scholarly journals Cause-Specific School Absenteeism Monitoring Identifies Community Influenza Outbreaks

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Jonathan Temte ◽  
Shari Barlow ◽  
Yenlik Zheteyeva ◽  
Maureen Landsverk ◽  
Emily Temte ◽  
...  
Keyword(s):  
School District ◽  
Regression Models ◽  
Influenza A ◽  
Influenza B ◽  
Driving Mechanism ◽  
School Absenteeism ◽  
Rt Pcr ◽  
12Th Grade ◽  
Influenza A H1n1 ◽  
Influenza Outbreaks

ObjectiveThe Oregon Child Absenteeism due to Respiratory Disease Study (ORCHARDS) was implemented to assess the relationships between cause-specific absenteeism within a school district and medically attended influenza visits within the same community.IntroductionTransmission and amplification of influenza within schools has been purported as a driving mechanism for subsequent outbreaks in surrounding communities. However, the number of studies assessing the utility of monitoring school absenteeism as an indicator of influenza in the community is limited. ORCHARDS was initiated to evaluate the relationships between all-cause (a-Tot), illness-related (a-I), and influenza-like illness (ILI)-related absenteeism (a-ILI) within a school district and medically attended influenza A or B visits within the same community.MethodsORCHARDS was based at the Oregon School District (OSD), which enrolls 3,640 students at six schools in south-central Wisconsin. Parents reported influenza-like symptoms on an existing phone-based absenteeism reporting system. Attendance staff identified ILI using a simple case definition. Absenteeism was logged into the OSD’s existing electronic information system (Infinite Campus), and an automated process extracted counts of a-Tot, a-I, and a-ILI each school day from 9/02/14 through 6/08/17.Parents of students with acute respiratory infections (ARI) were invited to contact study staff who assessed the students’ eligibility for the study based on presence of ILI symptoms. From 1/05/15 through 6/08/17, data and nasal swabs were collected from eligible OSD students whose parents volunteered to have a study home visit within 7 days of ILI onset. Specimens were tested for influenza A and B at the Wisconsin State Laboratory of Hygiene using the CDC Human Influenza Virus Real-time RT-PCR Diagnostic Panel.For community influenza, we used data from the Wisconsin Influenza Incidence Surveillance Project (WIISP) that monitors medically attended influenza using RT-PCR at five primary care clinics surrounding the OSD.Data analysis: Over-dispersed Poisson generalized additive log-linear regression models were fit to the daily number of medically attended influenza cases and daily absenteeism counts from three sources (a-Tot, a-I, and a-ILI) with year and season (calendar day within year) as smooth functions (thin plate regression splines). Two subgroups of a-ILI representing kindergarten through 4th grade (K-4) and 5th-12th grade (5-12) were also evaluated.ResultsDuring the study period, 168,859 total absentee days (8.57% of student days), 36,104 illness days (1.83%), and 4,232 ILI days (0.21%) were recorded. Home visits were completed on 700 children [mean age = 10.0 ± 3.5 (sd) years]. Influenza RT-PCR results were available for 695 (99.3%) children: influenza A was identified in 54 (13.3%) and influenza B in 51 (12.6%) specimens. There were one large and early outbreak of influenza A (H3N2) followed by B in 2014/15, an extremely late combined outbreak of influenza A (H1N1) and B in 2015/16, and a combined outbreak of influenza A/(H3N2) and B in 2016/17. PCR detection of influenza A or B, as compared to no influenza, was strongly associated with a child with a-ILI-positive status (OR=4.74; 95% CI: 2.78-8.18; P<0.001).Nearly 2,400 medically attended ARI visits were reported during the study period. Of these, 514 patients were positive for influenza (21.5%): 371 (15.5%) influenza A and 143 (6.0%) influenza B. The temporal patterns of medically attended influenza were very similar to influenza cases in OSD students.Comparisons of the regression models demonstrated the highest correlation between absenteeism and medically attended influenza for 5th-12th grade students absent with ILI with a -1 day time lag and for all students with a-ILI with a -1 day lag (Table); a-I also had moderate correlation with a -15 day lag period.ConclusionsCause-specific absenteeism measures (a-I and a-ILI) are moderately correlated with medically attended influenza in the community and are better predictors than all-cause absenteeism. In addition, a-I preceded community influenza cases by 15 days. The monitoring system was easily implemented: a-I surveillance was fully automated and a-ILI required only minor review by attendance staff. The resulting correlations were likely lowered by the presence of other viruses that resulted in a-ILI (e.g., adenovirus) and by breaks in the school year during which absenteeism data did not accrue.Automated systems that report cause-specific absenteeism data may provide a reliable method for the early identification of influenza outbreaks in communities. From a preparedness perspective, 15-day advance warning is significant. The addition of a laboratory component could increase usefulness of the cause-specific student absenteeism monitoring as an early-warning system during influenza pandemics. 

