1064. Intra-Host SARS-CoV-2 Evolution Dynamics

Background

Our understanding of SARS-CoV-2 evolution is limited. Most estimates arise from analysis of global databases populated with unrelated sequences and is currently estimated at ∼27.7 substitutions/genome/year. SARS-CoV-2 polymerase contains a proofreading function encoded by NSP-14 limiting change. Additionally, virus evolution may be influenced by patient comorbidity. Intra-host mutational rate (MR) during infection remain poorly studied.

Methods

To minimize effect of vaccination and/or natural immunity on MR analysis, paired samples from adults originating from the initial pandemic wave (3/17/2020 through 5/27/2020) were retrieved and analyzed at Cleveland Clinic. Viral genome analysis was performed using next generation sequencing, and mutations between paired samples were quantified at allele frequencies (AF) ≥ 0.1, ≥ 0.5 and ≥ 0.75 and compared. MR was calculated employing F81 and JC69 evolution­­­­ models and compared between isolates with (Δ NSP-14) and without (wildtype, wt) non-synonymous mutations in NSP-14 and by comorbidity.

Results

A total of 40 patients (80 sample pairs) were identified. Median interval between paired tests was 15 days [range 5-32]. The estimated MR by F81 modeling was 317.2 (95%CI 312.0-322.3), 54.6 (95%CI 52.5-56.7) and 45.1 (95%CI 43.1-47.0) substitutions/genome/year at AF of ≥0.1, ≥0.5, ≥0.75 respectively. Rates in ΔNSP-14 (n=13) vs wt (n=27) groups were 557.7 (95%CI 537.0-578.2) vs 193.1 (95%CI 187.1-199.1) p-value 0.001, 50.8 (95%CI 44.3-57.3) vs 56.3 (95%CI 53.1-59.4) p-value 0.144, and 31.0 (95%CI 25.9-36.1) vs 51.3 (95%CI 48.3-54.3) p- value < 0.001 at AF ≥0.1, ≥0.5, ≥0.75 respectively. Patients with immune comorbidities (n=6) had significantly higher MR of 137.6 (95%CI 114.6-160.5) vs 40.5 (95%CI 38.4-42.7) p-value < 0.001, and 113.7 (95%CI 92.8-134.5) vs 33.4 (95%CI 31.5-35.4) p-value < 0.001 at AF ≥0.5 and ≥0.75 respectively. Similar results were obtained when using the JC69 model.

Conclusion

Intra-host SARS-CoV-2 mutation rates are higher than those reported through population analysis. Virus strains with altered NSP-14 have accelerated MR at low AF. Immunosuppressed patients have elevated MR at higher AF. Understanding intra-host virus evolution will aid in current and future pandemic modeling.

Disclosures

Frank Esper, M.D, Johnson and Johnson: Advisor/Consultant Daniel D. Rhoads, M.D. PhD, Luminex: Advisor/Consultant|Talis Biomedical: Advisor/Consultant|Thermo Fisher: Advisor/Consultant.

Respiratory syncytial virus seropositivity at birth is associated with adverse neonatal respiratory outcomes

BACKGROUND

More than 60 years since the discovery of the respiratory syncytial virus (RSV), the effects of prenatal exposure to this virus remain largely unknown. In this investigation, we sought to find evidence of RSV seroconversion in cord blood and explore its clinical implications for the newborn.

METHODS

Offspring from 22 pregnant women with a history of viral respiratory infection during the third trimester of pregnancy (respiratory viral illness [RVI] group) and 40 controls were enrolled in this study between 1 September 2016 and 31 March 2019. Cord blood sera were tested for anti-RSV antibodies by indirect fluorescent antibody assay. RSV seropositivity was defined as the presence of anti-RSV immunoglobulin M (IgM) or immunoglobulin A (IgA), in addition to IgG in cord blood serum at ≥1:20 dilution.

RESULTS

Anti-RSV IgG was present in all cord blood serum samples from infants born to RVI mothers (95% confidence interval [CI] = 82%-100%), with 16 samples also having elevated titers for either anti-RSV IgA or IgM (73%; 95% CI = 52%-87%). No controls had evidence of anti-RSV antibodies. Eight (50%) seropositive newborns developed at least one respiratory tract finding, including respiratory distress syndrome (N = 8), respiratory failure (N = 3), and pneumonia (N = 1). RSV seropositive newborns also required more days on oxygen, had leukocytosis and elevated C-reactive protein (P = .025, P = .047, and P < .001, respectively).

