Exploring Clinical Predictors of Severe Human Metapneumovirus Respiratory Tract Infections in Children: Insights from a Recent Outbreak.

Human metapneumovirus (hMPV) is an important pathogen that causes both upper (URTIs) and lower respiratory tract infections (LRTIs) in children. The virus can be implicated in severe bronchiolitis and pneumonia, necessitating hospitalization, with certain cases requiring intensive care unit intervention. As part of a retrospective observational study, we aimed to identify indicators of severe hMPV respiratory tract infections in children referred to the University Children's Hospital Ljubljana and the Department of Infectious Diseases Ljubljana, Slovenia, during a recent outbreak. We analyzed clinical data from November 2022 to January 2023 and compared the characteristics of children presenting with URTIs and LRTIs. We also examined the characteristics of children with hMPV LRTIs, distinguishing between children with and without LRTI-associated hypoxemia. Of 78 hMPV-PCR-positive pediatric patients (mean age 3.1 years; 60.3% boys), 36% had a URTI, and 64% had an LRTI. Hospitalization was required in 64% (50/78), with 42% (21/50) requiring oxygen therapy. LRTI-associated hypoxemia was more common in patients with atopy who showed dyspnea, tachypnea, crackles, and wheezing on lung auscultation. In a multivariable logistic regression analysis, wheezing detected on lung auscultation was a significant predictive factor for hypoxemic hMPV-LRTI. Specifically, children presenting with wheezing were found to be ten times more likely to experience hypoxemia. Prematurity and chronic conditions did not influence the presentation or severity of hMPV infection. This study highlights wheezing and atopy as crucial indicators of severe hMPV LRTI in children, emphasizing the importance of early recognition and intervention.

Herpesviridae and Atypical Bacteria Co-Detections in Lower Respiratory Tract Samples of SARS-CoV-2-Positive Patients Admitted to an Intensive Care Unit.

Shortly after the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cases of viral, bacterial, and fungal coinfections in hospitalized patients became evident. This retrospective study investigates the prevalence of multiple pathogen co-detections in 1472 lower respiratory tract (LRT) samples from 229 SARS-CoV-2-positive patients treated in the largest intensive care unit (ICU) in Slovenia. In addition to SARS-CoV-2, (rt)RT-PCR tests were used to detect cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), varicella zoster virus (VZV), and atypical bacteria: Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila/spp. At least one co-detection was observed in 89.1% of patients. EBV, HSV-1, and CMV were the most common, with 74.7%, 58.1%, and 38.0% of positive patients, respectively. The median detection time of EBV, HSV-1, and CMV after initial SARS-CoV-2 confirmation was 11 to 20 days. Bronchoalveolar lavage (BAL) and tracheal aspirate (TA) samples showed equivalent performance for the detection of EBV, CMV, and HSV-1 in patients with both available samples. Our results indicate that SARS-CoV-2 infection could be a risk factor for latent herpesvirus reactivation, especially HSV-1, EBV, and CMV. However, additional studies are needed to elucidate the clinical importance of these findings.

Changes in HRSV Epidemiology but Not Circulating Variants in Hospitalized Children due to the Emergence of SARS-CoV-2.

This study assesses the circulation of human respiratory syncytial virus (HRSV) genotypes before, during, and toward the end of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in children and determines the influence of the pandemic on HRSV circulation patterns and evolution. Phylogenetic analysis of the hypervariable glycoprotein G gene was performed on 221/261 (84.7%) HRSV-positive samples and shows two separated clusters, one belonging to HRSV-A (129/221) and another to HRSV-B (92/221). All Slovenian HRSV-A strains contained the 72-nucleotide-long duplicated region in the attachment glycoprotein G gene and were classified as lineage GA2.3.5. All Slovenian HRSV-B strains similarly contained a 60-nucleotide-long duplicated region in the attachment glycoprotein G gene and were classified as lineage GB5.0.5a. During the 3-year period (2018-2021) covered by the study, no significant differences were observed within strains detected before the SARS-CoV-2 pandemic, during it, and after the implementation of nonpharmaceutical preventive measures. Slovenian HRSV-A strains seem to be more diverse than HRSV-B strains. Therefore, further whole-genome investigations would be required for better monitoring of the long-term impact of SARS-CoV-2 endemic circulation and the formation of new HRSV lineages and epidemiological patterns.

