Clinically, RSV's respiratory infection is similar to that caused by other respiratory viruses. Around 3-5 days after the first infection, patients most frequently have upper respiratory infection (URI) symptoms such nasal congestion and rhinorrhea (22–78%). Fever is typical in kids, and 40% of babies get bronchiolitis, a lower respiratory infection that causes coughing and wheezing. The prevalence of RSV-related illness in newborns and young children has been extensively defined, thus this review won't go into additional detail. Repeat infections are typically limited to the upper respiratory tract in young, healthy individuals, with nasal congestion, tiredness, fever, and cough being the main symptoms. However, the virus proceeds in a small percentage of patients to infect the lower respiratory tract, resulting in Dyspnea, wheezing, and a cough [3]. According to a retrospective cohort study done in Hong Kong, 70% of individuals referred to the hospital with RSV also had problems from lower respiratory tract infections, such as pneumonia, bronchitis, or flare-ups of asthma or COPD. 49.3% of patients had radiographic findings that are consistent with acute pneumonia, most frequently consolidations (23.8%) and ground-glass opacities (19.9%) that are difficult to identify from other infectious pneumonia causes. Additionally, bacterial co-infections are frequent; at the time of presentation, 12.5% of patients have one n [4].
Serology, cell culture, enzyme immunoassay (quick antigen detection test), and real-time polymerase chain reaction can all be used to detect RSV, although most of these techniques are time-consuming and ineffective. Due to the fact that all adult RSV infections are reinfections, serology (IgM and IgG) is useless. In order to determine an acute infection, two blood samples must be obtained that show a 4-fold increase in serum antibody. Given the lability of the virus, the length of time required for a conclusive diagnosis (days to weeks) and the diagnostic insensitivity (17–39%), diagnosing RSV by culture is not recommended. Finally, because the sensitivity of fast antigen testing is often less than 10%, they are not generally advised for correct diagnosis in adults. The gold standard is the reverse transcription polymerase chain reaction (RTPCR) [5].
84–100% sensitivities are used in a common approach for identifying acute RSV infection. The importance of gathering a sufficient sample cannot be overstated, with nasopharyngeal swabs showing to be more accurate than oropharyngeal swab specimens. Since viral replication is higher in the lower respiratory tract in advanced stages of sickness, lower respiratory samples are chosen for intubated patients. Regardless of the technique, RSV-related illness in adults is still difficult to diagnose accurately. Accurate identification requires numerous procedures or sample sites, as well as maintaining a high index of suspicion. It is crucial to note that many clinicians choose not to look for RSV as a probable aetiology of their patient's symptoms because there are currently no effective treatments for RSV only a few effective treatment options [6-10].