ABSTRACT
BACKGROUND: Common biologic samples used to diagnose COVID-19 include nasopharyngeal, nasal, or oropharyngeal swabs, and salivary samples. The performance characteristics of a sucked "lollipop" swab to detect SARS-CoV-2 virus is assessed in four small sub-studies. METHODS: In each sub-study, a flocked swab was sucked for 20 s and submitted for PCR detection of SARS-CoV-2 virus. RESULTS: Across all studies, 52 of 69 (75.4%) COVID-19 positive participants had positive "lollipop" swabs. Twelve of the 17 COVID-19 positive participants with negative "lollipop" swabs had known corresponding cycle threshold values of >37 from their nasal/nasopharyngeal swabs, an indication of low viral load at time of sampling. In a paired samples sub-study, the sensitivity and specificity of the "lollipop" swabs were 100% and 98%. CONCLUSIONS: "Lollipop" swabs performed satisfactorily especially in individuals with acute infection of COVID-19. "Lollipop" swabs are a simple method of sample collection for detecting SARS-CoV-2 virus and warrants additional consideration.
Subject(s)
COVID-19 , Nasopharynx , SARS-CoV-2 , Sensitivity and Specificity , Specimen Handling , Humans , COVID-19/diagnosis , COVID-19/virology , Specimen Handling/methods , SARS-CoV-2/isolation & purification , SARS-CoV-2/genetics , Nasopharynx/virology , Viral Load/methods , Male , Middle Aged , Female , Adult , COVID-19 Testing/methods , Oropharynx/virology , Aged , COVID-19 Nucleic Acid Testing/methodsABSTRACT
Channel catfish (Ictalurus punctatus) are a food fish extensively reared in aquaculture facilities throughout the world and are also among the most abundant wild catfish species in North America, making them a popular target of anglers. Furthermore, channel catfish are important members of aquatic ecosystems; for example, they serve as a glochidial host for the endangered winged mapleleaf mussel (Quadrula fragosa), making them critical for conserving this species through hatchery-based restoration efforts. During a routine health inspection, a novel aquareovirus was isolated from channel catfish used in mussel propagation efforts at a fish hatchery in Wisconsin. This virus was isolated on brown bullhead cells (ATCC CCL-59) and identified through metagenomic sequencing as a novel member of the family Spinareoviridae, genus Aquareovirus. The virus genome consists of 11 segments, as is typical of the aquareoviruses, with phylogenetic relationships based on RNA-dependent RNA polymerase and major outer capsid protein amino acid sequences showing it to be most closely related to golden shiner virus (aquareovirus C) and aquareovirus C/American grass carp reovirus (aquareovirus G) respectively. The potential of the new virus, which we name genictpun virus 1 (GNIPV-1), to cause disease in channel catfish or other species remains unknown.
Subject(s)
Fish Diseases , Genome, Viral , Ictaluridae , Phylogeny , Animals , Ictaluridae/virology , Wisconsin , Fish Diseases/virology , Reoviridae/isolation & purification , Reoviridae/genetics , Reoviridae/classification , Reoviridae/physiology , Bivalvia/virology , AquacultureABSTRACT
We describe the pathology of natural infection with highly pathogenic avian influenza A(H5N1) virus of Eurasian lineage Goose/Guangdong clade 2.3.4.4b in 67 wild terrestrial mammals throughout the United States during April 1âJuly 21, 2022. Affected mammals include 50 red foxes (Vulpes vulpes), 6 striped skunks (Mephitis mephitis), 4 raccoons (Procyon lotor), 2 bobcats (Lynx rufus), 2 Virginia opossums (Didelphis virginiana), 1 coyote (Canis latrans), 1 fisher (Pekania pennanti), and 1 gray fox (Urocyon cinereoargenteus). Infected mammals showed primarily neurologic signs. Necrotizing meningoencephalitis, interstitial pneumonia, and myocardial necrosis were the most common lesions; however, species variations in lesion distribution were observed. Genotype analysis of sequences from 48 animals indicates that these cases represent spillover infections from wild birds.
