[Show abstract][Hide abstract] ABSTRACT: Background. Viral lower respiratory tract illness (LRTI) frequently causes adult hospitalization and is linked to antibiotic overuse. European studies suggest serum procalcitonin (PCT) may be used to guide antibiotic therapy. We conducted a trial assessing the feasibility of using PCT algorithms with viral testing to guide antibiotic use in a US hospital. ClinicalTrials.gov (NCT01907659) Methods. 300 patients hospitalized with non-pneumonic LRTI from October 2013-April 2014 were randomized 1:1 to standard care or PCT-guided care and viral PCR testing. The primary outcome was antibiotic exposure and safety was assessed at one and three months. Results. Viruses were identified in 42% and 80% of intervention subjects had PCT values<0.25ug/ml. There were no significant differences in antibiotic use or adverse events between intervention and nonintervention subjects. Subgroup analyses revealed fewer viral (+)/low PCT subjects discharged on antibiotics (20% vs.45%,p=0.002) and shorter antibiotic duration in algorithm adherent versus nonintervention patients (2.0 vs.4.0 days,p=0.004). Compared to historical controls (2008-2011), antibiotic duration in nonintervention patients decreased by 2 days (6.0 vs.4.0 days,p<0.001), suggesting a study effect. Conclusions. Although antibiotic use was similar in the two arms, subgroup analyses of intervention group suggest physicians responded to viral/biomarker data. These data can inform design of future US studies.
Preview · Article · Apr 2015 · The Journal of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Respiratory tract infections (RTI) frequently cause hospital admissions among adults. Diagnostic viral reverse transcriptase PCR (RT-PCR) of nose and throat swabs (NTS) is useful for patient care by informing antiviral use and appropriate isolation. However, automated RT-PCR systems are not amenable to utilizing sputum due to its viscosity. We evaluated a simple method of processing sputum samples in a fully automated respiratory viral panel RT-PCR assay (FilmArray). Archived sputum and NTS samples collected in 2008-2012 from hospitalized adults with RTI were evaluated. A subset of sputum samples positive for 10 common viruses by a uniplex RT-PCR was selected. A sterile cotton-tip swab was dunked in sputum, swirled in 700 mu L of sterile water (dunk and swirl method) and tested by the FilmArray assay. Quantitative RT-PCR was performed on "dunked" sputum and NTS samples for influenza A (Flu A), respiratory syncytial virus (RSV), coronavirus OC43 (OC43), and human metapneumovirus (HMPV). Viruses were identified in 31% of 965 illnesses using a uniplex RT-PCR. The sputum sample was the only sample positive for 105 subjects, including 35% (22/64) of influenza cases and significantly increased the diagnostic yield of NTS alone (302/965 [31%] versus 197/965 [20%]; P = 0.0001). Of 108 sputum samples evaluated by the FilmArray assay using the dunk and swirl method, 99 (92%) were positive. Quantitative RT-PCR revealed higher mean viral loads in dunked sputum samples compared to NTS samples for Flu A, RSV, and HMPV (P = 0.0001, P = 0.006, and P = 0.011, respectively). The dunk and swirl method is a simple and practical method for reliably processing sputum samples in a fully automated PCR system. The higher viral loads in sputa may increase detection over NTS testing alone.
[Show abstract][Hide abstract] ABSTRACT: Background:
Respiratory tract infection is one of the most common reasons for hospitalization among adults, and recent evidence suggests that many of these illnesses are associated with viruses. Although bacterial infection is known to complicate viral infections, the frequency and impact of mixed viral-bacterial infections has not been well studied.
Adults hospitalized with respiratory illness during 3 winters underwent comprehensive viral and bacterial testing. This assessment was augmented by measuring the serum level of procalcitonin (PCT) as a marker of bacterial infection. Mixed viral-bacterial infection was defined as a positive viral test result plus a positive bacterial assay result or a serum PCT level of ≥ 0.25 ng/mL on admission or day 2 of hospitalization.
