U.S. Preparedness and Response to Increasing Clade I Mpox Cases in the Democratic Republic of the Congo - United States, 2024.

Clade I monkeypox virus (MPXV), which can cause severe illness in more people than clade II MPXVs, is endemic in the Democratic Republic of the Congo (DRC), but the country has experienced an increase in suspected cases during 2023-2024. In light of the 2022 global outbreak of clade II mpox, the increase in suspected clade I cases in DRC raises concerns that the virus could spread to other countries and underscores the importance of coordinated, urgent global action to support DRC's efforts to contain the virus. To date, no cases of clade I mpox have been detected outside of countries in Central Africa where the virus is endemic. CDC and other partners are working to support DRC's response. In addition, CDC is enhancing U.S. preparedness by raising awareness, strengthening surveillance, expanding diagnostic testing capacity for clade I MPXV, ensuring appropriate specimen handling and waste management, emphasizing the importance of appropriate medical treatment, and communicating guidance on the recommended contact tracing, containment, behavior modification, and vaccination strategies.

Epidemiologic, Immunologic, and Virus Characteristics in Patients With Paired Severe Acute Respiratory Syndrome Coronavirus 2 Serology and Reverse-Transcription Polymerase Chain Reaction Testing.

BACKGROUND: The natural history and clinical progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can be better understood using combined serological and reverse-transcription polymerase chain reaction (RT-PCR) testing. METHODS: Nasopharyngeal swabs and serum were collected at a single time-point from patients at an urban, public hospital during August-November 2020 and tested for SARS-CoV-2 using RT-PCR, viral culture, and anti-spike pan-immunoglobulin antibody testing. Participant demographics and symptoms were collected through interview. The χ 2 and Fisher exact tests were used to identify associations between RT-PCR and serology results with presence of viable virus and frequency of symptoms. RESULTS: Among 592 participants, 129 (21.8%) had evidence of SARS-CoV-2 infection by RT-PCR or serology. Presence of SARS-CoV-2 antibodies was strongly associated with lack of viable virus (P = .016). COVID-19 symptom frequency was similar for patients testing RT-PCR positive/seronegative and patients testing RT-PCR positive/seropositive. Patients testing RT-PCR positive/seronegative reported headaches, fatigue, diarrhea, and vomiting at rates not statistically significantly different from those testing RT-PCR negative/seropositive. CONCLUSIONS: While patients testing SARS-CoV-2 seropositive were unlikely to test positive for viable virus and were therefore at low risk for forward transmission, coronavirus disease 2019 (COVID-19) symptoms were common. Paired SARS-CoV-2 RT-PCR and antibody testing provides more nuanced understanding of patients' COVID-19 status.

Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Alpha Variant-United States, 2021.

BACKGROUND: In Spring 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.7 (Alpha) became the predominant variant in the United States. Research suggests that Alpha has increased transmissibility compared with non-Alpha lineages. We estimated household secondary infection risk (SIR), assessed characteristics associated with transmission, and compared symptoms of persons with Alpha and non-Alpha infections. METHODS: We followed households with SARS-CoV-2 infection for 2 weeks in San Diego County and metropolitan Denver, January to April 2021. We collected epidemiologic information and biospecimens for serology, reverse transcription-polymerase chain reaction (RT-PCR), and whole-genome sequencing. We stratified SIR and symptoms by lineage and identified characteristics associated with transmission using generalized estimating equations. RESULTS: We investigated 127 households with 322 household contacts; 72 households (56.7%) had member(s) with secondary infections. SIRs were not significantly higher for Alpha (61.0% [95% confidence interval, 52.4-69.0%]) than non-Alpha (55.6% [44.7-65.9%], P = .49). In households with Alpha, persons who identified as Asian or Hispanic/Latino had significantly higher SIRs than those who identified as White (P = .01 and .03, respectively). Close contact (eg, kissing, hugging) with primary cases was associated with increased transmission for all lineages. Persons with Alpha infection were more likely to report constitutional symptoms than persons with non-Alpha (86.9% vs 76.8%, P = .05). CONCLUSIONS: Household SIRs were similar for Alpha and non-Alpha. Comparable SIRs may be due to saturation of transmission risk in households due to extensive close contact, or true lack of difference in transmission rates. Avoiding close contact within households may reduce SARS-CoV-2 transmission for all lineages among household members.