Subject(s)
Influenza A Virus, H5N1 Subtype , Influenza in Birds , Animals , United States/epidemiology , Influenza A Virus, H5N1 Subtype/genetics , Mephitidae , Influenza in Birds/epidemiology , Mammals , Animals, Wild , FoxesABSTRACT
Canine distemper virus remains an important source of morbidity and mortality in animal shelters. RT-PCR is commonly used to aid diagnosis and has been used to monitor dogs testing positive over time to gauge the end of infectious potential. Many dogs excrete viral RNA for prolonged periods which has complicated disease management. The goal of this retrospective study was to describe the duration and characteristics of viral RNA excretion in shelter dogs with naturally occurring CDV and investigate the relationship between that viral RNA excretion and infectious potential using virus isolation data. Records from 98 different humane organizations with suspect CDV were reviewed. A total of 5,920 dogs were tested with 1,393; 4,452; and 75 found to be positive, negative, or suspect on RT-PCR respectively. The median duration of a positive test was 34 days (n = 325), and 25% (82/325) of the dogs still excreting viral RNA after 62 days of monitoring. Virus isolation was performed in six dogs who were RT-PCR positive for > 60 days. Infectious virus was isolated only within the first two weeks of monitoring at or around the peak viral RNA excretion (as detected by the lowest cycle threshold) reported for each dog. Our findings suggest that peak viral RNA excretion and the days surrounding it might be used as a functional marker to gauge the end of infectious risk. Clarifying the earliest point in time when dogs testing positive for canine distemper by RT-PCR can be considered non-contagious will improve welfare and lifesaving potential of shelters by enabling recovered dogs to be cleared more quickly for live release outcomes.
Subject(s)
Distemper Virus, Canine , Distemper , Dogs , Animals , Distemper Virus, Canine/genetics , Retrospective Studies , RNA, Viral/geneticsABSTRACT
Whole-genome sequencing (WGS) data have become an integral component of public health investigations and clinical diagnostics. Still, many veterinary diagnostic laboratories cannot afford to implement next generation sequencing (NGS) due to its high cost and the lack of bioinformatic knowledge of the personnel to analyze NGS data. Trying to overcome these problems, and make NGS accessible to every diagnostic laboratory, thirteen veterinary diagnostic laboratories across the United States (US) initiated the assessment of Illumina iSeq100 sequencing platform for whole genome sequencing of important zoonotic foodborne pathogens Escherichia coli, Listeria monocytogenes, and Salmonella enterica. The work presented in this manuscript is a continuation of this multi-laboratory effort. Here, seven AAVLD accredited diagnostic laboratories explored a further reduction in sequencing costs and the usage of user-friendly platforms for genomic data analysis. Our investigation showed that the same genomic library quality could be achieved by using a quarter of the recommended reagent volume and, therefore a fraction of the actual price, and confirmed that Illumina iSeq100 is the most affordable sequencing technology for laboratories with low WGS demand. Furthermore, we prepared step-by-step protocols for genomic data analysis in three popular user-friendly software (BaseSpace, Geneious, and GalaxyTrakr), and we compared the outcomes in terms of genome assembly quality, and species and antimicrobial resistance gene (AMR) identification. No significant differences were found in assembly quality, and the three analysis methods could identify the target bacteria species. However, antimicrobial resistance genes were only identified using BaseSpace and GalaxyTrakr; and GalaxyTrakr was the best tool for this task.
Subject(s)
Listeria , Computational Biology , Whole Genome Sequencing , High-Throughput Nucleotide Sequencing , Salmonella , Escherichia coli/genetics , Anti-Bacterial AgentsABSTRACT
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.
Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/epidemiology , Humans , Minnesota/epidemiology , RNA, Viral/genetics , SARS-CoV-2/genetics , Wisconsin/epidemiologyABSTRACT
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 and detected 106 SARS-CoV-2 positive samples, demonstrating SARS-CoV-2 can be detected in air collected from daily and weekly sampling intervals. 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 the community. In addition, we obtained SARS-CoV-2 genome sequences from air samples to identify variant lineages. Collectively, this shows air surveillance is a scalable, cost-effective, and high throughput alternative to individual testing for detecting respiratory pathogens in congregate settings.