CONCLUSION

This study provides evidence of acute seropositivity against RSV in cord blood of newborns delivered from mothers with a history of upper respiratory tract illness in the third trimester. Cord blood seropositivity for anti-RSV IgA or IgM was associated with adverse clinical and laboratory outcomes in newborns.

Respiratory syncytial virus exhibits differential tropism for distinct human placental cell types with Hofbauer cells acting as a permissive reservoir for infection

BACKGROUND

Respiratory syncytial virus (RSV) is capable of transient viremia and extrapulmonary dissemination. Recently, this virus has been identified in fetal cord blood, suggesting the possibility of in utero acquisition in humans. Here, we assess permissivity and kinetics of RSV replication in primary human placental cells, examine their potential to transfer this infection to neighboring cells, and measure the inflammatory response evoked by the virus.

METHODS AND FINDINGS

Human placental villus tissue was collected immediately upon delivery and processed for isolation of placental cytotrophoblast, fibroblast, and macrophage (Hofbauer) cells. Isolated cells were infected with a recombinant RSV-A2 strain (rrRSV) expressing red fluorescent protein (RFP) and analyzed by fluorescence microscopy, Western blot, and quantitative PCR (qPCR). Based on RFP expression, rrRSV exhibited differential tropism for the three major placental cell types. Placental fibroblasts and Hofbauer cells were permissive and supported productive rrRSV replication. While infected cytotrophoblast cells expressed viral glycoprotein (G protein), only limited RSV replication was detected. Importantly, qPCR and fluorescence-focused unit assay revealed that the viral progeny remains trapped within infected Hofbauer cells for up to 30 days, with no release into surrounding media. Yet, Hofbauer cells passed the infection onto overlaid naïve 16HBE cells, suggesting contact-dependent trans-infection. Lastly, a significant increase in proinflammatory cytokines, particularly IL-6, TNF-alpha, and IFN-gamma was measured in the supernatant of infected Hofbauer cells by multiplex cytokine assay and conventional ELISA.

CONCLUSIONS

This study demonstrates that RSV can replicate in human placenta, exhibits differential tropism for distinct placental cell types, can be stored and transferred to neighboring cells by Hofbauer cells, and elicits an inflammatory response. It also supports the hypothesis that this respiratory virus can be vertically transferred to the fetus and potentially affect its development and the outcome of pregnancies.

2627. Dynamics of Respiratory Viral Co-infections: Predisposition for and Clinical Impact of Viral Pairings in Children and Adults

Background

The clinical relevance of respiratory viral co-infections is unclear. Few studies determine epidemiology and impact of specific co-infection pairings. Here we assess the dynamics of respiratory viral co-infections, determine any predisposition for specific pairings to occur and evaluate resulting clinical impact on hospitalization.

Methods

We reviewed respiratory viral panel results collected at The Cleveland Clinic between November 2013 to Jun 2018. Monthly prevalences, mono-infections and co-infections of 13 viral pathogens were tabulated. Employing a mathematical model which utilized each individual virus’ co-infection rate and prevalence patterns of concurrent circulating respiratory viruses, we calculated an expected number of occurrences for 132 viral pairing permutations. Expected vs observed co-infection occurrences were compared using binomial tests. For viral pairings occurring at significantly higher prevalence than expected, logistic regression models were used to compare hospitalization between patients with co-infection to ones with mono-infection.

Results

Of 30,535 respiratory samples, 9,843 (32.2%) samples were positive for at least 1 virus and 1,018 (10.82%) were co-infected. Co-infections occurred in 18% of pediatric samples and only 3% of adult samples (P < 0.001). Adenovirus C (ADVC had the highest co-infection rate (68.3%) while influenza B had the lowest (10.07%). Using our model, ADVC – rhinovirus (HRV), RSVA - HRV, and RSVB - HRV pairings occurred at significantly higher prevalence than expected (P < 0.05). In children, HRV-RSVB co-infection were significantly less likely to be hospitalized than patients with HRV mono-infections (ORmono/co = 2.3; 95% CI 1.1 to 4.7; P = 0.028). Additionally, HRV - ADVC co-infected children were less likely to be hospitalized than either HRV (OR_mono/co = 3.3; 95% CI 1.6 to 6.8; P < 0.001) or ADVC (OR_mono/co = 1.9; 95% CI 1.1 to 3.2; P = 0.024) mono-infected children. Regardless of the infecting virus, children were less likely to be hospitalized than similarly-infected adults.