Of 842 hospitalizations (771 patients) evaluated, 348 (41%) had evidence of viral infection. A total of 212 hospitalizations (61%) involved patients with viral infection alone. Of the remaining 136 hospitalizations (39%) involving viral infection, results of bacterial tests were positive in 64 (18%), and PCT analysis identified bacterial infection in an additional 72 (21%). Subjects hospitalized with mixed viral-bacterial infections were older and more commonly received a diagnosis of pneumonia. Over 90% of hospitalizations in both groups involved subjects who received antibiotics. Notably, 4 of 10 deaths among subjects hospitalized with viral infection alone were secondary to complications of Clostridium difficile colitis.
Bacterial coinfection is associated with approximately 40% of viral respiratory tract infections requiring hospitalization. Patients with positive results of viral tests should be carefully evaluated for concomitant bacterial infection. Early empirical antibiotic therapy for patients with an unstable condition is appropriate but is not without risk.
No preview · Article · May 2013 · The Journal of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Background
Human rhinoviruses (HRV) can be detected by RT-PCR in a large proportion of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) but can also be detected in COPD patients without symptoms.Objectives
The purpose of this study was to compare host, virologic and environmental factors associated with symptomatic and asymptomatic HRV infection.Study designOne hundred twenty-seven patients with COPD were evaluated every 2 months routinely and for all respiratory illnesses during a one year period. RT-PCR testing for HRV was performed on nasal and sputum samples. Amplification products were sequenced to assign species HRV-A, B or C. Clinical, virologic and environmental factors were compared for those infected with HRV compared to those without HRV infection as well as symptomatic HRV infection and asymptomatic HRV infection.ResultsHRVs were detected in 29 participants during 20 illnesses and 11 routine visits. HRV was detected in nasal samples from 15/102 (14.7%) illnesses compared to 2/685 (0.4%) routine visits (p < .0001). Sputum samples were also more frequently positive from illnesses than routine visits [14/72 (19.4%) vs. 16/310 (5.2%) p < .0001]. Contact with school age children was the only factor that was significantly associated with HRV infection and symptomatic HRV illness. Severity of underlying lung disease and virologic factors were not associated with symptomatic illness.Conclusions
Contact with school aged children is a risk factor for both infection and symptomatic HRV illness. Attention to good hand hygiene and avoidance of direct contact with ill children may help patients with COPD avoid HRV related illness.
No preview · Article · Dec 2012 · Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology
[Show abstract][Hide abstract] ABSTRACT: Serum procalcitonin levels have been used as a biomarker of invasive bacterial infection and recently have been advocated to guide antibiotic therapy in patients with chronic obstructive pulmonary disease (COPD). However, rigorous studies correlating procalcitonin levels with microbiologic data are lacking. Acute exacerbations of COPD (AECOPD) have been linked to viral and bacterial infection as well as noninfectious causes. Therefore, we evaluated procalcitonin as a predictor of viral versus bacterial infection in patients hospitalized with AECOPD with and without evidence of pneumonia.
Adults hospitalized during the winter with symptoms consistent with AECOPD underwent extensive testing for viral, bacterial, and atypical pathogens. Serum procalcitonin levels were measured on day 1 (admission), day 2, and at one month. Clinical and laboratory features of subjects with viral and bacterial diagnoses were compared.
In total, 224 subjects with COPD were admitted for 240 respiratory illnesses. Of these, 56 had pneumonia and 184 had AECOPD alone. A microbiologic diagnosis was made in 76 (56%) of 134 illnesses with reliable bacteriology (26 viral infection, 29 bacterial infection, and 21 mixed viral bacterial infection). Mean procalcitonin levels were significantly higher in patients with pneumonia compared with AECOPD. However, discrimination between viral and bacterial infection using a 0.25 ng/mL threshold for bacterial infection in patients with AECOPD was poor.
Procalcitonin is useful in COPD patients for alerting clinicians to invasive bacterial infections such as pneumonia but it does not distinguish bacterial from viral and noninfectious causes of AECOPD.