ABSTRACT
There is a growing need for public health and veterinary laboratories to perform whole genome sequencing (WGS) for monitoring antimicrobial resistance (AMR) and protecting the safety of people and animals. With the availability of smaller and more affordable sequencing platforms coupled with well-defined bioinformatic protocols, the technological capability to incorporate this technique for real-time surveillance and genomic epidemiology has greatly expanded. There is a need, however, to ensure that data are of high quality. The goal of this study was to assess the utility of a small benchtop sequencing platform using a multi-laboratory verification approach. Thirteen laboratories were provided the same equipment, reagents, protocols and bacterial reference strains. The Illumina DNA Prep and Nextera XT library preparation kits were compared, and 2×150 bp iSeq i100 chemistry was used for sequencing. Analyses comparing the sequences produced from this study with closed genomes from the provided strains were performed using open-source programs. A detailed, step-by-step protocol is publicly available via protocols.io (https://www.protocols.io/view/iseq-bacterial-wgs-protocol-bij8kcrw). The throughput for this method is approximately 4-6 bacterial isolates per sequencing run (20-26 Mb total load). The Illumina DNA Prep library preparation kit produced high-quality assemblies and nearly complete AMR gene annotations. The Prep method produced more consistent coverage compared to XT, and when coverage benchmarks were met, nearly all AMR, virulence and subtyping gene targets were correctly identified. Because it reduces the technical and financial barriers to generating WGS data, the iSeq platform is a viable option for small laboratories interested in genomic surveillance of microbial pathogens.
Subject(s)
Escherichia coli/genetics , Genome, Bacterial , High-Throughput Nucleotide Sequencing/methods , Listeria/genetics , Salmonella/genetics , Whole Genome Sequencing/methods , Animals , Bacteria/genetics , DNA, Bacterial/genetics , Escherichia coli Infections/microbiology , Foodborne Diseases/microbiology , Gene Library , Genomics , Laboratories , Salmonella Infections/microbiology , Virulence/geneticsABSTRACT
The Boosepivirus is a newly proposed genus in the family Picornaviridae in 2020. Bovine boosepiviruses (BooV) were initially identified in diarrheal cattle through deep sequencing in Japan in 2009. These diarrheal cases were either BooV alone positive or coinfection with other viruses, suggesting that BooV is an enteric pathogen. In 2019, through metagenomic sequencing, a US BooV strain IL41203-19 was identified in the fecal sample of a 10-day old calf with diarrhea and characterized in the present study. Genomic characterization revealed that IL41203-19 share the highest identities with the Japan BooV strain (Bo-12-7/2009/JPN) at both the complete nucleotide and amino acid levels, belonging to Boosepivirus B species in the genus Boosepivirus. Further real-time RT-PCR testing of 84 clinical samples from the diarrheal testing panel showed that five were positive for BooV and were all coinfected with one to four other enteric pathogens. Our data provided further evidence that BooV might contribute to cattle diarrhea observed in different states. Future studies on epidemiology and pathogenesis of bovine BooV are warranted.
Subject(s)
Cattle Diseases , Picornaviridae , Amino Acids , Animals , Cattle , Diarrhea/diagnosis , Diarrhea/epidemiology , Diarrhea/veterinary , Feces , Metagenomics , Nucleotides , Phylogeny , Picornaviridae/genetics , United States/epidemiologyABSTRACT
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.
Subject(s)
COVID-19 , Cat Diseases , Dog Diseases , Animals , COVID-19/diagnosis , COVID-19/veterinary , Cat Diseases/diagnosis , Cat Diseases/epidemiology , Cats , Dog Diseases/diagnosis , Dog Diseases/epidemiology , Dogs , Humans , SARS-CoV-2 , TexasABSTRACT
Human-to-animal and animal-to-animal transmission of SARS-CoV-2 has been documented; however, investigations into SARS-CoV-2 transmission in congregate animal settings are lacking. We investigated four animal shelters in the United States that had identified animals with exposure to shelter employees with laboratory-confirmed COVID-19. Of the 96 cats and dogs with specimens collected, only one dog had detectable SARS-CoV-2 neutralizing antibodies; no animal specimens had detectable viral RNA. These data indicate a low probability of human-to-animal transmission events in cats and dogs in shelter settings with early implementation of infection prevention interventions.
ABSTRACT
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.
