Viruses and atypical bacteria in the respiratory tract of immunocompromised and immunocompetent patients with airway infection

Maria Reckziegel,Bernd Gruhn,Claudia Weber-Osel,Mario Walther,Renate Egerer,Roland Zell,Andi Krumbholz,Florian Kubek,Stefanie Wilhelm

doi:10.1007/s10096-020-03878-9

Abstract

Respiratory tract infections (RTI) can take a serious course under immunosuppression. Data on the impact of the underlying pathogens are still controversial. Samples from the upper (n = 322) and lower RT (n = 169) were collected from 136 children and 355 adults; 225 among them have been immunocompromised patients. Exclusion criteria were presence of relevant cultivable microorganisms, C-reactive protein > 20 mg/dl, or procalcitonin > 2.0 ng/ml. Samples were tested by PCR for the presence of herpesviruses (HSV-1/-2; VZV; CMV; HHV6; EBV), adenoviruses, bocaviruses, entero-/rhinoviruses (HRV), parechoviruses, coronaviruses, influenza viruses (IV), parainfluenza viruses as well as for pneumoviruses (HMPV and RSV), and atypical bacteria (Mycoplasma pneumoniae, M.p.; Chlamydia pneumoniae, C.p.). Viral/bacterial genome equivalents were detected in more than two-thirds of specimens. Under immunosuppression, herpesviruses (EBV 30.9%/14.6%, p < 0.001; CMV 19.6%/7.9%, p < 0.001; HSV-1: 14.2%/7.1%, p = 0.012) were frequently observed, mainly through their reactivation in adults. Immunocompromised adults tended to present a higher RSV prevalence (6.4%/2.4%, p = 0.078). Immunocompetent patients were more frequently tested positive for IV (15.0%/5.8%, p = 0.001) and M.p. (6.4%/0.4%, p < 0.001), probably biased due to the influenza pandemic of 2009 and an M.p. epidemic in 2011. About 41.8% of samples were positive for a single pathogen, and among them EBV (19.9%) was most prevalent followed by HRV (18.2%) and IV (16.6%). HSV-2 and C.p. were not found. Marked seasonal effects were observed for HRV, IV, and RSV. Differences in pathogen prevalence were demonstrated between immunocompetent and immunocompromised patients. The exact contribution of some herpesviruses to the development of RTI remains unclear.

Highlights

Infections of the upper respiratory tract (URTI) are among the most frequent infections worldwide
With respect to patients’ immune status, DNA of EBV (30.9% vs. 14.6%), CMV (19.6% vs. 7.9%), and HSV-1 (14.2% vs. 7.1%) was significantly more prevalent in immunocompromised patients while genome equivalents of influenza viruses (IV) (5.8% vs. 15.0%) or M.p. (0.4% vs. 6.4%) were more frequently observed in their immunocompetent counterpart
Since a contribution of relevant cultivable microorganisms to patient symptoms was largely excluded, a causative role of the pathogens detected in this study has to be considered

Summary

Introduction

Infections of the upper respiratory tract (URTI) are among the most frequent infections worldwide. These are mainly caused by RNA viruses. Serious RTI through respiratory viruses are frequently observed under immunosuppression, for example, in solid organ transplant recipients [2]. Multiple viral infections/reactivations can occur [21] as well as indirect interactions of viruses with bacteria [22,23,24]. These aspects may challenge interpretation of diagnostic findings. The frequency of viral infections/reactivations is influenced by factors like the underlying disease, therapeutic regimes, as well as the type of transplant and HLA mismatches [12, 19]

Methods

Results

Conclusion