Emerging Monkeypox Virus Sublineage C.1 Causing Community Transmission, Vietnam, 2023.

We studied a community cluster of 25 mpox cases in Vietnam caused by emerging monkeypox virus sublineage C.1 and imported into Vietnam through 2 independent events; 1 major cluster carried a novel APOBEC3-like mutation. Three patients died; all had advanced HIV co-infection. Viral evolution and its potential consequences should be closely monitored.

Reducing amplification cycles to improve the coverage of influenza A virus genome sequencing in heterosubtypic co-infection.

This study delineates the enhancement of a Reverse Transcription Polymerase Chain Reaction (RT-PCR) method for the amplification of the complete genome of the influenza A virus during heterosubtypic co-infection, relying on the amplification of intact gene segments. The precision of the method was assessed using all amplicons, which underwent both capillary electrophoresis and DNA sequencing. Five samples featuring co-infection of Influenza A viruses with H1N1 and H3N2 subtypes were evaluated. The improved strategy successfully amplified all eight segments of H3N2 strains in four samples, and the entire genome of H1N1 strains in three samples.

Evidence of Lineage 1 and 3 West Nile Virus in Person with Neuroinvasive Disease, Nebraska, USA, 2023.

West Nile virus (WNV) is the most common cause of human arboviral disease in the contiguous United States, where only lineage 1 (L1) WNV had been found. In 2023, an immunocompetent patient was hospitalized in Nebraska with West Nile neuroinvasive disease and multisystem organ failure. Testing at the Centers for Disease Control and Prevention indicated an unusually high viral load and acute antibody response. Upon sequencing of serum and cerebrospinal fluid, we detected lineage 3 (L3) and L1 WNV genomes. L3 WNV had previously only been found in Central Europe in mosquitoes. The identification of L3 WNV in the United States and the observed clinical and laboratory features raise questions about the potential effect of L3 WNV on the transmission dynamics and pathogenicity of WNV infections. Determining the distribution and prevalence of L3 WNV in the United States and any public health and clinical implications is critical.

Severe respiratory syncytial virus disease.

The burden of respiratory syncytial virus (RSV) disease is widely recognized. Main risk factors for severe disease, such as extreme ages, chronic cardiopulmonary conditions, and immunosuppression, typically coincide with poorer outcomes. While the majority of RSV hospitalizations involve healthy children, a higher proportion of hospitalized adults with underlying conditions need intensive care. Presently, treatment primarily consists of supportive measures. RSV-induced wheezing should be distinguished from respiratory tract thickening, without response to bronchodilators. Obstructive RSV disease frequently overlaps with viral pneumonia. Non-invasive mechanical ventilation and high-flow oxygen therapy represented significant advancements in the management of severe RSV disease in children and may also hold considerable importance in specific phenotypes of RSV disease in adults. Most severe infections manifest with refractory hypoxemia necessitating more advanced ventilatory support and/or extracorporeal membrane oxygenation therapy. Although bacterial co-infection rates are low, they have been associated with worse outcomes. Antibiotic prescription rates are high. Accurately diagnosing bacterial co-infections remains a challenge. Current evidence and antibiotic stewardship policies advise against indiscriminate antibiotic usage, even in severe cases. The role of currently developing antiviral therapies in severe RSV disease will be elucidated in the coming years, contingent upon the success of new vaccines and immune passive strategies involving nirsevimab.

Tropical Co-infection in a Tertiary Care Center in South India: A Case Report.

Tropical co-infections, characterized by overlapping clinical manifestations and the potential for diagnostic confusion, pose significant challenges in the management of febrile illnesses in endemic regions. This case report presents a 33-year-old male with a five-day history of fever, gastrointestinal symptoms, and dry cough, ultimately diagnosed with co-infections of dengue, leptospirosis, and Salmonella paratyphi A. This case underscores the challenges posed by the overlapping clinical features of endemic tropical diseases, emphasizing the necessity for comprehensive diagnostic strategies and tailored treatment protocols in managing febrile illnesses in endemic regions. Clinicians must also consider serological cross-reactivity when interpreting diagnostic tests, as it can complicate the identification of co-infections and impact treatment decisions, necessitating vigilance and an integrated approach in clinical practice.

Acute Retinal Necrosis Caused by Varicella Zoster Virus and Cytomegalovirus Co-Infection.

