Optimal number of samples to test for institutional respiratory infection outbreaks in Ontario

2012 ◽  
Vol 141 (8) ◽  
pp. 1781-1785 ◽  
Author(s):  
A. PECI ◽  
A. MARCHAND-AUSTIN ◽  
A-J. WINTER ◽  
J. B. GUBBAY

SUMMARYThe objective of this study was to determine the optimal number of respiratory samples per outbreak to be tested for institutional respiratory outbreaks in Ontario. We reviewed respiratory samples tested for respiratory viruses by multiplex PCR as part of outbreak investigations. We documented outbreaks that were positive for any respiratory viruses and for influenza alone. At least one virus was detected in 1454 (85·2%) outbreaks. The ability to detect influenza or any respiratory virus increased as the number of samples tested increased. When analysed by chronological order of when samples were received at the laboratory, percent positivity of outbreaks testing positive for any respiratory virus including influenza increased with the number of samples tested up to the ninth sample, with minimal benefit beyond the fourth sample tested. Testing up to four respiratory samples per outbreak was sufficient to detect viral organisms and resulted in significant savings for outbreak investigations.

Author(s):  
Aleksandra Kovacevic ◽  
Rosalind M Eggo ◽  
Marc Baguelin ◽  
Matthieu Domenech de Cellès ◽  
Lulla Opatowski

Abstract Background Circulation of seasonal non-SARS-CoV-2 respiratory viruses with syndromic overlap during the COVID-19 pandemic may alter quality of COVID-19 surveillance, with possible consequences for real-time analysis and delay in implementation of control measures. Methods Using a multi-pathogen Susceptible-Exposed-Infectious-Recovered (SEIR) transmission model formalizing co-circulation of SARS-CoV-2 and another respiratory virus, we assess how an outbreak of secondary virus may affect two COVID-19 surveillance indicators: testing demand and positivity. Using simulation, we assess to what extent the use of multiplex PCR tests on a subsample of symptomatic individuals can help correct of the observed SARS-CoV-2 percent positivity and improve surveillance quality. Results We find that a non-SARS-CoV-2 epidemic strongly increases SARS-CoV-2 daily testing demand and artificially reduces the observed SARS-CoV-2 percent positivity for the duration of the outbreak. We estimate that performing one multiplex test for every 1,000 COVID-19 tests on symptomatic individuals could be sufficient to maintain surveillance of other respiratory viruses in the population and correct the observed SARS-CoV-2 percent positivity. Conclusions This study highlights that co-circulating respiratory viruses can distort SARS-CoV-2 surveillance. Correction of the positivity rate can be achieved by using multiplex PCR tests, and a low number of samples is sufficient to avoid bias in SARS-CoV-2 surveillance.


2011 ◽  
Vol 53 (5) ◽  
pp. 241-246 ◽  
Author(s):  
Tatiana Mitiko Kanashiro ◽  
Lucy Santos Vilas Boas ◽  
Ana Maria Thomaz ◽  
Tania Regina Tozetto-Mendoza ◽  
Mônica Setsuko ◽  
...  

Respiratory virus infections are the main cause of infant hospitalization and are potentially severe in children with congenital heart disease (CHD). Rapid and sensitive diagnosis is very important to early introduction of antiviral treatment and implementation of precautions to control transmission, reducing the risk of nosocomial infections. In the present study we compare different techniques in the diagnosis of respiratory viruses in CHD infants. Thirty-nine samples of nasopharyngeal aspirate were obtained from CHD infants with symptoms of respiratory infection. The Multiplex PCR (Seeplex® RV 12 ACE Detection) driven to the detection of 12 respiratory viruses was compared with the direct immunofluorescence assay (DFA) and PCR, both targeting seven respiratory viruses. The positivity found by DFA, Multiplex and PCR was 33.3%, 51.3% and 48.7%, respectively. Kappa index comparing DFA and Multiplex, DFA and PCR and PCR and Multiplex PCR was 0.542, 0.483 and 0.539, respectively. The concordance between techniques was considered moderate. Both Multiplex PCR (p = 0.001) and PCR (p = 0.002) detected significantly more respiratory virus than DFA. As the performance of the tests may vary, the combination of two or more techniques may increase diagnostic sensitivity favoring the diagnosis of co-infections, early introduction of antiviral therapy and implementation of appropriate measures.


2021 ◽  
Author(s):  
Aleksandra Kovacevic ◽  
Rosalind M Eggo ◽  
Marc Baguelin ◽  
Matthieu Domenech de Cellès ◽  
Lulla Opatowski

