Impact of respirator versus surgical masks on SARS-CoV-2 acquisition in healthcare workers: a prospective multicentre cohort.

BACKGROUND: There is insufficient evidence regarding the role of respirators in the prevention of SARS-CoV-2 infection. We analysed the impact of filtering facepiece class 2 (FFP2) versus surgical masks on the risk of SARS-CoV-2 acquisition among Swiss healthcare workers (HCW). METHODS: Our prospective multicentre cohort enrolled HCW from June to August 2020. Participants were asked about COVID-19 risk exposures/behaviours, including preferentially worn mask type when caring for COVID-19 patients outside of aerosol-generating procedures. The impact of FFP2 on (1) self-reported SARS-CoV-2-positive nasopharyngeal PCR/rapid antigen tests captured during weekly surveys, and (2) SARS-CoV-2 seroconversion between baseline and January/February 2021 was assessed. RESULTS: We enrolled 3259 participants from nine healthcare institutions, whereof 716 (22%) preferentially used FFP2. Among these, 81/716 (11%) reported a SARS-CoV-2-positive swab, compared to 352/2543 (14%) surgical mask users; seroconversion was documented in 85/656 (13%) FFP2 and 426/2255 (19%) surgical mask users. Adjusted for baseline characteristics, COVID-19 exposure, and risk behaviour, FFP2 use was non-significantly associated with decreased risk for SARS-CoV-2-positive swab (adjusted hazard ratio [aHR] 0.8, 95% CI 0.6-1.0) and seroconversion (adjusted odds ratio [aOR] 0.7, 95% CI 0.5-1.0); household exposure was the strongest risk factor (aHR 10.1, 95% CI 7.5-13.5; aOR 5.0, 95% CI 3.9-6.5). In subgroup analysis, FFP2 use was clearly protective among those with frequent (> 20 patients) COVID-19 exposure (aHR 0.7 for positive swab, 95% CI 0.5-0.8; aOR 0.6 for seroconversion, 95% CI 0.4-1.0). CONCLUSIONS: Respirators compared to surgical masks may convey additional protection from SARS-CoV-2 for HCW with frequent exposure to COVID-19 patients.

The challenge of preventing and containing outbreaks of multidrug-resistant organisms and Candida auris during the coronavirus disease 2019 pandemic: report of a carbapenem-resistant Acinetobacter baumannii outbreak and a systematic review of the literature.

BACKGROUND: Despite the adoption of strict infection prevention and control measures, many hospitals have reported outbreaks of multidrug-resistant organisms (MDRO) during the Coronavirus 2019 (COVID-19) pandemic. Following an outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) in our institution, we sought to systematically analyse characteristics of MDRO outbreaks in times of COVID-19, focussing on contributing factors and specific challenges in controlling these outbreaks. METHODS: We describe results of our own CRAB outbreak investigation and performed a systematic literature review for MDRO (including Candida auris) outbreaks which occurred during the COVID-19 pandemic (between December 2019 and March 2021). Search terms were related to pathogens/resistance mechanisms AND COVID-19. We summarized outbreak characteristics in a narrative synthesis and contrasted contributing factors with implemented control measures. RESULTS: The CRAB outbreak occurred in our intensive care units between September and December 2020 and comprised 10 patients (thereof seven with COVID-19) within two distinct genetic clusters (both ST2 carrying OXA-23). Both clusters presumably originated from COVID-19 patients transferred from the Balkans. Including our outbreak, we identified 17 reports, mostly caused by Candida auris (n = 6) or CRAB (n = 5), with an overall patient mortality of 35% (68/193). All outbreaks involved intensive care settings. Non-adherence to personal protective equipment (PPE) or hand hygiene (n = 11), PPE shortage (n = 8) and high antibiotic use (n = 8) were most commonly reported as contributing factors, followed by environmental contamination (n = 7), prolonged critical illness (n = 7) and lack of trained HCW (n = 7). Implemented measures mainly focussed on PPE/hand hygiene audits (n = 9), environmental cleaning/disinfection (n = 9) and enhanced patient screening (n = 8). Comparing potentially modifiable risk factors and control measures, we found the largest discrepancies in the areas of PPE shortage (risk factor in 8 studies, addressed in 2 studies) and patient overcrowding (risk factor in 5 studies, addressed in 0 studies). CONCLUSIONS: Reported MDRO outbreaks during the COVID-19 pandemic were most often caused by CRAB (including our outbreak) and C. auris. Inadequate PPE/hand hygiene adherence, PPE shortage, and high antibiotic use were the most commonly reported potentially modifiable factors contributing to the outbreaks. These findings should be considered for the prevention of MDRO outbreaks during future COVID-19 waves.

