Clinical Utility of PCR for Common Viruses in Acute Respiratory Illness

Abstract

WHAT'S KNOWN ON THIS SUBJECT: Quantitative real-time polymerase chain reaction allows sensitive detection of respiratory viruses. The clinical significance of detection of specific viruses is not fully understood, however, and several viruses have been detected in the respiratory tract of asymptomatic children. WHAT THIS STUDY ADDS:Our results indicate that quantitative real-time polymerase chain reaction is limited at distinguishing acute infection from detection in asymptomatic children for rhinovirus, bocavirus, adenovirus, enterovirus, and coronavirus. abstract BACKGROUND: Acute respiratory illness (ARI) accounts for a large proportion of all visits to pediatric health facilities. Quantitative real-time polymerase chain reaction (qPCR) analyses allow sensitive detection of viral nucleic acids, but it is not clear to what extent specific viruses contribute to disease because many viruses have been detected in asymptomatic children. Better understanding of how to interpret viral findings is important to reduce unnecessary use of antibiotics. OBJECTIVE:To compare viral qPCR findings from children with ARI versus asymptomatic control subjects.METHODS: Nasopharyngeal aspirates were collected from children aged #5 years with ARI and from individually matched, asymptomatic, population-based control subjects during a noninfluenza season. Samples were analyzed by using qPCR for 16 viruses. RESULTS:Respiratory viruses were detected in 72.3% of the case patients (n 5 151) and 35.4% of the control subjects (n 5 74) (P 5 .001). Rhinovirus was the most common finding in both case patients and control subjects (47.9% and 21.5%, respectively), with a population-attributable proportion of 0.39 (95% confidence interval: 0.01 to 0.62). Metapneumovirus, parainfluenza viruses, and respiratory syncytial virus were highly overrepresented in case patients. Bocavirus was associated with ARI even after adjustment for coinfections with other viruses and was associated with severe disease. Enterovirus and coronavirus were equally common in case patients and control subjects.CONCLUSIONS: qPCR detection of respiratory syncytial virus, metapneumovirus, or parainfluenza viruses in children with ARI is likely to be causative of disease; detection of several other respiratory viruses must be interpreted with caution due to high detection rates in asymptomatic children. Although acute respiratory illness (ARI) in childrenaccountsfora large part ofall visits to pediatric health facilities and is a great economic burden on society, 1,2 our tools to diagnose the etiologic agents have until recently been limited. 3 Treatment with antibiotics induces development of antibiotic resistance in bacteria 4 and has a negligible effect on most ARIs, which generally are of viral origin. 5,6 Nevertheless, antibiotics are frequently prescribed due to lack of clinically valid diagnostic tests verifying a viral etiology. 7 Sensitive methods, such as quantitative real-time polymerase chain reaction (qPCR) analyses on nasopharyngeal samples, for a number of viru...

Detection of Respiratory Co-Infections in Children Less Than Five Years With Adenovirus Infection

“…In the present study, the differences between infections by single or multiple pathogens were not significant in terms of clinical presentation and severity, with the exception of the higher rate of dyspnea observed in the cases of co-infection. Although some studies found that multiple viral infections were associated with more severe fever, a higher rate of hospitalization and more severe disease (20,32), our findings are in agreement with other studies which have shown that the presence of multiple pathogens was not associated with the severity of the clinical presentation (33,34).…”

Vitamin D status is associated with treatment failure and duration of illness in Nepalese children with severe pneumonia

“…Stratification of the data on the basis of virus-positive or -negative NPA results indicated a stronger relationship between low vitamin D status and pneumonia outcomes in patients in whom we detected a respiratory virus. However, the interpretation of this finding is limited by a lack of bacterial diagnostics and the relatively low detection rate of virus compared with reports from similar populations (29,30).…”

Human metapneumovirus-associated severe acute respiratory illness hospitalisation in HIV-infected and HIV-uninfected South African children and adults

“…HMPV has, however, been shown to be more prevalent among case patients with acute respiratory illness than asymptomatic controls in studies in both adults and children. 17,31,35 While HMPV seems likely to be a significant respiratory pathogen capable of causing disease, the proportion of SARI caused by HMPV is lower than the proportion in which HMPV is detected. Our incidence estimates of HMPV-associated SARI may thus overestimate the true incidence of disease.…”

“…However, co-detection does not always mean co-infection as, some of the viruses co-detected with HMPV in our study, for example adenovirus, rhinovirus and enterovirus, have been found to have high detection rates in asymptomatic individuals. 17,31 Viral-bacterial co-infections are important in the pathogenesis of viral-associated LRTI in children. 36 We showed co-detection of HMPV and S. pneumoniae in 7% of children and 12% of adults, but did not find a significant difference in HIV-infected compared to HIVuninfected adults or children, although numbers were small.…”