Antigen-based tests for SARS-CoV-2, the virus that causes coronavirus disease 2019 , 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 antigenpositive 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

Pulmonary fibrosis and interstitial lung disease are poorly understood in horses; the causes of such conditions are rarely identified. Equine herpesvirus 5 (EHV-5) is a gamma-herpesvirus of horses that has not been associated with disease in horses. Pathologic and virologic findings from 24 horses with progressive nodular fibrotic lung disease associated with EHV-5 infection are described and compared with 23 age-matched control animals. Gross lesions consisted of multiple nodules of fibrosis throughout the lungs. Histologically, there was marked interstitial fibrosis, often with preservation of an "alveolar-like" architecture, lined by cuboidal epithelial cells. The airways contained primarily neutrophils and macrophages. Rare macrophages contained large eosinophilic intranuclear viral inclusion bodies; similar inclusion bodies were also found cytologically. The inclusions were identified as herpesviral-like particles by transmission electron microscopy in a single horse. In situ hybridization was used to detect EHV-5 nucleic acids within occasional macrophage nuclei. With polymerase chain reaction (PCR), the herpesviral DNA polymerase gene was detected in 19/24 (79.2%) of affected horses and 2/23 (8.7%) of the control horses. Virus genera-specific PCR was used to detect EHV-5 in all of the affected horses and none of the control horses. EHV-2 was detected in 8/24 (33.3%) of affected horses and 1/9 (11.1%) of the control horses. This disease has not been reported before, and the authors propose that based upon the characteristic gross and histologic findings, the disease be known as equine multinodular pulmonary fibrosis. Further, we propose that this newly described disease develops in association with infection by the equine gamma-herpesvirus, EHV-5.

Gammaherpesviruses (γHV) are implicated in the pathogenesis of pulmonary fibrosis in humans and murine models of lung fibrosis, however there is little direct experimental evidence that such viruses induce lung fibrosis in the natural host. The equine γHV EHV 5 is associated with equine multinodular pulmonary fibrosis (EMPF), a progressive fibrosing lung disease in its natural host, the horse. Experimental reproduction of EMPF has not been attempted to date. We hypothesized that inoculation of EHV 5 isolated from cases of EMPF into the lungs of clinically normal horses would induce lung fibrosis similar to EMPF. Neutralizing antibody titers were measured in the horses before and after inoculation with EHV 5. PCR and virus isolation was used to detect EHV 5 in antemortem blood and BAL samples, and in tissues collected postmortem. Nodular pulmonary fibrosis and induction of myofibroblasts occurred in EHV 5 inoculated horses. Mean lung collagen in EHV 5 inoculated horses (80 µg/mg) was significantly increased compared to control horses (26 µg/mg) (p < 0.5), as was interstitial collagen (32.6% ± 1.2% vs 23% ± 1.4%) (mean ± SEM; p < 0.001). Virus was difficult to detect in infected horses throughout the experiment, although EHV 5 antigen was detected in the lung by immunohistochemistry. We conclude that the γHV EHV 5 can induce lung fibrosis in the horse, and hypothesize that induction of fibrosis occurs while the virus is latent within the lung. This is the first example of a γHV inducing lung fibrosis in the natural host.

As part of a longitudinal household transmission study of pets living with persons with COVID‐19 in Texas, two pets were confirmed to be infected with the SARS‐CoV‐2 B.1.1.7 variant of concern (VOC). The pets were a dog and a cat from the same household, sampled two days after their owner tested positive for COVID‐19. The oral, nasal and fur swabs for both pets tested positive for SARS‐CoV‐2 by qRT‐PCR and consensus whole‐genome sequences from the dog and cat were 100% identical and matched the B.1.1.7 VOC. Virus was isolated from the cat's nasal swab. One month after initial detection of infection, the pets were re‐tested twice at which time only the fur swabs (both pets) and oral swab (dog only) remained positive, and neutralizing antibodies for SARS‐CoV‐2 were present in both animals. Sneezing by both pets was noted by the owner in the weeks between initial and follow‐up testing. This study documents the first detection of B.1.1.7. in companion animals in the United States, and the first genome recovery and isolation of B.1.1.7 variant of concern globally in any animal.