Conclusion

Respiratory viral co-infections are largely a pediatric phenomenon. Select viral pairings occur more often than predicted by our model, many of which are associated with altered severity of resultant disease.

Disclosures

All authors: No reported disclosures.

782. Provider to Provider Electronic Consultation (E-consult): A Tool for the Pediatric Infectious Diseases Specialist to Document Encounters and Quantify Effort

Background

Curbside consultation is a ubiquitous practice within the medical field informally providing advice to community providers. The electronic consult (E-Consult) allows direct provider-to-provider communication between the primary care provider (PCP) and specialists using a secure electronic platform while documenting these interactions within the patient’s medical record (EMR). They offer PCP’s a forum for asking nonurgent questions. For the specialist, it allows review of the EMR, reduces medical liability of the curbside consult and provides a mechanism for generating RVUs. This service was implemented in our healthcare network (of over 300 pediatricians and pediatric specialists who see more than 500,000 pediatric visits each year) in April 2018. Our aim was to review and analyze the E-consults provided by the Pediatric Infectious Diseases (PID) service.

Methods

Cross-sectional study of E-consults performed by the PID from April 11 -2018-April 22 2019. Clinical queries were categorized by type and tabulated. Consult Billing was as following: Level 1=5 minutes (min); Level 2 =10min; Level 3= 15 minutes; Level 4= 25 minutes. RVU values were institutionally derived and assigned.

Results

We performed 171 E- consults with an average of 13 per month (range 3–18) generated from 59 providers (52 (88%) physicians and 7 (12%) certified nurse practitioners). Common reasons for the E-consult included: vaccine questions (25.7%), diagnosis questions (21.6%), exposure questions (20.4%) and treatment recommendations (10.5%). Of vaccine questions, 43% related to vaccine schedules /boosters, 13% vaccines for travel and 11.3% vaccines for the immunocompromised host. Consultation in the PID clinic was recommended for 25.7% patients, 9% requiring urgent evaluation. Of the 171 E-consults, 12.2% were evaluated in the PID clinic and 5% by another specialty. Billing was performed for 168 of the E consults= 9 level 1, 35 level 2, 83 level 3 and 41 level 4 generating 161 RVUs (equivalent to 53 level 4 new outpatient visits at our institution).

Conclusion

E-consults are an alternative to informal curbside consults for nonurgent clinical queries. Encounters are documented in the EMR and professional effort devoted to the task is tracked providing an additional source of RVU generation for the PID physician.

Disclosures

All authors: No reported disclosures.

Human Coronavirus (HCoV) Infection Among Adults in Cleveland, Ohio: An Increasingly Recognized Respiratory Pathogen

Background

Human Coronaviruses (CoV) have been long recognized as a common cause of respiratory tract disease including severe respiratory tract illness, yet there are few recent studies characterizing disease among adults in the United States. Here, we describe CoV infections and clinical characteristics among adults (>18 years) presenting with respiratory illness in Cleveland, Ohio.

Methods

Between February 1, 2016 and April 30, 2017, 2949 nasopharyngeal swab specimens were analyzed by NxTAG Respiratory Pathogen Panel in adults presenting with respiratory illness at MetroHealth Medical Center. Clinical data were collected on adults whose samples screened positive for CoV-HKU1, CoV-OC43, CoV-229E or CoV-NL63.

Results

Coronaviruses were detected in 192 (6.5%) adults including 105 (3.5%) OC43, 67 (2.3%) 229E, 13 (0.4%) HKU1 and 7 (0.2%) NL63. The majority of adults with coronavirus infection were females (66.2%) with a median age of 53 years. Common comorbidities included smoking (40.0%), asthma (38.0%), COPD (35.4%), and inhaled corticosteroid use (28.6%). Eighty-five (46.4%) required admission to the hospital. Common presenting symptoms included shortness of breath (42.7%) and cough (31.0%) whereas fever was uncommon (12.5%). Gastrointestinal symptoms were more common in HKU1 and NL63 infected adults. Seventy-three percent of coronavirus disease occurred between the months of January and March. Despite the recognition of coronavirus infection, 70 (36.5%) received antibiotics for their disease.

