Transmission of Onychomycosis and Dermatophytosis between Household Members: A Scoping Review

Onychomycosis is a common fungal infection of the nail, caused by dermatophytes, non-dermatophytes, and yeasts. Predisposing factors include older age, trauma, diabetes, immunosuppression, and previous history of nail psoriasis or tinea pedis. Though many biological risk factors have been well characterized, the role of the environment has been less clear. Studies have found evidence of transmission in 44% to 47% of households with at least one affected individual, but the underlying mechanisms and risk factors for transmission of onychomycosis between household members are incompletely understood. A scoping literature review was performed to characterize and summarize environmental risk factors involved in the transmission of onychomycosis within households. A total of 90 papers met the inclusion criteria, and extracted data was analyzed in an iterative manner. Shared household surfaces may harbor dermatophytes and provide sources for infection. Shared household equipment, including footwear, bedding, and nail tools, may transmit dermatophytes. The persistence of dermatophytes on household cleaning supplies, linen, and pets may serve as lasting sources of infection. Based on these findings, we provide recommendations that aim to interrupt household transmission of onychomycosis. Further investigation of the specific mechanisms behind household spread is needed to break the cycle of transmission, reducing the physical and social impacts of onychomycosis.

Exploration of a new hepatitis a surveillance system in Beijing, China: based on molecular epidemiology

Background The incidence of hepatitis A virus (HAV) infection is low in Beijing, China, but the risk of outbreaks still exists. It is difficult to identify possible sources of infection among sporadic cases based on a routine surveillance system. Therefore, a more effective surveillance system needs to be established. Methods The epidemiological data of hepatitis A were obtained from a routine surveillance system. Patients with HAV confirmed at the local hospitals were asked to complete a questionnaire that included additional case information and possible sources of infection. Serum and fecal specimens were also collected for testing HAV RNA by polymerase chain reaction. In addition, the 321-nucleotide segment of the VP1/2A junction region was sequenced to determine the HAV genotype. Results In 2019, 110 HAV cases were reported in Beijing, with an incidence rate of 0.51/100,000. 61(55.5%) of these patients were male. The greatest proportion of these patients were aged from 30 to 60 years. The rate was lower in suburban and rural areas compared to urban areas. Contaminated food consumption, particularly seafood consumption, was the primary potential source of infection. Among the 16 specimens of confirmed HAV cases that could be sequenced, 93.8% were HAV IA, and 6.3% were HAV IB. In addition, the samples collected from all HAV sequences in this investigation showed 89.4–100% nucleotide homology. Two groups (each with three sporadic cases) showed 100% nucleotide homology. The three sporadic cases in one group had the same possible source of infection: contaminated salad with raw vegetables and seafood. In the other group, the three sporadic cases did not have an epidemiological connection. Conclusions In a low HAV prevalent area, such as in Beijing, incorporating molecular epidemiology into the routine surveillance system could help inform possible clusters of outbreaks and provide support for earlier control of HAV transmission. Nevertheless, increased sampling from detected cases and improved specimen quality are needed to implement such a system.

A Retrospective Outbreak Investigation of a COVID-19 Case Cluster in a Berlin Kindergarten, November 2020

While SARS-CoV-2 infection activity in German kindergartens during the first year of the pandemic appeared to be overall low, outbreaks did occur. We retrospectively investigated an outbreak in November and December 2020 in a Berlin kindergarten participating in the Berlin Corona School and Kindergarten Study (BECOSS). Interviews were conducted with affected families regarding symptomatology, contact persons and possible sources of infection, as well as relevant information on the conditions on-site and infection prevention measures. A chronology of the outbreak was elaborated, and based on data on contacts and symptoms, we mapped the most likely chains of infection. Overall, 24 individuals, including ten educators, seven children, and seven household members, were infected with SARS-CoV-2 in a four-week time interval. Courses of infection ranged from asymptomatic to severe, with children less affected by symptoms. Viral spread within the facility seemed to occur mainly through kindergarten staff, while children primarily transmitted infections within their families. Interviewees reported that hygiene measures were not always adhered to inside the facility. To prevent outbreaks in kindergartens, especially in the light of current and newly emerging viral variants of concern, strict compliance to hygiene rules, staff vaccinations against SARS-CoV-2, and immediate reaction to suspected cases by quarantining and frequent testing seem reasonable measures.