Subject(s)
COVID-19/epidemiology , COVID-19/virology , Pets/virology , SARS-CoV-2 , Animals , COVID-19/history , COVID-19/transmission , Cats , Dogs , Family Characteristics , History, 21st Century , Humans , Pets/history , Phylogeny , Population Surveillance , RNA, Viral , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies , Utah/epidemiology , Viral Zoonoses/epidemiology , Wisconsin/epidemiologyABSTRACT
BACKGROUND: High-frequency, rapid-turnaround severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, 2 SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester, despite mandatory directly observed daily antigen testing. METHODS: During the fall 2020 semester, athletes and staff in both programs were tested daily using Quidel's Sofia SARS Antigen Fluorescent Immunoassay, with positive antigen results requiring confirmatory testing with real-time reverse-transcription polymerase chain reaction. We used genomic sequencing to investigate transmission dynamics in these 2 outbreaks. RESULTS: In the first outbreak, 32 confirmed cases occurred within a university athletics program after the index patient attended a meeting while infectious, despite a negative antigen test on the day of the meeting. Among isolates sequenced from that outbreak, 24 (92%) of 26 were closely related, suggesting sustained transmission following an initial introduction event. In the second outbreak, 12 confirmed cases occurred among athletes from 2 university programs that faced each other in an athletic competition, despite receipt of negative antigen test results on the day of the competition. Sequences from both teams were closely related and distinct from viruses circulating in the community for team 1, suggesting transmission during intercollegiate competition in the community for team 2. CONCLUSIONS: These findings suggest that antigen testing alone, even when mandated and directly observed, may not be sufficient as an intervention to prevent SARS-CoV-2 outbreaks in congregate settings, and they highlight the importance of vaccination to prevent SARS-CoV-2 outbreak in congregate settings.
Subject(s)
COVID-19 , Sports , Humans , Immunologic Tests , SARS-CoV-2 , UniversitiesABSTRACT
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 valuesâ <â 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.
Subject(s)
COVID-19 , SARS-CoV-2 , Antigens, Viral , Humans , RNA , Reverse Transcriptase Polymerase Chain Reaction , Reverse Transcription , Sensitivity and Specificity , UniversitiesABSTRACT
BACKGROUND: High frequency, rapid turnaround SARS-CoV-2 testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, two SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester despite mandatory directly observed daily antigen testing. METHODS: During the fall 2020 semester, athletes and staff in both programs were tested daily using Quidel's Sofia SARS Antigen Fluorescent Immunoassay (FIA), with positive antigen results requiring confirmatory testing with real-time reverse transcription polymerase chain reaction (RT-PCR). We used genomic sequencing to investigate transmission dynamics in these two outbreaks. RESULTS: In Outbreak 1, 32 confirmed cases occurred within a university athletics program after the index patient attended a meeting while infectious despite a negative antigen test on the day of the meeting. Among isolates sequenced from Outbreak 1, 24 (92%) of 26 were closely related, suggesting sustained transmission following an initial introduction event. In Outbreak 2, 12 confirmed cases occurred among athletes from two university programs that faced each other in an athletic competition despite receiving negative antigen test results on the day of the competition. Sequences from both teams were closely related and unique from strains circulating in the community, suggesting transmission during intercollegiate competition. CONCLUSIONS: These findings suggest that antigen testing alone, even when mandated and directly observed, may not be sufficient as an intervention to prevent SARS-CoV-2 outbreaks in congregate settings, and highlights the importance of supplementing serial antigen testing with appropriate mitigation strategies to prevent SARS-CoV-2 outbreak in congregate settings. SUMMARY: High frequency, rapid turnaround SARS-CoV-2 testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, here we describe two SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester.