A simplified nasopharyngeal swab collection procedure for minimizing patient discomfort while retaining sample quality.

A nasopharyngeal swab (NPS) is the most frequently collected sample type when molecular diagnosis of respiratory viruses, including SARS CoV-2, is required. An optimal collection technique would provide sufficient sample quality for the diagnostic process and would minimize the discomfort felt by the patient. This study compares a simplified NPS collection procedure with only one rotation of the swab to a more standard procedure with five rotations. Swabs were collected from 76 healthy volunteers by the same healthcare professional on 2 consecutive days at a similar hour to minimize variability. The number of Ubiquitin C copy number per sample was measured by real-time quantitative PCR and patient discomfort was assessed by questionnaire. No statistically significant difference (p = 0.15) was observed in the Ubiquitin C copy number per sample between a NPS collected with one rotation (5.2 ± 0.6 log UBC number copies/sample) or five rotations (5.3 ± 0.5 log UBC number copies/sample). However, a statistically significant difference was observed in discomfort between these two procedures, the second being much more uncomfortable. Additional analysis of the results showed a weak correlation between discomfort and the number of human cells recovered (Spearman's rho = 0.202) and greater discomfort in younger people. The results of this study show that a NPS collected with one slow rotation has the same quality as a NPS collected with five rotations. However, the collection time is shorter and, most importantly, less unpleasant for patients.

Postnatal CMV Infection and Antiviral Treatment in Extremely Premature Infants: A 12-Year Retrospective Analysis.

BACKGROUND: The impact and outcomes of postnatal cytomegalovirus (CMV) infection are not entirely clear. We aimed to determine the associations between treatment outcomes of postnatal CMV infection and its antiviral treatment. METHODS: Retrospective study in a tertiary center. Infants of < 29 weeks gestational age who were tested for postnatal CMV infection were included. CMV-infected infants were compared to uninfected infants (control group). CMV-infected infants were either treated with ganciclovir and/or valganciclovir (CMVPT group) or not (CMVPNT group). Demographic, clinical, laboratory, treatment, and outcome data were collected. Primary outcomes were the length of stay, death before discharge and hearing impairment, cognitive and motor development as assessed by the Denver Developmental Screening Test II, and neurologic impairment at the corrected age of 1.5-2 years. RESULTS: We included 103 extremely premature infants. The Median (interquartile range [IQR]) length of stay was 94 (69-112) days in control, 85 (70-102) days in CMVPNT, and 100 (88-137) days in the CMVPT group. Mortality before discharge was 6% in control, 3.8% in CMVPNT, and 3.7% in the CMVPT group. Normal hearing at follow-up was found in 30/37 infants in control (81.1%), 13/13 infants in CMVPNT (100%), and 17/20 infants in the CMVPT group (85%). Denver Developmental Screening Test II results did not differ among the three groups. Neurologic impairment was found in 21/37 infants (56.8%) in control, 9/13 infants in CMVPNT (69.2%), and 14/20 infants in CMVPT group (70%). CONCLUSIONS: The associations between antiviral treatment of postnatal CMV infection and better treatment outcomes were nonsignificant.

Evaluation of Two Broadly Used Commercial Methods for Detection of Respiratory Viruses with a Recently Added New Target for Detection of SARS-CoV-2.

