Objectives: Many healthcare workers and patients in intensive care units of Sardjito Hospital, a referral and academic hospital in Yogyakarta, Indonesia, were infected with SARS-CoV-2 in June–August 2021, during the second wave of the COVID-19 pandemic. Much evidence has shown that SARS-CoV-2 persists on hospital environmental surfaces and medical equipment. We investigated the potential sources of virus in our cases, particularly environmental contamination. Methods: Environmental screening for SARS-CoV-2 was conducted using RT-PCR of swabs collected from case-related medical equipment and hospital surfaces. We examined the environmental cleaning method in these areas as well. Results: We swabbed medical equipment in close contact with patient droplets such as the ventilator, the high-flow nasal cannula, the nebulizer, and suction equipment, as well as some environmental surfaces near the patient, such as the bed rail, air conditioning unit, and portable HEPA-filter outlet. Among 19 samples, genetic material of SARS-CoV-2 was detected only on a sample from a nebulizer. The point of contamination was on the outer body of that nebulizer, which indicated that the contact transmission source might be from patient droplets and/or inadequate cleaning. No more positive results emerged from our screening, indicating that the environmental cleaning was adequate. The IPC team recommended that we no longer use nebulizers for COVID-19 patients and that the cleaning procedure be improved, particularly after the device is used. Conclusions: Environmental screening for SARS-CoV-2 can be used to support investigations of inpatient COVID-19 outbreaks in hospitals. Adequate cleaning and care procedures for medical equipment are very important in preventing the transmission of SARS-CoV-2 in the hospital setting.

Background: With the emergence of new infectious diseases, infection control nursing (ICN) in hospitals has become increasingly significant. Consequently, research on ICN has been actively performed. We examined the knowledge structure and trends addressed in Korean ICN research. Methods: From 5 web-based Korean academic databases (DBpia, KISS, KMbase, KoreaMed, and RISS), 2,244 studies published between 2013 and 2022 were retrieved using ICN-related search terms (eg, “nurse” or “nursing” along with “infection control,” “infection prevention,” “healthcare-associated infection,” or “standard precautions”). After deleting duplicates, the authors assessed titles and abstracts and included 250 research abstracts in this study. Using NetMiner 4.4 software (Cyram, Seoul, Korea), words from abstracts of published articles were extracted and refined, then text network analysis and topic modeling were performed. A text network was structured based on the co-occurrence matrix of key words (semantic morphemes) and was analyzed to identify the main key words. Through topic modeling using the Latent Dirichlet Allocation algorithm, latent topics in the research abstracts were extracted. The authors verified the key words comprising the topic and the result of classifying the documents by topic and named topics. Results: The number of studies, which increased following the outbreak of Middle East respiratory syndrome in 2015, has declined over time but peaked in 2021 with the COVID-19 pandemic. The text network composed of the key words of the research abstracts was generated and visualized (Fig. 1). As a result of text network analysis, the 5 most common key words were ‘nurse,’ ‘infection control,’ ‘nursing care,’ ‘practice,’ and ‘perception’ in terms of degree and betweenness centrality. Other prominent main keywords were also identified: ‘knowledge,’ ‘compliance,’ ‘education,’ ‘intervention,’ ‘intention,’ and ‘safety.’ With the application of topic modeling to the research abstracts, 5 topics were derived and named as follows (Fig. 2): “infection control in nursing care for patient safety,” “infection control measures for healthcare personnel safety,” “burdens and obstacles for infection control among nurses,” “infection control for multidrug-resistant organisms,” and “knowledge, attitude, practice for infection control among nurses.” Conclusions: By applying text-network analysis and topic modeling, we obtained insights into Korean ICN research trends. To explore global ICN research trends, further study is necessary to analyze internationally published studies reflecting each country’s nursing work conditions.