Relationship of SARS-CoV-2 Antigen and Reverse Transcription PCR Positivity for Viral Cultures.

We assessed the relationship between antigen and reverse transcription PCR (RT-PCR) test positivity and successful virus isolation. We found that antigen test results were more predictive of virus recovery than RT-PCR results. However, virus was isolated from some antigen-negative and RT-PCR‒positive paired specimens, providing support for the Centers for Disease Control and Prevention antigen testing algorithm.

Performance Characteristics of the Abbott BinaxNOW SARS-CoV-2 Antigen Test in Comparison to Real-Time Reverse Transcriptase PCR and Viral Culture in Community Testing Sites during November 2020.

Point-of-care antigen tests are an important tool for SARS-CoV-2 detection. Antigen tests are less sensitive than real-time reverse transcriptase PCR (rRT-PCR). Data on the performance of the BinaxNOW antigen test compared to rRT-PCR and viral culture by symptom and known exposure status, timing during disease, or exposure period and demographic variables are limited. During 3 to 17 November 2020, we collected paired upper respiratory swab specimens to test for SARS-CoV-2 by rRT-PCR and Abbott BinaxNOW antigen test at two community testing sites in Pima County, Arizona. We administered a questionnaire to capture symptoms, known exposure status, and previous SARS-CoV-2 test results. Specimens positive by either test were analyzed by viral culture. Previously we showed overall BinaxNOW sensitivity was 52.5%. Here, we showed BinaxNOW sensitivity increased to 65.7% among currently symptomatic individuals reporting a known exposure. BinaxNOW sensitivity was lower among participants with a known exposure and previously symptomatic (32.4%) or never symptomatic (47.1%) within 14 days of testing. Sensitivity was 71.1% in participants within a week of symptom onset. In participants with a known exposure, sensitivity was highest 8 to 10 days postexposure (75%). The positive predictive value for recovery of virus in cell culture was 56.7% for BinaxNOW-positive and 35.4% for rRT-PCR-positive specimens. Result reporting time was 2.5 h for BinaxNOW and 26 h for rRT-PCR. Point-of-care antigen tests have a shorter turnaround time than laboratory-based nucleic acid amplification tests, which allows for more rapid identification of infected individuals. Antigen test sensitivity limitations are important to consider when developing a testing program.

Household Transmission and Symptomology of Severe Acute Respiratory Syndrome Coronavirus 2 Alpha Variant among Children-California and Colorado, 2021.

OBJECTIVE: To assess the household secondary infection risk (SIR) of B.1.1.7 (Alpha) and non-Alpha lineages of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children. STUDY DESIGN: During January to April 2021, we prospectively followed households with a SARS-CoV-2 infection. We collected questionnaires, serial nasopharyngeal swabs for reverse transcription polymerase chain reaction testing and whole genome sequencing, and serial blood samples for serology testing. We calculated SIRs by primary case age (pediatric vs adult), household contact age, and viral lineage. We evaluated risk factors associated with transmission and described symptom profiles among children. RESULTS: Among 36 households with pediatric primary cases, 21 (58%) had secondary infections. Among 91 households with adult primary cases, 51 (56%) had secondary infections. SIRs among pediatric and adult primary cases were 45% and 54%, respectively (OR, 0.79; 95% CI, 0.41-1.54). SIRs among pediatric primary cases with Alpha and non-Alpha lineage were 55% and 46%, respectively (OR, 1.52; 95% CI, 0.51-4.53). SIRs among pediatric and adult household contacts were 55% and 49%, respectively (OR, 1.01; 95% CI, 0.68-1.50). Among pediatric contacts, no significant differences in the odds of acquiring infection by demographic or household characteristics were observed. CONCLUSIONS: Household transmission of SARS-CoV-2 from children and adult primary cases to household members was frequent. The risk of secondary infection was similar among child and adult household contacts. Among children, household transmission of SARS-CoV-2 and the risk of secondary infection was not influenced by lineage. Continued mitigation strategies (eg, masking, physical distancing, vaccination) are needed to protect at-risk groups regardless of virus lineage circulating in communities.

