Infection control operations of a large hospital in Taiwan to prevent nosocomial outbreaks during COVID-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) is highly contagious, with a potential to cause large nosocomial outbreaks in the hospital setting. We report the advance deployment of comprehensive, multi-level infection control measures in a 3,700-bed large hospital to prevent nosocomial outbreaks of COVID-19 during the pandemic. METHODS: We implemented a series of dynamic infection control policies during the pandemic. A confirmed COVID-19 case was defined by positive real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay. All healthcare worker (HCW) having symptoms or close contact with the confirmed case received the RT-PCR test. RESULTS: A total of 5,722 patients were tested in our hospital from January to May 2020. Twenty-five patients were confirmed COVID-19, including two inpatients. A cluster of 4 HCWs with COVID-19 associated with the 2nd inpatient was identified in the early stage of epidemic. Our enhanced traffic control bundling, mask wearing, hand hygiene and environmental cleaning were reinforced after the outbreak. All other confirmed cases were identified at our outdoor quarantine station or epidemic clinic afterwards, and the results of testing for 146 symptomatic HCWs were all negative. CONCLUSIONS: Integrated teamwork, advance deployment of infection control measures and efficient diagnostic testing and response protected HCW and facilities from large SARS-CoV-2 outbreaks and preserved the capacity and function of the health care system during the pandemic.

Adequacy of Hemodialysis Serves as an Independent Predictor of Humoral Response to ChAdOx1 Prime-Boost Vaccination in Hemodialysis Patients.

BACKGROUND: Immune response assessed by the quantification of neutralizing antibodies (nAbs) and predictors associated with immunogenicity after the prime-boost ChAdOx1 (Oxford-AstraZeneca) COVID-19 vaccine in hemodialysis (HD) patients remains unclear. METHODS: This prospective study enrolled 174 HD patients and 67 healthy subjects to evaluate antibodies against the spike protein 1 and receptor-binding domain of severe acute respiratory syndrome coronavirus type 2 after prime-booster vaccination, by using enzyme-linked immunosorbent assay and applied spline-based generalized additive model regression analysis to predict 50% neutralization titer (NT50). The correlation between HD parameters and NT50 was analyzed. RESULTS: NT50 was lower in HD patients compared with healthy controls after the prime-boost dose (p < 0.001). The geometric mean titer ratios were higher in first-dose seronegative than in the seropositive subgroup in HD patients and healthy controls (6.96 vs. 2.36, p = 0.002, and 9.28 vs. 1.26, p = 0.011, respectively). After two doses of ChAdOx1, one-way ANOVA showed that Ca × P was positively associated with NT50 (p trend = 0.043) and multiple linear regression showed the similar results (p = 0.021). Kt/V (a quantification of dialysis adequacy) (OR = 20.295, p = 0.005) could independently predict seroconversion (NT50 ≥ 35.13 IU/mL). CONCLUSION: Adequacy of hemodialysis could independently predict seroconversion in HD subjects vaccinated with prime-boost doses of ChAdOx1.

Single-Layer Inverted Internal Limiting Membrane Flap Versus Conventional Peel for Small- or Medium-Sized Full-Thickness Macular Holes.

PURPOSE: To analyze the outcomes of using an internal limiting membrane (ILM) flap and the conventional ILM peel technique for small- or medium-sized full-thickness macular hole (FTMH) repair. DESIGN: Retrospective, interventional case series. METHODS: Eyes with an FTMH ≤400 µm that underwent vitrectomy with a single-layer inverted ILM flap (flap group, 55 eyes) or an ILM peel (peel group, 62 eyes) were enrolled. Best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) measurements were obtained preoperatively and at 1, 3, 6, and 12 months postoperatively. RESULTS: Primary hole closure was achieved in 54 (98%) and 60 (97%) eyes in the flap and peel groups, respectively. The preoperative and postoperative 12-month BCVA values were comparable between the groups but were significantly better in the flap than in the peel group at 1 month (mean ± SD logMAR: 0.83 ± 0.43 vs 1.14 ± 0.50; P = .001), 3 months (0.58 ± 0.33 vs 0.82 ± 0.43; P = .002), and 6 months (0.56 ± 0.32 vs. 0.72 ± 0.48; P = .028). In the flap group, foveal gliosis was less common than in the peel group at 1 month (P = .030), and restored external limiting membrane and interdigitation zone was more common at 3 months (P = .046 and P < .001, respectively). CONCLUSIONS: The single-layer ILM flap and conventional ILM peel techniques both closed FTMHs and improved vision. ILM flaps were associated with better visual outcomes up to 6 months postoperatively and should be considered in FTMHs ≤400 µm.

