Viral pneumonia

Abstract

About 200 million cases of viral community-acquired pneumonia occur every year-100 million in children and 100 million in adults. Molecular diagnostic tests have greatly increased our understanding of the role of viruses in pneumonia, and findings indicate that the incidence of viral pneumonia has been underestimated. In children, respiratory syncytial virus, rhinovirus, human metapneumovirus, human bocavirus, and parainfluenza viruses are the agents identified most frequently in both developed and developing countries. Dual viral infections are common, and a third of children have evidence of viral-bacterial co-infection. In adults, viruses are the putative causative agents in a third of cases of community-acquired pneumonia, in particular influenza viruses, rhinoviruses, and coronaviruses. Bacteria continue to have a predominant role in adults with pneumonia. Presence of viral epidemics in the community, patient's age, speed of onset of illness, symptoms, biomarkers, radiographic changes, and response to treatment can help differentiate viral from bacterial pneumonia. However, no clinical algorithm exists that will distinguish clearly the cause of pneumonia. No clear consensus has been reached about whether patients with obvious viral community-acquired pneumonia need to be treated with antibiotics. Apart from neuraminidase inhibitors for pneumonia caused by influenza viruses, there is no clear role for use of specific antivirals to treat viral community-acquired pneumonia. Influenza vaccines are the only available specific preventive measures. Further studies are needed to better understand the cause and pathogenesis of community-acquired pneumonia. Furthermore, regional differences in cause of pneumonia should be investigated, in particular to obtain more data from developing countries.

Bacterial and viral etiology in hospitalized community acquired pneumonia with molecular methods and clinical evaluation

“…Development of several multiplex assays has enabled simultaneous detection of up to 15 different viruses and the use of these tests is becoming standard for identification of respiratory viruses. Lower-respiratory specimens have obvious advantages for establishing the cause of pneumonia because they come from the site of infection [30]. The fact that persistence of viral nucleic acids is relatively short-lasting in the respiratory epithelia [5] decreases the probability of colonization and suggests that viral detections in our study have clinical relevance.…”

Do pollution and climate influence respiratory tract infections in children?

“…Humidity appears to perform an important role, with absolute humidity associated with greater infection rates for the influenza virus. 31,32 The tendency for RSV epidemics in Bologna (Italy) is related to the average minimum temperature and average concentration of MP 10 Beneli 53 verified that there was an association between climatological factors and respiratory infections caused by Parainfluenza. An association was noted between MP 10 and lag3 (three days) and the infection caused by Parainfluenza.…”

“…8 Studies on preschool children in developed and developing countries indicate that the majority of respiratory tract infections generally have a viral etiology 9,10 and the clinical diagnosis of ARIs in the lower tract (pneumonia and bronchiolitis) are often confused mainly in younger children.…”

Diagnostic Methods of Influenza a From Clinical Specimens: A Critical Review of Literature

“…Rapid tests are best recognized for their detection ability, more sensitivity and specificity in comparison to viral isolation or PCR-based methods (Ruuskanen et al 2011). However, the rapid tests results depend on the viral titer present in the sample and those with low viral titer should be analyzed by PCR assays, given that the molecular technique yields higher sensitivity and specificity (Chu et al 2012).…”