Performance Evaluation of Serial SARS-CoV-2 Rapid Antigen Testing During a Nursing Home Outbreak.

BACKGROUND: To address high COVID-19 burden in U.S. nursing homes, rapid SARS-CoV-2 antigen tests have been widely distributed in those facilities. However, performance data are lacking, especially in asymptomatic people. OBJECTIVE: To evaluate the performance of SARS-CoV-2 antigen testing when used for facility-wide testing during a nursing home outbreak. DESIGN: A prospective evaluation involving 3 facility-wide rounds of testing where paired respiratory specimens were collected to evaluate the performance of the BinaxNOW antigen test compared with virus culture and real-time reverse transcription polymerase chain reaction (RT-PCR). Early and late infection were defined using changes in RT-PCR cycle threshold values and prior test results. SETTING: A nursing home with an ongoing SARS-CoV-2 outbreak. PARTICIPANTS: 532 paired specimens collected from 234 available residents and staff. MEASUREMENTS: Percentage of positive agreement (PPA) and percentage of negative agreement (PNA) for BinaxNOW compared with RT-PCR and virus culture. RESULTS: BinaxNOW PPA with virus culture, used for detection of replication-competent virus, was 95%. However, the overall PPA of antigen testing with RT-PCR was 69%, and PNA was 98%. When only the first positive test result was analyzed for each participant, PPA of antigen testing with RT-PCR was 82% among 45 symptomatic people and 52% among 343 asymptomatic people. Compared with RT-PCR and virus culture, the BinaxNOW test performed well in early infection (86% and 95%, respectively) and poorly in late infection (51% and no recovered virus, respectively). LIMITATION: Accurate symptom ascertainment was challenging in nursing home residents; test performance may not be representative of testing done by nonlaboratory staff. CONCLUSION: Despite lower positive agreement compared with RT-PCR, antigen test positivity had higher agreement with shedding of replication-competent virus. These results suggest that antigen testing could be a useful tool to rapidly identify contagious people at risk for transmitting SARS-CoV-2 during nascent outbreaks and help reduce COVID-19 burden in nursing homes. PRIMARY FUNDING SOURCE: None.

Clinical and Laboratory Findings in Patients With Potential Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Reinfection, May-July 2020.

BACKGROUND: We investigated patients with potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection in the United States during May-July 2020. METHODS: We conducted case finding for patients with potential SARS-CoV-2 reinfection through the Emerging Infections Network. Cases reported were screened for laboratory and clinical findings of potential reinfection followed by requests for medical records and laboratory specimens. Available medical records were abstracted to characterize patient demographics, comorbidities, clinical course, and laboratory test results. Submitted specimens underwent further testing, including reverse transcription polymerase chain reaction (RT-PCR), viral culture, whole genome sequencing, subgenomic RNA PCR, and testing for anti-SARS-CoV-2 total antibody. RESULTS: Among 73 potential reinfection patients with available records, 30 patients had recurrent coronavirus disease 2019 (COVID-19) symptoms explained by alternative diagnoses with concurrent SARS-CoV-2 positive RT-PCR, 24 patients remained asymptomatic after recovery but had recurrent or persistent RT-PCR, and 19 patients had recurrent COVID-19 symptoms with concurrent SARS-CoV-2 positive RT-PCR but no alternative diagnoses. These 19 patients had symptom recurrence a median of 57 days after initial symptom onset (interquartile range: 47-76). Six of these patients had paired specimens available for further testing, but none had laboratory findings confirming reinfections. Testing of an additional 3 patients with recurrent symptoms and alternative diagnoses also did not confirm reinfection. CONCLUSIONS: We did not confirm SARS-CoV-2 reinfection within 90 days of the initial infection based on the clinical and laboratory characteristics of cases in this investigation. Our findings support current Centers for Disease Control and Prevention (CDC) guidance around quarantine and testing for patients who have recovered from COVID-19.