Spectrum of antibiotic resistance in UTI caused by Escherichia coli among HIV-infected patients in Uganda: a cross-sectional study.

BACKGROUND: Antimicrobial drug resistance is one of the top ten threats to global health according to the World Health Organization. Urinary tract infections (UTIs) are among the most common bacterial infections and main reason for antibiotic prescription. The incidence of UTIs appears to be high among people living with HIV. We sought to determine the most common UTI pathogens among HIV infected patients and evaluate their susceptibility towards antibiotics. METHODS: We performed a cross-sectional study among HIV-infected patients aged ≥ 18 years presenting at an HIV care specialized clinic with symptoms suggestive of a urethritis. Urine cultures were subjected to antibiotic susceptibility testing according to Clinical Laboratory Standards Institute. The data was analyzed using STATA, we performed Pearson's Chi-square and Fisher's exact tests to compare differences between proportions. RESULTS: Out of the 200 patients, 123 (62%) were female. The median age was 41.9 years (IQR 34.7-49.3). Only 32 (16%) urine cultures showed bacterial growth. Escherichia coli was the most commonly isolated uropathogen (72%), followed by Klebsiella pneumoniae (9%). E. coli was completely resistant to cotrimoxazole and ampicillin; resistance to ciprofloxacin and ceftriaxone was 44% and 35% respectively; 9% to gentamicin; no resistance detected to nitrofurantoin and imipenem. CONCLUSIONS: Our findings are congruent with the Uganda national clinical guidelines which recommends nitrofurantoin as the first line antibiotic for uncomplicated UTI. Significant ciprofloxacin and ceftriaxone resistance was detected. In the era of emerging antibiotic resistance, understanding the local susceptibilities among sub-populations such as HIV infected patients is crucial. Further investigation is needed to address reasons for the low bacterial growth rate observed in the urine cultures.

Gender differences among patients with drug resistant tuberculosis and HIV co-infection in Uganda: a countrywide retrospective cohort study.

BACKGROUND: Gender differences among patients with drug resistant tuberculosis (DRTB) and HIV co-infection could affect treatment outcomes. We compared characteristics and treatment outcomes of DRTB/HIV co-infected men and women in Uganda. METHODS: We conducted a retrospective chart review of patients with DRTB from 16 treatment sites in Uganda. Eligible patients were aged ≥ 18 years, had confirmed DRTB, HIV co-infection and a treatment outcome registered between 2013 and 2019. We compared socio-demographic and clinical characteristics and tuberculosis treatment outcomes between men and women. Potential predictors of mortality were determined by cox proportional hazard regression analysis that controlled for gender. Statistical significance was set at p < 0.05. RESULTS: Of 666 DRTB/HIV co-infected patients, 401 (60.2%) were men. The median (IQR) age of men and women was 37.0 (13.0) and 34.0 (13.0) years respectively (p < 0.001). Men were significantly more likely to be on tenofovir-based antiretroviral therapy (ART), high-dose isoniazid-containing DRTB regimen and to have history of cigarette or alcohol use. They were also more likely to have multi-drug resistant TB, isoniazid and streptomycin resistance and had higher creatinine, aspartate and gamma-glutamyl aminotransferase and total bilirubin levels. Conversely, women were more likely to be unemployed, unmarried, receive treatment from the national referral hospital and to have anemia, a capreomycin-containing DRTB regimen and zidovudine-based ART. Treatment success was observed among 437 (65.6%) and did not differ between the genders. However, mortality was higher among men than women (25.7% vs. 18.5%, p = 0.030) and men had a shorter mean (standard error) survival time (16.8 (0.42) vs. 19.0 (0.46) months), Log Rank test (p = 0.046). Predictors of mortality, after adjusting for gender, were cigarette smoking (aHR = 4.87, 95% CI 1.28-18.58, p = 0.020), an increase in alanine aminotransferase levels (aHR = 1.05, 95% CI 1.02-1.07, p < 0.001), and history of ART default (aHR = 3.86, 95% CI 1.31-11.37, p = 0.014) while a higher baseline CD4 count was associated with lower mortality (aHR = 0.94, 95% CI 0.89-0.99, p = 0.013 for every 10 cells/mm3 increment). CONCLUSION: Mortality was higher among men than women with DRTB/HIV co-infection which could be explained by several sociodemographic and clinical differences.

An unusual case of multiple hepatic and pulmonary abscesses caused by Aggregatibacter aphrophilus in a young man: a case report.

