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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 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.

We conducted public health investigations of 8 organ transplant recipients who tested positive for severe acute respiratory syndrome coronavirus 2 infection. Findings suggest the most likely source of transmission was community or healthcare exposure, not the organ donor. Transplant centers should educate transplant candidates and recipients about infection prevention recommendations.

To assess transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a detention facility experiencing a coronavirus disease outbreak and evaluate testing strategies, we conducted a prospective cohort investigation in a facility in Louisiana, USA. We conducted SARS-CoV-2 testing for detained persons in 6 quarantined dormitories at various time points. Of 143 persons, 53 were positive at the initial test, and an additional 58 persons were positive at later time points (cumulative incidence 78%). In 1 dormitory, all 45 detained persons initially were negative; 18 days later, 40 (89%) were positive. Among persons who were SARS-CoV-2 positive, 47% (52/111) were asymptomatic at the time of specimen collection; 14 had replication-competent virus isolated. Serial SARS-CoV-2 testing might help interrupt transmission through medical isolation and quarantine. Testing in correctional and detention facilities will be most effective when initiated early in an outbreak, inclusive of all exposed persons, and paired with infection prevention and control.

HIGHLIGHTS • Staff at pediatric long-term care facilities (pLTCF) were responsive to electronic messages asking about acute respiratory illness symptoms. • Staff in pLTCFs had respiratory viruses detected during acute respiratory infections and while asymptomatic. • Contagious presenteeism occurred as some participants with ARIs worked while symptomatic. • Staff with ARI may pose a risk of transmitting respiratory viral infections to frail and medically complex pLTCF residents., Background Transmission of respiratory viruses between staff and residents of pediatric long-term care facilities (pLTCFs) can occur. We assessed the feasibility of using text or email messages to perform surveillance for acute respiratory infections (ARIs) among staff. Methods From December 7, 2016 to May 7, 2017, 50 staff participants from two pLTCFs received weekly text or email requests to report the presence or absence of ARI symptoms. Those who fulfilled the ARI case definition (≥2 symptoms) had respiratory specimens collected to detect viruses by reverse transcriptase polymerase chain reaction assays. Pre- and post-surveillance respiratory specimens were collected to assess subclinical viral shedding. Results The response rate to weekly electronic messages was 93%. Twenty-one ARIs reported from 20 (40%) participants fulfilled the case definition. Respiratory viruses were detected in 29% (5/17) of specimens collected at symptom onset (influenza B, respiratory syncytial virus, coronavirus [CoV] 229E, rhinovirus [RV], and dual detection of CoV OC43 and bocavirus). Four participants had positive pre-surveillance (4 RV), and six had positive post-surveillance specimens (3 RV, 2 CoV NL63 and 1 adenovirus). Conclusions Electronic messaging to conduct ARI surveillance among pLTCF staff was feasible.

To determine prevalence of, seroprevalence of, and potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among a cohort of evacuees returning to the United States from Wuhan, China, in January 2020, we conducted a cross-sectional study of quarantined evacuees from 1 repatriation flight. Overall, 193 of 195 evacuees completed exposure surveys and submitted upper respiratory or serum specimens or both at arrival in the United States. Nearly all evacuees had taken preventive measures to limit potential exposure while in Wuhan, and none had detectable SARS-CoV-2 in upper respiratory tract specimens, suggesting the absence of asymptomatic respiratory shedding among this group at the time of testing. Evidence of antibodies to SARS-CoV-2 was detected in 1 evacuee, who reported experiencing no symptoms or high-risk exposures in the previous 2 months. These findings demonstrated that this group of evacuees posed a low risk of introducing SARS-CoV-2 to the United States.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified as the etiologic agent associated with coronavirus disease, which emerged in late 2019. In response, we developed a diagnostic panel consisting of 3 real-time reverse transcription PCR assays targeting the nucleocapsid gene and evaluated use of these assays for detecting SARS-CoV-2 infection. All assays demonstrated a linear dynamic range of 8 orders of magnitude and an analytical limit of detection of 5 copies/reaction of quantified RNA transcripts and 1 x 10-1.5 50% tissue culture infectious dose/mL of cell-cultured SARS-CoV-2. All assays performed comparably with nasopharyngeal and oropharyngeal secretions, serum, and fecal specimens spiked with cultured virus. We obtained no false-positive amplifications with other human coronaviruses or common respiratory pathogens. Results from all 3 assays were highly correlated during clinical specimen testing. On February 4, 2020, the Food and Drug Administration issued an Emergency Use Authorization to enable emergency use of this panel.