The clinical symptoms caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are nonspecific and can be associated with most other respiratory viruses that cause acute respiratory tract infections (ARI). Because the clinical differentiation of COVID-19 patients from those with other respiratory viruses is difficult, the evaluation of automated methods to detect important respiratory viruses together with SARS-CoV-2 seems necessary. Therefore, this study compares two molecular assays for the detection of respiratory viruses, including SARS-CoV-2: the Respiratory Viruses 16-Well Assay (AusDiagnostics, Pty Ltd., Mascot, Australia) and the Allplex™ RV Essential Assay coupled with the Allplex™-nCoV Assay (Seegene Inc., Seoul, Korea). The two methods (AusDiagnostics and AlplexTM-nCoV Assay SARS-CoV-2) had 98.6% agreement with the reference method, cobas 6800, for the detection of SARS-CoV-2. Agreement between the AusDiagnostics assay and the AlplexTM RV Essential Assay for the detection of seven respiratory viruses was 99%. In our experience, the Respiratory Viruses 16-Well Assay proved to be the most valuable and useful medium-throughput method for simultaneous detection of important respiratory viruses and SARS-CoV-2. The main advantages of the method are high specificity for all targets included and their simultaneous detection and medium throughput with the option of having multiple instruments provide a constant run.

Performance of nasopharyngeal swab and saliva in detecting Delta and Omicron SARS-CoV-2 variants.

A prospective cohort study was conducted during the Delta and Omicron severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) epidemic waves from paired nasopharyngeal swab (NPS or NP swab) and saliva samples taken from 624 participants. The study aimed to assess if any differences among participants from both waves could be observed and if any difference in molecular diagnostic performance could be observed among the two sample types. Samples were transported immediately to the laboratory to ensure the highest possible sample quality without any freezing and thawing steps before processing. Nucleic acids from saliva and NPS were prospectively extracted and SARS-CoV-2 was detected using a real-time reverse-transcription polymerase chain reaction. All observed results were statistically analyzed. Although the results obtained with NP and saliva agreed overall, higher viral loads were observed in NP swabs regardless of the day of specimen collection in both SARS-CoV-2 epidemic waves. No significant difference could be observed between the two epidemic waves characterized by Delta or Omicron SARS-CoV-2. To note, Delta infection resulted in higher viral loads both in NP and saliva and more symptoms, including rhinorrhea, cough, and dyspnea, whereas Omicron wave patients more frequently reported sore throat. An increase in the mean log RNA of SARS-CoV-2 was observed with the number of expressed symptoms in both waves, however, the difference was not significant. Data confirmed that results from saliva were concordant with those from NP swabs, although saliva proved to be a challenging sample with frequent inhibitions that required substantial retesting.

Outbreak of Human Metapneumovirus Infection in Zoo, Slovenia.

We report a case of human metapneumovirus infection that spread from humans to chimpanzees and back to humans. Bronchopneumonia developed in 4 of 6 members of a chimpanzee family, and 2 subsequently died. The chimpanzees' keeper also became ill. Sequencing showed 100% identity between virus sequences from chimpanzees and the keeper.

Clinical Evaluation of the cobas SARS-CoV-2 Test and a Diagnostic Platform Switch during 48 Hours in the Midst of the COVID-19 Pandemic.

Laboratories are currently witnessing extraordinary demand globally for sampling devices, reagents, consumables, and diagnostic instruments needed for timely diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To meet diagnostic needs as the pandemic grows, the U.S. Food and Drug Administration (FDA) recently granted several commercial SARS-CoV-2 tests Emergency Use Authorization (EUA), but manufacturer-independent evaluation data are scarce. We performed the first manufacturer-independent evaluation of the fully automated sample-to-result two-target test cobas 6800 SARS-CoV-2 (cobas) (Roche Molecular Systems, Branchburg, NJ), which received U.S. FDA EUA on 12 March 2020. The comparator was a standardized 3-h SARS-CoV-2 protocol, consisting of RNA extraction using an automated portable instrument, followed by a two-target reverse transcription real-time PCR (RT-PCR), which our laboratory has routinely used since January 2020 [V. M. Corman, O. Landt, M. Kaiser, R. Molenkamp, et al., Euro Surveill 25(3):pii=2000045, 2020, https://doi.org/10.2807/1560-7917.ES.2020.25.3.2000045]. cobas and the comparator showed overall agreement of 98.1% and a kappa value of 0.95 on an in-house validation panel consisting of 217 well-characterized retrospective samples. Immediate prospective head-to-head comparative evaluation followed on 502 samples, and the diagnostic approaches showed overall agreement of 99.6% and a kappa value of 0.98. A good correlation (r2 = 0.96) between cycle threshold values for SARS-CoV-2-specific targets obtained by cobas and the comparator was observed. Our results showed that cobas is a reliable assay for qualitative detection of SARS-CoV-2 in nasopharyngeal swab samples collected in the Universal Transport Medium System (UTM-RT) (Copan, Brescia, Italy). Under the extraordinary circumstances that laboratories are facing worldwide, a safe diagnostic platform switch is feasible in only 48 h and in the midst of the COVID-19 pandemic if carefully planned and executed.