PURPOSE: To report the clinical course of two cases of acute retinal necrosis (ARN) caused by varicella zoster virus (VZV) and cytomegalovirus (CMV) co-infection detected by polymerase chain reaction (PCR) on aqueous tap. METHODS: Observational case reports. RESULTS: Two patients presented to our services with unilateral panuveitis suggestive of ARN complicated by hemorrhagic vasculitis and started empirical therapy. Aqueous PCR was performed on the same day and showed double positivity for VZV and CMV, which guided treatment. At follow-up, wide-field color fundus imaging and high-resolution optical coherence tomography showed resolution of active retinitis. CONCLUSION: Our cases suggest that ARN complicated by hemorrhagic vasculitis may be secondary to CMV and VZV co-infection, both in patients with an unremarkable clinical history and in those with immunodeficiency. In our cases, aqueous PCR testing was of paramount importance to determine the aetiology of ARN and to adjust the antiviral therapy accordingly.

Seroprevalence of bovine leukemia virus and association with bovine infectious abortion in Creole breeds from tropical grazing herds in the Colombian Caribbean.

Background and Aim: In the Caribbean region of Colombia, the concomitance of endemic infectious agents is a common problem, and coinfections are possible, increasing the complexity of cattle herds' sanitary, reproductive, and productive problems. This study aimed to estimate the seroprevalence of bovine leukemia virus and its association with bovine infectious abortion in grazing Creole breeds from tropical herds in the Colombian Caribbean. Materials and Methods: For the determination of bovine leukemia virus (BLV), bovine viral diarrhea virus (BVDV), bovine herpes virus-1 (BoHV-1), and Neospora Caninum (NC), the enzyme-linked immunosorbent assay technique was used. Matrix analysis was performed to represent multiple seroprevalence in the same cow. To explore the association between the seroprevalence of BLV and bovine infectious abortion agents, a multivariate logistic regression model was used. Results: The seroprevalence was as follows: BLV 30.78%, BVDV 33.01%, BoHV-1 12.85%, and NC 8.96%. In the multivariate logistic regression model, seroprevalence of BVDV (OR 10.8; 95% CI: 7.5-15.6) and seroprevalence of BoHV-1 (OR 1.8; 95% CI: 1.1-3.0) were associated with the seroprevalence of BLV. Conclusion: Animals infected with BLV are more susceptible to coinfections with BVDV and BoHV-1. Implementing healthy measures against these two immunosuppressive infections could enhance the hygiene of numerous cattle herds. This study was designed as a retrospective cross-sectional study, which limits the ability to confirm that BLV is the primary infection. Further studies to confirm the primary infection of BLV with an active viral coinfection are necessary and the factors associated with these phenomena.

Identification and pathogenicity of Alternaria and Fusarium species associated with bagged apple black spot disease in Shaanxi, China.

Apple is an economically important fruit crop in northern Shaanxi Province in China. In recent years, a new type of apple black spot disease, "bagged apple black spot disease," has occurred in the main apple production area of Yan'an City, Shaanxi Province, during the apple ripening season. It seriously affects the appearance quality and commercial value of apples. In this study, 120 isolates recovered from symptomatic apples were identified based on morphological characteristics, pathogenicity, and multilocus sequence analyses of the internal transcribed spacer of ribosomal DNA (rDNA-ITS), translation elongation factor 1-α (EF1-α), RNA polymerase II subunit B (RPB2), endopolygalacturonase (endo-PG), and anonymous region OPA1-3. Alternaria alternata was the most abundant species (64%), followed by Fusarium acuminatum (36%). Pathogenicity assays were conducted by inoculating them individually and together on detached apples (Venus Golden and Fuji varieties). The results showed that the two fungal species could infect apples individually and together. Co-infection enhanced the disease severity. F. acuminatum led to increased severity and speed of disease development compared to A. alternata. This is the first report of Fusarium and Alternaria co-infection causing apple black spot disease worldwide, and the first report of F. acuminatum affecting apples. The optimal growth of A. alternata occurred at 25-30°C and pH 7; the optimal growth of F. acuminatum occurred at 25°C and pH 7. The results of this study can provide a theoretical basis for exploring the occurrence and epidemiology of apple black spot disease and strategies for its control.

Co-Infection of Bertiella studeri and Mycobacterium tuberculosis in a Captive Rhesus Macaque (Macaca mulatta).

