Detection of human bocavirus and human metapneumovirus by real-time PCR from patients with respiratory symptoms in Southern Brazil

Abstract

The introduction of newer molecular methods has led to the discovery of new respiratory viruses, such as human metapneumovirus (hMPV) and human bocavirus (hBoV), in respiratory tract specimens. We have studied the occurrence of hMPV and hBoV in the Porto Alegre (PA) metropolitan area, one of the southernmost cities of Brazil, evaluating children with suspected lower respiratory tract infection from May 2007-June 2008. A real-time polymerase chain reaction method was used for amplification and detection of hMPV and hBoV and to evaluate coinfections with respiratory syncytial virus (RSV), influenza A and B, parainfluenza 1, 2 and 3, human rhinovirus and human adenovirus. Of the 455 nasopharyngeal aspirates tested, hMPV was detected in 14.5% of samples and hBoV in 13.2%. A unique causative viral agent was identified in 46.2% samples and the coinfection rate was 43.7%. For hBoV, 98.3% of all positive samples were from patients with mixed infections. Similarly, 84.8% of all hMPV-positive results were also observed in mixed infections. Both hBoV and hMPV usually appeared with RSV. In summary, this is the first confirmation that hMPV and hBoV circulate in PA; this provides evidence of frequent involvement of both viruses in children with clinical signs of acute viral respiratory tract infection, although they mainly appeared as coinfection agents

High frequency of human bocavirus 1 DNA in infants and adults with lower acute respiratory infection

“…However, considering the high frequency of HBoV1 detection in infants younger than 1 year and during the fall-winter period, plus the circulation pattern of RSV (Leung et al, 2005), a high rate of HBoV1-RSV co-infection is most likely. Elevated percentages of RSV-HBoV1 co-infections have been observed by others and RSV is commonly cited as the most frequent respiratory virus in co-infection with HBoV1 (Kaplan et al, 2006;Weissbrich et al, 2006;Gerna et al, 2007;Cilla et al, 2008;Pilger et al, 2011). Interestingly, we did not find co-infections in HBoV + samples from adults.…”

“…With a ubiquitous distribution, the presence of HBoV DNA has been reported mostly in children with ARI in a variable range from 1.5 to 19 % (Allander, 2008), although recently even higher prevalence (33 %) has been observed in ill children (Martin et al, 2010). Although the virus is associated with ARI, the elevated rates of coinfection with other respiratory viruses with well-established pathogenic potential (Kaplan et al, 2006;Allander et al, 2007;Fry et al, 2007; Gerna et al, 2007;Kleines et al, 2007; Christensen et al, 2008 Christensen et al, , 2010Cilla et al, 2008;Pilger et al, 2011), the detection in asymptomatic individuals (Christensen et al, 2010) and the possibility of a persistent infection (Martin et al, 2010) make it difficult to allocate a causative role for HBoV in respiratory disease. Not only is the aetiological capacity of HBoV under investigation, but the natural history of the infection is still unknown.…”

The Prevalence of Human Metapneumovirus and Respiratory Syncytial Virus and Coinfection With Both in Hospitalized Children With Acute Respiratory Infection in South of Iran

“…The results showed that among 2384 patients hospitalized for acute bronchiolitis, 1495 (62.7%) were infected with RSV (22). In another study performed on 455 cases in Brazil, the prevalence of RSV was reported to be 49.3% (23).…”

Viral epidemiology of respiratory infections among children at a tertiary hospital in Southern Brazil

“…Virus detection (except for H1N1) was evaluated by IIF, which is not a molecular test with increased sensitivity. The IIF assay can display low sensitivity for ADV and IF detection 5 . Moreover, the lack of data about other respiratory viruses, such as rhinovirus, bocavirus, and metapneumovirus, is a limitation in this study.…”

“…The importance of respiratory virus surveillance has grown over the last 10 years because of the unexpected emergence of several new respiratory viruses, including infl uenza A (H5N1), severe acute respiratory syndrome (SARS) coronavirus, coronavirus NL63, human bocavirus, and infl uenza A virus (H1N1) 5 . Furthermore, the seasonality of some respiratory viruses is well established, and viral surveillance and laboratorybased diagnostics play an important role in guiding the timing of prophylaxis and other interventions.…”