Disclosure: None

Background: Infection prevention teams utilize policies to guide practice; however, some policies may inadvertently uphold institutional racism and discrimination. Our institution utilizes an equity impact assessment tool during new policy creation or existing policy updates to identify, reduce, eliminate, and prevent inequities in care. Methods: We reviewed all 119 current institution-wide policy documents related to or managed by the infection prevention division at Seattle Children’s Hospital using an institutional equity impact assessment tool. The tool asks 6 open-ended questions to help policy owners identify potential inequities and to evaluate how marginalized groups may be affected. Each policy was assessed for its potential to create or sustain inequities for patients, families, or staff. Policies determined to have potential inequities were examined for any language to suggest that equity considerations had been incorporated into the existing policy. Initial policy review was performed by 2 infection prevention physicians, and disagreements were resolved by consensus. We defined the presence of equity considerations as any explicit mention of disparate impact of the policy on marginalized groups or mitigation of such effect. Results: Of the 119 policies reviewed, 43 (36%) were identified as having substantial potential to impact marginalized groups and create or sustain inequities. Among them, 42 (98%) of these policies lacked existing equity considerations. The policies with potential equity implications covered the following categories: COVID-19 (including masking, workforce restriction, testing), visitor restrictions, tuberculosis, central-line–associated bloodstream infections (CLABSIs), multidrug-resistant organisms (MDROs), public health reporting, medical behavioral unit policies, off-site affiliate housing policies, special pathogens program (including Ebola, MERS, SARS), surgical-site infections, home care including dialysis, and occupational health-related policies. Examples of policies that did not highlight inequities included those pertaining to construction, water intrusion, and transmission-based precautions. One example of change driven by use of the equity impact assessment tool concerned communication with patients and families about tuberculosis isolation and resulted in creation of a standardized multidisciplinary care conference to better communicate tuberculosis isolation processes (including testing required, visitor restrictions, and anticipated duration of isolation) to families in their language of care. Conclusions: Hospital-wide infection prevention policies have the potential to create or sustain existing inequities. Systematic consideration of equity implications using an equity impact assessment framework could be the first step in mitigating these effects and can result in concrete actions to reduce systemic racism.

Disclosure: None

Objectives: To determine the factors influencing COVID-19 prevention practices among healthcare personnel. Methods: The sample consisted of healthcare personnel working in the emergency department, inpatient wards, and the outpatient department in 250 Rajavithi hospitals selected using a purposive sampling method. Data were collected using questionnaires that were validated by 5 experts and had a content validity index of 0.83. The reliability of the questionnaires was 0.91. Data were analyzed using descriptive statistics and multiple regression. Results: Study participants had good attitudes toward behaviors, subjective norms, perceived behavioral control, and intention to prevent COVID-19. In addition, perceived behavioral control was the only factor that statistically predicted intention to perform COVID-19 infection prevention and may explain 25.6% of the variability of intention (P < .001). Conclusions: Based on the results of this study, relevant authorities, including wards and infection control units, should support perceived behavioral control among registered nurses to encourage COVID-19 prevention practices.

Objectives: The disruptions wrought by COVID-19 have spurred the development of vaccines at a pace unprecedented in global history. We have witnessed vaccine development from in vivo testing to population-wide implementation in just under 1 year. Singapore’s vaccination rate of 80%, attained at the start of September 2021, marks a milestone. It signals that plans to shift from a “zero transmission” approach to an endemic “living with COVID-19” approach is headed in the right direction, albeit cautiously and with some uncertainty. Although we ask ourselves at what rate our society should be reopened, we acknowledge that such questions are not easily answered because newer variants are proving more transmissible and, possibly, vaccine resistant compared to earlier variants. Methods: COVID-19 vaccination milestones were plotted. A timeline was used to map key events of Singapore’s vaccination strategy in terms of legislation, logistics and operations, vaccination eligibility, vaccination sites, and measures implemented to encourage vaccine uptake. These factors were compared with Singapore’s vaccination rate from December 2020 to early September 2021. Results: The successful vaccination strategy in Singapore has been explored in 4 main areas: good leadership and evidence-based decision making, use of communications, utilizing existing logistics, and an ever-ready primary care. Conclusions: As we transition to our second year of combating COVID-19, emerging variants, spread despite vaccination, and the contesting voices of antivaxxers pose new challenges. Vaccine-generated immunity is only one, albeit an important, element of a comprehensive COVID-19 strategy. The strategy must also entail surveillance, self-testing, contact tracing, quarantine, legislation, financial support, and strengthened social responsibility. As providers of vaccination and translators of upstream evidence and policy decisions in the community, primary care providers should be involved early in decision making regarding interventions in the community because they can foresee challenges on the ground. Let us put our continued trust in primary care providers to contribute to making Singapore a COVID-19–resilient nation.