Epidemiologic Characteristics Associated With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antigen-Based Test Results, Real-Time Reverse Transcription Polymerase Chain Reaction (rRT-PCR) Cycle Threshold Values, Subgenomic RNA, and Viral Culture Results From University Testing.

BACKGROUND: Real-time reverse transcription polymerase chain reaction (rRT-PCR) and antigen tests are important diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sensitivity of antigen tests has been shown to be lower than that of rRT-PCR; however, data to evaluate epidemiologic characteristics that affect test performance are limited. METHODS: Paired mid-turbinate nasal swabs were collected from university students and staff and tested for SARS-CoV-2 using both Quidel Sofia SARS Antigen Fluorescent Immunoassay (FIA) and rRT-PCR assay. Specimens positive by either rRT-PCR or antigen FIA were placed in viral culture and tested for subgenomic RNA (sgRNA). Logistic regression models were used to evaluate characteristics associated with antigen results, rRT-PCR cycle threshold (Ct) values, sgRNA, and viral culture. RESULTS: Antigen FIA sensitivity was 78.9% and 43.8% among symptomatic and asymptomatic participants, respectively. Among rRT-PCR positive participants, negative antigen results were more likely among asymptomatic participants (odds ratio [OR] 4.6, 95% confidence interval [CI]: 1.3-15.4) and less likely among participants reporting nasal congestion (OR 0.1, 95% CI: .03-.8). rRT-PCR-positive specimens with higher Ct values (OR 0.5, 95% CI: .4-.8) were less likely, and specimens positive for sgRNA (OR 10.2, 95% CI: 1.6-65.0) more likely, to yield positive virus isolation. Antigen testing was >90% positive in specimens with Ct values < 29. Positive predictive value of antigen test for positive viral culture (57.7%) was similar to that of rRT-PCR (59.3%). CONCLUSIONS: SARS-CoV-2 antigen test advantages include low cost, wide availability and rapid turnaround time, making them important screening tests. The performance of antigen tests may vary with patient characteristics, so performance characteristics should be accounted for when designing testing strategies and interpreting results.

Point-of-Care Antigen Test for SARS-CoV-2 in Asymptomatic College Students.

We used the BinaxNOW COVID-19 Ag Card to screen 1,540 asymptomatic college students for severe acute respiratory syndrome coronavirus 2 in a low-prevalence setting. Compared with reverse transcription PCR, BinaxNOW showed 20% overall sensitivity; among participants with culturable virus, sensitivity was 60%. BinaxNOW provides point-of-care screening but misses many infections.

Performance of an Antigen-Based Test for Asymptomatic and Symptomatic SARS-CoV-2 Testing at Two University Campuses - Wisconsin, September-October 2020.