BACKGROUND: Aggregatibacter aphrophilus, formerly known as Haemophilus aphrophilus, belongs to the HACEK organisms, a group of pathogens classically associated with infectious endocarditis. A. aphrophilus is a rarely found pathogen, though abscess formation in various organs has been described, typically due to spread from an infected heart valve. Here we describe the unusual case of multiple hepatic abscesses caused by A. aphrophilus. CASE PRESENTATION: A 33-year-old Caucasian man presented at our hospital with fever and malaise, elevated inflammatory markers, and liver enzymes. Imaging was compatible with multiple liver and pulmonary abscesses, without evidence of endocarditis. Cultures of blood and liver abscess material remained without growth. Polymerase chain reaction finally revealed Aggregatibacter aphrophilus in the liver tissue. The patient recovered fully within 6 weeks of doxycycline treatment. CONCLUSIONS: There are only a few case descriptions of liver abscesses caused by A. aphrophilus. As a ubiquitous organism in the gastrointestinal tract, A. aphrophilus may reach the liver via the portal venous system, as well as through hematogenous spread from the oropharynx. HACEK organisms are notoriously difficult to grow on culture, which highlights the diagnostic importance of eubacterial PCR.

[Medical Daily Routine in the Tropics: A Case-Based Overview]. / Medizinischer Alltag in den Tropen ­ eine fallbezogene Übersicht.

Medical Daily Routine in the Tropics: A Case-Based Overview Abstract. When we speak about «medicine in the tropics¼ it is malaria epidemics, diarrheal diseases and worm infections that come to mind. A lesser-known fact is the impact of the new epidemic of non-communicable diseases, which are currently responsible for about half of all deaths occurring in the tropical world regions. Changing demographic, social and economic factors are the drivers for diseases such as hypertension, diabetes and obesity. The observed increase in non-communicable diseases coupled with the persistence of classic infectious tropical diseases creates a double medical burden and presents a great challenge in these low-resource settings.

High colonization rates of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in Swiss travellers to South Asia- a prospective observational multicentre cohort study looking at epidemiology, microbiology and risk factors.

BACKGROUND: International travel contributes to the worldwide spread of multidrug resistant Gram-negative bacteria. Rates of travel-related faecal colonization with extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae vary for different destinations. Especially travellers returning from the Indian subcontinent show high colonization rates. So far, nothing is known about region-specific risk factors for becoming colonized. METHODS: An observational prospective multicentre cohort study investigated travellers to South Asia. Before and after travelling, rectal swabs were screened for third-generation cephalosporin- and carbapenem-resistant Enterobacteriaceae. Participants completed questionnaires to identify risk factors for becoming colonized. Covariates were assessed univariately, followed by a multivariate regression. RESULTS: Hundred and seventy persons were enrolled, the largest data set on travellers to the Indian subcontinent so far. The acquired colonization rate with ESBL-producing Escherichia coli overall was 69.4% (95% CI 62.1-75.9%), being highest in travellers returning from India (86.8%; 95% CI 78.5-95.0%) and lowest in travellers returning from Sri Lanka (34.7%; 95% CI 22.9-48.7%). Associated risk factors were travel destination, length of stay, visiting friends and relatives, and eating ice cream and pastry. CONCLUSIONS: High colonization rates with ESBL-producing Enterobacteriaceae were found in travellers returning from South Asia. Though risk factors were identified, a more common source, i.e. environmental, appears to better explain the high colonization rates.

[Malaria and children who travel - prophylaxis and therapy]. / Malaria und Kinder, die reisen - Prophylaxe und Therapie.

Children account for between 15 - 20 % of all imported malaria cases worldwide. Immigrant children visiting their families in the country of origin in sub-Saharan Africa are at highest risk. Prevention of malaria in children who travel to endemic areas is guided by the ABCD principles - Awareness of risk, Bite prevention, Chemoprophylaxis for high risk areas and rapid Diagnosis and treatment when malaria is suspected. The use of anti-malarial medication in small children is hampered by a paucity of dosage, pharmcokinetic and tolerability data. In the pre-travel consultation parents should be provided with practical advice on anti-mosquito measures, exact, (weight-based) dosages of chemoprophylaxis medication and/or stand-by treatment as indicated. A paediatric formulation is available for daily atovaquone-proguanil chemoprophylaxis (children > 11 kg) and mefloquine is a cost-effective, once weekly prophylaxis that is useful for children > 5 kg who travel for longer periods. The bitter taste of mefloquine should be disguised to increase adherence. When a Stand-by Emergency Treatment (SBET) is indicated, artemether-lumefantrine cherry flavoured dispersible tablets are a good choice for small children. Post-travel to endemic areas, malaria should always be suspected if a child becomes ill. Paediatric malaria is an emergency requiring prompt diagnosis and appropriate treatment.

Coronary artery imaging with contrast-enhanced MDCT: extracardiac findings.