We compared optimal antibiotic prescribing before and after implementing an interpretive β-lactamase microbiology comment for Haemophilus influenzae and Moraxella catarrhalis in lower respiratory-tract infections. The postintervention group was associated with 5-fold increased odds of optimal de-escalation (adjusted odds ratio, 5.03; 95% confidence interval, 2.57–9.87).

Background: LivaNova 3T heating and cooling devices (HCDs) have been associated with Mycobacterium chimaera, a Mycobacterium avium-intracellulare (MAIC) species, infections after cardiothoracic surgery. We describe our outbreak, which persisted despite escalating infection control measures. Methods: We identified patients with a positive MAIC culture following cardiothoracic surgery from January 2015 to the present at our institution. We classified these as “definite,” “possible,” or “operating room contamination” cases based on positive cultures from sterile sites, airway, or surgical specimens without evidence of infection. To identify patient or surgery characteristics associated with risk for MAIC infection, we conducted a case–control study comparing definite cases to randomly selected unmatched controls of patients over the same period without a positive MAIC culture after cardiothoracic surgery. Results: We identified 26 patients with a positive MAIC culture after cardiothoracic surgery: 13 definite, 9 possible, and 4 contamination cases. Among definite cases, the most common surgeries were valve replacements and left ventricular assist devices (5 cases each). The mean time from cardiothoracic surgery to diagnosis was 525 days. Overall, 10 (77%) cases occurred after exposure to our oldest HCDs (manufactured in 2013 or earlier). To date, 16 (62%) have undergone or are undergoing treatment for MAIC infection, and 4 (15%) have died due to NTM infection or complications. Compared to 47 controls, definite cases were associated with chronic kidney disease, implants, procedure type, use of cardiopulmonary bypass, and HCD age. Cases were not associated with time on bypass, time in the operating room, or other comorbid conditions (Table). All cases occurred despite enhanced disinfection and reorienting the HCD within the operating room, according to manufacturer recommendations. Moreover, 18 cases, including 7 definite cases, occurred after most HCDs were either deep cleaned or upgraded by the manufacturer. Also, 5 cases, including 3 possible cases and 2 contamination cases, occurred after physical separation of the HCD from the operating room. In August 2022, we purchased a fleet of glycol-cooled HCDs, and we have not identified additional MAIC cases since their deployment (Fig.). Conclusions: MAIC infections after cardiothoracic surgery were associated with procedure type, especially implants, use of cardiopulmonary bypass, and HCD age. Contrary to prior reports, neither operative nor CPB time was associated with MAIC infection after cardiothoracic surgery. The outbreak persisted despite disinfection and/or deep cleaning and reorienting HCDs within the operating room; some possible and contamination cases occurred even after moving HCDs outside the operating room. Thus, HCD water contamination events in the operating room (eg, spills from HCD tubing) may be a route of exposure, and different infection prevention measures are needed.