Detection of herpes simplex and varicella-zoster virus from skin lesions: comparison of RT-PCR and isothermal amplification for rapid identification.

We compared 2 molecular tests for detection of herpes simplex viruses 1 and 2 (HSV-1, HSV-2) and varicella-zoster virus (VZV): real-time polymerase chain reaction (RT-PCR) (Argene, BioMerieux, France) performed on an LC480 platform (Roche Applied Science, Mannheim, Germany) and isothermal amplification using a Solana HSV1 + 2/VZV assay (Quidel Corporation Worldwide Headquarters, San Diego, CA) with helicase-dependent amplification performed by a Solana® instrument. With both methods, HSV-1 was detected in 68/291 (23.4%), HSV-2 in 23/291 (7.9%), and VZV in 48/291 (16.5%) skin lesions. Both methods agreed completely only in detection of HSV-2 (kappa = 1). Concordance between Solana HSV1 + 2/VZV and RT-PCR was 98.3% (kappa = 0.95) for HSV-1 and 99.3% (kappa = 0.98) for VZV. Rapid detection of HSV-1, HSV-2, and VZV using the Solana platform is a useful method for routine diagnostics and for urgent swab samples requiring a short turnaround time.

Atypical hand, foot, and mouth disease in an adult patient: a case report and literature review.

Hand, foot, and mouth disease is a highly contagious disease that predominantly affects children under the age of five. The illness is much less common in adults and often presents with atypical skin lesions. Here we describe the case of a 19-year-old healthy, immunocompetent male patient with atypical clinical presentation, with a macular rash on the scalp, palms, soles, and shins, and with minimal lesions in the oral cavity. The diagnosis of hand, foot, and mouth disease was confirmed by isolation of coxsackievirus A6 from a vesicle smearobtained on the right sole. The skin lesions resolved spontaneously in 1 week. This case emphasizes the underestimated fact that hand, foot, and mouth disease can also occur in adults, in either typical or frequently atypical form, and it highlights the role of coxsackievirus A6. Together with the case presentation, a review of the literature describing the disease in adults is presented.

Human Herpesvirus 6 Infection Presenting as an Acute Febrile Illness Associated with Thrombocytopenia and Leukopenia.

We present an infant with acute fever, thrombocytopenia, and leukopenia, coming from an endemic region for tick-borne encephalitis, human granulocytic anaplasmosis, and hantavirus infection. The primary human herpesvirus 6 infection was diagnosed by seroconversion of specific IgM and IgG and by identification of viral DNA in the acute patient's serum. The patient did not show skin rash suggestive of exanthema subitum during the course of illness.

Viral respiratory infections in a nursing home: a six-month prospective study.

