Influenza C virus in pre-school children with respiratory infections: retrospective analysis of data from the national influenza surveillance system in Germany, 2012 to 2014

Abstract

IntroductionRecent data on influenza C virus indicate a possible higher clinical impact in specified patient populations than previously thought.AimWe aimed to investigate influenza C virus circulation in Germany.MethodsA total of 1,588 samples from 0 to 4 year-old children presenting as outpatients with influenza-like illness (ILI) or acute respiratory infection were analysed retrospectively. The samples represented a subset of all samples from the German national surveillance system for influenza in this age group in 2012–14. The presence of influenza C virus was investigated by real-time PCR. For positive samples, information on symptoms as well as other respiratory virus co-infections was considered. Retrieved influenza C viral sequences were phylogenetically characterised.ResultsInfluenza C viral RNA was detected in 20 (1.3% of) samples, including 16 during the 2012/13 season. The majority (18/20) of influenza C-positive patients had ILI according to the European Union definition, one patient had pneumonia. Viruses belonged to the C/Sao Paulo and C/Kanagawa lineages. Most (11/20) samples were co-infected with other respiratory viruses.ConclusionOur data are the first on influenza C virus circulation in Germany and notably from a European national surveillance system. The low detection frequency and the identified virus variants confirm earlier observations outside a surveillance system. More virus detections during the 2012/13 season indicate a variable circulation intensity in the different years studied. Influenza C virus can be considered for ILI patients. Future studies addressing its clinical impact, especially in patients with severe disease are needed.

Epidemiology and Clinical Characteristics of Influenza C Virus

“…Gouarin et al reported a peak of disease in France in winter-spring of 2005 while little ICV was detected in the two following seasons [101]. Fritsch et al noted a similar seasonal pattern in Germany, with a peak of ICV detection in fall-winter-spring of 2012-2013, with minimal detection in the seasons preceding and following [99]. Thielen et al describe a winter-spring outbreak of 51 cases in the US during 2013-2015 while in the seasons before and after only 2 and 8 cases were reported, respectively [103].…”

“…A Japanese longitudinal study of 190 ICV isolates collected over seven years found that nearly all were <6 years old, with the highest rates of infection in children 1-2 years old [60]. Rates of detection of ICV in outpatient or hospitalized children with acute respiratory illness have ranged from 0.7-10% in studies from Australia, Canada, Cuba, India, Italy, Japan, Nigeria, Peru, Scotland, and Spain [1,12,20,61,63,68,70,[91][92][93][94][95][96][97][98][99][100][101][102]. Most of these studies found higher rates of ICV infection in younger children.…”

“…Several studies have reported ICV as a cause of radiographic pneumonia in children, in some series as frequently as IBV [92,95,102]. These widely varied rates are likely due to varying circulation of ICV in different years; several studies have reported large outbreaks in a single year [61,94,98,99]. Outbreaks have been reported in long-term pediatric residential facilities and schools [68,91].…”

Growth Kinetics of Influenza C Virus Antigenic Mutants That Escaped from Anti-Hemagglutinin Esterase Monoclonal Antibodies and Viral Antigenic Changes Found in Field Isolates

“…Evolutionary tree analyses have revealed that six antigenic lineages of influenza C virus diverged by approximately 1980 [ 5 , 34 ]. Although the C/Sao Paulo lineage and the C/Kanagawa lineage are now circulating worldwide [ 2 , 3 , 18 , 19 , 35 , 36 ], antigenic cross-reactivity between the C/Ann Arbor/1/50 (C/Taylor lineage) and recent isolates in Japan has been still confirmed [ 19 ]. We investigated whether the stable antigenicity of influenza C virus relates to the functional constraints on variation in the antigenic region of the HE glycoprotein.…”

DNA/RNA Electrochemical Biosensing Devices a Future Replacement of PCR Methods for a Fast Epidemic Containment

“…Currently, quantitative real time-polymerase chain reaction (qPCR) is a standard method where a fluorescent signal is coupled with DNA polymerase chain reaction for quantification of DNA [ 2 , 3 , 4 , 5 , 6 ]. Though this method affords the detection of the presence of 1–10 copies/mL of DNA sample, PCR is still restricted to professional laboratories due to the need for specialized instrumentation [ 7 , 8 ].…”