Disclosure: None

Background: The Centers for Disease Control and Prevention’s Emerging Infections Program conducts active laboratory- and population-based surveillance for carbapenem-resistant Enterobacterales (CRE) and extended spectrum beta-lactamase-producing Enterobacterales (ESBL-E). To better understand the U.S. epidemiology of these organisms among children, we determined the incidence of pediatric CRE and ESBL-E cases and described their clinical characteristics. Methods: Surveillance was conducted among children <18 years of age for CRE from 2016–2020 in 10 sites, and for ESBL-E from 2019–2020 in 6 sites. Among catchment-area residents, an incident CRE case was defined as the first isolation of Escherichia coli, Enterobacter cloacae complex, Klebsiella aerogenes, K. oxytoca, or K. pneumoniae in a 30-day period resistant to ≥1 carbapenem from a normally sterile site or urine. An incident ESBL-E case was defined as the first isolation of E. coli, K. pneumoniae, or K. oxytoca in a 30-day period resistant to any third-generation cephalosporin and non-resistant to all carbapenems from a normally sterile site or urine. Case records were reviewed. Results: Among 159 CRE cases, 131 (82.9%) were isolated from urine and 19 (12.0%) from blood; median age was 5 years (IQR 1–10) and 94 (59.1%) were female. Combined CRE incidence rate per 100,000 population by year ranged from 0.47 to 0.87. Among 207 ESBL-E cases, 160 (94.7%) were isolated from urine and 6 (3.6%) from blood; median age was 6 years (IQR 2–15) and 165 (79.7%) were female. Annual ESBL incidence rate per 100,000 population was 26.5 in 2019 and 19.63 in 2020. Incidence rates of CRE and ESBL-E were >2-fold higher in infants (children <1 year) than other age groups. Among those with data available, CRE cases were more likely than ESBL-E cases to have underlying conditions (99/158 [62.7%] versus 59/169 [34.9%], P<0.0001), prior healthcare exposures (74/158 [46.8%] versus 38/169 [22.5%], P<0.0001), and be hospitalized for any reason around time of their culture collection (75/158 [47.5%] versus 38/169 [22.5%], P<0.0001); median duration of admission was 18 days [IQR 3–103] for CRE versus 10 days [IQR 4–43] for ESBL-E. Urinary tract infection was the most frequent infection for CRE (89/158 [56.3%]) and ESBL-E (125/169 [74.0%]) cases. Conclusion: CRE infections occurred less frequently than ESBL-infections in U.S. children but were more often associated with healthcare risk factors and hospitalization. Infants had highest incidence of CRE and ESBL-E. Continued surveillance, infection prevention and control efforts, and antibiotic stewardship outside and within pediatric care are needed

Disclosure: None

Objectives: In early 2021, when the COVID-19 vaccine was scarce in Vietnam, healthcare workers (HCWs) were prioritized for vaccination due to high risk of occupational exposure. However, there is some COVID-19 vaccine hesitancy within HCW communities. Assessing COVID-19 severity among vaccinated and nonvaccinated HCWs would contribute essential information to assure people of vaccine effectiveness and reduce vaccine hesitancy. Methods: We conducted a descriptive cross-sectional study at the National Hospital for Tropical Diseases in Hanoi, Vietnam, from May to June 2021. Clinical and epidemiological data from HCWs with positive polymerase chain reaction (PCR) results were collected. The severity of symptoms were classified according to Vietnam Ministry of Health guideline (Decision no. 3416 issued  July 14, 2021) into 5 categories: asymptomatic, mild, moderate, severe, and critical conditions Results: Overall, 25 HCWs qualified for this study (14 women and 11 men), with a median age of 31 years. Among them, 3 HCWs were infected due to community exposure, and the rest were infected due to occupational exposure. Also, 3 HCWs received the Astra Zeneca vaccine before being infected with SARS-CoV-2 (one fully vaccinated with 2 doses and the other 2 had had the first dose). Categorized by the severity of infection, 28% were asymptomatic, 44% had mild symptoms, 20% had moderate symptoms, and 8% experienced severe symptoms. All 3 vaccinated HCWs showed only mild symptoms. Cough and sore throat were the main symptoms recorded (60%), followed by fever (56%). Blood test results did not show significant differences between the severe and mild COVID-19 groups. Conclusions: COVID-19 vaccination reduced the severity of COVID-19 in this small sample of HCWs. Full COVID-19 vaccination is strongly recommended for HCWs to reduce the spread of COVID-19 and to limit the number of cases with severe disease.