ABSTRACT
A cow dairy (n = 2000) in close proximity to a sheep flock had third-trimester abortions and fatalities in cows and calves over a 14-month period. Eighteen of 33 aborted fetuses (55%) had multifocal random suppurative or mononuclear meningoencephalitis with vasculitis. Seventeen of these affected fetuses had intracytoplasmic bacteria in endothelial cells, and 1 fetus with pericarditis had similar bacteria within mesothelial cells or macrophages. Immunohistochemistry for Chlamydia spp. or polymerase chain reaction (PCR) for Chlamydia pecorum or both, performed on brain or pooled tissue, were positive in all 14 tested fetuses that had meningoencephalitis and in 4/4 calves and in 3/4 tested cows that had meningoencephalitis and thrombotic vasculitis. In 1 calf and 11/11 fetuses, C. pecorum PCR amplicon sequences were 100% homologous to published C. pecorum sequences. Enzootic chlamydiosis due to C. pecorum was the identified cause of the late term abortions and the vasculitis and meningoencephalitis in fetuses, calves, and cows. C. pecorum, an uncommon bovine abortogenic agent, is a differential diagnosis in late-term aborted fetuses with meningoencephalitis, vasculitis, and polyserositis.
Subject(s)
Cattle Diseases , Chlamydia Infections , Chlamydia , Meningoencephalitis , Sheep Diseases , Vasculitis , Abortion, Veterinary , Animals , Cattle , Chlamydia/genetics , Chlamydia Infections/veterinary , Endothelial Cells , Female , Meningoencephalitis/veterinary , Pregnancy , Sheep , Vasculitis/veterinaryABSTRACT
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).
Subject(s)
Antigens, Viral/analysis , COVID-19 Testing/methods , COVID-19/diagnosis , SARS-CoV-2/immunology , Student Health Services , Adolescent , Adult , Asymptomatic Diseases , COVID-19/epidemiology , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Universities , Wisconsin/epidemiology , Young AdultABSTRACT
OBJECTIVE To determine whether Mycobacterium bovis remains viable in ensiled forages. SAMPLE Alfalfa, mixed mostly grass, and corn silages. PROCEDURES For each of 10 sampling days, six 250-g replicate samples of each feedstuff were created and placed in a film pouch that could be vacuum sealed to simulate the ensiling process. Within each set of replicate samples, 4 were inoculated with 10 mL of mycobacterial liquid culture medium containing viable M bovis and 2 were inoculated with 10 mL of sterile mycobacterial liquid culture medium (controls) on day 0. Pouches were vacuum sealed and stored in the dark at room temperature. On the designated sampling day, 1 control pouch was submitted for forage analysis, and the other pouches were opened, and forage samples were obtained for M bovis culture and analysis with a PCR assay immediately and 24 hours later. RESULTS None of the control samples had positive M bovis culture or PCR assay results. Among M bovis-inoculated samples, the organism was not cultured from alfalfa and corn silage for > 2 days but was cultured from mixed mostly grass silage for 28 days after inoculation and ensiling initiation. Mycobacterium bovis DNA was detected by PCR assay in samples of all 3 feedstuffs throughout the 112-day observation period. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that properly ensiled forages would be an unlikely source for M bovis transmission to cattle. Further research is necessary to determine whether ensiling kills M bovis or forces it to become dormant and, if the latter, elucidate the conditions that cause it to revert to an infectious state.
Subject(s)
Animal Feed/microbiology , Animal Husbandry , Food Microbiology , Mycobacterium bovis/physiology , Animals , Cattle , Medicago/microbiology , Medicago sativa/microbiology , Poaceae/microbiology , Silage/microbiology , Tuberculosis, Bovine/microbiology , Zea mays/microbiologyABSTRACT
Equine multinodular pulmonary fibrosis (EMPF) diagnosed at the Laboratório Regional de Diagnóstico of Faculdade de Medicina Veterinária, Universidade Federal de Pelotas (LRD/UFPel), is described. Differential aspects of other pulmonary diseases in horses with pneumonia and interstitial fibrosis were discussed. The disease occurred in a 15-year-old equine that presented with clinical signs of respiratory distress, intermittent fever, anorexia, and dyspnea. Macroscopically, there was enlargement of the lungs with whitish, pale, firm and well-delimited nodules, approximately 7-10 cm in diameter, distributed throughout the parenchyma. Histologically, the lung nodules had alveolar spaces with walls covered by cuboidal epithelium containing