Bertiella studeri, a typical intestinal cestode of nonhuman primates, accidentally infects human beings. However, B. studeri infection in monkeys has been rarely reported in recent years. A case of B. studeri infection was identified in one captive rhesus macaque with natural infection of Mycobacterium tuberculosis. This study contributes to alerting the public of this helmintic zoonosis, though its infection rate is quite lower in recent years.

Co-infection is linked to infection prevalence and intensity in oysters amidst high environmental and spatial variation.

Co-infecting parasites modify infection outcomes in the wild. However, it is unclear how multiple environmental factors influence co-infection. The Chesapeake Bay metapopulation of the eastern oyster, Crassostrea virginica, provides an opportunity to test the importance of co-infection across heterogeneous environments because multiple parasites infect oysters across a broad salinity gradient. This study leverages Maryland and Virginia oyster monitoring for a large-scale survey of four co-infecting organisms, including two tissue parasites and two shell bio-eroding parasites. We diagnosed infection in 440 oysters across 16 paired harvested and unharvested reefs and tested the importance of co-infecting organisms for each parasite relative to environmental conditions, host traits, and marine spatial management. Microscopic visual methods were used to diagnose prevalence and intensity of tissue infections with Perkinsus marinus (the causative agent of dermo disease) and Haplosporidium nelsoni (the causative agent of MSX disease). Macroscopic visual methods were used to diagnose prevalence and intensity of shell infections with Cliona boring sponges and blister-inducing Polydora worms. For the three oyster parasites that were detected [H. nelsoni infections were absent in all oysters], salinity was the overall strongest predictor, corresponding to bay-wide patterns of parasite prevalence and/or intensity. Despite high environmental and spatial variation, co-infections corresponded to altered prevalence and/or intensity for all three oyster parasites. The correlational patterns suggest that P. marinus acts as a lynchpin in co-infection, as its intensity increased with Cliona sponge prevalence and P. marinus co-infection predicted higher Polydora blister intensity. Oyster shell height, reef habitat, and harvest status also predicted parasite prevalence and intensity, further reflecting the multivariate drivers of infections in this system. Unharvested reefs had greater vertical habitat structure and higher intensities of Cliona sponge infections, but no differences in the prevalence of any of the three parasites. Spatial patterns unexpectedly show that reef-level predictors of parasite patterns were more important than differences between tributaries. This correlational survey provides novel insights through the statistical relationships between the three oyster parasites, environmental conditions, host traits, and human resource management. New and more detailed scenarios are needed to expand disease ecological theory to encompass co-infection in anthropogenically impacted wildlife populations.

A Case of Severe Adenovirus Infection with SARS-CoV-2 Co-infection.

A 34-year-old man with no medical history presented to our hospital with a sore throat and difficult oral intake for two days before admission. He had various symptoms, including red eyes, ocular discharge, a fever, and intraoral ulcers, and he was admitted immediately. The polymerase chain reaction test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was positive, as was the adenovirus antigen test of the pharyngeal swab fluid, suggesting overlapping adenovirus and SARS-CoV-2 infections. The patient's condition improved with conservative treatment. This case of severe and varied symptoms caused by co-infection with adenovirus and SARS-CoV-2 has been previously reported.

Concurrent TB and HIV therapies effectively control clinical reactivation of TB during co-infection but fail to eliminate chronic immune activation.