Prevention and Control Strategies of African Swine Fever and Progress on Pig Farm Repopulation in China

African swine fever (ASF) is a devastating disease in domestic and wild pigs. Since the first outbreak of ASF in August 2018 in China, the disease has spread throughout the country with an unprecedented speed, causing heavy losses to the pig and related industries. As a result, strategies for managing the disease are urgently needed. This paper summarizes the important aspects of three key elements about African swine fever virus (ASFV) transmission, including the sources of infection, transmission routes, and susceptible animals. It overviews the relevant prevention and control strategies, focusing on the research progress of ASFV vaccines, anti-ASFV drugs, ASFV-resistant pigs, efficient disinfection, and pig farm biosecurity. We then reviewed the key technical points concerning pig farm repopulation, which is critical to the pork industry. We hope to not only provide a theoretical basis but also practical strategies for effective dealing with the ASF epidemic and restoration of pig production.

Reconstructing SARS-CoV-2 infection dynamics through the phylogenetic inference of unsampled sources of infection

The COVID-19 pandemic has illustrated the importance of infection tracking. The role of asymptomatic, undiagnosed individuals in driving infections within this pandemic has become increasingly evident. Modern phylogenetic tools that take into account asymptomatic or undiagnosed individuals can help guide public health responses. We finetuned established phylogenetic pipelines using published SARS-CoV-2 genomic data to examine reasonable estimate transmission networks with the inference of unsampled infection sources. The system utilised Bayesian phylogenetics and TransPhylo to capture the evolutionary and infection dynamics of SARS-CoV-2. Our analyses gave insight into the transmissions within a population including unsampled sources of infection and the results aligned with epidemiological observations. We were able to observe the effects of preventive measures in Canada’s “Atlantic bubble” and in populations such as New York State. The tools also inferred the cross-species disease transmission of SARS-CoV-2 transmission from humans to lions and tigers in New York City’s Bronx Zoo. These phylogenetic tools offer a powerful approach in response to both the COVID-19 and other emerging infectious disease outbreaks.

Laboratory diagnostic, epidemiological, and clinical characteristics of human leptospirosis in Okinawa Prefecture, Japan, 2003–2020

Background Leptospirosis is considered an endemic disease among agricultural workers in Okinawa Prefecture, which is the southernmost part of Japan and has a subtropical climate, but data on the current status and trend of this disease are scarce. Methodology/principal findings We conducted a retrospective study of clinically suspected leptospirosis patients whose sample and information were sent to the Okinawa Prefectural Institute of Health and Environment from November 2003 to December 2020. Laboratory diagnosis was established using culture, nested polymerase chain reaction (PCR), and/or microscopic agglutination test (MAT) with blood, cerebrospinal fluid, and/or urine samples. Statistical analyses were performed to compare the epidemiological information, clinical features, and sensitivities of diagnostic methods among laboratory-confirmed cases. Serogroups and the species of Leptospira isolates were determined by MAT using 13 antisera and flaB sequencing. A total of 531 clinically suspected patients were recruited, among whom 246 (46.3%) were laboratory confirmed to have leptospirosis. Among the confirmed cases, patients aged 20–29 years (22.4%) and male patients (85.7%) were the most common. The most common estimated sources of infection were recreation (44.5%) and labor (27.8%) in rivers. Approximately half of the isolates were of the L. interrogans serogroup Hebdomadis. The main clinical symptoms were fever (97.1%), myalgia (56.3%), and conjunctival hyperemia (52.2%). Headache occurred significantly more often in patients with Hebdomadis serogroup infections than those with other serogroup infections. The sensitivities of culture and PCR exceeded 65% during the first 6 days, while the sensitivity of MAT surpassed that of culture and PCR in the second week after onset. PCR using blood samples was a preferable method for the early diagnosis of leptospirosis. Conclusions/significance The results of this study will support clinicians in the diagnosis and treatment of undifferentiated febrile patients in Okinawa Prefecture as well as patients returning from Okinawa Prefecture.

Regular testing of asymptomatic healthcare workers identifies cost-efficient SARS-CoV-2 preventive measures

Protecting healthcare professionals is crucial in maintaining a functioning healthcare system. The risk of infection and optimal preventive strategies for healthcare workers during the COVID-19 pandemic remain poorly understood. Here we report the results of a cohort study that included pre- and asymptomatic healthcare workers. A weekly testing regime has been performed in this cohort since the beginning of the COVID-19 pandemic to identify infected healthcare workers. Based on these observations we have developed a mathematical model of SARS-CoV-2 transmission that integrates the sources of infection from inside and outside the hospital. The data were used to study how regular testing and a desynchronisation protocol are effective in preventing transmission of COVID-19 infection at work, and compared both strategies in terms of workforce availability and cost-effectiveness. We showed that case incidence among healthcare workers is higher than would be explained solely by community infection. Furthermore, while testing and desynchronisation protocols are both effective in preventing nosocomial transmission, regular testing maintains work productivity with implementation costs.