Neutralization Assessments Reveal High Cardiothoracic Ratio and Old Age as Independent Predictors of Low Neutralizing Antibody Titers in Hemodialysis Patients Receiving a Single Dose of COVID-19 Vaccine.

BACKGROUND: Data are lacking regarding predictors of quantification of neutralizing antibodies (nAbs) based on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 50% neutralization titer (NT50) after a single dose of COVID-19 vaccine in hemodialysis (HD) patients. METHODS: This prospective single-center study enrolled 200 HD patients and 82 healthy subjects to estimate antibodies against the SARS-CoV-2 viral spike protein 1 and receptor-binding domain after a first dose of a COVID-19 vaccine (ChAdOx1 or mRNA-1273), measured by enzyme-linked immunosorbent assay and applied spline-based generalized additive model regression analysis to predict NT50 converted to international units. RESULTS: After the first dose of ChAdOx1, multiple linear regression showed that age (p = 0.011) and cardiothoracic ratio (p = 0.002) were negatively associated with NT50. Older age (OR = 0.958, p = 0.052) and higher cardiothoracic ratio (OR < 0.001, p = 0.037) could predict negative humoral response (NT50 < 35.13 IU/mL). NT50 was lower in HD patients compared with healthy controls receiving ChAdOx1 (10.68 vs. 43.01 IU/m, p < 0.001) or mRNA-1273 (36.39 vs. 262.2 IU/mL, p < 0.001). ChAdOx1 elicited lower GMTs than mRNA-1273 in the HD cohort (10.68 vs. 36.39 IU/mL, p < 0.001) and in healthy controls (43.01 vs. 262.22 IU/mL, p < 0.001). CONCLUSION: High cardiothoracic ratio and old age could independently predict a decline in nAb titers in an HD cohort vaccinated with a single dose of ChAdOx1.

Effective Preventive Strategies to Prevent Secondary Transmission of COVID-19 in Hemodialysis Unit: The First Month of Community Outbreak in Taiwan.

BACKGROUND: Dialyzed patients are vulnerable to coronavirus infection disease 2019 (COVID-19). The incidence and outcome of COVID-19 in hemodialysis (HD) patients in Taiwan remain unclear. A series of preventive measures were executed to combat COVID-19 transmission among HD patients. METHODS: We carried out a series of forward-looking and practical preventive strategies of COVID-19 control in our HD center. Incidences of COVID-19 of our HD unit were compared with those of national and local estimates from a community outbreak from 15 May to 30 June 2021. Prognostic factors associated with mortality were analyzed. RESULTS: The national incidence of COVID-19 was 0.062%; being highest in Taipei City (0.173%), followed by New Taipei City (0.161%) and Keelung (0.083%). The overall incidence in Keelung HD patients was 0.666%. One patient of our HD center contracted COVID-19 from the household; however, we have contained secondary transmission in our HD center by implementing strict preventive measures. The mortality rate of HD patients in Keelung was 66.6%. The median Ct value of HD patients was 17.53 (11.75-27.90) upon diagnosis. The deceased patients had a higher cardiac/thoracic ratio than alive (0.61 vs. 0.55, p = 0.036). CONCLUSIONS: Taking aggressive and proactive infection preventive measures impedes the secondary transmission of COVID-19 in HD facilities. COVID-19-associated mortality was high in HD patients, being the high cardiac-thoracic ratio, an important prognostic factor for clinical outcome of infected HD patients.

A hospital cluster of COVID-19 associated with a SARS-CoV-2 superspreading event.

BACKGROUND/PURPOSE: Superspreading events (SSEs) are pivotal in the spread of SARS-CoV-2. This study aimed to investigate an SSE of COVID-19 in a hospital and explore the transmission dynamics and heterogeneity of SSE. METHODS: We performed contact tracing for all close contacts in a cluster. We did nasopharyngeal or throat swabbing for SARS-CoV-2 by real-time RT-PCR. Environmental survey was performed. The epidemiological and clinical characteristics of the SSE were studied. RESULTS: Patient 1 with congestive heart failure and cellulitis, who had onset of COVID-19 two weeks after hospitalization, was the index case. Patient 1 led to 8 confirmed cases, including four health care workers (HCW). Persons tested positive for SARS-CoV-2 were HCW (n = 4), patient 1's family (n = 2), an accompanying person of an un-infected in-patient (n = 1), and an in-patient admitted before the SSE (n = 1). The attack rate among the HCW was 3.2 % (4/127). Environmental survey confirmed contamination at the bed rails, mattresses, and sink in the room patient 1 stayed, suggesting fomite transmission. The index case's sputum remained positive on illness day 35. Except one asymptomatic patient, at least three patients acquired the infection from the index case at the pre-symptomatic period. The effective reproduction number (Rt) was 0.9 (8/9). CONCLUSION: The host factor (heart failure, longer viral shedding), transmissibility of SARS-CoV-2 (Rt, pre-symptomatic transmission), and possible multiple modes of transmission altogether contributed to the SSE. Rapid response and advance deployment of multi-level protection in hospitals could mitigate COVID-19 transmission to one generation, thereby reducing its impact on the healthcare system.