Conclusion

This study provides needed insight into clinical characteristics and severity associated with coronavirus infection in adults. Coronavirus infection should be considered in differential diagnosis of respiratory tract illness in adults including those that require hospitalization, have a history of smoking and have pulmonary comorbidities.

Disclosures

All authors: No reported disclosures.

Cetylpyridinium Chloride (CPC) Exhibits Potent, Rapid Activity Against Influenza Viruses in vitro and in vivo

Background:

There is a continued need for strategies to prevent influenza. While cetylpyridinium chloride (CPC), a broad-spectrum antimicrobial agent, has an extensive antimicrobial spectrum, its ability to affect respiratory viruses has not been studied in detail.

Objectives:

Here, we evaluate the ability of CPC to disrupt influenza viruses in vitro and in vivo.

Methods:

The virucidal activity of CPC was evaluated against susceptible and oseltamivir- resistant strains of influenza viruses. The effective virucidal concentration (EC) of CPC was determined using a hemagglutination assay and tissue culture infective dose assay. The effect of CPC on viral envelope morphology and ultrastructure was evaluated using transmission electron microscopy (TEM). The ability of influenza virus to develop resistance was evaluated after multiple passaging in sub-inhibitory concentrations of CPC. Finally, the efficacy of CPC in formulation to prevent and treat influenza infection was evaluated using the PR8 murine influenza model.

Results:

The virucidal effect of CPC occurred within 10 minutes, with mean EC₅₀ and EC_2log ranging between 5 to 20 μg/mL, for most strains of influenza tested regardless of type and resistance to oseltamivir. Examinations using TEM showed that CPC disrupted the integrity of the viral envelope and its morphology. Influenza viruses demonstrated no resistance to CPC despite prolonged exposure. Treated mice exhibited significantly increased survival and maintained body weight compared to untreated mice.

Conclusions:

The antimicrobial agent CPC possesses virucidal activity against susceptible and resistant strains of influenza virus by targeting and disrupting the viral envelope. Substantial virucidal activity is seen even at very low concentrations of CPC without development of resistance. Moreover, CPC in formulation reduces influenza-associated mortality and morbidity in vivo.

Human Coronavirus-HKU1 Infection Among Adults in Cleveland, Ohio

BACKGROUND

Human coronaviruses (CoV) have been long recognized as a common cause of respiratory tract disease including severe respiratory tract illness. Coronavirus-HKU1 has been described predominantly among children less than 5 years of age in the United States with few studies characterizing the disease spectrum among adults.

METHODS

Nasopharyngeal specimens of patients with respiratory symptoms were analyzed for CoV-HKU1 by NxTAG Respiratory Pathogen Panel multiplex assay from February 7, 2016 to April 30, 2016. Epidemiologic, clinical, and laboratory data were collected on adults (patients >18 years) whose samples screened positive.

RESULTS

Of 832 adult respiratory specimens screened, 13 (1.6%) cases of CoV-HKU1 were identified. Adults age ranged between 23 and 75 years and 6 (46%) were males. All of whom had 1 or more respiratory symptoms, and 5 (38%) also reported 1 or more gastrointestinal symptoms. Eleven (85%) reported history of smoking and 5 (38%) used inhaled steroids. Seven (54%) required hospitalization, 5 (71%) of these needed supplemental oxygen, and 2 (29%) were admitted to intensive care. Median length of hospitalization was 5 days. Eight (62%) received antibiotics despite identification of CoV-HKU1. Infectious work-up in 1 patient who died did not reveal any other pathogen. In 2 (15%) CoV-HKU1-positive adults, the only viral coinfection detected was influenza A.

CONCLUSIONS

Coronavirus-HKU1 accounted for 1.6% of adult respiratory infections and should be considered in differential diagnosis of severe respiratory illnesses among adults.