Outbreaks of COVID-19 in Medical organizations

Relevance. Prevention of the outbreak of a new coronavirus infection in medical organizations (MO) is one of the tasks facing the Rospotrebnadzor service and practical health care. Analysis of the causes and conditions of the spread of SARS-CoV-2 in the MO allows us to determine the most effective measures to contain the infection and prevent the occurrence of subsequent diseases in the focus.The aim is to characterize the epidemiological features of a new coronavirus infection during its nosocomial spread in medical organizations based on the analysis of outbreak incidence.Materials and methods. The data of the reporting forms «General information on patients with positive COVID-19», «General information on patients with community-acquired pneumonia with positive COVID-19» (138 pieces of information), copies of «Acts of epidemiological investigation of foci of infectious (parasitic) diseases with the establishment of a causal relationship» (57 pieces of information), copies of extraordinary reports on an emergency of a sanitary and epidemiological nature (57 pieces of information) were analyzed. The work uses epidemiological and statistical methods of research.Results. When analyzing 57 COVID-19 outbreaks in 30 medical organizations, it was found that the outbreak incidence was more often registered in multidisciplinary hospitals – 70.2% compared to 12.3% in specialized organizations of noninfectious profile, 10.5% of outbreaks were in polyclinics, 1.8% at emergency medical stations. The total number of people affected by the spread of the infection was 961, with a small proportion of children (15 people or 1.7%). Among those who fell ill with the spread of infection in the foci, the share of employees of medical organizations was 62.6%, including doctors – 16.6%, middle and junior medical workers-50.6% and 11.3%, respectively, and other categories – 21.5%. In nosocomial outbreaks of COVID-19, the focality index corresponded to 16.9, and the average duration of the focus was 32.4 days. The construction of the so-called «combined» outbreak diagram in the course of the epidanalysis allowed us to establish its total duration, which was 71 days, with the peaks of morbidity within the outbreak at intervals of 3–7 days, the greatest number of cases in the 1st and 8th days, and the gradual «extinction» of its activity in dynamics.Conclusions. The outbreak of COVID-19 in medical organizations usually occurred when there was an epidemic problem with COVID-19 in the territory. The peculiarity of nosocomial outbreaks was a significant proportion of adults (98.3%), mainly employees of medical organizations, who were often active sources of infection, as well as the involvement of structural units and hospitals for adults in the epidemic process, a high frequency of etiological interpretation of outbreaks (95.9%), a significant proportion of asymptomatic forms of infection and carrier, and the complexity of differential diagnosis of cases of out – of-hospital and nosocomial infection. The patterns of occurrence and spread of morbidity in medical organizations can be used in practical anti-epidemic work.