Antigen-based tests for SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), are inexpensive and can return results within 15 minutes (1). Antigen tests have received Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in asymptomatic and symptomatic persons within the first 5-12 days after symptom onset (2). These tests have been used at U.S. colleges and universities and other congregate settings (e.g., nursing homes and correctional and detention facilities), where serial testing of asymptomatic persons might facilitate early case identification (3-5). However, test performance data from symptomatic and asymptomatic persons are limited. This investigation evaluated performance of the Sofia SARS Antigen Fluorescent Immunoassay (FIA) (Quidel Corporation) compared with real-time reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 detection among asymptomatic and symptomatic persons at two universities in Wisconsin. During September 28-October 9, a total of 1,098 paired nasal swabs were tested using the Sofia SARS Antigen FIA and real-time RT-PCR. Virus culture was attempted on all antigen-positive or real-time RT-PCR-positive specimens. Among 871 (79%) paired swabs from asymptomatic participants, the antigen test sensitivity was 41.2%, specificity was 98.4%, and in this population the estimated positive predictive value (PPV) was 33.3%, and negative predictive value (NPV) was 98.8%. Antigen test performance was improved among 227 (21%) paired swabs from participants who reported one or more symptoms at specimen collection (sensitivity = 80.0%; specificity = 98.9%; PPV = 94.1%; NPV = 95.9%). Virus was isolated from 34 (46.6%) of 73 antigen-positive or real-time RT-PCR-positive nasal swab specimens, including two of 18 that were antigen-negative and real-time RT-PCR-positive (false-negatives). The advantages of antigen tests such as low cost and rapid turnaround might allow for rapid identification of infectious persons. However, these advantages need to be balanced against lower sensitivity and lower PPV, especially among asymptomatic persons. Confirmatory testing with an FDA-authorized nucleic acid amplification test (NAAT), such as RT-PCR, should be considered after negative antigen test results in symptomatic persons, and after positive antigen test results in asymptomatic persons (1).

Evaluation of Abbott BinaxNOW Rapid Antigen Test for SARS-CoV-2 Infection at Two Community-Based Testing Sites - Pima County, Arizona, November 3-17, 2020.

Rapid antigen tests, such as the Abbott BinaxNOW COVID-19 Ag Card (BinaxNOW), offer results more rapidly (approximately 15-30 minutes) and at a lower cost than do highly sensitive nucleic acid amplification tests (NAATs) (1). Rapid antigen tests have received Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in symptomatic persons (2), but data are lacking on test performance in asymptomatic persons to inform expanded screening testing to rapidly identify and isolate infected persons (3). To evaluate the performance of the BinaxNOW rapid antigen test, it was used along with real-time reverse transcription-polymerase chain reaction (RT-PCR) testing to analyze 3,419 paired specimens collected from persons aged ≥10 years at two community testing sites in Pima County, Arizona, during November 3-17, 2020. Viral culture was performed on 274 of 303 residual real-time RT-PCR specimens with positive results by either test (29 were not available for culture). Compared with real-time RT-PCR testing, the BinaxNOW antigen test had a sensitivity of 64.2% for specimens from symptomatic persons and 35.8% for specimens from asymptomatic persons, with near 100% specificity in specimens from both groups. Virus was cultured from 96 of 274 (35.0%) specimens, including 85 (57.8%) of 147 with concordant antigen and real-time RT-PCR positive results, 11 (8.9%) of 124 with false-negative antigen test results, and none of three with false-positive antigen test results. Among specimens positive for viral culture, sensitivity was 92.6% for symptomatic and 78.6% for asymptomatic individuals. When the pretest probability for receiving positive test results for SARS-CoV-2 is elevated (e.g., in symptomatic persons or in persons with a known COVID-19 exposure), a negative antigen test result should be confirmed by NAAT (1). Despite a lower sensitivity to detect infection, rapid antigen tests can be an important tool for screening because of their quick turnaround time, lower costs and resource needs, high specificity, and high positive predictive value (PPV) in settings of high pretest probability. The faster turnaround time of the antigen test can help limit transmission by more rapidly identifying infectious persons for isolation, particularly when used as a component of serial testing strategies.

Revisiting the genotyping scheme for varicella-zoster viruses based on whole-genome comparisons.