scholarly journals 714. Predictors of Influenza-Associated Hospitalization and Pneumonia in a Pediatric Population in Bangkok, Thailand

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S256-S257
Author(s):  
Ali Sawani ◽  
Detchvijitr Suwanpakdee ◽  
Veerachai Watanaveeradej ◽  
Alden Weg ◽  
Damon Ellison ◽  
...  
Keyword(s):  
Influenza A ◽  
Pediatric Patients ◽  
Pediatric Population ◽  
Clinical Care ◽  
Influenza B ◽  
Rt Pcr ◽  
Early Presentation ◽  
Fever Onset ◽  
Increased Risk ◽  
Influenza A H1n1

Abstract Background Influenza infection in children can be severe, resulting in complications such as pneumonia, but may be mitigated by early recognition and administration of antivirals. In this study, we identified risk factors for hospitalization and pneumonia in a pediatric population presenting with influenza-like illness (ILI) in Thailand. Methods Our study included pediatric patients (age &lt; 18 years) presenting with ILI to inpatient and outpatient departments at a public hospital in Bangkok, Thailand, from 2009 to 2016. ILI was defined as fever plus cough or sore-throat, and pneumonia was defined as either lung radiographic or pulmonary examination abnormalities. Demographic and clinical data, as well as nasal and throat swabs, were collected during a one-time interview with patients presenting with ILI. Influenza infections were confirmed via RT-PCR testing of respiratory specimens. Retrospective chart review was used to collect data on individuals with influenza admitted for inpatient care. Results 5,968 children (33.6%) were enrolled with ILI, of whom 1,530 (25.6%) were confirmed to be influenza by RT-PCR, of which 25.5% were influenza A(H1N1)pdm09, 31.5% influenza A(H3N2), and 43.0% influenza B. 124 (8.1%) patients were admitted, and 41 of these children (33.1%) developed pneumonia. Predictors of hospitalization included younger age (4.1 yrs for inpatients vs. 5.6 yrs) and higher presenting temperature (38.6C for inpatient vs. 38.0C) (both P &lt; 0.05). Among children hospitalized with influenza, influenza subtype was not associated with pneumonia risk. Co-detection of Klebsiella pneumoniae was associated with an increased risk of pneumonia (P &lt; 0.05. Patients with pneumonia were younger (4.1 yrs with vs. 6.4 yrs, P = NS), had a longer interval from fever onset to presentation at the hospital, and required longer hospital stays. Risk of pneumonia was decreased in patients who received oseltamivir within 48 hours of fever onset (odds ratio 0.36, 95% confidence interval 0.16–0.91). Conclusion Post viral pneumonia is a potentially serious complication of influenza, requiring longer hospitalization stay and affecting more than one-third of hospitalized pediatric patients with influenza. The risk of pneumonia can be reduced with early presentation for clinical care and prompt administration of oseltamivir following fever onset. Disclosures All authors: No reported disclosures.

scholarly journals 686. Use of an Influenza-Like Illness School Absenteeism Monitoring System to Identify Seasonal Influenza Outbreaks in the Community: ORCHARDS (Wisconsin, September 2014–June 2017)

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S248-S248
Author(s):  
Jonathan Temte ◽  
Yenlik Zheteyeva ◽  
Shari Barlow ◽  
Maureen Goss ◽  
Emily Temte ◽  
...  
Keyword(s):  
Lead Time ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Influenza B ◽  
Linear Regression Models ◽  
Rt Pcr ◽  
Human Influenza Virus ◽  
Influenza Like Illness ◽  
K 12 ◽  
Influenza Outbreaks