Randomized, double-blind, placebo-controlled clinical trial to assess the safety and effectiveness of a novel dual-action oral topical formulation against upper respiratory infections

Background

Current prevention options for upper respiratory infections (URIs) are not optimal. We conducted a randomized, double-blinded, placebo-controlled pilot clinical trial to evaluate the safety and efficacy of ARMS-I™ (currently marketed as Halo™) in the prevention of URIs.

Methods

ARMS-I is patented novel formulation for the prevention and treatment of influenza, comprising a broad-spectrum antimicrobial agent (cetylpyridinium chloride, CPC) and components (glycerin and xanthan gum) that form a barrier on the host mucosa, thus preventing viral contact and invasion. Healthy adults (18–45 years of age) were randomized into ARMS-I or placebo group (50 subjects each). The drug was sprayed intra-orally (3× daily) for 75 days. The primary objectives were to establish whether ARMS-I decreased the frequency, severity or duration of URIs. Secondary objectives were to evaluate safety, tolerability, rate of virus detection, acceptability and adherence; effect on URI-associated absenteeism and medical visits; and effect of prior influenza vaccination on study outcomes.

Results

Of the 94 individuals who completed the study (placebo: n = 44, ARMS-I: n = 50), six presented with confirmed URI (placebo: 4, ARMS-I: 2), representing a 55% relative reduction, albeit this was statistically not significant). Influenza, coronavirus or rhinovirus were detected in three participants; all in the placebo group. Moreover, frequency of post-treatment exit visits was reduced by 55% in ARMS-I compared to the placebo group (N = 4 and 2, respectively). Fever was reported only in the placebo group. ARMS-I significantly reduced the frequency and severity of cough and sore throat, and duration of cough (P ≤ .019 for all comparisons). ARMS-I was safe, well tolerated, had high acceptability and high adherence to medication use. Medical visits occurred only in the placebo group while absenteeism did not differ between the two arms. Prior influenza vaccination had no effect on study outcome.

Conclusions

This randomized proof-of-concept clinical trial demonstrated that ARMS-I tended to provide protection against URIs in the enrolled study participants, while reducing severity and duration of cough and sore throat. A clinical trial with a larger number of study participants is warranted.

Trial registration

ClinicalTrials.gov NCT02644135 (retrospectively registered).

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2177-8) contains supplementary material, which is available to authorized users.

HSV IgG antibody inhibits virus detection in CSF

BACKGROUND

Before PCR testing of cerebrospinal fluid (CSF), laboratory diagnosis of herpes encephalitis (HSE) was based on virus isolation from brain biopsy. Viral isolation from CSF has limited clinical value due to low virus recovery; the cause for which has not been demonstrated.

OBJECTIVE

To investigate the role of anti-HSV antibodies on recovery of HSV from CSF via cell culture.

STUDY DESIGN

HSV-positive CSF samples were evaluated for their ability to neutralize HSV in cell culture. The presence of HSV-specific IgG and IgM antibodies were analyzed using HSV-infected cells. To identify whether HSV-specific IgG is the cause of viral inhibition, IgG was removed using anti-human IgG magnetic beads. Viral inhibition from CSF originating from asymptomatic patients was examined as a comparison.

RESULTS

CSF from 13 patients with acute HSV CNS disease was analyzed. All displayed high levels of viral neutralization to both HSV-1 and HSV-2 regardless of the infecting subtype. Interestingly, all the CSF samples stained strongly for anti-IgG antibody but none for anti-IgM antibody. Removal of IgG from CSF eliminated the viral inhibitory activity. Neutralizing IgG antibody was also found to be common in CSF of most patients, even in the absence of HSV disease.

CONCLUSIONS

Viral specific IgG is the major determinant of viral inhibition in CSF and prevents virus recovery in cell culture. In CSF from HSE un-infected patients, viral inhibitory IgG originates from circulating serum antibody and is commonly present in CSF. However, this inhibitory IgG is not protective for the development of HSV disease.