The etiologic agent of an outbreak of pneumonia in Wuhan, China, was identified as severe acute respiratory syndrome coronavirus 2 in January 2020. A patient in the United States was given a diagnosis of infection with this virus by the state of Washington and the US Centers for Disease Control and Prevention on January 20, 2020. We isolated virus from nasopharyngeal and oropharyngeal specimens from this patient and characterized the viral sequence, replication properties, and cell culture tropism. We found that the virus replicates to high titer in Vero-CCL81 cells and Vero E6 cells in the absence of trypsin. We also deposited the virus into 2 virus repositories, making it broadly available to the public health and research communities. We hope that open access to this reagent will expedite development of medical countermeasures.

Background The International Health Regulations state that early detection and immediate reporting of unusual health events is important for early warning and response systems. Objective To describe a pilot surveillance program established in health facilities in Yaounde, Cameroon in 2017 which aimed to enable detection and reporting of public health events. Methods Cameroon's Ministry of Health, in partnership with the US Centers for Disease Control and Prevention, Cameroon Pasteur Center, and National Public Health Laboratory, implemented event-based surveillance (EBS) in nine Yaounde health facilities. Four signals were defined that could indicate possible public health events, and a reporting, triage, and verification system was established among partner organizations. A pre-defined laboratory algorithm was defined, and a series of workshops trained health facilities, laboratory, and public health staff for surveillance implementation. Results From May 2017 to January 2018, 30 signals were detected, corresponding to 15 unusual respiratory events. All health facilities reported a signal at least once, and more than three-quarters of health facilities reported ≥2 times. Among specimens tested, the pathogens detected included Klebsiella pneumoniae, Moraxella catarrhalis, Streptococcus pneumoniae, Haemophilus influenza, Staphylococcus aureus, Pneumocystis jiroveci, influenza A (H1N1) virus, rhinovirus, and adenovirus. Conclusions The events detected in this pilot were caused by routine respiratory bacteria and viruses, and no novel influenza viruses or other emerging respiratory threats were identified. The surveillance system, however, strengthened relationships and communication linkages between health facilities and public health authorities. Astute clinicians can play a critical role in early detection and EBS is one approach that may enable reporting of emerging outbreaks and public health events.

We conducted active surveillance of acute respiratory viral infections (ARIs) among residents and healthcare personnel (HCP) at a long-term care facility during the 2015–2016 respiratory illness season. ARIs were observed among both HCP and patients, highlighting the importance of including HCP in surveillance programs.

Historical specimens collected from hospitalized children were tested for the following 13 viruses: influenza A and B; respiratory syncytial virus (RSV); parainfluenza viruses 1–3; human metapneumovirus; rhinovirus; coronaviruses 229E, OC43, NL63 and HKU1 and Adenovirus using monoplex real-time reverse transcriptase polymerase chain reaction (rRT-PCR). They were retested using TaqMan Array Card (TAC), a micro-fluidic system, capable of simultaneous multi-pathogen testing, to evaluate its sensitivity and specificity against monoplex rRT-PCR. TAC showed high sensitivity (71%–100%) and specificity (98%–100%) for these viruses in comparison to monoplex rRT-PCR. Multi-specimen detection with high sensitivity and specificity makes TAC a potentially useful tool for both surveillance and outbreak investigations.