Objectives: The infection prevention team (IPT) was tasked with providing technical guidance for the construction and setup of a community treatment facility in 3 weeks at a Formula 1 (F1) racing pit to house elderly SARS-CoV-2–positive cases. Methods: The facility was setup with 737 beds including an isolation unit and a resuscitation bay. The multidisciplinary team decided on zone segregation (ie, green and hot zones) and discussed the clean–dirty workflow. IPC measures were revisited, especially regarding the layout of the donning and doffing station, as the facility expanded to accommodate patients with more comorbidities and those who needed dialysis. IPC training for nominated infection control liaison officers (ICLOs) was conducted using a “train the trainer” approach for mask fitting, hand hygiene, donning and doffing of personal protective equipment (PPE). Enhanced IPC measures, including weekly audit and staff surveillance, were mandatory, and monitoring was performed according to MOH guidelines. Linen and waste management and the cleaning and disinfection process were established at the beginning of the project. Results: Construction was completed within 3 weeks. The setup was completed in November 2021 for 737 beds. There were 758 admissions during the 4-month operation. In total, 12 trained ICLOs oversaw the training of 200 healthcare workers. They conducted 12 IPC audits and provided feedback to all staff. Compliance with PPE practices was inconsistent, and findings were shared during daily after-action reviews for improvement. The greatest challenges were converting the F1 facility to a healthcare facility, training staff with no IPC knowledge, and monitoring IPC on the ground. The trained ICLOs were successful in implementing, practicing, and monitoring IPC measures with minimal assistance from the infection prevention team. Conclusions: Operation began on November 5, 2021, and ceased on March 9, 2022. The community treatment facility construction, setup, and operations were completed within a short timeframe due to the efforts of various stakeholders. We faced many challenges, but we managed to implement and uphold IPC standards from beginning to end.

Background: Environmental contamination is a major risk factor for multidrug-resistant organism (MDRO) exposure and transmission in the healthcare setting. Sponge-stick sampling methods have been developed and validated for MDRO epidemiological investigations, leading to their recommendation by public health agencies. However, similar bacteriological yields with more readily available methods that require less processing time or specialized equipment have also been reported. We compared the ability of 4 sampling methods to recover a variety of MDRO taxa from a simulated contaminated surface. Methods: We assessed the ability of (1) cotton swabs moistened with phosphate buffer solution (PBS), (2) e-swabs moistened with e-swab solution, (3) cellulose-containing sponge sticks (CSS), and (4) non–cellulose-containing sponge sticks (NCS) to recover extended-spectrum β-lactamase (ESBL)–producing Escherichia coli, carbapenem-resistant Pseudomonas aeruginosa (CRPA), carbapenem-resistant Acinetobacter baumannii (CRAB), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), and a mixture that contained VRE, MRSA, and ESBL organisms. A solution of known bacterial inoculum (~105 CFU/mL) was made for each MDRO. Then, 1 mL solution was pipetted on a stainless-steel surface (8 × 12 inch) in 5 µL dots and allowed to dry for 1 hour. All samples were collected by 1 individual to minimize variation in technique. Sponge sticks were expressed in PBS containing 0.02% Tween 80 using a stomacher, were centrifuged, and were then resuspended in PBS. Cotton and e-swabs were spun in a vortexer. Then, 1 mL of fluid from each method was plated to selective and nonselective media in duplicate and incubated at 35°C for 24 hours (MRSA plates, 48 hours) (Fig. 1). CFU per square inch and percentage recovery were calculated. Results: Table 1 shows the CFU per square inch and percentage recovery for each sampling method–MDRO taxa combination. The percentage recovery varied across MDRO taxa. Across all methods, the lowest rate of recovery was for CRPA and the highest was for VRE. Regardless of MDRO taxa, the percentage recovery was highest for the sponge stick (CSS and NCS) compared to swab (cotton and E-swab) methods across all taxa (Table 1 and Fig. 2).

Conclusions: These findings support the preferential use of sponge sticks for the recovery of MDROs from the healthcare environment, despite the additional processing and equipment time needed for sponge sticks. Further studies are needed to assess the robustness of these findings in noncontrived specimens as well as the comparative effectiveness of different sampling methods for non–culture-based MDRO detection.

