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Twelve years' detection of respiratory viruses by immunofluorescence in hospitalised children: impact of the introduction of a new respiratory picornavirus assay.

Sadeghi CD, Aebi C, Gorgievski-Hrisoho M, Mühlemann K, Barbani MT - BMC Infect. Dis. (2011)

Bottom Line: Addition of assays for respiratory picornaviruses and hMPV raised the proportion of positive DFA results from 35% to 58% (p < 0.0001).DFA is a valid, rapid, flexible and inexpensive method.The addition of assays for respiratory picornaviruses and hMPV broadens its range of viral detection.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, CH-3010 Bern, Switzerland.

ABSTRACT

Background: Direct immunofluorescence assays (DFA) are a rapid and inexpensive method for the detection of respiratory viruses and may therefore be used for surveillance. Few epidemiological studies have been published based solely on DFA and none included respiratory picornaviruses and human metapneumovirus (hMPV). We wished to evaluate the use of DFA for epidemiological studies with a long-term observation of respiratory viruses that includes both respiratory picornaviruses and hMPV.

Methods: Since 1998 all children hospitalized with respiratory illness at the University Hospital Bern have been screened with DFA for common respiratory viruses including adenovirus, respiratory syncytial virus (RSV), influenza A and B, and parainfluenza virus 1-3. In 2006 assays for respiratory picornaviruses and hMPV were added. Here we describe the epidemiological pattern for these respiratory viruses detected by DFA in 10'629 nasopharyngeal aspirates collected from 8'285 patients during a 12-year period (1998-2010).

Results: Addition of assays for respiratory picornaviruses and hMPV raised the proportion of positive DFA results from 35% to 58% (p < 0.0001). Respiratory picornaviruses were the most common viruses detected among patients ≥ 1 year old. The seasonal patterns and age distribution for the studied viruses agreed well with those reported in the literature. In 2010, an hMPV epidemic of unexpected size was observed.

Conclusions: DFA is a valid, rapid, flexible and inexpensive method. The addition of assays for respiratory picornaviruses and hMPV broadens its range of viral detection. DFA is, even in the "PCR era", a particularly adapted method for the long term surveillance of respiratory viruses in a pediatric population.

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Mean monthly distribution of respiratory viruses detected by DFA in nasopharyngeal aspirates from hospitalized children from November 2006 to April 2010. picorna = respiratory picornaviruses; hMPV = human metapneumovirus; others = adenovirus, respiratory syncytial virus, influenza A and B, parainfluenza viruses 1-3.
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Figure 1: Mean monthly distribution of respiratory viruses detected by DFA in nasopharyngeal aspirates from hospitalized children from November 2006 to April 2010. picorna = respiratory picornaviruses; hMPV = human metapneumovirus; others = adenovirus, respiratory syncytial virus, influenza A and B, parainfluenza viruses 1-3.

Mentions: Before the addition of DFA for picornavirus and hMPV, the rate of viral detection was dominated by the RSV season, with a yearly average rate of 35%, peaks of up to 64% (average 46%) in winter seasons, and troughs as low as 4% (average 16%) during summer time. The addition of DFA for picornaviruses increased the positivity rate, and dampened the seasonal variations. The positivity rate after 2006 was on average 65% in winter and 52% in summer, with a yearly average of 58% (versus 35%; p < 0.0001) (Figure 1, Table 1). For comparison, analysis performed on 256 specimens in parallel to DFA screening with the xTag Respiratory Viral Panel (Luminex Molecular Diagnostics) between November 2006 and September 2007 yielded a positivity rate of 78%. The higher detection rate by PCR could mostly be attributed to increased detection of respiratory picornaviruses; 57 from the 78 additional positive results were respiratory picornaviruses (unpublished data).


Twelve years' detection of respiratory viruses by immunofluorescence in hospitalised children: impact of the introduction of a new respiratory picornavirus assay.

Sadeghi CD, Aebi C, Gorgievski-Hrisoho M, Mühlemann K, Barbani MT - BMC Infect. Dis. (2011)

Mean monthly distribution of respiratory viruses detected by DFA in nasopharyngeal aspirates from hospitalized children from November 2006 to April 2010. picorna = respiratory picornaviruses; hMPV = human metapneumovirus; others = adenovirus, respiratory syncytial virus, influenza A and B, parainfluenza viruses 1-3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3044667&req=5

Figure 1: Mean monthly distribution of respiratory viruses detected by DFA in nasopharyngeal aspirates from hospitalized children from November 2006 to April 2010. picorna = respiratory picornaviruses; hMPV = human metapneumovirus; others = adenovirus, respiratory syncytial virus, influenza A and B, parainfluenza viruses 1-3.
Mentions: Before the addition of DFA for picornavirus and hMPV, the rate of viral detection was dominated by the RSV season, with a yearly average rate of 35%, peaks of up to 64% (average 46%) in winter seasons, and troughs as low as 4% (average 16%) during summer time. The addition of DFA for picornaviruses increased the positivity rate, and dampened the seasonal variations. The positivity rate after 2006 was on average 65% in winter and 52% in summer, with a yearly average of 58% (versus 35%; p < 0.0001) (Figure 1, Table 1). For comparison, analysis performed on 256 specimens in parallel to DFA screening with the xTag Respiratory Viral Panel (Luminex Molecular Diagnostics) between November 2006 and September 2007 yielded a positivity rate of 78%. The higher detection rate by PCR could mostly be attributed to increased detection of respiratory picornaviruses; 57 from the 78 additional positive results were respiratory picornaviruses (unpublished data).

Bottom Line: Addition of assays for respiratory picornaviruses and hMPV raised the proportion of positive DFA results from 35% to 58% (p < 0.0001).DFA is a valid, rapid, flexible and inexpensive method.The addition of assays for respiratory picornaviruses and hMPV broadens its range of viral detection.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, CH-3010 Bern, Switzerland.

ABSTRACT

Background: Direct immunofluorescence assays (DFA) are a rapid and inexpensive method for the detection of respiratory viruses and may therefore be used for surveillance. Few epidemiological studies have been published based solely on DFA and none included respiratory picornaviruses and human metapneumovirus (hMPV). We wished to evaluate the use of DFA for epidemiological studies with a long-term observation of respiratory viruses that includes both respiratory picornaviruses and hMPV.

Methods: Since 1998 all children hospitalized with respiratory illness at the University Hospital Bern have been screened with DFA for common respiratory viruses including adenovirus, respiratory syncytial virus (RSV), influenza A and B, and parainfluenza virus 1-3. In 2006 assays for respiratory picornaviruses and hMPV were added. Here we describe the epidemiological pattern for these respiratory viruses detected by DFA in 10'629 nasopharyngeal aspirates collected from 8'285 patients during a 12-year period (1998-2010).

Results: Addition of assays for respiratory picornaviruses and hMPV raised the proportion of positive DFA results from 35% to 58% (p < 0.0001). Respiratory picornaviruses were the most common viruses detected among patients ≥ 1 year old. The seasonal patterns and age distribution for the studied viruses agreed well with those reported in the literature. In 2010, an hMPV epidemic of unexpected size was observed.

Conclusions: DFA is a valid, rapid, flexible and inexpensive method. The addition of assays for respiratory picornaviruses and hMPV broadens its range of viral detection. DFA is, even in the "PCR era", a particularly adapted method for the long term surveillance of respiratory viruses in a pediatric population.

Show MeSH
Related in: MedlinePlus