The majority of Human Immunodeficiency Virus (HIV) negative individuals exposed to Mycobacterium tuberculosis (Mtb) control the bacillary infection as latent TB infection (LTBI). Co-infection with HIV, however, drastically increases the risk to progression to tuberculosis (TB) disease. TB is therefore the leading cause of death in people living with HIV (PLWH) globally. Combinatorial antiretroviral therapy (cART) is the cornerstone of HIV care in humans and reduces the risk of reactivation of LTBI. However, the immune control of Mtb infection is not fully restored by cART as indicated by higher incidence of TB in PLWH despite cART. In the macaque model of co-infection, skewed pulmonary CD4+ TEM responses persist, and new TB lesions form despite cART treatment. We hypothesized that regimens that concurrently administer anti-TB therapy and cART would significantly reduce TB in co-infected macaques than cART alone, resulting in superior bacterial control, mitigation of persistent inflammation and lasting protective immunity. We studied components of TB immunity that remain impaired after cART in the lung compartment, versus those that are restored by concurrent 3 months of once weekly isoniazid and rifapentine (3HP) and cART in the rhesus macaque (RM) model of LTBI and Simian Immunodeficiency Virus (SIV) co-infection. Concurrent administration of cART + 3HP did improve clinical and microbiological attributes of Mtb/SIV co-infection compared to cART-naïve or -untreated RMs. While RMs in the cART + 3HP group exhibited significantly lower granuloma volumes after treatment, they, however, continued to harbor caseous granulomas with increased FDG uptake. cART only partially restores the constitution of CD4 + T cells to the lung compartment in co-infected macaques. Concurrent therapy did not further enhance the frequency of reconstituted CD4+ T cells in BAL and lung of Mtb/SIV co-infected RMs compared to cART, and treated animals continued to display incomplete reconstitution to the lung. Furthermore, the reconstituted CD4+ T cells in BAL and lung of cART + 3HP treated RMs exhibited an increased frequencies of activated, exhausted and inflamed phenotype compared to LTBI RMs. cART + 3HP failed to restore the effector memory CD4+ T cell population that was significantly reduced in pulmonary compartment post SIV co-infection. Concurrent therapy was associated with the induction of Type I IFN transcriptional signatures and led to increased Mtb-specific TH1/TH17 responses correlated with protection, but decreased Mtb-specific TNFa responses, which could have a detrimental impact on long term protection. Our results suggest the mechanisms by which Mtb/HIV co-infected individuals remain at risk for progression due to subsequent infections or reactivation due of persisting defects in pulmonary T cell responses. By identifying lung-specific immune components in this model, it is possible to pinpoint the pathways that can be targeted for host-directed adjunctive therapies for TB/HIV co-infection.

Virology-The next fifty years.

Virology has made enormous advances in the last 50 years but has never faced such scrutiny as it does today. Herein, we outline some of the major advances made in virology during this period, particularly in light of the COVID-19 pandemic, and suggest some areas that may be of research importance in the next 50 years. We focus on several linked themes: cataloging the genomic and phenotypic diversity of the virosphere; understanding disease emergence; future directions in viral disease therapies, vaccines, and interventions; host-virus interactions; the role of viruses in chronic diseases; and viruses as tools for cell biology. We highlight the challenges that virology will face moving forward-not just the scientific and technical but also the social and political. Although there are inherent limitations in trying to outline the virology of the future, we hope this article will help inspire the next generation of virologists.

Virus transmission frequencies in the pine root rot pathogen Heterobasidion annosum.

The combined use of Heterobasidion partitiviruses 13 and 15 (HetPV13-an1 and HetPV15-pa1) is considered a promising biocontrol approach against Heterobasidion root and butt rot. In a previous study, the transmission frequency of HetPV15-pa1 was found to be higher from a double partitivirus-infected donor than from a single partitivirus-infected donor. In this study, we included a wider array of recipient isolates to assess whether the phenomenon is widespread across different host strains and conducted transmission experiments on artificial media (in vitro) using a total of 45 different H. annosum donor-recipient pairs. In addition to investigating whether double partitivirus infection improves the transmission of HetPV13-an1 and HetPV15-pa1, we examined for the first time how efficiently co-infecting ssRNA viruses are concomitantly transmitted with the partitiviruses, and whether pre-existing ssRNA viruses in the recipients affect virus transmission. Generally, the transmission rates of HetPV13-an1 and HetPV15-pa1 were high from both single partitivirus-infected and double partitivirus-infected donors to most of the H. annosum recipient strains, with few exceptions. However, in contrast to previous experiments, the transmission frequency was not higher from the double partitivirus-infected donors. Also, ourmiavirus was transmitted between H. annosum strains, but the presence of another ourmiavirus in the recipient might affect the efficacy.

Detection of community-acquired respiratory viruses during COVID-19 pandemic in subtropical region in Japan.