Background There are limited data on incidence, risk factors and etiology of acute lower respiratory tract infection (LRTI) among older adults in low- and middle-income countries. Methods We established a cohort of community dwelling older adults ≥60 years and conducted weekly follow-up for acute respiratory infections (ARI) during 2015-2017. Nurses assessed ARI cases for LRTI, collecting combined nasal/throat swabs from all LRTI cases and an equal number of age- and sex-matched asymptomatic neighbourhood controls. Swabs were tested for influenza viruses, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and parainfluenza viruses (PIV) using polymerase chain reaction. LRTI and virus-specific LRTI incidence was calculated per 1000 person-years. We estimated adjusted incidence rate ratios (IRR) for risk factors using Poisson regression and calculated etiologic fractions (EF) using adjusted odds ratios for detection of viral pathogens in LRTI cases vs controls. Results We followed 1403 older adults for 2441 person-years. LRTI and LRTI-associated hospitalization incidences were 248.3 (95% confidence interval (CI) = 229.3-268.8) and 12.7 (95% CI = 8.9-18.1) per 1000 person-years. Persons with pre-existing chronic bronchitis as compared to those without (incidence rate ratio (IRR) = 4.7, 95% CI = 3.9-5.6); aged 65-74 years (IRR = 1.6, 95% CI = 1.3-2.0) and ≥75 years (IRR = 1.8, 95% CI = 1.4-2.4) as compared to 60-64 years; and persons in poorest wealth quintile (IRR = 1.4, 95% CI = 1.1-1.8); as compared to those in wealthiest quintile were at higher risk for LRTI. Virus was detected in 10.1% of LRTI cases, most commonly influenza (3.8%) and RSV (3.0%). EF for RSV and influenza virus was 83.9% and 83.6%, respectively. Conclusion In this rural cohort of older adults, the incidence of LRTI was substantial. Chronic bronchitis was an important risk factor; influenza virus and RSV were major viral pathogens.

Background To estimate the infectious period of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in older adults with underlying conditions, we assessed duration of coronavirus disease 2019 (COVID-19) symptoms, reverse-transcription polymerase chain reaction (RT-PCR) positivity, and culture positivity among nursing home residents. Methods We enrolled residents within 15 days of their first positive SARS-CoV-2 test (diagnosis) at an Arkansas facility from July 7 to 15, 2020 and instead them for 42 days. Every 3 days for 21 days and then weekly, we assessed COVID-19 symptoms, collected specimens (oropharyngeal, anterior nares, and saliva), and reviewed medical charts. Blood for serology was collected on days 0, 6, 12, 21, and 42. Infectivity was defined by positive culture. Duration of culture positivity was compared with duration of COVID-19 symptoms and RT-PCR positivity. Data were summarized using measures of central tendency, frequencies, and proportions. Results We enrolled 17 of 39 (44%) eligible residents. Median participant age was 82 years (range, 58–97 years). All had ≥3 underlying conditions. Median duration of RT-PCR positivity was 22 days (interquartile range [IQR], 8–31 days) from diagnosis; median duration of symptoms was 42 days (IQR, 28–49 days). Of 9 (53%) participants with any culture-positive specimens, 1 (11%) severely immunocompromised participant remained culture-positive 19 days from diagnosis; 8 of 9 (89%) were culture-positive ≤8 days from diagnosis. Seroconversion occurred in 12 of 12 (100%) surviving participants with ≥1 blood specimen; all participants were culture-negative before seroconversion. Conclusions Duration of infectivity was considerably shorter than duration of symptoms and RT-PCR positivity. Severe immunocompromise may prolong SARS-CoV-2 infectivity. Seroconversion indicated noninfectivity in this cohort.

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).

Background In 2016, as a component of the Global Health Security Agenda, the Vietnam Ministry of Health expanded its existing influenza sentinel surveillance for severe acute respiratory infections (SARI) to include testing for 7 additional viral respiratory pathogens. This article describes the steps taken to implement expanded SARI surveillance in Vietnam and reports data from 1 year of expanded surveillance. Methods The process of expanding the suite of pathogens for routine testing by real‐time reverse transcriptase–polymerase chain reaction (rRT‐PCR) included laboratory trainings, procurement/distribution of reagents, and strengthening and aligning SARI surveillance epidemiology practices at sentinel sites and regional institutes (RI). Results Surveillance data showed that of 4003 specimens tested by the RI laboratories, 20.2% (n = 810) were positive for influenza virus. Of the 3193 influenza‐negative specimens, 41.8% (n = 1337) were positive for at least 1 non‐influenza respiratory virus, of which 16.2% (n = 518), 13.4% (n = 428), and 9.6% (n = 308) tested positive for respiratory syncytial virus, rhinovirus, and adenovirus, respectively. Conclusions The Government of Vietnam has demonstrated that expanding respiratory viral surveillance by strengthening and building upon an influenza platform is feasible, efficient, and practical.

