Influenza Co-infection Research Articles

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.

Influenza A/H3N2 and Its Co-infection with Other Respiratory Pathogens: Higher Pneumonia Rates and Prolonged Hospital Stays in Pediatric Patients

Background: In pediatric populations, influenza viruses such as influenza B, influenza A/H1N1, and influenza A/H3N2 present unique clinical challenges due to their distinct characteristics. Co-infections with other respiratory pathogens can lead to more severe disease progression in children, although the specific impacts of these co-infections are not yet fully understood. Objectives: To explore the differences in clinical characteristics among children with single infections of influenza B, influenza A/H1N1, and influenza A/H3N2, and to assess the impact of co-infections with other respiratory pathogens on the severity of disease in children. Methods: This retrospective study evaluated the severity of pediatric influenza hospitalizations during 2022 - 2023 by correlating virus types/subtypes with clinical outcomes, including pneumonia incidence, mechanical ventilation requirements, PICU admissions, and duration of hospital stay. Results: The study included 1,380 pediatric patients with influenza: 343 with influenza A/H1N1, 678 with A/H3N2, and 359 with influenza B. In children aged six and older, influenza A/H3N2 infection resulted in higher pneumonia rates and longer hospital stays compared to influenza A/H1N1 and influenza B (P < 0.05). Laboratory result differences were also observed between single infections of influenza A and B in this age group. The co-infection rate for influenza A/H1N1 was 3.5%, significantly lower than that for H3N2 (11.9%) and influenza B (10.6%) (P < 0.05). Clinical differences were noted between single and co-infections of influenza A/H3N2 and B, with co-infections showing higher pneumonia rates and longer hospital stays compared to single infections (P < 0.05). Conclusions: In children aged six and older, influenza A/H3N2 is associated with higher rates of pneumonia and longer hospital stays. Co-infections involving Influenza B or A/H3N2 with additional respiratory pathogens further increase the risk of pneumonia and extend the duration of hospitalization.

Changes in the incidence, clinical features and outcomes of tuberculosis during COVID-19 pandemic

BackgroundCOVID-19 pandemic has disrupted tuberculosis (TB) services in many countries, but the impacts on sites of involvement, drug susceptibility, smear positivity and clinical outcomes, and clinical outcomes of co-infection with influenza and COVID-19 remain unclear. MethodsDescriptive epidemiological study using episode-based and patient unique data of tuberculosis from Hospital Authority’s territory-wide electronic medical record database, comparing baseline (January 2015-December 2019) and COVID-19 period (January 2020-December 2022), followed by univariate and multivariate analyses. Effects of co-infection with influenza and COVID-19 were investigated. ResultsThe study included 10,473 episodes of laboratory-confirmed TB, with 6818 in baseline period and 3655 during COVID-19 period. During COVID-19 period, TB patients had a lower proportion of smear positivity (49.2 % vs 54.7 %, P < 0.001), and fewer cases of extrapulmonary TB (7.0 % vs 8.0 %, P = 0.078) and multidrug resistant TB (1.0 % vs 1.6 %, P = 0.020). Mortality was higher in TB patients with COVID-19 coinfection (OR 1.7, P = 0.003) and influenza coinfection (OR 2.6, P = 0.004). During COVID-19 period, there were higher rates of treatment delay (20.5 % vs 15.5 %, P < 0.001) and episodic death (15.1 % vs 13.3 %, P = 0.006). Factors associated with higher mortality included age ≥ 70 years (OR 7.24), treatment delay (OR 2.16), extrapulmonary TB (OR 2.13). smear positivity (OR 1.71) and Charlson comorbidity index score ≥ 3 (OR 1.37). Higher mortality was observed with co-infection by influenza (OR 1.18) and COVID-19 (OR 1.7). ConclusionsThe epidemiology and outcomes of TB were changed during COVID-19 period. Mortality was higher during COVID-19 period and with co-infection by influenza and COVID-19.

Development of a Recombinant Live Attenuated Influenza Vaccine Virus Expressing Pneumococcal Surface Antigen A as a Strategy for Combined Protection Against Influenza and Bacterial Coinfection Caused by Streptococcus pneumoniae

Introduction Bacterial superinfection with Streptococcus pneumoniae following the influenza virus infection complicates the course of the disease and is a major cause of mortality during influenza virus epidemics. The effectiveness of licensed polysaccharide vaccines is limited by the serotypes included in the vaccine and possible immune tolerance during revaccination. Pneumococcal surface protein A (PspA), which includes conserved regions and has at least two functions in pathogen virulence, is considered a promising target for the development of new-generation vaccines, including gene-engineering constructions. Therefore, the development of an influenza virus vector-based vaccine expressing conserved bacterial proteins seems to be a promising strategy for designing combined vaccines against influenza and bacterial pathogens. Methods A recombinant live attenuated influenza virus (LAIV) expressing PspA fragment in a modified hemagglutinin was rescued on the A/Leningrad/134/17/57 (H2N2) backbone. This recombinant virus was assessed for its growth characteristics in vitro, as well as for its immunogenicity and protective capacity, using a mouse model of influenza-bacterial coinfection. Results The rescued recombinant LAIV/HA+PspA virus was genetically stable after sequential passaging in embryonated chicken eggs and possessed an attenuated phenotype similar to the classical LAIV strain. The LAIV/HA+PspA bivalent vaccine-induced IgG antibodies specific to both influenza virus and S. pneumoniae and provided complete protection of vaccinated mice against lethal influenza infection, as well as a 40% survival rate for lethal homologous and heterologous influenza infection complicated by concomitant bacterial infection with S. pneumoniae. Conclusion The presented design of a recombinant influenza virus carrying immunogenic fragments of a bacterial pathogen can be considered a promising strategy for the combined protection of vaccinated individuals against influenza and its bacterial complications, and further in-depth studies of such recombinant viruses in preclinical studies are warranted.

Severe necrotizing tracheobronchitis caused by influenza B and methicillin-resistant Staphylococcus aureus co-infection in an immunocompetent patient

Purpose and methodNecrotizing tracheobronchitis is a rare clinical entity presented as a necrotic inflammation involving the mainstem trachea and distal bronchi. We reported a case of severe necrotizing tracheobronchitis caused by influenza B and methicillin-resistant Staphylococcus aureus (MRSA) co-infection in an immunocompetent patient.Case presentationWe described a 36-year-old man with initial symptoms of cough, rigors, muscle soreness and fever. His status rapidly deteriorated two days later and he was intubated. