g_MM-GBSA module and with it, the molecular docking studies show that the ligands have interaction characteristics capable of adsorbing the structures. Molecular dynamics provided information on the root-mean-square deviation of the atomic positions provided values between 1 and 2.5. The generalized Born implicit solvation model, Gibbs free energy, and solvent accessible surface area approach were used. Among the results obtained through molecular dynamics, it was noticed that interactions occur since Pc could bind to residues of the active site of macromolecules, demonstrating good interactions; in particular with CoPc. Molecular couplings and free energy showed that S-gly active site residues interacted strongly with phthalocyanines with values ​​of − 182.443 kJ/mol (CoPc), 158.954 kJ/mol (CuPc), and − 129.963 kJ/mol (NoPc). The interactions of Pc's with SARS-CoV-2 may predict some promising candidates for antagonists to the virus, which if confirmed through experimental approaches, may contribute to resolving the global crisis of the COVID-19 pandemic.

Multi-country surveillance of Clostridioides difficile demonstrates high prevalence of spores in non-healthcare environmental settings

BackgroundC. difficile spores are frequently isolated from hospital and non-healthcare settings but a worldwide analysis has not been done. The study objectives were to assess C. difficile spore contamination in the hospital and non-healthcare environments across a variety of countries. MethodsField studies assessed hospital vs. non-healthcare C. difficile spore contamination in hospitals, non-healthcare buildings, outdoor environments, and shoes. Swabs were cultured anaerobically for C. difficile and typed using PCR-fluorescent ribotyping. C. difficile contamination by swabbing area and geographic locations were compared. FindingsA total of 7,857 unique samples were collected primarily from the USA (89%) in addition to 9 other countries. The global prevalence of C difficile from environmental samples was 25.3% and did not differ between countries. In USA based studies, C. difficile contamination rates were similar for healthcare buildings (23.2%), non-healthcare buildings (23.4%), and outdoor spaces (24.7%). Floor samples had significantly higher (p < 0.001) C. difficile contamination rate (46.5%) followed by non-floor samples (21.1%), and bathrooms (15.3%). In a comparison of USA to other country samples, C. difficile contamination rates were similar for USA samples (21.5%) compared to rest of world samples (22.3%; p = 0.61). The most common ribotypes included F014-020 (15.7%), F106 (12.6%), F010 (8.9%), F027 (8.8%), and F002 (8.1%) and did not differ significantly between USA and non-USA samples. Finally, 546 of 1,218 (44.8%) shoe soles swabbed from the USA were contaminated with C. difficile spores. InterpretationThis large surveillance study of several countries demonstrated high prevalence of toxigenic C. difficile in non-healthcare environments with high contamination rates from floors and shoe soles.

Tissue Contamination During Transportation of Formalin-Fixed, Paraffin-Embedded Blocks.

Tissue carryovers are contaminants of surgical pathology cases in which extraneous tissue is incorporated into tissue blocks. Carryovers occur most frequently at the grossing or embedding stations, but little is published about them. We sought to analyze their transmission during transit to the histology lab. Cassettes of friable donor tissue were mixed with cassettes of spongy recipient tissue in formalin-filled containers and agitated by shipment via pneumatic tube. The tissue cassettes were processed, embedded as blocks, and cut as usual. Liquid samples were prepared from the submission containers as well as from workstation submission containers and histology tissue processor waste. A high rate of contamination (14.9%) was observed under these artificial conditions. Friable donor tissue, including urothelium and colorectal adenocarcinoma, were promiscuous contaminants, as were placental villi. Fluid from submission containers showed viable tumor cells and fragments, which were also present in workstation submission containers and in tissue processor waste fluid. This study implicates liquid transport media as a possible avenue of contamination during submission and transportation of tissue cassettes for histologic processing. Attention should be given to the friability of submitted tissue and physical agitation of the cassettes in transit. Such contaminants may be present in the fluid in tissue submission bins and in tissue processor fluid.

Predictive Analysis of COVID-19 Symptoms in Social Networks through Machine Learning

Social media is a great source of data for analyses, since they provide ways for people to share emotions, feelings, ideas, and even symptoms of diseases. By the end of 2019, a global pandemic alert was raised, relative to a virus that had a high contamination rate and could cause respiratory complications. To help identify those who may have the symptoms of this disease or to detect who is already infected, this paper analyzed the performance of eight machine learning algorithms (KNN, Naive Bayes, Decision Tree, Random Forest, SVM, simple Multilayer Perceptron, Convolutional Neural Networks and BERT) in the search and classification of tweets that mention self-report of COVID-19 symptoms. The dataset was labeled using a set of disease symptom keywords provided by the World Health Organization. The tests showed that Random Forest algorithm had the best results, closely followed by BERT and Convolution Neural Network, although traditional machine learning algorithms also have can also provide good results. This work could also aid in the selection of algorithms in the identification of diseases symptoms in social media content.

Blood culture contamination in the departments of paediatrics and child health at two tertiary training hospitals in central South Africa

Background. Bloodstream infections are an important cause of mortality in children. Blood cultures (BCs) remain the primary means of identifying organisms and their antibiotic susceptibility profiles. A shortcoming of BCs is that up to 56% of positive cultures will represent contaminants. Poor adherence to standard practices applicable to BC sampling could explain an unacceptable contamination rate. Objectives. To determine: (i) the BC contamination rate in the departments of paediatrics and child health at two tertiary hospitals in central South Africa; and (ii) BC sampling practices among paediatric clinicians. Methods. The author determined the prevalence of BC contamination by analysis of laboratory data for the period 1 May - 27 August 2019, and assessed possible factors contributing to BC contamination by surveying paediatric medical staff with a self-administered BC practices questionnaire. Results. Of the 244 BCs reviewed, 25.4% were positive. The most commonly isolated pathogens were coagulase-negative staphylococci (CoNS) (33.3%), Escherichia coli (22.2%), Enterococcus faecium (16.7%) and Acinetobacter baumannii (11.1%). In total, 15.2% of the BCs yielded contaminants and 2.9% had polymicrobial growth. The most common contaminant was CoNS. Approximately 68% of clinicians were not aware of BC sampling guidelines, and even among those who were aware of the guidelines, non-compliance was reported. Conclusions. The BC contamination rate was higher than internationally accepted rates. Educating clinicians on specific BC sampling guidelines is strongly recommended to decrease the high rate of contamination observed in this study.

COVID-19 Knowledge, attitudes, and practices in the community of the Evangelical University of Cameroon

Background: COVID-19 was thought to have made its global debut in the Chinese city of Wuhan. In Cameroon central Africa, close to 11,000 cases of the disease have been identified, with a high rate of progression. The Evangelical University of Cameroon (UEC), like many other academic institutions, has made significant investments in equipping the campus with anti-pandemic measures. Objective: This study aimed to examine the knowledge, attitudes, and practices of UEC students, faculty, and administrative staff regarding COVID-19 and its preventive measures. Materials and Methods: A questionnaire was used to collect data on respondents’ sociodemographic profile, knowledge, attitude, and practices regarding COVID-19. The Google Forms application was used to mount and distribute the questionnaire, and the results were organized in tables and graphs. Additional analyses were carried out with the help of Excel and SPSS software. Results: A total of 214 people took part in the study. More than half of participants (79.4 percent) believed that COVID-19 is a serious respiratory disease caused by a virus that affects everyone. While 11.2 percent thought it was a biological weapon used to control or reduce the population. Participants identified the market, bars, and hospitals as the most vulnerable places to contract the coronavirus, with percentages ranging from 37.4 percent, 17.8 percent, and 14.0 percent, respectively. Respondents were aware of COVID-19 prevention: hand washing (95.32 percent), social distancing (95.32 percent), and consumption of some medicinal plants with antiviral or immunoregulatory properties, such as ginger (Zingiber officinale) and Artemisia annua (54.20 percent). The majority of participants did not follow barrier measures such as hand washing (64.43 percent), social distancing (66.67 percent), and face mask use (66.49 percent). In comparison to other levels, first-year students observed prevention measures (P=0.01). Conclusion: This study showed acceptable knowledge but limited compliance to COVID-19 preventive measures, which could explain the high rate of contamination in the country. Keywords: Knowledge, Attitude, Practice; COVID-19; Evangelical University of Cameroun.