Background During the 2014-2015 US influenza season, 320 cases of non-mumps parotitis (NMP) among residents of 21 states were reported to the Centers for Disease Control and Prevention (CDC). We conducted an epidemiologic and laboratory investigation to determine viral etiologies and clinical features of NMP during this unusually large occurrence. Methods NMP was defined as acute parotitis or other salivary gland swelling of >2 days duration in a person with a mumps- negative laboratory result. Using a standardized questionnaire, we collected demographic and clinical information. Buccal samples were tested at the CDC for selected viruses, including mumps, influenza, human parainfluenza viruses (HPIVs) 1-4, adenoviruses, cytomegalovirus, Epstein-Barr virus (EBV), herpes simplex viruses (HSVs) 1 and 2, and human herpes viruses (HHVs) 6A and 6B. Results Among the 320 patients, 65% were male, median age was 14.5 years (range, 0-90), and 67% reported unilateral parotitis. Commonly reported symptoms included sore throat (55%) and fever (48%). Viruses were detected in 210 (71%) of 294 NMP patients with adequate samples for testing, ≥2 viruses were detected in 37 samples, and 248 total virus detections were made among all samples. These included 156 influenza A(H3N2), 42 HHV6B, 32 EBV, 8 HPIV2, 2 HPIV3, 3 adenovirus, 4 HSV-1, and 1 HSV-2. Influenza A(H3N2), HHV6B, and EBV were the most frequently codetected viruses. Conclusions Our findings suggest that, in addition to mumps, clinicians should consider respiratory viral (influenza) and herpes viral etiologies for parotitis, particularly among patients without epidemiologic links to mumps cases or outbreaks.

Highlights • Surveillance for respiratory illness in Hajj pilgrims took place in Jordan in 2014. • 58% of the 125 subjects returning from Hajj tested positive for at least one virus. • Rhino/enterovirus was the most commonly detected viral pathogen (47% of subjects). • No cases of Middle East Respiratory Syndrome coronavirus were detected., Background The emergence of Middle East Respiratory Syndrome coronavirus (MERS-CoV) has prompted enhanced surveillance for respiratory infections among pilgrims returning from the Hajj, one of the largest annual mass gatherings in the world. Objectives To describe the epidemiology and etiologies of respiratory illnesses among pilgrims returning to Jordan after the 2014 Hajj. Study design Surveillance for respiratory illness among pilgrims returning to Jordan after the 2014 Hajj was conducted at sentinel health care facilities using epidemiologic surveys and molecular diagnostic testing of upper respiratory specimens for multiple respiratory pathogens, including MERS-CoV. Results Among the 125 subjects, 58% tested positive for at least one virus; 47% tested positive for rhino/enterovirus. No cases of MERS-CoV were detected. Conclusions The majority of pilgrims returning to Jordan from the 2014 Hajj with respiratory illness were determined to have a viral etiology, but none were due to MERS-CoV. A greater understanding of the epidemiology of acute respiratory infections among returning travelers to other countries after Hajj should help optimize surveillance systems and inform public health response practices.

New diagnostic platforms often use nasopharyngeal or oropharyngeal (NP/OP) swabs for pathogen detection for patients hospitalized with community-acquired pneumonia (CAP). We applied multipathogen testing to high-quality sputum specimens to determine if more pathogens can be identified relative to NP/OP swabs. Children (P < 0.0001) and adults (88% versus 61%; P < 0.0001); for each pathogen targeted, crossing threshold ( C T ) values were earlier in sputum. Both bacterial (361 versus 294) and viral detections (245 versus 140) were more common in sputum versus NP/OP specimens, respectively, in both children and adults. When available, high-quality sputum may be useful for testing in hospitalized CAP patients.