BACKGROUND: The knowledge on viral respiratory infections in nursing home (NH) residents and their caregivers is limited. The purpose of the present study was to assess and compare the incidence of acute respiratory infections (ARI) in nursing home (NH) residents and staff, to identify viruses involved in ARI and to correlate viral etiology with clinical manifestations of ARI. METHODS: The prospective surveillance study was accomplished in a medium-sized NH in Slovenia (central Europe). Ninety NH residents and 42 NH staff were included. Nasopharyngeal swabs were collected from all participants at enrollment (December 5th, 2011) and at the end of the study (May 31st, 2012), and from each participant that developed ARI within this timeframe. Molecular detection of 15 respiratory viruses in nasopharyngeal swab samples was performed. RESULTS: The weekly incidence rate of ARI in NH residents and NH staff correlated; however, it was higher in staff members than in residents (5.9 versus 3.8/1,000 person-days, P = 0.03), and was 2.5 (95 % CI: 1.36-4.72) times greater in residents without dementia than in residents with dementia. Staff members typically presented with upper respiratory tract involvement, whereas in residents lower respiratory tract infections predominated. Respiratory viruses were detected in 55/100 ARI episodes. In residents, influenza A virus, respiratory syncytial virus, and human metapneumovirus were detected most commonly, whereas in NH staff rhinovirus and influenza A virus prevailed. 38/100 ARI episodes (30/56 in residents, 8/44 in staff) belonged to one of three outbreaks (caused by human metapneumovirus, influenza A virus and respiratory syncytial virus, respectively). NH residents had higher chances for virus positivity within outbreak than HN staff (OR = 7.4, 95 % CI: 1.73-31.48, P < 0.01). CONCLUSIONS: ARI are common among NH residents and staff, and viruses were detected in a majority of the episodes of ARI. Many ARI episodes among NH residents were outbreak cases and could be considered preventable. TRIAL REGISTRATION: The study was registered on the 1th of December 2011 at ClinicalTrials ( NCT01486160 ).

Narrowing of the Diagnostic Gap of Acute Gastroenteritis in Children 0-6 Years of Age Using a Combination of Classical and Molecular Techniques, Delivers Challenges in Syndromic Approach Diagnostics.

BACKGROUND: Twenty-five percent to 50% of acute gastroenteritis (AGE) cases remain etiologically undiagnosed. Our main aim was to determine the most appropriate list of enteric pathogens to be included in the daily diagnostics scheme of AGE, ensuring the lowest possible diagnostic gap. METHODS: Two hundred ninety seven children ≤6 years of age, admitted to hospital in Slovenia, October 2011 to October 2012, with AGE, and 88 ≤6 years old healthy children were included in the study. A broad spectrum of enteric pathogens was targeted with molecular methods, including 8 viruses, 6 bacteria and 2 parasites. RESULTS: At least one enteric pathogen was detected in 91.2% of cases with AGE and 27.3% of controls. Viruses were the most prevalent (82.5% and 15.9%), followed by bacteria (27.3% and 10.2%) and parasites (3.0% and 1.1%) in cases and controls, respectively. A high proportion (41.8%) of mixed infections was observed in the cases. For cases with undetermined etiology (8.8%), stool samples were analyzed with next generation sequencing, and a potential viral pathogen was detected in 17 additional samples (5.8%). CONCLUSIONS: Our study suggests that tests for rotaviruses, noroviruses genogroup II, adenoviruses 40/41, astroviruses, Campylobacter spp. and Salmonella sp. should be included in the initial diagnostic algorithm, which revealed the etiology in 83.5% of children tested. The use of molecular methods in diagnostics of gastroenteritis is preferable because of their high sensitivity, specificity, fast performance and the possibility of establishing the concentration of the target. The latter may be valuable for assessing the clinical significance of the detected enteric, particularly viral pathogens.

Laboratory diagnosis and epidemiology of herpes simplex 1 and 2 genital infections.

Herpes simplex virus types 1 and 2 are the main cause of genital ulcers worldwide. Although herpes simplex virus type 2 is the major cause of genital lesions, herpes simplex virus type 1 accounts for half of new cases in developed countries. Herpes simplex virus type 2 seroprevalence rises with sexual activity from adolescence through adulthood. Slovenian data in a high-risk population shows 16% seroprevalence of HSV-2. HSV-1 and HSV-2 DNA in genital swabs was detected in 19% and 20.7%, respectively. In most cases, genital herpes is asymptomatic. Primary genital infection with herpes simplex virus types 1 and 2 can be manifested by a severe clinical picture, involving the vesicular skin and mucosal changes and ulcerative lesions of the vulva, vagina, and cervix in women and in the genital region in men. Direct methods of viral genome detection are recommended in the acute stage of primary and recurrent infections when manifest ulcers or lesions are evident. Serological testing is recommended as an aid in diagnosing genital herpes in patients with reinfection in atypical or already healed lesions. When herpes lesions are present, all sexual activities should be avoided to prevent transmission of infection. Antiviral drugs can reduce viral shedding and thus reduce the risk of sexual transmission of the virus.