We report whole-genome sequences (WGSs) for four varicella-zoster virus (VZV) samples from a shingles study conducted by Kaiser Permanente of Southern California. Comparative genomics and phylogenetic analysis of all published VZV WGSs revealed that strain KY037798 is in clade IX, which shall henceforth be designated clade 9. Previously published single nucleotide polymorphisms (SNP)-based genotyping schemes fail to discriminate between clades 6 and VIII and employ positions that are not clade-specific. We provide an updated list of clade-specific positions that supersedes the list determined at the 2008 VZV nomenclature meeting. Finally, we propose a new targeted genotyping scheme that will discriminate the circulating VZV clades with at least a twofold redundancy. Genotyping strategies using a limited set of targeted SNPs will continue to provide an efficient 'first pass' method for VZV strain surveillance as vaccination programmes for varicella and zoster influence the dynamics of VZV transmission.

Herpes zoster caused by vaccine-strain varicella zoster virus in an immunocompetent recipient of zoster vaccine.

We report the first laboratory-documented case of herpes zoster caused by the attenuated varicella zoster virus (VZV) contained in Zostavax in a 68-year-old immunocompetent adult with strong evidence of prior wild-type VZV infection. The complete genome sequence of the isolate revealed that the strain carried 15 of 42 (36%) recognized varicella vaccine-associated single-nucleotide polymorphisms, including all 5 of the fixed vaccine markers present in nearly all of the strains in the vaccine. The case of herpes zoster was relatively mild and resolved without complications.

Characteristics of nursing home residents and healthcare personnel with repeated severe acute respiratory coronavirus virus 2 (SARS-CoV-2) tests positive ≥90 days after initial infection: Four US jurisdictions, July 2020-March 2021.

One in six nursing home residents and staff with positive SARS-CoV-2 tests ≥90 days after initial infection had specimen cycle thresholds (Ct) <30. Individuals with specimen Ct<30 were more likely to report symptoms but were not different from individuals with high Ct value specimens by other clinical and testing data.

Repeated antigen testing among severe acute respiratory coronavirus virus 2 (SARS-CoV-2)-positive nursing home residents.

Repeated antigen testing of 12 severe acute respiratory coronavirus virus 2 (SARS-CoV-2)-positive nursing home residents using Abbott BinaxNOW identified 9 of 9 (100%) culture-positive specimens up to 6 days after initial positive test. Antigen positivity lasted 2-24 days. Antigen positivity might last beyond the infectious period, but it was reliable in residents with evidence of early infection.

Risk-Factors for Exposure Associated With SARS-CoV-2 Detection After Recent Known or Potential COVID-19 Exposures Among Patients Seeking Medical Care at a Large Urban, Public Hospital in Fulton County, Georgia - A Cross-Sectional Investigation.

We aimed to describe frequency of COVID-19 exposure risk factors among patients presenting for medical care at an urban, public hospital serving mostly uninsured/Medicare/Medicaid clients and risk factors associated with SARS-CoV-2 infection. Consenting, adult patients seeking care at a public hospital from August to November 2020 were enrolled in this cross-sectional investigation. Saliva, anterior nasal and nasopharyngeal swabs were collected and tested for SARS-CoV-2 using RT-PCR. Participant demographics, close contact, and activities ≤14 days prior to enrollment were collected through interview. Logistic regression was used to identify risk factors associated with testing positive for SARS-CoV-2. Among 1,078 participants, 51.8% were male, 57.0% were aged ≥50 years, 81.3% were non-Hispanic Black, and 7.6% had positive SARS-CoV-2 tests. Only 2.7% reported COVID-19 close contact ≤14 days before enrollment; this group had 6.79 adjusted odds of testing positive (95%CI = 2.78-16.62) than those without a reported exposure. Among participants who did not report COVID-19 close contact, working in proximity to ≥10 people (adjusted OR = 2.17; 95%CI = 1.03-4.55), choir practice (adjusted OR = 11.85; 95%CI = 1.44-97.91), traveling on a plane (adjusted OR = 5.78; 95%CI = 1.70-19.68), and not participating in an essential indoor activity (i.e., grocery shopping, public transit use, or visiting a healthcare facility; adjusted OR = 2.15; 95%CI = 1.07-4.30) were associated with increased odds of testing positive. Among this population of mostly Black, non-Hispanic participants seeking care at a public hospital, we found several activities associated with testing positive for SARS-CoV-2 infection in addition to close contact with a case. Understanding high-risk activities for SARS-CoV-2 infection among different communities is important for issuing awareness and prevention strategies.