Background: Circulation of non-SARS-CoV-2 respiratory viruses during the COVID-19 pandemic may alter quality of COVID-19 surveillance, with possible consequences for real-time analysis and delay in implementation of control measures. Here, we assess the impact of an increased circulation of other respiratory viruses on the monitoring of positivity rates of SARS-CoV-2 and interpretation of surveillance data. Methods: Using a multi-pathogen Susceptible-Exposed-Infectious-Recovered (SEIR) transmission model formalizing co-circulation of SARS-CoV-2 and another respiratory we assess how an outbreak of secondary virus may inflate the number of SARS-CoV-2 tests and affect the interpretation of COVID-19 surveillance data. Using simulation, we assess to what extent the use of multiplex PCR tests on a subsample of symptomatic individuals can support correction of the observed SARS-CoV-2 percent positive during other virus outbreaks and improve surveillance quality. Results: Model simulations demonstrated that a non-SARS-CoV-2 epidemic creates an artificial decrease in the observed percent positivity of SARS-CoV-2, with stronger effect during the growth phase, until the peak is reached. We estimate that performing one multiplex test for every 1,000 COVID-19 tests on symptomatic individuals could be sufficient to maintain surveillance of other respiratory viruses in the population and correct the observed SARS-CoV-2 percent positive. Conclusions: This study highlights that co-circulating respiratory viruses can disrupt SARS-CoV-2 surveillance. Correction of the positivity rate can be achieved by using multiplex PCR, and a low number of samples is sufficient to avoid bias in SARS-CoV-2 surveillance.


2006 ◽  
Vol 134 (4) ◽  
pp. 792-798 ◽  
Author(s):  
M. KAYE ◽  
S. SKIDMORE ◽  
H. OSMAN ◽  
M. WEINBREN ◽  
R. WARREN

Both influenza and respiratory syncytial virus (RSV) cause epidemics of respiratory illness of variable severity during the winter season. Influenza in particular has been blamed for hospital winter bed pressures, although it is thought that RSV may also play a role. Human metapneumovirus (hMPV) is a new respiratory virus reported to be important in children; only a limited number of studies are available for adult populations. We aimed to determine initially the burden of virologically confirmed infections, i.e. influenza, RSV and hMPV using polymerase chain reaction (PCR) technology and, in addition, to assess the feasibility of this approach as a surveillance tool for these respiratory viruses. Adult patients admitted to hospital in the previous 24 hours with onset of acute respiratory symptoms in the last 14 days were asked to participate. Informed written consent was obtained and nose and throat swabs taken. Multiplex PCR for influenza A (H1N1 and H3N2), influenza B and RSV A and B were carried out together with a separate PCR for hMPV. A total of 219 patients in 2001–2002 and 216 in 2002–2003 were tested and the combined results for both seasons were: 8 positive for influenza A/H1N1, 14 for influenza A/H3N2, 2 for influenza B, 14 for RSV A and 6 for RSV B. Most patients (261/435) were >65 years and most positives (30/44) were found within this age group. A number of patients aged >65 years who were positive for influenza (12/15) reported having had vaccine. In total, 373 samples were tested for hMPV and 20 were found positive across all age groups except the 45–54 years age group. As influenza activity was low during the study period the impact of infection on admissions could not be assessed. Nevertheless the viruses studied accounted for 15% of hospital admissions for respiratory infection. Most patients were aged >65 years, as expected. In the two years studied RSV and hMPV were each responsible for as many hospitalized cases of respiratory infection as influenza. Influenza infection must be considered even in those who give a history of vaccination. The molecular methods used in this study showed that surveillance of these respiratory viruses can be conducted and may help in the management of patients.


Author(s):  
Michael Klompas ◽  
Peter B. Imrey ◽  
Pei-Chun Yu ◽  
Chanu Rhee ◽  
Abhishek Deshpande ◽  
...  

Abstract Objective: Viruses are more common than bacteria in patients hospitalized with community-acquired pneumonia. Little is known, however, about the frequency of respiratory viral testing and its associations with antimicrobial utilization. Design: Retrospective cohort study. Setting: The study included 179 US hospitals. Patients: Adults admitted with pneumonia between July 2010 and June 2015. Methods: We assessed the frequency of respiratory virus testing and compared antimicrobial utilization, mortality, length of stay, and costs between tested versus untested patients, and between virus-positive versus virus-negative patients. Results: Among 166,273 patients with pneumonia on admission, 40,787 patients (24.5%) were tested for respiratory viruses, 94.8% were tested for influenza, and 20.7% were tested for other viruses. Viral assays were positive in 5,133 of 40,787 tested patients (12.6%), typically for influenza and rhinovirus. Tested patients were younger and had fewer comorbidities than untested patients, but patients with positive viral assays were older and had more comorbidities than those with negative assays. Blood cultures were positive for bacterial pathogens in 2.7% of patients with positive viral assays versus 5.3% of patients with negative viral tests (P < .001). Antibacterial courses were shorter for virus-positive versus -negative patients overall (mean 5.5 vs 6.4 days; P < .001) but varied by bacterial testing: 8.1 versus 8.0 days (P = .60) if bacterial tests were positive; 5.3 versus 6.1 days (P < .001) if bacterial tests were negative; and 3.3 versus 5.2 days (P < .001) if bacterial tests were not obtained (interaction P < .001). Conclusions: A minority of patients hospitalized with pneumonia were tested for respiratory viruses; only a fraction of potential viral pathogens were assayed; and patients with positive viral tests often received long antibacterial courses.


Author(s):  
Sinha Pranay ◽  
Katherine Reifler ◽  
Michael Rossi ◽  
Manish Sagar

Abstract Detection of diverse respiratory viruses in Boston was around 80% lower after practices were instituted to limit COVID-19 spread compared to the same time period during the previous five years. Continuing the strategies that lower COVID-19 dissemination may be useful in decreasing the incidence of other viral respiratory infections.


Sign in / Sign up

Export Citation Format

Share Document