Disclosure: None

Infection surveillance is one of the cornerstones of infection prevention and control. Measurement of process metrics and clinical outcomes, such as detection of healthcare-associated infections (HAIs), can be used to support continuous quality improvement. HAI metrics are reported as part of the CMS Hospital-Acquired Conditions Program, and they influence facility reputation and financial outcomes.

Objectives: COVID-19 cases continue to climb in the community from the SARS-CoV-2 δ (delta) variant wave. To prepare for cases that may be nosocomial or detected late, the infection prevention team constructed a ‘hot ward’ tool kit to guide implementation of infection control measures. Methods: We engaged the NUH Facilities Management ventilation engineers to understand every ward’s mechanical ventilation setup. With this information, we created of “green” and “hot” zones within ward. After conducting assessments on individual wards, we created the “hot ward” tool kit: (1) 38 ward floor plans indicating ventilation setup, “green” zones, and “hot” zones; (2) a risk matrix to guide ward actions based on cycle threshold (Ct) value and duration of exposure; and (3) “hot ward” checklists. The tool kit was presented to infectious disease clinicians on the infection prevention team and senior nursing leaders for input and guidance. To ensure that these plans were practical, we conducted numerous site walks with HOD and ward nurse managers (ie, for the ICUs and psychiatric units). Finally, the tool kit was shared in a meeting with key stakeholders and senior leaders. It was also uploaded to the NUH COVID-19 quick-reference intranet page for easy staff access. Results: The tool kit was used by 2 general wards when cases of confirmed COVID-19 were detected among patients. Overall, the tool kit helped HOD and nurse managers with the immediate actions required and it provides useful guidance for the infection prevention team to assess and guide decisions regarding whether a ward lockdown is necessary. Conclusions: Although the guidance was useful, from the site walk we learned that the mechanical ventilation system of some wards is shared, making it challenging to prevent cross contamination between wards because any shared ventilation between unmasked areas can be pose a risk for both patients and staff. Additional measures were instituted to mitigate this risk.

Current methods of emergency-room–based syndromic surveillance were insufficient to detect early community spread of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in the United States, which slowed the infection prevention and control response to the novel pathogen. Emerging technologies and automated infection surveillance have the potential to improve upon current practice standards and to revolutionize the practice of infection detection, prevention and control both inside and outside of healthcare settings. Genomics, natural language processing, and machine learning can be leveraged to improve identification of transmission events and aid and evaluate outbreak response. In the near future, automated infection detection strategies can be used to advance a true “Learning Healthcare System” that will support near–real-time quality improvement efforts and advance the scientific basis for the practice of infection control.

Background: Evaluation of the adequacy of prophylactic antibiotics in surgery has been implemented as a national policy in Korea since August 2007, and the appropriate use of prophylactic antibiotics has improved. However, antibiotic prescriptions that are not recommended or discontinuation of prophylactic antibiotic administration within 24 hours after surgery are still not well done. This study introduced a program to improve the adequacy of prophylactic antibiotics for surgery and analyzed its effects. Methods: We retrospectively analyzed the effectiveness of the appropriate prophylactic antibiotic use program for surgery conducted at a university hospital in Seoul. The participants were patients aged ≥18 years who underwent any of 18 types of surgery. The program started was implemented in June 2020. First, a computer system was used to confirm the antibiotic prescription recommended for each surgery. It also assessed whether the number of days of administration was exceeded, whether antibiotics were prescribed in combination, and whether antibiotics prescribed for discharge medicine were checked in 4 steps. A pop-up window appeared in each patient record to enter the reason for the prescription. If the reason was appropriate, the prescription was allowed, but if not, the prescription was restricted. In addition, infectious diseases physicians and an insurance review team visited each department to conduct an education session. To analyze the effect 3 months before activity (January–March 2020) and 3 months after activity (October–December 2020), we compared the first antibiotic administration rate within 1 hour prior to skin incision, the recommended prophylactic antibiotic administration rate, and surgery type. The rate of discontinuation of prophylactic antibiotics within 24 hours after administration and the rate of prescription of prophylactic antibiotics at discharge were compared. Results: In total, 1,339 surgeries during the study period were included in the analysis. There were 695 cases before the introduction of the program and 644 cases after the introduction. The rate of first antibiotic use within 1 hour prior to skin incision was 93.1%–99.5% (P < .001), the rate of recommended prophylactic antibiotic administration was 85.0%–99.2% (P < .001), and the rate of discontinuation of antibiotic administration within 24 hours after surgery improved from 51.8% to 98.3% (P < .001), respectively. The prescription rate of antibiotics at discharge improved from 20.7% to 0.8% (P <.001) (Table 1). Conclusions: A computerized program to improve the adequacy of prophylactic antibiotic use in surgery combined with education of medical staff was very effective.