Preview · Article · Feb 2012 · International Journal of COPD
[Show abstract][Hide abstract] ABSTRACT: Diagnostic tests for respiratory viral infections have traditionally been performed on nasopharyngeal swabs or washings. Reverse transcriptase PCR (RT-PCR) is rapid, sensitive, and specific for viral infection diagnosis but is rarely applied to sputum samples. Thus, we evaluated the diagnostic yield of RT-PCR for detection of nine virus types by the use of nose and throat swabs (NTS) and sputum samples from patients admitted to the hospital with acute respiratory tract illnesses. Adults hospitalized with acute respiratory tract illnesses were recruited during the winters of 2008 and 2009. At enrollment, combined nose and throat swabs and sputum samples were collected for RT-PCR for detection of nine common respiratory virus types. A total of 532 subjects admitted for 556 respiratory illnesses were enrolled. A total of 189 virus strains were identified. The diagnostic yields for detection of any virus were 23% (126/556) for NTS RT-PCR and 36% (146/404) for sputum RT-PCR. A total of 83 (44%) of 189 viral detections were positive by both methods, 43 (23%) were positive by NTS alone, and 63 (33%) were positive only with sputum samples. The inclusion of RT-PCR performed with sputum samples significantly increased the diagnostic yield for respiratory viral infections in adults. Further studies designed to adapt the use of sputum samples for commercial RT-PCR respiratory virus assays are needed.
Preview · Article · Nov 2011 · Journal of clinical microbiology
[Show abstract][Hide abstract] ABSTRACT: Human metapneumovirus (hMPV) is a significant cause of respiratory illness in children and adults. Presently, there are no human data regarding the role of antibody for protection against hMPV illness. Therefore, we measured serum and nasal antibody titers against hMPV by EIA and neutralization assay at baseline in hMPV infected adults compared with subjects who remained uninfected. Antibody titers were also compared in patients with mild and severe illness. Mean serum binding and neutralizing antibody titers of hMPV infected subjects were significantly lower compared to uninfected subjects. Seventy-one percent of subjects with titers <or=10.5 (log2) were infected compared to 36% with titers >10.5, p=0.003. There was no difference in the mean acute antibody titers for patients with mild compared to severe illness. Serum antibody may play a role in protection from hMPV infection supporting the development of an hMPV vaccine that stimulates humoral immunity.
[Show abstract][Hide abstract] ABSTRACT: Human metapneumovirus (hMPV) is a newly discovered virus which causes respiratory illness in persons of all ages.
A simple and rapid method to determine neutralizing antibody titers against hMPV is needed to facilitate the development of vaccines and therapeutics for hMPV. Therefore, we sought to adapt the methodology used for RSV microneutralization assay (MNA) to measure neutralizing antibody titers against hMPV.
Serial 2-fold dilutions of serum were made in 96 well microtiter plates and incubated with approximately 50pfu of hMPV A or B strain for 60min at room temperature. LLC-MK2 cells were added to the serum-virus mixtures and plates incubated at 35 degrees C in CO(2) for 5 days. Plates were fixed with acetone; air dried, blocked and then developed with monoclonal antibody to the hMPV N protein followed by horse radish peroxidase labeled antibody and substrate. Neutralization titer was defined as the titer of serum that reduced color development by 50% compared to the positive control wells.
Titers measured by MNA correlated well with those determined by standard plaque reduction assay (R=0.77). Neutralization titers determined by MNA demonstrated excellent inter-assay variability (coefficient of variance=7%). In addition, there was good correlation of antibody titers from 10 hMPV infected adults measured by MNA using either group A or group B hMPV (R=0.87).
MNA is a simple and reproducible method for the measurement of serum neutralizing antibody against hMPV.
Preview · Article · Oct 2009 · Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology
[Show abstract][Hide abstract] ABSTRACT: To determine the frequency and types of respiratory viruses circulating in Boston long-term care facilities (LTCFs) during a 3-year period.
Thirty-three Boston-area LTCFs over a 3-year period.
Residents of long-term care who had previously participated in a trial of vitamin E supplementation and had paired serum samples available for viral analysis.
Viral antibody titers to eight respiratory viruses (influenza A and B, respiratory syncytial virus (RSV), parainfluenza virus serotype three (PIV-3), PIV-2, human metapneumovirus (hMPV), and coronaviruses 229E and OC43) were measured using enzyme immunoassay at baseline and 53 weeks. Infection was defined as a more than quadrupling of viral titers. Clinical data on respiratory illnesses were collected throughout the study period.