Background Real-time reverse transcription polymerase chain reaction (rRT-PCR) and antigen tests are important diagnostics for 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 (OR 4.6, CI:1.3-15.4) and less likely among participants reporting nasal congestion (OR 0.1, CI:0.03-0.8). rRT-PCR-positive specimens with higher Ct values (OR 0.5, CI:0.4-0.8) were less likely, and specimens positive for sgRNA (OR 10.2, CI:1.6-65.0) more likely, to yield positive virus isolation. Antigen testing was &gt;90% positive in specimens with Ct values &lt;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.

Approximately 67% of U.S. households have pets. Limited data are available on SARS-CoV-2 in pets. We assessed SARS-CoV-2 infection in pets during a COVID-19 household transmission investigation. Pets from households with ≥1 person with laboratory-confirmed COVID-19 were eligible for inclusion from April–May 2020. We enrolled 37 dogs and 19 cats from 34 households. All oropharyngeal, nasal, and rectal swabs tested negative by rRT-PCR; one dog’s fur swabs (2%) tested positive by rRT-PCR at the first sampling. Among 47 pets with serological results, eight (17%) pets (four dogs, four cats) from 6/30 (20%) households had detectable SARS-CoV-2 neutralizing antibodies. In households with a seropositive pet, the proportion of people with laboratory-confirmed COVID-19 was greater (median 79%; range: 40–100%) compared to households with no seropositive pet (median 37%; range: 13–100%) (p = 0.01). Thirty-three pets with serologic results had frequent daily contact (≥1 h) with the index patient before the person’s COVID-19 diagnosis. Of these 33 pets, 14 (42%) had decreased contact with the index patient after diagnosis and none were seropositive; of the 19 (58%) pets with continued contact, four (21%) were seropositive. Seropositive pets likely acquired infection after contact with people with COVID-19. People with COVID-19 should restrict contact with pets and other animals.

Eastern equine encephalitis (EEE) virus has been recognized as affecting horses and humans in the eastern United States for 70 yr. Evidence of exposure with EEE virus has been reported in a variety of free-ranging wild birds and mammals but cases of clinical disease are much less commonly reported. In Michigan, reports of outbreaks of EEE virus in equine species extend back more than a half century. We report diagnosis of EEE virus infection of multiple free-ranging white-tailed deer (Odocoileus virginianus) from three Michigan counties during late summer of 2005. Infection was confirmed in seven of 30 deer collected based on reported neurologic signs and results from immunohistochemistry, polymerase chain reaction, and/or virus isolation. One of the deer also was infected with West Nile virus and an eighth deer had microscopic lesions in the cerebrum consistent with those reported for EEE. To our knowledge, this is the first report of multiple cases of EEE in free-ranging white-tailed deer, and highlights several issues of significance to wildlife managers and public health officials.

Two years after the emergence of SARS-CoV-2, there is still a need for better ways to assess the risk of transmission in congregate spaces. We deployed active air samplers to monitor the presence of SARS-CoV-2 in real-world settings across communities in the Upper Midwestern states of Wisconsin and Minnesota. Over 29 weeks, we collected 527 air samples from 15 congregate settings. We detected 106 samples that were positive for SARS-CoV-2 viral RNA, demonstrating that SARS-CoV-2 can be detected in continuous air samples collected from a variety of real-world settings. We expanded the utility of air surveillance to test for 40 other respiratory pathogens. Surveillance data revealed differences in timing and location of SARS-CoV-2 and influenza A virus detection. In addition, we obtained SARS-CoV-2 genome sequences from air samples to identify variant lineages. Collectively, this shows air sampling is a scalable, high throughput surveillance tool that could be used in conjunction with other methods for detecting respiratory pathogens in congregate settings.