Ocular manifestation, comorbidities, and detection of severe acute respiratory syndrome-coronavirus 2 from conjunctiva in coronavirus disease 2019: A systematic review and meta-analysis.

The coronavirus disease 2019 (COVID 19) pandemic has presented major challenges to ophthalmologists. Reports have shown that ocular manifestations can be the first presenting symptoms of COVID 19 infection and conjunctiva may be a portal of entry for the severe acute respiratory syndrome (SARS) associated coronavirus 2 (SARS CoV 2). The purpose of this article is to provide general guidance for ophthalmologists to understand the prevalence of ocular presentation in COVID 19 patients and to reduce the risk of transmission during practice. Relevant studies published in the period of November 1, 2019, and July 15, 2020, regarding ocular manifestations of COVID 19 and detection of SARS CoV 2 in the eye were included in this systematic review and meta analysis. The pooled prevalence of the ocular manifestations has been estimated at 7% (95% confidence interval [CI]: 0.03-0.10) among COVID 19 patients. The pooled detection rate of SARS CoV 2 from conjunctiva was low (1%, 95% CI: 0.00-0.03). Conjunctival symptoms were the most common ocular manifestations in COVID 19, but the positive detection rate of the SARS CoV 2 virus by reverse transcription-polymerase chain reaction of conjunctival tears or secretions remained low. No study has shown a definite transmission of COVID 19 through ocular mucosa or secretions. In summary, ocular manifestations in COVID 19 patients commonly comprise ocular surface symptoms. Although a low prevalence of ocular symptoms was encountered among patients infected by SARS CoV 2, it is imperative for all ophthalmologists to understand the full spectrum of COVID 19 symptoms or signs including those of the eyes as well as to adopt appropriate protective measures during clinical practice.

Proposed measures to be taken by ophthalmologists during the coronavirus disease 2019 pandemic: Experience from Chang Gung Memorial Hospital, Linkou, Taiwan.

PURPOSE: Although Taiwan was one of the first countries to develop coronavirus disease 2019 (COVID-19), with effective antiepidemic measures, Taiwan has effectively controlled the spread of the disease. The purpose of this article is to provide useful safety strategies for ophthalmologists in daily practice during the COVID-19 pandemic. MATERIALS AND METHODS: Infection control strategies in the hospital and Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, are discussed. RESULTS: Ophthalmologists are at high risk of contracting COVID-19 infection, as they have close contact with patients during ocular examinations, and are also facing high patient volume in outpatient clinics as well as emergency consultations. Furthermore, ocular symptoms, such as conjunctivitis, may be the presenting signs of COVID-19 infection. We provide our strategies, which include hospital's gate control with triage station, patient volume control, proper personal protective equipment, and consultation with telemedicine technology, to decrease the risk of cross-infection between medical staffs and patients. CONCLUSION: To achieve the goal of preventing viral spread and maximizing patient and medical staffs' safety, besides providing proper protective equipment, it is also crucial for staffs and patients to strictly follow antiepidemic measures. We hope that our experience can help ophthalmologists and health-care workers to have a safer working environment when facing COVID-19 pandemic.

Chloroquine and Hydroxychloroquine Retinal Toxicity Consideration in the Treatment of COVID-19.

The proposed doses of chloroquine (CQ) and hydroxychloroquine (HCQ) for treatment of COVID-19 (1000 mg/day for 10 days, CQ; 800 mg first day then 400 mg/day for 5 days, HCQ) in many guidelines worldwide, are considerably higher than the maximum recommended daily safe doses of both agents (≤2.3 mg/kg/day, CQ; ≤5.0 mg/kg/day, HCQ) for development of retinal toxicity. Irreversible retinal damage can occur if the exposure to the safe doses is >5 years. It is not known whether exposure to high doses over a short period of time can also cause the damage. We recommend that before prescribing CQ or HCQ, history of ocular disease should be obtained to avoid the prescription if appropriate. If either agent is to be used, routine baseline ocular examination is not absolutely necessary. Patients who do not have ocular disease should also be informed about the potential risk of retinal toxicity. Both agents, however, have not yet been proven to be beneficial to COVID-19.