A total of 617 persons were enrolled in the trial. Of these, 382 (62%) had sera available for viral analysis. A total of 204 viral infections were documented in 157 subjects. Serological responses to all eight viruses were documented, with hMPV (12.8%) and coronavirus 229E (10.5%) being the most common and PIV-2 (2.4%) the least common. The occurrence of bronchitis (P=.007), pneumonia (P=.02), and any lower respiratory tract infection (P=.002) was significantly associated with having a viral diagnosis.
A wide range of respiratory viruses cocirculates in LTCFs and contributes to respiratory illness morbidity in these populations.
Preview · Article · Jul 2008 · Journal of the American Geriatrics Society
[Show abstract][Hide abstract] ABSTRACT: Recently, respiratory syncytial virus (RSV) RNA has been identified by reverse transcriptase-polymerase chain reaction (RT-PCR) from a high percentage of patients with stable chronic obstructive pulmonary disease (COPD). These data raise the possibility of persistent low-grade infection in this population, which could have implications in COPD pathogenesis.
RSV persistence was investigated by testing respiratory secretions from subjects with COPD during illness and at regular intervals over 1 yr.
Nasal and sputum samples from subjects with COPD were tested by one-tube nested RT-PCR for RSV every 2 mo and during respiratory illnesses for 1 yr. Subjects positive for RSV were evaluated weekly until negative in two consecutive samples. Nasal secretions and serum were tested for RSV antibody. A rise of fourfold or greater was defined as evidence of RSV infection.
A total of 112 patients were enrolled and the illnesses of 92 patients were evaluated. RSV was detected by RT-PCR in 6/92 (6.5%) illness nasal samples versus 0/685 routine nasal samples and in 5/69 (7.2%) illness sputum samples versus 3 /315 (0.9%) routine. Four additional RSV infections were identified by serum antibody responses. Of the RSV infections 86% were associated with serum or nasal antibody responses and 73% had symptoms of acute respiratory illness.
Most RSV infections in patients with COPD are associated with symptomatic respiratory illnesses and measurable immune responses. Our data do not support the concept of RSV persistence in this population.
Preview · Article · Apr 2006 · American Journal of Respiratory and Critical Care Medicine
[Show abstract][Hide abstract] ABSTRACT: Respiratory syncytial virus (RSV) is an increasingly recognized cause of illness in adults. Data on the epidemiology and clinical effects in community-dwelling elderly persons and high-risk adults can help in assessing the need for vaccine development.
During four consecutive winters, we evaluated all respiratory illnesses in prospective cohorts of healthy elderly patients (> or =65 years of age) and high-risk adults (those with chronic heart or lung disease) and in patients hospitalized with acute cardiopulmonary conditions. RSV infection and influenza A were diagnosed on the basis of culture, reverse-transcriptase polymerase chain reaction, and serologic studies.
A total of 608 healthy elderly patients and 540 high-risk adults were enrolled in prospective surveillance, and 1388 hospitalized patients were enrolled. A total of 2514 illnesses were evaluated. RSV infection was identified in 102 patients in the prospective cohorts and 142 hospitalized patients, and influenza A was diagnosed in 44 patients in the prospective cohorts and 154 hospitalized patients. RSV infection developed annually in 3 to 7 percent of healthy elderly patients and in 4 to 10 percent of high-risk adults. Among healthy elderly patients, RSV infection generated fewer office visits than influenza; however, the use of health care services by high-risk adults was similar in the two groups. In the hospitalized cohort, RSV infection and influenza A resulted in similar lengths of stay, rates of use of intensive care (15 percent and 12 percent, respectively), and mortality (8 percent and 7 percent, respectively). On the basis of the diagnostic codes of the International Classification of Diseases, 9th Revision, Clinical Modification at discharge, RSV infection accounted for 10.6 percent of hospitalizations for pneumonia, 11.4 percent for chronic obstructive pulmonary disease, 5.4 percent for congestive heart failure, and 7.2 percent for asthma.
RSV infection is an important illness in elderly and high-risk adults, with a disease burden similar to that of nonpandemic influenza A in a population in which the prevalence of vaccination for influenza is high. An effective RSV vaccine may offer benefits for these adults.