macrophages, neutrophils, lymphocytes, hyperplasia of type II pneumocytes and, eventually, multinucleated giant cells. The interstitium was markedly thickened by mature fibrous connective tissue and collagen. There were intranuclear inclusion bodies in the macrophages. The PCR technique for detecting the EHV-5 DNA was positive. In a retrospective study of pneumonia cases in horses with interstitial fibrosis diagnosed in the LRD/UFPel, two animals had macroscopic and histological lesions similar to those with EMPF, but they were negative for EHV-5 in PCR. Four cases diagnosed with pneumonia and interstitial tissue fibrosis had a histological pattern that was different from that observed in the EMPF animal, thus eliminating the possibility of EMPF. It is concluded that EMPF is a sporadic disease that should be considered in cases of respiratory disease in horses. Reports of such cases are important to alert technicians about the occurrence of rare diseases in Brazil. It is also necessary to establish the true role of EHV-5 in the pathogenesis of EMPF. Cases of pulmonary fibrosis such as EMPF, in which the virus is not present, should be studied to establish whether it could be an idiopathic form of the disease.(AU)
Descreve-se a fibrose multinodular pulmonar equina (EMPF) diagnosticado no Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas. Foram discutidos a patologia da doença e os aspectos diferenciais de outras enfermidades pulmonares de equinos que cursam com pneumonia e fibrose intersticial. A doença ocorreu em um equino sem raça definida de 15 anos de idade que apresentou sinais clínicos de dificuldade respiratória febre intermitente, anorexia e dispneia, com evolução de aproximadamente 10 dias. Macroscopicamente havia aumento de volume dos pulmões e nódulos esbranquiçados, pálidos, firmes e bem delimitados, de aproximadamente 7-10 cm de diâmetro, distribuídos pelo parênquima. Histologicamente, o tecido pulmonar apresentava nódulos caracterizados pela presença de espaços alveolares, com paredes revestidas por epitélio cuboidal achatado, contendo macrófagos e neutrófilos e havia, também, linfócitos e hiperplasia de pneumócitos tipo II e eventualmente células gigantes multinuacleadas. O interstício estava acentuadamente espessado por tecido conjuntivo fibroso maduro e por colágeno. Havia corpúsculos de inclusão intranucleares em macrófagos. A técnica de PCR para detecção do DNA de herpes vírus equino-5 (EHV-5) resultou positiva. Em um estudo retrospectivo de casos de pneumonia com fibrose intersticial diagnosticados no LRD entre 2000 e 2015, dois equinos apresentaram lesões macroscópicas e histológicas similares às de EMPF, porém resultaram negativos na PCR para detecção de EHV-5. Quatro casos de pneumonia com fibrose do tecido intersticial apresentaram padrão histológico diverso da EMPF descartando-se a possibilidade de tratar-se da doença. Conclui-se que EMPF é uma enfermidade esporádica, no entanto deve ser levada em consideração em casos de doença respiratória em equinos. A descrição dos casos diagnosticados é importante para alertar técnicos sobre a ocorrência da mesma no Brasil. É necessário estabelecer o real papel do EHV-5 na patogenia da doença. Casos de fibrose pulmonar semelhantes à EMPF em que não esteja presente o vírus, devem ser estudados a fim de ficar estabelecido se poderia ser uma forma idiopática da mesma doença.(AU)
Subject(s)
Animals , Pulmonary Fibrosis/pathology , Pulmonary Fibrosis/veterinary , Horse Diseases , Retrospective Studies , Diagnosis, DifferentialABSTRACT
A 5-y-old Holstein dairy cow had surgery for a suspected displaced abomasum 10 d postpartum, developed acute neurologic signs at day 19, and was found dead 21 d postpartum. At autopsy, there was a peri-incisional intramuscular abscess that communicated with the peritoneal cavity, as well as hemorrhage and malacia involving the brain, and multiple nodules in the liver, kidneys, and lungs. Fungal hyphae were seen histologically at the surgery site, on the surface of the liver, and in lesions of severe necrotizing vasculitis in the lungs, kidneys, brain, and liver. The uterus was free of fungal organisms. Pan-fungal PCR and DNA sequencing identified the fungus as Mortierella wolfii. Previously reported deaths from M. wolfii have been related to abortion, but in this case, there was no histologic evidence of fungal organisms in the uterus, calving was routine, and there was a several week delay between calving and development of neurologic signs. The findings suggested a unique case of surgical site infection with subsequent embolic mycosis.