Disclosure: None

The rich and complex electronic health record presents promise for expanding infection detection beyond currently covered settings of care. Here, we review the “how to” of leveraging electronic data sources to expand surveillance to settings of care and infections that have not been the traditional purview of the National Healthcare Safety Network (NHSN), including a discussion of creation of objective and reproducible infection surveillance definitions. In pursuit of a ‘fully automated’ system, we also examine the promises and pitfalls of leveraging unstructured, free-text data to support infection prevention activities and emerging technological advances that will likely affect the practice of automated infection surveillance. Finally, barriers to achieving a completely ‘automated’ infection detection system and challenges with intra- and interfacility reliability and missing data are discussed.

Background: Antiviral chemoprophylaxis for influenza is recommended in nursing homes to prevent transmission and severe disease among residents with higher risk of severe influenza complications. Interim CDC guidance recommends that long-term care facilities initiate antiviral chemoprophylaxis with oral oseltamivir for all non-ill residents living in the same unit following the start of an outbreak in a facility (ie, ≥2 patients ill within 72 hours and of whom at least 1 resident has laboratory-confirmed influenza). Prophylaxis continues for a minimum of 2 weeks and for at least 7 days after the last laboratory-confirmed case. However, facilities may not strictly adhere to this guidance, with 1 study showing up to 68% of facilities were nonadherent to national guidance (Silva et al 2020). Here, we model the potential impacts of different antiviral prophylaxis strategies. Methods: We developed a susceptible–exposed–asymptomatic–infected–recovered (SEAIR) compartmental model of an average-sized nursing home comprising short-stay residents, long-stay residents, and healthcare personnel (HCP). Persons treated with antiviral chemoprophylaxis were less susceptible to infection, had a lower probability of symptoms if infected, a reduced viral load, and a shortened duration of infectiousness. We included influenza vaccination for residents and HCP through reduced probability of symptomatic infection. Coverage rates were estimated from CDC FluVaxView and CMS COVID-19 nursing home data. As a base case, we modeled a scenario with prophylaxis implemented according to guidance. We varied uptake by residents and HCP (from 10% to 90%), case thresholds for prophylaxis initiation (1–5 cases identified), and timing of prophylaxis cessation: either time dependent (ie, 10–14 days of prophylaxis) or case-dependent (ie, continuing prophylaxis for 1–7 days with no cases). Results: In the scenario based on current guidance, prophylaxis reduced resident cases by 16% and resident hospitalizations by 45%, compared to no prophylaxis (Fig. 1A). Scenarios that differed from the guidance altered case burden and timing: Time-dependent prophylaxis cessation increased resident cases and hospitalizations (Fig. 1A). Timing of prophylaxis initiation had slight effects on the timing of the epidemic and minimal effects on resident cases and hospitalizations (Fig. 1B). High resident uptake was important for reducing resident cases and hospitalizations (Fig. 1C), but increasing HCP uptake had minimal effect (Fig. 1D). Conclusions: Our findings support the current prophylaxis guidance. Promptly implementing prophylaxis reduces resident cases and hospitalizations. Continuing prophylaxis until cases are no longer identified reduces cases and hospitalizations.

Disclosure: None