269. A Review of Gram Negative Endogenous Endophthalmitis at University Hospital in Newark

Background Endophthalmitis (EO) is an ocular emergency characterized by intraocular inflammation, usually in response to infection. While most cases are exogenous, gram negative (GN) EO account for 10-24% of all cases, and endogenous EO (EEO) account for 2-8% of all cases. Risk factors for EEO include diabetes mellitus (DM), IV drug use, and indwelling catheters. Major sources of infection are urinary tract infections (UTI), liver abscesses, pneumonia, and bacteremia. Common pathogens include K. pneumoniae, P. aeruginosa, and H. influenzae. Outcomes are poor, with only 20% of patients achieving improved visual acuity, and 30-40% requiring enucleation. Methods Retrospective analysis was performed on patients diagnosed with EO (n=89) at University Hospital in Newark from January 2016 to December 2020 using ICD-10 codes H44.0-H44.009, H44.1, and H44.19. Patients included were 18 years of age or older with culture proven GN endogenous EO (GNEEO) (n=7). Outcomes included anatomical success, functional success, and mortality at 28 days and 3 months. Results 7 of 89 patients met criteria for GNEEO (median age 67, 4 males, 71.4% Hispanic/Latino). Comorbidities included hepatobiliary disease (57.1%) and DM (42.9%). All 7 patients presented with ocular symptoms and 3 had non-ocular symptoms. Primary sources of infection included UTI, prostate abscess, and pneumonia/empyema. Eye cultures identified Pseudomonas in 4 patients and Klebsiella in 3 patients. Mean antibiotic length was 17.7 days with 6 patients receiving intravitreal antibiotics. Enucleation was performed in 3 patients. 2 patients had functional success and 4 had anatomical success, with 0 mortality at 28 days and 3 months. Table 1. Ocular symptoms on presentation of cases of gram negative endogenous endophthalmitis Table 2. Positives cultures obtained from cases of gram negative endogenous endophthalmitis Conclusion Although rare, GNEEO causes significant morbidity, with only 2 recovering visual acuity and 3 requiring enucleation. Risk factors, sources of infection, and microbes were all consistent with those in previous reports. Hepatobiliary disease and DM were the most prominent risk factors while sources of infection included UTI and empyema. Eye cultures were positive for K. pneumoniae and P. aeruginosa, two common pathogens previously identified. This case series highlights the importance of prompt recognition and initial treatment of GNEEO with empiric coverage that includes vancomycin and ceftazidime. Disclosures All Authors: No reported disclosures

789. Susceptibility of Phenotypic Subsets of Pseudomonas aeruginosa Isolates to Cefiderocol and Comparator Agents from SIDERO-WT 2014-2019

Background Multidrug-resistant (MDR) phenotypes are frequently observed among P. aeruginosa (PsA) isolated from hospitalized patients. This study describes the in vitro activities of cefiderocol (CFDC) and comparator agents against various non-susceptible (NS) phenotypic subsets of MDR PsA isolates from the SIDERO-WT multi-national surveillance program. Methods Clinical PsA isolates were collected from North America (NA) and Europe in 2014-2019 and tested for susceptibility at a central laboratory. MICs (μg/ml) were determined for CFDC, ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), colistin, cefepime, meropenem (MEM), and ciprofloxacin by broth microdilution according to CLSI guidelines. Aztreonam-avibactam (avibactam fixed concentration of 4 µg/ml) and imipenem/relebactam (I/R) were only tested during SIDERO-WT Year 5 (i.e. 2019). Susceptibility was interpreted according to current FDA and 2021 CLSI breakpoints. Results The different phenotypic subsets and susceptibility of tested compounds are shown in the table. Among 7700 PsA isolates, 47.7% and 23% were from respiratory and gastrointestinal sources of infection. CFDC inhibited 97.5% and 99.9% of all PsA at its FDA-S and CLSI-S MIC breakpoint of ≤1 and ≤4, respectively. CFDC had the lowest MIC90 of all tested agents and >99% S at an MIC ≤4 for all phenotypic subsets. At a MIC ≤1, CFDC displayed high susceptibility rates against all subsets including ≥88% S against CZA-NS, C/T-NS, I/R-NS, and MEM+I/R-NS isolates. Against MDR subsets, comparator agents consistently demonstrated lower activity than CFDC; 88% of MEM+C/T-NS and MEM+CZA-NS isolates had a CFDC MIC≤1 while 15.6% and 20.3% were S to I/R, respectively. 86% of MEM+CZA+C/T-NS and 80.4% CZA+C/T+I/R-NS isolates were S to CFDC. CFDC inhibited 98.1% and 99.4% of PsA isolates from NA (n = 3548) at a MIC of ≤1 and ≤4, respectively. In NA isolates that were MEM+C/T-NS; 85.7% of PsA isolates had a MIC ≤1 to CFDC and 33.3% and 28.6% were S to CZA and I/R, respectively. MEM: Meropenem; NS: Non-susceptible; CZA: Ceftazidime/avibactam; C/T: Ceftolozane/tazobactam; I/R: Imipenem/relebactam Conclusion CFDC demonstrated potent in vitro activity against a variety of phenotypic subsets of MDR P. aeruginosa isolates as compared to agents that are commonly used to treat MDR PsA infections including strains NS to other agents. These data support the use of CFDC as an important treatment option for MDR PsA. Disclosures Sean Nguyen, PharmD, Shionogi Inc (Employee) David Fam, PharmD, Shionogi (Employee) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Meredith Hackel, PhD MPH, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Roger Echols, MD, Shionogi (Consultant) Yoshinori Yamano, PhD, Shionogi (Employee)