Specimen self-collection for SARS-CoV-2 testing: Patient performance and preferences-Atlanta, Georgia, August-October 2020.

Self-collected specimens can expand access to SARS-CoV-2 testing. At a large inner-city hospital 1,082 participants self-collected saliva and anterior nasal swab (ANS) samples before healthcare workers collected nasopharyngeal swab (NPS) samples on the same day. To characterize patient preferences for self-collection, this investigation explored ability, comfort, and ease of ANS and saliva self-collection for SARS-CoV-2 testing along with associated patient characteristics, including medical history and symptoms of COVID-19. With nearly all participants successfully submitting a specimen, favorable ratings from most participants (at least >79% in ease and comfort), and equivocal preference between saliva and ANS, self-collection is a viable SARS-CoV-2 testing option.

Longitudinal serologic and viral testing post-SARS-CoV-2 infection and post-receipt of mRNA COVID-19 vaccine in a nursing home cohort-Georgia, October 2020‒April 2021.

There are limited data describing SARS-CoV-2-specific immune responses and their durability following infection and vaccination in nursing home residents. We conducted a prospective longitudinal evaluation of 11 consenting SARS-CoV-2-positive nursing home residents to evaluate the quantitative titers and durability of binding antibodies detected after SARS-CoV-2 infection and subsequent COVID-19 vaccination. The evaluation included nine visits over 150 days from October 25, 2020, through April 1, 2021. Visits included questionnaire administration, blood collection for serology, and paired anterior nasal specimen collection for testing by BinaxNOW™ COVID-19 Ag Card (BinaxNOW), reverse transcription polymerase chain reaction (RT-PCR), and viral culture. We evaluated quantitative titers of binding SARS-CoV-2 antibodies post-infection and post-vaccination (beginning after the first dose of the primary series). The median age among participants was 74 years; one participant was immunocompromised. Of 10 participants with post-infection serology results, 9 (90%) had detectable Pan-Ig, IgG, and IgA antibodies, and 8 (80%) had detectable IgM antibodies. At first antibody detection post-infection, two-thirds (6/9, 67%) of participants were RT-PCR-positive, but none were culture- positive. Ten participants received vaccination; all had detectable Pan-Ig, IgG, and IgA antibodies through their final observation ≤90 days post-first dose. Post-vaccination geometric means of IgG titers were 10-200-fold higher than post-infection. Nursing home residents in this cohort mounted robust immune responses to SARS-CoV-2 post-infection and post-vaccination. The augmented antibody responses post-vaccination are potential indicators of enhanced protection that vaccination may confer on previously infected nursing home residents.

Household characteristics associated with surface contamination of SARS-CoV-2 and frequency of RT-PCR and viral culture positivity-California and Colorado, 2021.

While risk of fomite transmission of SARS-CoV-2 is considered low, there is limited environmental data within households. This January-April 2021 investigation describes frequency and types of surfaces positive for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (RT-PCR) among residences with ≥1 SARS-CoV-2 infection, and associations of household characteristics with surface RT-PCR and viable virus positivity. Of 1232 samples from 124 households, 27.8% (n = 342) were RT-PCR positive with nightstands (44.1%) and pillows (40.9%) most frequently positive. SARS-CoV-2 lineage, documented household transmission, greater number of infected persons, shorter interval between illness onset and sampling, total household symptoms, proportion of infected persons ≤12 years old, and persons exhibiting upper respiratory symptoms or diarrhea were associated with more positive surfaces. Viable virus was isolated from 0.2% (n = 3 samples from one household) of all samples. This investigation suggests that while SARS-CoV-2 on surfaces is common, fomite transmission risk in households is low.