PURPOSE: Coronavirus disease 2019 (COVID-19) pandemic changed the dynamics of other community-acquired respiratory viruses (CARVs), however, information regarding the frequency of CARV detection during COVID-19 pandemic in subtropical regions is limited. Additionally, studies comparing the diagnostic accuracy between multiplex and monoplex PCR for the diagnosis of COVID-19 are scarce. METHODS: We evaluated samples collected from patients suspected of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Okinawa, a subtropical climate in Japan, from March 2020 to March 2021. For SARS-CoV-2, results obtained from monoplex (NIID method) and multiplex (Allplex™ SARS-CoV-2 Assay) PCR were compared. RESULTS: In total, 744 samples were collected and 238 viruses were detected in 205 specimens, of which 22 showed viral co-infection. Viral co-infection was more common in patients aged 10 and under than in older patients (p = 0.0054). For CARV, 142 viruses were detected in 127 specimens (17.1%), and human rhinovirus (HRV) was most common. Overall concordance rate for two SARS-CoV-2 assays was 94.1%; 7 and 37 specimens were detected only by NIID and Allplex™ SARS-CoV-2 Assay, respectively. The median cycling threshold values of the 44 samples that were only positive for either the NIID or Allplex™ SARS-CoV-2 Assay were 37.91 for E gene, 38.13 for RdRp/S gene, 38.21 for N gene and 39.16 for N2 gene. CONCLUSION: HRV was continuously detected during COVID-19 pandemic in the subtropical region and viral co-infection was more common in younger patients. For the diagnosis of COVID-19, multiplex PCR was more reliable, especially in samples with low viral load.

HEV Infection in the Context of Prior HBV-Related Liver Injury: Case Series.

Hepatitis E virus (HEV) is a common cause of acute hepatitis, with increasing incidence in Europe, including Romania. Concurrently, Romania has a high prevalence of chronic hepatitis B (CHB). There is limited research on the clinical presentation and outcomes of HEV infection in patients with pre-existing chronic hepatitis B (CHB), especially in resource-rich settings. Most literature data come from South, East, and Southeast Asia. A review of the literature on HEV and HBV co-infection indicates a severe prognosis, particularly in patients with underlying liver disease. However, the cases in this study, which did not display cirrhosis, showed varied outcomes. The role of anti-HBV treatment in improving prognosis remains uncertain and warrants further investigation. Acute HEV infection superimposed on chronic HBV infection poses significant clinical challenges, with outcomes ranging from full recovery to fatality. Preventive measures, including sanitation and vaccination against HBV, are crucial. More studies are needed to establish effective treatment protocols for this co-infection. In this study, we will analyze the clinical setting, diagnosis, particularities, and outcomes of five such cases of dual hepatotropic viral infection recorded over a period of 6 years (2018-2023) at a large Infectious Diseases clinic in Bucharest, Romania.

Identification of concurrent infection with Jaagsiekte sheep retrovirus and maedi-visna virus in China.

IMPORTANCE: Ovine pulmonary adenomatosis (OPA) and maedi-visna disease (MVD) are chronic and progressive infectious diseases in sheep caused by Jaagsiekte sheep retrovirus (JSRV) and maedi-visna virus (MVV), respectively. OBJECTIVE: To investigate the pathological changes and conduct viral gene analysis of OPA and MVD co-occurrence in Inner Mongolia, China. METHODS: Using gross pathology, histopathology, immunohistochemistry, ultrastructural pathology, PCR, and sequence analysis, we investigated the concurrent infection of JSRV and MVV in 319 Dorper rams slaughtered in a private slaughterhouse in Inner Mongolia, in 2022. RESULTS: Of the 319 rams included, 3 showed concurrent JSRV and MVV infection. Gross lung pathology showed diffuse enlargement, consolidation, and greyish-white miliary nodules on the lung surface; the trachea was filled with a white foamy fluid; hilar and mediastinal lymph nodes were significantly enlarged. Histopathology results revealed typical OPA and MVD lesions in the lung tissue. Immunohistochemical results were positive for JSRV envelope protein (Env) in the tumor cells and MVV CA in alveolar macrophages. Transmission electron microscopy showed several virions and autophagosomes in the lung tissue, severely damaged mitochondria, and the induced mitophagy. Nucleotide sequences obtained for JSRV env and MVV gag showed the highest homology with the Inner Mongolian strains of JSRV env (JQ837489) and MVV gag (MW248464). CONCLUSIONS AND RELEVANCE: Our study confirmed that OPA and MVD co-occurrence and identified the pathological changes in Inner Mongolia, China, thereby providing references for the identification of concurrent JSRV and MVV infections.

Co-Infection with Nocardia Terpene and Pneumocystis Jirovecii in a Patient with Anti-Synthetase Syndrome: A Case Report.