Serological studies confirm the novel astrovirus HMOAstV-C as a highly prevalent human infectious agent

Molecular identification of a microbe is the first step in determining its prevalence of infection and pathogenic potential. Detection of specific adaptive immune responses can provide insights into whether a microbe is a human infectious agent and its epidemiology. Here we characterized human anti-IgG antibody responses by luciferase immunoprecipitation systems (LIPS) against two protein fragments derived from the capsid protein of the novel HMOAstV-C astrovirus. While antibodies to the N-terminal fragment were not informative, the C-terminal capsid fragment of HMOAstV-C showed a high frequency of immunoreactivity with serum from healthy blood donors. In contrast, a similar C-terminal capsid fragment from the related HMOAstV-A astrovirus failed to show immunoreactivity. Detailed analysis of adult serum from the United Sates using a standardized threshold demonstrated HMOAstV-C seropositivity in approximately 65% of the samples. Evaluation of serum samples from different pediatric age groups revealed that the prevalence of antibodies in 6-12 month, 1-2 year, 2-5 year and 5-10 year olds was 20%, 23%, 32% and 36%, respectively, indicating rising seroprevalence with age. Additionally, 50% (11/22) of the 0-6 month old children showed anti-HMOAstV-C antibody responses, likely reflecting maternal antibodies. Together these results document human humoral responses to HMOAstV-C and validate LIPS as a facile and effective approach for identifying humoral responses to novel infectious agents.

Human coronaviruses are uncommon in patients with gastrointestinal illness

Background

Coronaviruses infect numerous animal species causing a variety of illnesses including respiratory, neurologic and enteric disease. Human coronaviruses (HCoV) are mainly associated with respiratory tract disease but have been implicated in enteric disease.

Objectives

To investigate the frequency of coronaviruses in stool samples from children and adults with gastrointestinal illness by RT-PCR.

Study design

Clinical samples submitted for infectious diarrhea testing were collected from December 2007 through March 2008. RNA extraction and RT-PCR was performed for stools negative for Clostridium difficile using primer sets against HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1. Clinical data from samples positive for coronaviruses were reviewed and recorded.

Results

Samples from 479 patients were collected including 151 pediatric (≤18 years), and 328 adults (>18 years). Of these samples, 4 patients (1.3%, 2 adult; 2 pediatric) screened positive for the presence of a coronavirus. All detected coronaviruses were identified as HCoV-HKU1. No stools screened positive for either HCoV-229E, HCoV-NL63 or HCoV-OC43. All HCoV-HKU1 positive samples occurred between mid-January to mid-February. Clinical manifestations from HCoV-HKU1 positive patients included diarrhea, emesis and respiratory complaints. Three (75%) patients were admitted to the hospital with a median length of stay of 6 days.

Conclusions

Coronaviruses as a group are not commonly identified in stool samples of patients presenting with gastrointestinal illness. HCoV-HKU1 can be identified in stool samples from children and adults with gastrointestinal disease, with most individuals having respiratory findings as well. No stool samples screened positive for HCoV-NL63, HCoV-229E, or HCoV-OC43.

Pulmonary tuberculosis presenting as fever without source in a pediatric patient with acute lymphoblastic leukemia

Children who undergo treatment for malignancies are at high for infection with both typical and opportunistic pathogens. Fever in these children prompts extensive evaluation and empiric treatment with broad-spectrum antimicrobials. In the United States (US), tuberculosis is an infrequently reported cause of fever in the pediatric cancer patient and has not been well described. In this report we describe a case of primary pulmonary tuberculosis (TB) in a boy with precursor B-cell acute lymphoblastic leukemia (ALL) and review the pertinent literature.

Seroepidemiology of group I human coronaviruses in children

BACKGROUND

Recently, several new human coronaviruses have been identified.

OBJECTIVES

To define the seroepidemiology of group I human coronaviruses.

STUDY DESIGN

A recombinant protein enzyme linked immunosorbent assay (ELISA) based on portions of the nucleocapsid protein of group I human coronaviruses was developed and was used to screen serum from 243 children and young adults.

RESULTS

For HCoV-229E, the percentages of seropositive individuals were 57.1% for infants <2 months old; 38.9% for infants 2-3 months old; 4.7% for infants 4-5 months old; 42.9-50.0% for infants 6-12 months old; 34.8-62.5% for individuals 1-20 years old. For HCoV-NL63, the percentages of seropositive individuals were 45.2% for infants <2 months old; 11.1% for infants 2-3 months old; 4.7% for infants 4-5 months old; 28.6-40.0% for infants 6-12 months old; 25.0-70.3% for individuals 1-20 years old.