Preview · Article · May 2005 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: Respiratory syncytial virus (RSV) has recently been recognized as a serious pathogen in elderly and immunocompromised adults.
Diagnosis of acute infection in adults is often difficult due to the insensitivity of viral culture, and reverse transcription-PCR
(RT-PCR) is a more sensitive alternative. The relationship of quantitative RT-PCR to viable virus has never been studied for
RSV. Therefore, we compared a quantitative real-time RT-PCR with viral culture to assess viral load in adult volunteers challenged
with the RSV A2 strain. Twelve of 13 volunteers were infected, and there was a high correlation (r = 0.84) between quantitative RT-PCR and viral titer by cell culture. However, RT-PCR was more sensitive, with 73 of 169 (43%)
samples positive compared to 58 (34%) samples positive by culture. The correlation between the two tests was highest early
in the course of viral shedding (r = 0.91, days 0 to 6), whereas during days 7 to 13, there was more variability (r = 0.70). All subjects were culture negative by day 11, whereas one subject remained RT-PCR positive on day 12. All subjects
were RT-PCR negative at day 28 postinfection. Quantitative RT-PCR has an excellent correlation with viral titers, as measured
by culture, and should be a useful tool for future studies addressing viral load and disease pathogenesis.
Preview · Article · Oct 2003 · Journal of Clinical Microbiology
[Show abstract][Hide abstract] ABSTRACT: Diagnosis of respiratory syncytial virus (RSV) during acute infection in adults is difficult because of the poor sensitivity
of viral culture and antigen detection. A recently developed single-tube nested reverse transcription-PCR (RT-PCR) was compared
to viral culture and serology by enzyme immunoassay for the diagnosis of RSV in adults with respiratory illness. Nasal swab
samples were collected during respiratory illnesses from five groups of subjects: healthy young adults, healthy elderly adults,
adults with chronic heart and lung disease, nursing home residents, and adults admitted to the hospital during the winter
with cardiopulmonary illnesses. Of 1,112 samples for which all three tests were available, 117 were positive by at least one
method and 995 were negative by all methods. One hundred ten were considered true positives because culture and/or serology
was positive. Of these, 80 (73%) were PCR positive compared to 43 (39%) that were culture positive. Seven PCR results were
considered false positives due to negative culture and serology. The overall RT-PCR sensitivity was 73%, and specificity was
99%. These data indicate that RT-PCR is an excellent method for the diagnosis of acute RSV infection in adults.
[Show abstract][Hide abstract] ABSTRACT: Rapid diagnosis of Respiratory Syncytial virus (RSV) infection is difficult in elderly persons due to the low quantities of virus shed. Therefore, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect viral RNA in respiratory secretions. A single-tube nested RT-PCR that used primers from a conserved F gene sequence was developed using a "hanging droplet" to physically separate outer and inner primer pairs during the first round of the PCR reaction. This was accomplished by placing the inner primers in a 5 microL droplet on the underside on the reaction tube cap and mixing after the first round of PCR. As few as 0.05 pfu of virus could be detected and gave positive results with RSV strains that represented the major groups and subgroups of RSV grown in tissue culture. The nested PCR was approximately 100-fold more sensitive than standard single primer PCR reactions and equivalent to standard two-tube nested PCR. Viral RNA was detected in nasopharyngeal samples from 12 of 15 culture positive illnesses and in 5 of 17 culture-negative, seropositive illnesses despite specimen volumes less than 1 microL in some samples. The method was also positive in 14 of 25 elderly volunteers inoculated with a live attenuated RSV vaccine candidate, only one of whom was culture positive. Use of a nested RT-PCR significantly improves the ability to detect RSV in respiratory samples and should improve the ability to rapidly diagnose RSV infection in adults, especially in the elderly.