Background: Pulmonary infection is a common clinical complication associated with glucocorticoid. There have been no reported cases of mixed infections involving Nocardia and Pneumocystis jirovecii combined with anti-synthetase syndrome (ASS) activity. Methods: This study conducted a retrospective analysis of the clinical data from a patient with active ASS, treated for a pulmonary coinfection. Results: The patient exhibited fever, asthma, and cough as initial symptoms. Chest CT scan revealed multiple infiltration shadows, consolidation shadows, nodules, mass shadows, and internal cavities in both lungs. BALF mNGS detected Nocardia terpene and Pneumocystis jiroveci. Treatment with sulfamethoxazole/trimethoprim and corticosteroids led to an improvement. However, the patient experienced recurrent fever and a new rash with the reduction of the glucocorticoid dosage. Further investigation identified positive anti-Jo-1 and anti-Ro-52 antibodies and myogenic lesions on electromyography, which confirmed the diagnosis of ASS. Following treatment with immunoglobulin, methylprednisolone, and cyclosporine, the patient's condition significantly improved. Conclusion: Immunodeficiency patients are susceptible to opportunistic infections. mNGS is valuable for diagnosis and treatment. Although the image of Nocardia terpene and Pneumocystis jiroveci infections lack specificity, they exhibit distinctive features. Should fever and skin lesions reoccur post-effective anti-infective therapy, it is imperative to explore non-infectious causes and expedite autoantibody testing.

Co-Infection of Chickens with Staphylococcus lentus and Staphylococcus aureus from an Outbreak of Arthritis, Synovitis, and Osteomyelitis Argues for Detailed Characterisation of Isolates.

Staphylococcus species are widespread in poultry environments and can cause various infections, often when the host's defences are compromised. This manuscript reports on a co-infection of chickens with Staphylococcus lentus and Staphylococcus aureus associated with an outbreak of arthritis, synovitis, and osteomyelitis in an organic broiler breeder flock in Austria. Clinically, the affected flock showed weakness, lethargy, lameness, and increased mortality. Post-mortem examinations identified purulent arthritis and femoral head necrosis. Bacteriological analysis using MALDI-TOF MS identified both S. aureus and S. lentus in the affected joints. Antibiotic resistance testing revealed significant resistance, particularly in S. lentus. Histological analysis showed severe inflammation and bacterial colonies in the joints. While S. aureus is a common pathogen in poultry, S. lentus is less frequently reported. This study emphasises the need for detailed bacterial characterisation in outbreaks to better understand the role of less common pathogens like S. lentus. Further research is necessary to elucidate the impact of S. lentus on poultry health and its role in causing arthritis and synovitis, highlighting the importance of comprehensive investigation in such outbreaks.

Comparison of clinical characteristics and severity of COVID-19 with or without viral co-infection in hospitalized children.

BACKGROUND: Co-infection with other pathogens can alter the severity and clinical outcomes of viral infections. However, the information regarding viral co-infections in pediatric coronavirus disease 2019 (COVID-19) cases is still limited. METHODS: This is a nationwide, retrospective cohort study using the data from the COVID-19 Registry Japan. The pediatric (<18 years), laboratory confirmed, hospitalized COVID-19 patients in the Omicron variant of concern predominant period (January 2022 to January 2024) were included. Co-infection was investigated by multiplex PCR. We compared clinical characteristics, symptoms, severity, and outcomes between children with and without co-infection. RESULTS: Among 245 hospitalized pediatric COVID-19 patients, 78 (31.8 %) had co-infections. The patient backgrounds of the "co-infection" and "SARS-CoV-2 alone" groups were similar, although age distribution was different, with a lower number of patients over 12 years in the co-infection group (n = 2, 2.6 % vs. n = 29, 17.4 %; P < 0.001). Among the patients with co-infection, the most common pathogen was enterovirus/rhinovirus (51.3 %), followed by parainfluenza virus (23.1 %) and adenovirus (12.8 %). Patients with co-infection more commonly had respiratory symptoms, including SpO2 < 96 %, shortness of breath, runny nose, and wheezing. Requirement of non-invasive oxygen support was higher in the co-infection group (n = 27, 34.6 % vs. n = 28, 16.8 %, P = 0.006). By multivariable logistic regression analysis, co-infection and presence of any comorbidity were identified as significant risk factors for necessity of oxygen therapy (odds ratio [95 % confidence interval] 2.44 [1.29-4.63] and 3.99 [2.07-7.82], respectively). CONCLUSIONS: Viral co-infection may increase the risk of respiratory distress in pediatric COVID-19 patients.