CONCLUSIONS

Infection with these viruses is common in childhood though the prevalence of these viruses may vary from year to year.

Coronavirus HKU1 infection in the United States

In 2005, a new human coronavirus, HCoV-HKU1, was identified in Hong Kong. We screened respiratory specimens collected from December 16, 2001, to December 15, 2002, from children <5 years of age who tested negative for respiratory syncytial virus, parainfluenza viruses, influenza virus, and adenovirus for HCoV-HKU1 by reverse transcription-polymerase chain reaction. Overall, 1,048 respiratory specimens from 851 children were tested, and 9 HCoV-HKU1-positive children (1%) were identified, 2 of whom had 2 positive specimens. Children who had HCoV-HKU1 infection had evidence of either upper or lower respiratory tract infection or both. Two patients had disease beyond the respiratory tract. HCoV-HKU1 was identified from December 2001 to February 2002. Sequence analyses suggest that a single strain was circulating. HCoV-HKU1 is therefore likely circulating in the United States and is associated with upper and lower respiratory tract disease.

Human metapneumovirus and exacerbations of chronic obstructive pulmonary disease

OBJECTIVE

Respiratory viruses are a common trigger for exacerbations of chronic obstructive pulmonary disease (COPD). Human metapneumovirus (hMPV) is a paramyxovirus associated with respiratory tract infections and wheezing. Our aim was to determine whether hMPV was associated with exacerbations of COPD.

METHODS

The study was designed as an observational cohort study carried out in a 944-bed urban teaching hospital located in New Haven, Connecticut. Between December 2002 and May 2003, patients hospitalized due to an exacerbation of COPD were identified. Nasopharyngeal specimens obtained from these patients were tested for human metapneumovirus by RT-PCR and for respiratory syncytial virus, influenza A and B, parainfluenza-1, -2, and -3 and adenovirus by a cytospin-enhanced direct immunofluorescence assay and/or viral culture.

RESULTS

Fifty individuals met enrollment criteria and hMPV was identified in 6 (12%), respiratory syncytial virus in 4 (8%), influenza A in 2 (4%) and parainfluenza type 3 in 1 (2%) patients. Both A and B hMPV genotypes were identified in patients hospitalized due to exacerbations of COPD.

CONCLUSION

hMPV was frequently identified in patients hospitalized due to an exacerbation of COPD. Further studies are necessary to determine the epidemiology and the impact of hMPV in COPD patients.

Seroepidemiology of human metapneumovirus (hMPV) on the basis of a novel enzyme-linked immunosorbent assay utilizing hMPV fusion protein expressed in recombinant vesicular stomatitis virus

Human metapneumovirus (hMPV) is a newly identified human respiratory virus now recognized as a major respiratory pathogen of infants and children. To define the seroepidemiology of hMPV, we developed a novel enzyme-linked immunosorbent assay (ELISA) based on expression of the fusion protein of hMPV (hMPV F) in recombinant vesicular stomatitis virus (VSV). Western blot analysis using an hMPV F-specific antiserum confirmed the expression of hMPV in recombinant VSV. The ELISA is specific for hMPV F; antibody specific for the most closely related human paramyxovirus, respiratory syncytial virus, does not bind to hMPV F. Overall, 216 serum specimens were tested. The percentages of seropositive individuals were 89.1% in children < or =5 months old, 55.0% in children 6 to 11 months old, 36.0% in children 12 to 23 months old, 45.0% in children 24 to 47 months old, 77.3% in children 48 to 59 months old, 91.3% in children 5 to 10 years old, and 95.5% for individuals 11 to 20 years old. This is the first seroepidemiological survey of hMPV in the United States and the first analysis to determine the prevalence of antibody to a specific hMPV protein. The data suggest that exposure to hMPV is common in childhood and that hMPV F is an antigenic determinant of hMPV.