Abstract Background Schools are purported to be primary venues of influenza transmission and amplification with secondary spread to communities. We assessed K—12 student absenteeism monitoring as a means for early detection of influenza activity in the community. Methods. We conducted a 3-year, prospective observational study of all-cause (a-TOT), illness-associated (a-I), and influenza-like illness-associated (a-ILI) absenteeism within the Oregon School District, Oregon, WI (OSD: enrollment = 3,900 students). Absenteeism reporting was facilitated by automated processes within OSD’s electronic student information system. Students were screened for ILI, and, if eligible, visited at home, where pharyngeal specimens were collected for influenza RT-PCR (IVD CDC Human Influenza Virus RT-PCR Diagnostic Panel) and multipathogen testing (Luminex NxTAG RPP). The study definition of a-ILI was validated for 700 children with acute respiratory infections using binomial logistic regression. Surveillance of medically attended laboratory-confirmed influenza (MAI) occurred in five primary care clinics in and adjoining OSD as part of the Wisconsin Influenza Incidence Surveillance Project using the same laboratory testing. Poisson general additive log linear regression models of daily counts of absenteeism and MAI were compared using correlation analysis. Results. Influenza A and B were detected in 54 and 51 of the 700 visited students, respectively. Influenza was significantly associated with a-ILI status (OR = 4.74; 95% CI: 2.78—8.18; P &lt; 0.001). Of MAI patients, 371 had influenza A and 143 had influenza B. a-I was significantly correlated with MAI in the community (r = 0.472; P &lt; 0.001) with a 15-day lead time. a-ILI was significantly correlated with MAI in the community (r = 0.480; P &lt; 0.001) with a 1-day lead time. a-TOT performed poorly (r = 0.278; P &lt; 0.001), following MAI by 9 days (Figure 1). Conclusion. Surveillance using cause-specific absenteeism was feasible to implement in OSD and performed well over a 3-year period marked by diverse presentations of seasonal influenza. Monitoring a-I and a-ILI can detect influenza outbreaks in the community, providing early warning in time for community mitigation efforts for seasonal and pandemic influenza. Disclosures All authors: No reported disclosures.

scholarly journals 2553. Individual Patient-Level Data Meta-Analysis of Live Attenuated and Inactivated Influenza Vaccine Effectiveness Among US Children, 2013–2014 Through 2015–2016

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S68-S68
Author(s):  
Jessie Chung ◽  
Brendan Flannery ◽  
Rodolfo Begue ◽  
Herve Caspard ◽  
Laurie Demarcus ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Influenza A ◽  
The United States ◽  
Vaccine Effectiveness ◽  
Vaccination Status ◽  
Influenza B ◽  
Rt Pcr ◽  
Current Season ◽  
Influenza A H1n1 ◽  
Vaccine Type

