Comparison of Results of Detection of Rhinovirus by PCR and Viral Culture in Human Nasal Wash Specimens from Subjects with and without Clinical Symptoms of Respiratory Illness

Abstract

Human rhinoviruses (HRV) cause acute upper respiratory illness. The frequency of HRV-associated illnesses appears greater when PCR assays are used to detect rhinoviruses. The present study performed PCR-based detection of HRV upon entry of subjects into respiratory syncytial virus and parainfluenza type 3 vaccine trials when subjects were symptom-free and upon subsequent development of clinical symptoms of respiratory illness during the trial. The background of HRV PCR positivity in symptom-free individuals (30/139 [22%]) was only slightly lower than in those with respiratory illness (28/77 [36%]). For subjects with multiple samples, it was estimated that HRV was detectable by PCR for approximately 100 days before, during, and after clinical symptoms were documented. PCR is a remarkably more sensitive method of detecting HRV than is tissue culture. The presence of HRV RNA may not always reflect an association with infectious virus production. The limited association of HRV RNA with illness suggests caution in assigning causality of HRV PCR positivity to clinical symptoms of respiratory illness.Over 100 serotypes of human rhinoviruses (HRV), members of the family Picornaviridae, have been identified through community surveillance of respiratory illness (19). HRV has traditionally been identified by growth in tissue culture, as characterized by cytopathic effect. HRV are differentiated from enteroviruses by the capacity to grow at 33°C and acid lability. HRV are responsible for a substantial proportion of upper respiratory illnesses (19). Because infectious HRV are difficult to recover from clinical samples, it has been postulated that HRV may be responsible for other respiratory illnesses currently of unknown etiology (1,8,18,24). The fact that less than 1 50% tissue culture infectious dose of HRV caused an experimental human rhinovirus infection (5) suggests that tissue culture may not efficiently detect HRV. Recent reports suggest that PCR detection extends the scope of HRV illness to include lower respiratory tract illness (10) and establishes a strong association between rhinovirus and exacerbations of asthma (12,26). HRV has been shown to replicate in cells of both the upper (14, 27) and lower (21) respiratory tracts and can grow at the higher temperature of the lower respiratory tract (22).However, more limited studies have detected HRV by PCR in 12 to 20% of asymptomatic children and in a relatively high percentage of adenoid and tonsillar tissues, suggesting that identification of HRV by PCR may not necessarily confirm it as the etiologic agent (16,20,23,25). Identification of rhinovirus infection by PCR may not be accompanied by a serologic response, an unusual occurrence with most symptomatic respiratory viral infections (4).Clinical studies evaluating the safety of live, attenuated strains of respiratory syncytial virus (RSV) (17, 29) and parainfluenza virus type 3 (PIV3) (3) have recently been carried out with adults and children as young as 4 weeks of age. Nasal wash samples were collected from sympt...

Real-Time Reverse Transcription-PCR Assay for Comprehensive Detection of Human Rhinoviruses

“…Moreover, despite our efforts to design an HRV-specific assay, some HEVs present at high titers in the respiratory specimen could be misidentified as HRV. In addition to these technical issues, the potential for long-term shedding of HRVs in some populations (20,23,28,51) and the high rates of asymptomatic HRV infection found in some studies (11,39,51) make it more difficult to establish an etiologic link to disease. By restricting the testing to HRVs alone, other members of the Picornaviridae that have been implicated in acute respiratory disease would not be identified.…”

“…More recently, real-time RT-PCR assays have been described for HRVs/HEVs (8,9,25,38,44) that offer potentially rapid, sensitive, and quantitative results and that are less prone to amplicon contamination. However, because of the more extensive genetic variability of the HRVs and the lack of available sequence data in the public domain, few real-time RT-PCR assays have been described specifically for the HRVs (8,9,44,51), and none to our knowledge has been shown to successfully detect all recognized HRV prototype strains. In this study, we sequenced a portion of the 5ЈNCR of all HRV prototype strains as well as multiple recently circulating field isolates and used these data to develop and evaluate an HRV real-time RT-PCR assay.…”

Detection of Viruses in Human Adenoid Tissues by Use of Multiplex PCR

“…In contrast, the picornaviruses, EnVs and RhVs, were seen in 31% and 17%, respectively, of tissues tested. We and others have recently demonstrated that RhVs from well children and adults are frequently identified by PCR (12,20). The high frequency of EnVs was unexpected, as they are most commonly associated with enteric disease.…”

Human Rhinovirus Infection in Children with Cystic Fibrosis

“…Furthermore, it is well known that the presence of a virus in the nasopharynx of a patient with pulmonary disease does not necessarily signify that it is the cause of the disease because it may simply indicate a coincidental upper airways infection, a carrier state, or prolonged shedding of a pathogen that caused a previous infection (9). This may be particularly important in the case of HRV because a number of epidemiological studies have shown that it can be found in the respiratory secretions of 12-22z of asymptomatic subjects (10,11).…”