Diagnosing cytomegalovirus in patients with inflammatory bowel disease--by immunohistochemistry or polymerase chain reaction?

Cytomegalovirus (CMV) reactivation is a common complication in patients with inflammatory bowel diseases (IBD), particularly in those with steroid-resistant ulcerative colitis. It is usually diagnosed by histopathologic and immunohistochemical examination of the colon biopsy. The introduction of quantitative, real-time polymerase chain reaction (qPCR) has been recommended to improve the sensitivity, but there is little consensus on how to use it. We compared the two methods in samples from resected bowel of patients with IBD. Twelve patients with IBD who had undergone bowel resection were analysed for CMV, using qPCR and immunohistochemistry. In all cases, tissue samples from the base and the edge of ulcers and from uninvolved mucosa were obtained. The highest densities of CMV-positive cells were found in samples from the base of ulcers (immunohistochemistry 0-0.47 positive cells/mm(2); qPCR 10-3809 viral copies/mg) or the edge of ulcers (immunohistochemistry 0.06-0.32 positive cells/mm(2); qPCR 35-1049 viral copies/mg). In samples of uninvolved mucosa, immunohistochemistry was negative, whereas qPCR was either negative or showed very low values (0-3 viral copies/mg). We conclude that both immunohistochemistry and qPCR can be successfully used for diagnosing CMV reactivation in patients with IBD. The base and the edge of ulcers are the optimal sites for endoscopic biopsies. The density of CMV-positive cells was low and their distribution within the colon uneven. It therefore seems that the number of sampled biopsies and/or the number of investigated levels is more important that the choice of diagnostic method.

Fatal human bocavirus infection in an 18-month-old child with chronic lung disease of prematurity.

A fatal case of human bocavirus 1 pulmonary infection in an 18-month-old prematurely born child is described. Despite conventional and oscillatory ventilatory support, intractable hyperinflation developed with bilateral pneumothorax and acute cardiac failure 3 days after the onset of respiratory symptoms.

Two episodes of systemic capillary leak syndrome in an 8-year-old boy, following influenza A virus infection.

Systemic capillary leak syndrome is a rare condition, characterized by hypotension, edema, hemoconcentration and hypoalbuminemia. We describe 2 episodes of systemic capillary leak syndrome, following influenza A virus infection, occurring during 2 subsequent influenza seasons, in an 8-year-old boy.

Coronavirus infections in hospitalized pediatric patients with acute respiratory tract disease.

BACKGROUND: Acute viral respiratory infections are an important cause of morbidity and mortality in humans worldwide. The etiological backgrounds of these infections remain unconfirmed in most clinical cases. The aim of this study was to estimate the prevalence of human coronavirus infections in a series of children hospitalized with symptoms of acute respiratory tract disease in a one-year period in Slovenia. METHODS: The 664 specimens from 592 children under six years of age hospitalized at the University Children's Hospital in Ljubljana were sent for the routine laboratory detection of respiratory viruses. Respiratory viruses were detected with a direct immunofluorescence assay and human coronaviruses were detected with a modified real-time RT-PCR. RESULTS: HCoV RNA was detected in 40 (6%, 95% CI: 4.3%-8.1%) of 664 samples. Of these specimens, 21/40 (52.5%) were identified as species HKU1, 7/40 (17.5%) as OC43, 6/40 (15%) as 229E, and 6/40 (15%) as NL63. Infection with HCoV occurred as a coinfection with one or more other viruses in most samples (70%). Of the HCoV-positive children, 70.3% had lower respiratory tract infections. CONCLUSION: The results of our study show that HCoV are frequently detected human pathogens, often associated with other respiratory viruses and acute respiratory tract infections in hospitalized children. An association between age and the viral load was found. The highest viral load was detected in children approximately 10 months of age.