Abstract Background Quadrivalent live attenuated influenza vaccine (LAIV4) was not recommended for use in the United States for the 2016–2017 and 2017–2018 influenza seasons based on US observational studies of vaccine effectiveness (VE) from 2013–2014 to 2015–2016. We pooled individual patient data on children aged 2–17 years enrolled in 5 US studies during these 3 influenza seasons to further investigate VE by vaccine type. Methods Analyses included 17,173 children enrolled in the US Department of Defense Global Laboratory-based Influenza Surveillance Program, US Influenza Vaccine Effectiveness Network, Influenza Incidence Surveillance Project, Influenza Clinical Investigation for Children, and a Louisiana State University study. Participants’ specimens were tested for influenza by reverse transcription-polymerase chain reaction (RT-PCR), culture, or a combination of rapid antigen testing and RT-PCR. VE was calculated by comparing odds of vaccination with either inactivated influenza vaccine (IIV) or LAIV4 among influenza-positive cases to test-negative controls and calculated as 100 × (1 − odds ratio) in logistic regression models with age, calendar time, influenza season, and study site (random effect). Patients were stratified by prior season vaccination status in a subanalysis. Results Overall, 38% of patients (N = 6,558) were vaccinated in the current season, of whom 30% (N = 1,979) received LAIV4. Pooled VE of IIV against any influenza virus was 51% (95% CI: 47, 54) versus 26% (95% CI: 15, 36) for LAIV4. Point estimates for pooled VE against any influenza by age group ranged from 45% to 58% for IIV and 19% to 34% for LAIV4 during the 3 seasons (Figures 1 and 2). Pooled VE against influenza A(H1N1)pdm09 was 67% (95% CI: 62, 72) for IIV versus 20% (95% CI: −6, 39) for LAIV4. Pooled VE against influenza A(H3N2) was 29% (95% CI: 14, 42) for IIV versus 7% (95% CI: −11, 23) for LAIV4, and VE against influenza B was 52% (95% CI: 42, 60) for IIV and 66% (95% CI: 47, 77) for LAIV4. VE against influenza A(H1N1)pdm09 was lower for LAIV4 versus IIV across all strata of prior season vaccination (Figure 3). Conclusion Consistent with individual studies, our pooled analyses found that LAIV4 effectiveness was reduced for all age groups against influenza A(H1N1)pdm09 compared with IIV. This result did not vary based on prior vaccination status. Disclosures H. Caspard, AstraZeneca: Employee, Salary.

scholarly journals Descripción de características demográficas y clínicas de una cohorte pacientes fallecidos por infección respiratoria aguda en Colombia durante los años 2009 a 2013

Infectio ◽  
2019 ◽  
Vol 23 (2) ◽  
pp. 148
Author(s):  
Héctor Julio Amaya Santiago ◽  
Juliana Barbosa ◽  
Carlos Humberto Saavedra Trujillo
Keyword(s):  
Influenza A ◽  
Influenza B ◽  
Rt Pcr ◽  
Influenza A H1n1 ◽  
Virus Influenza

Objetivo: Describir las características clínicas, demográficas, aislamientos virales y hallazgos de histopatología de individuos que fallecieron por Infección Respiratoria Aguda (IRA) y que fueron notificados al Instituto Nacional de Salud (INS) entre los años 2009 y 2013.Métodos: Estudio observacional, descriptivo, retrospectivo, basado en la revisión de fichas epidemiológicas y reportes de estudios de virología e histopatología de muestras respiratorias de individuos fallecidos con diagnóstico de IRAResultados: De 1604 personas fallecidas se encontró que, 55% fueron hombres, 46,5% de los individuos tenía entre 20 y 59 años. La RT-PCR fue positiva en 18,3% de los casos, los virus más frecuentes fueron: influenza A(H1N1)pdm09 13,9%, A(H3N3) 1,9% e influenza B 0,5%. La letalidad de IRA fue mayor en los individuos que recibieron antiviral o antibiótico OR 2,80 (IC 95% 2,29 - 3,43) y 3,19 (IC 95% 2,63 – 3,86), respectivamente.Conclusión: El virus influenza A(H1N1) pdm09 fue el principal agente identificado en los casos fatales de IRA confirmada por laboratorio durante los años 2009 a 2013, con mayor letalidad en individuos entre 20 y 59 años; 64,7% de los casos fatales presentaron neumonitis. Se debe aclarar si el inicio de antivirales afecta el pronóstico en los casos graves de IRA.

scholarly journals A multiplex one-step real-time RT-PCR assay for influenza surveillance

2011 ◽  
Vol 16 (7) ◽  
Author(s):  
I Huber ◽  
H Campe ◽  
D Sebah ◽  
C Hartberger ◽  
R Konrad ◽  
...  
Keyword(s):  
Real Time ◽  
High Throughput ◽  
Influenza A ◽  
Multiplex Assay ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Rt Pcr ◽  
Influenza A H1n1 ◽  
One Step