Background In India, community-based acute lower respiratory infections (ALRI) burden studies are limited, hampering development of prevention and control strategies. Methods We surveyed children

Background Endemic and emerging respiratory viruses are a threat to public health, and a robust public health laboratory system is essential to ensure global health security. Objective This program sought to expand molecular laboratory testing capacity to detect a broad range of respiratory pathogens in clinical respiratory specimens collected during disease surveillance and outbreak investigations. Methods As a part of the Global Health Security Agenda (GHSA), the United States Centers for Disease Control and Prevention utilised the equipment and training infrastructure already in place at the World Health Organization National Influenza Centers to expand testing capacity for respiratory viruses in laboratories in GHSA partner countries. This was done through the provision of quality assured reagents, including multiplex platforms and technical guidance for laboratory staff, as well as the assessment of laboratory testing accuracy. Conclusion Early findings illustrated that GHSA laboratories have been able to expand testing capacity using specimens from routine surveillance, as well as from outbreak situations.

Supplemental Digital Content is available in the text., Background: Parainfluenza viruses (PIV) have been shown to contribute substantially to pediatric hospitalizations in the United States. However, to date, there has been no systematic surveillance to estimate the burden among pediatric outpatients. Methods: From August 2010 through July 2014, outpatient health care providers with enumerated patient populations in 13 states and jurisdictions participating in the Influenza Incidence Surveillance Project conducted surveillance of patients with influenza-like illness (ILI). Respiratory specimens were collected from the first 10 ILI patients each week with demographic and clinical data. Specimens were tested for multiple respiratory viruses, including PIV1–4, using reverse transcriptase–polymerase chain reaction assays. Cumulative incidence was calculated using provider patient population size as the denominator. Results: PIVs 1–3 were detected in 8.0% of 7716 ILI-related outpatient specimens: 30% were PIV1, 26% PIV2 and 44% PIV3. PIV circulation varied noticeably by year and type, with PIV3 predominating in 2010–2011 (incidence 110 per 100,000 children), PIV1 in 2011–2012 (89 per 100,000), dual predominance of PIV2 and PIV3 (88 and 131 per 100,000) in 2012–2013 and PIV3 (100 per 100,000) in 2013–2014. The highest incidence of PIV detections was among patients aged

Early detection and adherence to infection prevention recommendations are necessary to avoid transmission., Middle East respiratory syndrome coronavirus (MERS-CoV) infections sharply increased in the Arabian Peninsula during spring 2014. In Abu Dhabi, United Arab Emirates, these infections occurred primarily among healthcare workers and patients. To identify and describe epidemiologic and clinical characteristics of persons with healthcare-associated infection, we reviewed laboratory-confirmed MERS-CoV cases reported to the Health Authority of Abu Dhabi during January 1, 2013–May 9, 2014. Of 65 case-patients identified with MERS-CoV infection, 27 (42%) had healthcare-associated cases. Epidemiologic and genetic sequencing findings suggest that 3 healthcare clusters of MERS-CoV infection occurred, including 1 that resulted in 20 infected persons in 1 hospital. MERS-CoV in healthcare settings spread predominantly before MERS-CoV infection was diagnosed, underscoring the importance of increasing awareness and infection control measures at first points of entry to healthcare facilities.

We found that this virus may be detected in mildly ill and asymptomatic case-patients., In January 2013, several months after Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in Saudi Arabia, Abu Dhabi, United Arab Emirates, began surveillance for MERS-CoV. We analyzed medical chart and laboratory data collected by the Health Authority–Abu Dhabi during January 2013–May 2014. Using real-time reverse transcription PCR, we tested respiratory tract samples for MERS-CoV and identified 65 case-patients. Of these patients, 23 (35%) were asymptomatic at the time of testing, and 4 (6%) showed positive test results for >3 weeks (1 had severe symptoms and 3 had mild symptoms). We also identified 6 clusters of MERS-CoV cases. This report highlights the potential for virus shedding by mildly ill and asymptomatic case-patients. These findings will be useful for MERS-CoV management and infection prevention strategies.