OBJECTIVE: The purpose of our study was to evaluate the incidence of extracardiac findings on contrast-enhanced MDCT of the coronary arteries and to assess the effect of different field-of-view settings. SUBJECTS AND METHODS: Patients with suspected coronary artery disease (n = 166) were examined with contrast-enhanced MDCT (16 x 0.75 mm focused on the heart) during injection of contrast material (80 mL injected at a rate of 4 mL/sec) followed by saline (20 mL injected at 4 mL/sec). Retrospectively gated images were reconstructed at a 1-mm slice thickness and a 0.5-mm increment with isotropic voxels of 1 mm3. Images were reviewed for extracardiac findings, which were then classified as none, minor, or major with respect to their impact on patient management and treatment. In a different group of patients (n = 20), chest scans (16 x 1.5 mm) were used for measuring volumes of displayed body structures on wholechest scans, coronary artery MDCT images, and coronary artery MDCT images reconstructed with the maximum field of view. RESULTS: Extracardiac findings were detected in 41 patients (24.7%). Findings were classified as minor (19.9%) or major (4.8%). Among the major findings, which had an immediate impact on patient management and treatment, were bronchial carcinoma and pulmonary emboli. Volume analysis revealed that 35.5% of the total chest volume was displayed on dedicated coronary artery MDCT focused on the heart, whereas 70.3% of the chest was visible when coronary artery MDCT raw data were reconstructed with the maximal field of view (p < 0.001). CONCLUSION: Coronary artery MDCT can reveal important findings and disease in extracardiac structures. Thus, the entire examination should be reconstructed with the maximum field of view and should be reviewed by a qualified radiologist.

Limited diagnostic yield of non-invasive coronary angiography by 16-slice multi-detector spiral computed tomography in routine patients referred for evaluation of coronary artery disease.

AIMS: Multislice spiral computed tomography (MSCT) is a promising non-invasive method to diagnose coronary artery disease (CAD). As no detailed comparative evaluation in consecutive patients referred for evaluation of CAD has been reported, this prospective study evaluating 2384 coronary segments in 149 consecutive patients was performed. METHODS AND RESULTS: The coronary artery tree was analysed in 16 segments both for coronary angiography (CA) and MSCT; a luminal narrowing > or = 50% based on visual assessment was considered significant. By MSCT, 77% of 2110 angiographically assessable segments could be evaluated, 94% per patient in proximal and 70% in distal segments (P<0.001). Sensitivity of MSCT to detect significant stenoses was 30% in all, but only 10% in peripheral segments. The main limitations were calcifications in 34% of segments and motion artefacts in 24% of patients. Overall diagnostic sensitivity for the presence of significant CAD was 86% but specificity was only 49%. CONCLUSION: When compared with invasive CA, 16-slice MSCT is of limited diagnostic value for the diagnosis of CAD in consecutive patients. Despite a clinically useful sensitivity for the overall diagnosis of significant CAD, specificity is low. Thus, relevant decisions regarding the need of and suitability for possible revascularization procedures cannot be based on MSCT findings alone.

Lipooligosaccharide and polysaccharide capsule: virulence factors of Neisseria meningitidis that determine meningococcal interaction with human dendritic cells.

In this work we analyzed the roles of meningococcal lipooligosaccharide (LOS) and capsule expression in the interaction of Neisseria meningitidis with human dendritic cells (DC). Infection of DC with serogroup B wild-type meningococci induced a strong burst of the proinflammatory cytokines and chemokines tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-8. In contrast, a serogroup B mutant strain lacking LOS expression barely led to cytokine induction, demonstrating that meningococcal LOS is the main mediator of the proinflammatory response in human DC. Sialylation of meningococcal LOS did not influence cytokine secretion by DC. However, we found the phagocytosis of N. meningitidis by human DC to be inhibited by LOS sialylation. In addition, the expression of the meningococcal serogroup A, B, and C capsules dramatically reduced DC adherence of N. meningitidis and phagocytosis to some extent. Hence, LOS sialylation and capsule expression are independent mechanisms protecting N. meningitidis from the phagocytic activity of human DC.

Analysis of the heat shock response of Neisseria meningitidis with cDNA- and oligonucleotide-based DNA microarrays.

Oligonucleotide- and cDNA-based microarrays comprising a subset of Neisseria meningitidis genes were assessed for study of the meningococcal heat shock response and found to be highly suitable for transcriptional profiling of N. meningitidis. Employing oligonucleotide arrays encompassing the entire genome of N. meningitidis, we analyzed the meningococcal heat shock response on a global scale and identified 55 heat shock-deregulated open reading frames (34 induced and 21 repressed).