For surveillance purposes real-time PCR assays for influenza viruses had to be adapted to the pandemic influenza A(H1N1)2009 strain. We combined published primers and probes for influenza A, influenza B and an internal amplification control with a detection system for influenza A(H1N1)2009 to set up a rapid, reliable, simple and cost-effective high-throughput multiplex one-step real-time RT-PCR. The workflow also includes automated sample preparation for high-throughput screening. The lower limit of detection of the multiplex assay was 3.5x102 RNA copies per PCR reaction. The diagnostic sensitivity of the multiplex assay was 87.7%, but increased to 99.4% for influenza-positive samples yielding Ct values of less than 34 cycles in the respective diagnostic assay. High specificity was confirmed by sequencing and correct detection of 15 reference samples from two quality assurance studies. The multiplex PCR was introduced for surveillance of samples from a network of general practitioners and paediatricians in Bavaria, Germany during the influenza pandemic of 2009. Comparison with surveillance data from reported cases proved the reliability of the multiplex assay for influenza surveillance programmes.

scholarly journals Influenza: An Emerging and Re-emerging Public Health Threat in Nepal

2018 ◽  
Vol 3 (2) ◽  
pp. 1-2
Author(s):  
Bishnu Prasad Upadhyay
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Winter Season ◽  
Emerging Infectious Diseases ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Influenza A H1n1 ◽  
New Variant ◽  
Seasonal Epidemics

Influenza virus type A and B are responsible for seasonal epidemics as well as pandemics in human. Influenza A viruses are further divided into two major groups namely, low pathogenic seasonal influenza (A/H1N1, A/H1N1 pdm09, A/H3N2) and highly pathogenic influenza virus (H5N1, H5N6, H7N9) on the basis of two surface antigens: hemagglutinin (HA) and neuraminidase (NA). Mutations, including substitutions, deletions, and insertions, are one of the most important mechanisms for producing new variant of influenza viruses. During the last 30 years; more than 50 viral threat has been evolved in South-East Asian countriesof them influenza is one of the major emerging and re-emerging infectious diseases of global concern. Similar to tropical and sub-tropical countries of Southeast Asia; circulation of A/H1N1 pdm09, A/H3N2 and influenza B has been circulating throughout the year with the peak during July-November in Nepal. However; the rate of infection transmission reach peak during the post-rain and winter season of Nepal.

scholarly journals Effectiveness of seasonal influenza vaccine for adults and children in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2015/16 end-of-season results

2016 ◽  
Vol 21 (38) ◽  
Author(s):  
Richard Pebody ◽  
Fiona Warburton ◽  
Joanna Ellis ◽  
Nick Andrews ◽  
Alison Potts ◽  
...  
Keyword(s):  
Primary Care ◽  
United Kingdom ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Immunisation Programme ◽  
Influenza B ◽  
Live Attenuated Influenza Vaccine ◽  
The United Kingdom ◽  
Influenza A H1n1 ◽  
The Uk

The United Kingdom (UK) is in the third season of introducing universal paediatric influenza vaccination with a quadrivalent live attenuated influenza vaccine (LAIV). The 2015/16 season in the UK was initially dominated by influenza A(H1N1)pdm09 and then influenza of B/Victoria lineage, not contained in that season’s adult trivalent inactivated influenza vaccine (IIV). Overall adjusted end-of-season vaccine effectiveness (VE) was 52.4% (95% confidence interval (CI): 41.0–61.6) against influenza-confirmed primary care consultation, 54.5% (95% CI: 41.6–64.5) against influenza A(H1N1)pdm09 and 54.2% (95% CI: 33.1–68.6) against influenza B. In 2–17 year-olds, adjusted VE for LAIV was 57.6% (95% CI: 25.1 to 76.0) against any influenza, 81.4% (95% CI: 39.6–94.3) against influenza B and 41.5% (95% CI: −8.5 to 68.5) against influenza A(H1N1)pdm09. These estimates demonstrate moderate to good levels of protection, particularly against influenza B in children, but relatively less against influenza A(H1N1)pdm09. Despite lineage mismatch in the trivalent IIV, adults younger than 65 years were still protected against influenza B. These results provide reassurance for the UK to continue its influenza immunisation programme planned for 2016/17.

scholarly journals No evidence of SARS-CoV-2 in hospitalized patients with severe acute respiratory syndrome in five Italian hospitals from 1st November 2019 to 29th February 2020