Association between a novel human coronavirus and Kawasaki disease

Kawasaki disease is a systemic vasculitis of childhood; its etiology is unknown. We identified evidence of a novel human coronavirus, designated “New Haven coronavirus” (HCoVNH), in respiratory secretions from a 6-month-old infant with classic Kawasaki disease. To further investigate the possible association between HCoV-NH infection and Kawasaki disease, we conducted a case-control study. Specimens of respiratory secretions from 8 (72.7%) of 11 children with Kawasaki disease and from 1 (4.5%) of 22 control subjects (children without Kawasaki disease matched by age and the time the specimens were obtained) tested positive for HCoVNH by reverse-transcriptase polymerase chain reaction (Mantel-Haenszel matched odds ratio, 16.0 [95% confidence interval, 3.4–74.4]; P = .0015). These data suggest that HCoV-NH infection is associated with Kawasaki disease.

Evidence of a novel human coronavirus that is associated with respiratory tract disease in infants and young children

BACKGROUND

The etiological agents responsible for a substantial proportion of respiratory tract diseases have not been identified. We sought to determine whether novel human coronaviruses (HCoVs) are circulating in New Haven, Connecticut, and, if so, whether they are associated with respiratory tract disease in infants and young children.

METHODS

We developed a polymerase chain reaction (PCR)-based approach for screening specimens from the respiratory tracts of symptomatic children. PCR probes that target regions of the replicase 1a gene that are conserved among genetically diverse animal CoVs and HCoVs were designed. Using these probes, we identified genomic sequences of a novel HCoV, designated "New Haven coronavirus" (HCoV-NH). Thereafter, we designed specific probes to screen respiratory specimens from children <5 years old for this novel HCoV. Clinical features associated with HCoV-NH infection were identified.

RESULTS

Seventy-nine (8.8%) of 895 children tested positive for HCoV-NH. Cough, rhinorrhea, tachypnea, fever, abnormal breath sounds, and hypoxia were the most common findings associated with HCoV-NH infection. Sequence analysis revealed that HCoV-NH is closely related to a novel HCoV recently reported in The Netherlands.

CONCLUSIONS

The novel HCoVs identified in New Haven and The Netherlands are similar and likely represent the same species. This newly discovered virus may have worldwide distribution and may account for a significant proportion of respiratory tract disease in infants and young children.

A 1-year experience with human metapneumovirus in children aged <5 years

Human metapneumovirus (hMPV) is a recently discovered respiratory pathogen. We tested respiratory specimens for the presence of hMPV by reverse-transcription polymerase chain reaction. These specimens were obtained over a 1-year period from children aged <5 years and had negative results by the direct fluorescent antibody test for respiratory syncytial virus, influenza A and B, parainfluenza viruses 1-3, and adenovirus. Overall, 54 (8.1%) of 668 individuals tested positive for hMPV. During March and April of the study period, hMPV was detected in 17.6% and 25.0% of specimens tested, respectively. At least 2 distinct genotypes of hMPV circulated during the study period. Fever, tachypnea, cough, rhinorrhea, retractions of the chest wall, and wheezing were common findings. Of hMPV-positive children, 60.4% were aged <12 months. hMPV accounted for a small but significant proportion of respiratory-tract disease in infants and children.

Human metapneumovirus infection in the United States: clinical manifestations associated with a newly emerging respiratory infection in children

OBJECTIVE

Respiratory tract infections are a leading cause of morbidity and mortality worldwide. Recently, a newly identified human respiratory virus, human metapneumovirus (hMPV), was reported by investigators in the Netherlands. We sought to determine whether hMPV was circulating in our community and to determine the clinical features associated with hMPV infection.

METHODS

Respiratory specimens from children who were younger than 5 years and had a negative result for respiratory syncytial virus, influenza A and B, parainfluenza viruses 1 to 3, and adenovirus by direct fluorescent antibody test were screened for hMPV by reverse transcriptase-polymerase chain reaction. Samples were collected from October 30, 2001, to February 28, 2002.

RESULTS

Of the 296 patients screened, 19 (6.4%) had evidence of hMPV infection. hMPV was identified in patients with either upper or lower respiratory tract infection or both. Clinical manifestations included wheezing, hypoxia, and abnormal findings on chest radiographs (eg, focal infiltrates, peribronchial cuffing). Nosocomial infection occurred in at least 1 patient.

CONCLUSIONS

hMPV is circulating in the United States and is associated with respiratory tract disease in patients with respiratory illnesses not caused by respiratory syncytial virus, influenza, parainfluenza viruses, and adenovirus. Additional studies are required to define the epidemiology and the extent of disease in the general population caused by hMPV.