Distinct differences in clinical manifestation and viral laboratory parameters between children and adults with influenza A(H1N1)pdm09 infection—A retrospective comparative analysis

Abstract

During the influenza pandemic 2009 children and adults differed in the clinical course of the influenza disease. In following the question arose, if the case definitions used within the national and international organizations are an adequate tool for the clinical diagnosis of influenza in children as well as in adults. Therefore medical charts from 146 children and 229 adults were retrospectively analyzed. In addition, the initial viral loads of all 375 patients and the duration of virus shedding of a subset of 79 patients were also investigated. Children show a wider clinical spectrum including gastro enteric symptoms and also a different spectrum of laboratory parameters like elevated CRP-levels, leucocytosis, and higher viral loads. Further, children show significantly more often complications, for example, myositis that may be underdiagnosed. In patients receiving antiviral-therapy complications occurred significantly less often and the presence of symptoms was significantly shorter compared to the untreated group (2.3 days vs. 6.0 days). In summary, the differences in the clinical picture between children and adults should be taken into consideration for the clinical diagnosis of influenza and also for a future discussion on age specific influenza case definitions.

Viral Infection in the Development and Progression of Pediatric Acute Respiratory Distress Syndrome

“…As would be expected children have a higher influenza A (H1N1) viral load compared to adults because of less exposure to influenza antigens. However, this finding did not correlate with the occurrence of disease complications (83). …”

Secondary myopathy due to systemic diseases

“…In a study of 355 pediatric patients with laboratory‐confirmed influenza‐B, 17.9% developed myositis . During the influenza pandemic in 2009, children developed more frequently myositis as compared to adults . Infections with human T‐cell lymphotropic virus (HTLV‐1) may manifest as axial myositis .…”

“…Concerning the causative agents, viral myositis has been reported following infections with influenza‐B , influenza‐A , parainfluenza‐1 , parvoviruses , HTLV‐1 , Epstein‐Barr virus , arboviruses (e.g., dengue myositis) , adenovirus , coxsackie , herpes , human immunodeficiency virus‐1 (HIV‐1) , or chickenpox . Most frequently myositis is due to infection with the influenza or parainfluenza virus .…”

Evaluation of the point-of-care Becton Dickinson Veritor™ Rapid influenza diagnostic test in Kenya, 2013–2014

“…The moderately high sensitivity observed in this study may relate to the fact that 80% of the ILI and SARI case-patients tested were aged <5 years, and RIDTs have been shown to have relative high sensitivity among young children because of increased influenza viral load compared to older children and adults [26, 27]. The sensitivity of RIDTs can be substantially diminished among adults (~18%), [28] and some studies have shown even lower sensitivity among those ≥65 years (8%) [29–31], leading to underestimation of disease burden [32, 33].…”