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260947
Author(s):  
Donatella Panatto ◽  
Andrea Orsi ◽  
Beatrice Marina Pennati ◽  
Piero Luigi Lai ◽  
Stefano Mosca ◽  
...  
Keyword(s):  
Phase I ◽  
Influenza A ◽  
Hospitalized Patients ◽  
Influenza Viruses ◽  
Influenza B ◽  
Molecular Testing ◽  
Rt Pcr ◽  
The Real ◽  
Severe Acute Respiratory Infection ◽  
Novel Coronavirus

Background On 9th January 2020, China CDC reported a novel coronavirus (later named SARS-CoV-2) as the causative agent of the coronavirus disease 2019 (COVID-19). Identifying the first appearance of virus is of epidemiological importance to tracking and mapping the spread of SARS-CoV-2 in a country. We therefore conducted a retrospective observational study to detect SARS-CoV-2 in oropharyngeal samples collected from hospitalized patients with a Severe Acute Respiratory Infection (SARI) enrolled in the DRIVE (Development of Robust and Innovative Vaccine Effectiveness) study in five Italian hospitals (CIRI-IT BIVE hospitals network) (1st November 2019 – 29th February 2020). Objectives To acquire new information on the real trend in SARS-CoV-2 infection during pandemic phase I and to determine the possible early appearance of the virus in Italy. Materials and methods Samples were tested for influenza [RT-PCR assay (A/H1N1, A/H3N2, B/Yam, B/Vic)] in accordance with the DRIVE study protocol. Subsequently, swabs underwent molecular testing for SARS-COV-2. [one-step real-time multiplex retro-transcription (RT) PCR]. Results In the 1683 samples collected, no evidence of SARS-CoV-2 was found. Moreover, 28.3% (477/1683) of swabs were positive for influenza viruses, the majority being type A (358 vs 119 type B). A/H3N2 was predominant among influenza A viruses (55%); among influenza B viruses, B/Victoria was prevalent. The highest influenza incidence rate was reported in patients aged 0–17 years (40.3%) followed by those aged 18–64 years (24.4%) and ≥65 years (14.8%). Conclusions In Italy, some studies have shown the early circulation of SARS-CoV-2 in northern regions, those most severely affected during phase I of the pandemic. In central and southern regions, by contrast no early circulation of the virus was registered. These results are in line with ours. These findings highlight the need to continue to carry out retrospective studies, in order to understand the epidemiology of the novel coronavirus, to better identify the clinical characteristics of COVID-19 in comparison with other acute respiratory illnesses (ARI), and to evaluate the real burden of COVID-19 on the healthcare system.

scholarly journals Virological analysis of fatal influenza cases in the United Kingdom during the early wave of influenza in winter 2010/11

2011 ◽  
Vol 16 (1) ◽  
Author(s):  
J Ellis ◽  
M Galiano ◽  
R Pebody ◽  
A Lackenby ◽  
CI Thompson ◽  
...  
Keyword(s):  
United Kingdom ◽  
Vaccine Strain ◽  
Influenza A ◽  
Influenza Season ◽  
Severe Illness ◽  
Influenza B ◽  
The United Kingdom ◽  
Influenza A H1n1 ◽  
Influenza Activity ◽  
Children And Young Adults

The 2010/11 winter influenza season is underway in the United Kingdom, with co-circulation of influenza A(H1N1)2009 (antigenically similar to the current 2010/11 vaccine strain), influenza B (mainly B/Victoria/2/87 lineage, similar to the 2010/11 vaccine strain) and a few sporadic influenza A(H3N2) viruses. Clinical influenza activity has been increasing. Severe illness, resulting in hospitalisation and deaths, has occurred in children and young adults and has predominantly been associated with influenza A(H1N1)2009, but also influenza B viruses.

Detection of novel influenza A(H1N1) virus by real-time RT-PCR

2009 ◽  
Vol 45 (3) ◽  
pp. 203-204 ◽  
Author(s):  
David M. Whiley ◽  
Seweryn Bialasiewicz ◽  
Cheryl Bletchly ◽  
Cassandra E. Faux ◽  
Bruce Harrower ◽  
...  
Keyword(s):  
Real Time ◽  
Influenza A ◽  
H1n1 Virus ◽  
Rt Pcr ◽  
Influenza A H1n1 ◽  
Novel Influenza A
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