No preview · Article · Apr 2001 · Journal of Medical Virology
[Show abstract][Hide abstract] ABSTRACT: Little information about immunity to respiratory syncytial virus (RSV) and disease pathogenesis in elderly persons exists. Humoral immunity to RSV was assessed in 41 young, 56 healthy elderly, and 49 frail elderly adults by measuring baseline RSV specific IgG by enzyme immunoassay (EIA) and microneutralization assay (MNA) in serum. A comparison of the immune response of 11 young and 28 elderly persons with natural RSV infection was also performed. Despite significant differences in age and functional status, no decreases in RSV antibody levels by either EIA or MNA were noted in the elderly compared with the young. Mean baseline MNA titers expressed as log2 were 10.5 +/- 1.1 for the young, 10.5 +/- 1.5 for the healthy elderly, and 10.9 +/- 1.6 for the frail elderly. The frail elderly who attend a daycare had the highest RSV titers to F by EIA at 16.6 +/- 2.0, compared with 15.4 +/- 1.4 and 15.1 +/- 1.4 in the healthy elderly and young, respectively. This finding may reflect recent infection due to their communal setting or increased production of non-neutralizing antibody. The immune response of older persons to RSV infection was as vigorous as the younger subjects, with 79% having a >/=fourfold rise in MNA titers compared to 64% in the young. These data suggest that the severe clinical manifestations of RSV in the elderly are not due to a significant defect in humoral immunity.
No preview · Article · Oct 1999 · Journal of Medical Virology
[Show abstract][Hide abstract] ABSTRACT: To evaluate the incidence and impact of rhinovirus and coronavirus infections in older persons attending daycare.
Prospective descriptive study.
Three senior daycare centers in Rochester, New York.
Frail older persons and staff members of the daycare centers who developed signs or symptoms of an acute respiratory illness.
Demographic, medical, and physical findings were recorded on subjects at baseline and during respiratory illness. Nasopharyngeal specimens for viral culture as well as acute and convalescent sera for coronavirus 229E enzyme immunoassay (EIA) were obtained for all illnesses.
During the 44 months of study, 352 older persons experienced 522 illnesses. Thirty-five (7%) of 522 cultures were positive for rhinovirus and 37 (8%) of 451 serologies were positive for coronavirus 229E infection. The clinical syndromes associated with rhinovirus and coronavirus infection were similar and characterized by nasal congestion, cough, and constitutional symptoms. No patient died or was hospitalized, but approximately 50% had evidence of lower respiratory tract involvement. The average illness lasted 14 days. During the same period, 113 staff developed 338 respiratory illnesses. Eight percent were identified as coronavirus and 9% as rhinovirus. Cough, sputum production, and constitutional symptoms were significantly more common among older persons.
Rhinovirus and coronavirus 229E are common causes of moderately debilitating acute respiratory illnesses among older persons attending daycare.
No preview · Article · Jul 1997 · Journal of the American Geriatrics Society
[Show abstract][Hide abstract] ABSTRACT: To evaluate the rate of specific pathogens and clinical syndromes associated with acute respiratory tract infections (ARTI) in frail older persons attending daycare.
Prospective descriptive study, without intervention.
Two sites of a senior daycare program providing all-inclusive care for the older persons in Rochester, New York.
Staff members and participants of the day-care.
Demographic, medical, and physical findings were collected from older subjects at baseline and while ill with respiratory illnesses. Nasopharyngeal specimens for viral and Chlamydia culture and sputum for bacterial culture were obtained from subjects when ill. Acute and convalescent sera were also collected with each illness and examined for viral, chlamydial, and mycoplasma infection.
One hundred sixty-five illnesses were documented in 165 older daycare participants as well as 113 illnesses among 67 staff members during the 15-month study. The rate of ARTI in the elderly group was 10.8 per 100 person months. The most common etiologies in both the staff and elderly participants were respiratory syncytial virus (RSV), Influenza A, and coronavirus. The etiologies of illnesses in the staff compared with those in elderly group were similar except that bacterial infections were significantly more common among the elderly (7% vs. 0, P = 0.05). Multiple pathogens were found to cocirculate within centers, and no clear outbreak of a predominant organism was noted. Cough and nasal congestion characterized most illnesses. The elderly experienced significantly more cough, dyspnea, and sputum production than did the staff. There were 10 hospitalizations related to respiratory infections and four deaths during the acute illness among the elderly group and none in staff.
No preview · Article · Feb 1995 · Journal of the American Geriatrics Society