Objective: Characterize the role of human parainfluenza virus and its clinical features in Brazilian children under 2 years of age presenting with acute lower respiratory tract infections. Methods: Real-time assays were used to identify strains of human parainfluenza virus and other common respiratory viruses in nasopharyngeal aspirates. One thousand and two children presenting with acute lower respiratory tract illnesses were enrolled from February 2008 to August 2010. Results: One hundred and four (10.4%) patients were human parainfluenza virus positive, of whom 60 (57.7%) were positive for human parainfluenza virus-3, 30 (28.8%) for human parainfluenza virus-4, 12 (11.5%) for human parainfluenza virus-1, and two (1.9%) for human parainfluenza virus-2. Seven (6.7%) patients had more than one strain of human parainfluenza virus detected. The most frequent symptoms were tachypnea and cough, similar to other viral respiratory infections. Clinical manifestations did not differ significantly between human parainfluenza virus-1, -2, -3, and -4 infections. Human parainfluenza virus-1, -3, and -4 were present in the population studied throughout the three years of surveillance, with human parainfluenza virus-3 being the predominant type identified in the first two years. Conclusion: Human parainfluenza viruses contribute substantially to pediatric acute respiratory illness (ARI) in Brazil, with nearly 30% of this contribution attributable to human parainfluenza virus-4. Resumo: Objetivo: Caracterizar o papel do VPH-4 e suas características clínicas em crianças brasileiras com menos de dois anos de idade com infecções agudas do trato respiratório inferior. Métodos: Ensaios em tempo real foram utilizados para identificar tipos de VPH e outros vírus respiratórios comuns em aspirados nasofaríngeos. Mil e duas crianças com doença aguda do trato respiratório inferior foram inscritas para participar de fevereiro de 2008 a agosto de 2010. Resultados: 104 (10,4%) pacientes eram VPH positivos, dos quais 60 (57,7%) eram positivos para VPH-3, 30 (28,8%) para VPH-4, 12 (11,5%) para VPH-1 e dois (1,9%) para VPH-2. Sete (6,7%) pacientes apresentaram mais de um tipo de VPH detectado. Os sintomas mais frequentes foram tosse e taquipneia, semelhantes a outras infecções respiratórias virais. As manifestações clínicas não diferiram de forma significativa entre as infecções por VPH-1, -2, -3 e -4. Os VPH-1, -3 e -4 estavam presentes na população estudada ao longo dos três anos de vigilância, e o VPH-3 foi o tipo predominante identificado nos primeiros dois anos. Conclusão: Os VPHs contribuem substancialmente para a DRA pediátrica no Brasil com quase 30% dessa contribuição atribuível ao VPH-4. Keywords: Human parainfluenza virus, Respiratory virus, Pediatric patients, Acute respiratory illness, Human respirovirus 4, Palavras-chave: Vírus da parainfluenza humana, Vírus respiratório, Pacientes pediátricos, Doença respiratória aguda, Respirovírus humano 4

Background Multipathogen reverse transcription real-time PCR (RT-qPCR) platforms have proven useful in surveillance for acute respiratory illness (ARI) and study of respiratory outbreaks of unknown etiology. The TaqMan® Array Card (TAC, Life Technologies™), can simultaneously test 7 clinical specimens for up to 21 individual pathogens (depending on arrangement of controls and use of duplicate wells) by arrayed singleplex RT-qPCR on a single assay card, using minimal amounts of clinical specimens. A previous study described the development of TAC for the detection of respiratory viral and bacterial pathogens; the assay was evaluated against well-characterized analytical materials and a limited collection of human clinical specimens. Objectives We wished to compare TAC assay performance against standard individual RT-qPCR assays for respiratory viral detection, focusing on 10 viruses (adenovirus, human metapneumovirus, human parainfluenza viruses 1–4, influenza viruses A and B, respiratory syncytial virus, and rhinovirus) from a larger collection of human specimens. Study design We used specimens from 942 children with ARI enrolled systematically in a population-based, ARI surveillance study (New Vaccine Surveillance Network, NVSN). Results Compared with standard individual RT-qPCR assays, the sensitivity of TAC for the targeted viruses ranged from 54% to 95% (54%, 56%, and 75% for adenovirus, human parainfluenza viruses-1 and -2, respectively, and 82%–95% for the other viruses). Assay specificity was 99%, and coefficients of variation for virus controls ranged from 1.5% to 4.5%. Conclusion The TAC assay should prove useful for multipathogen studies and rapid outbreak response.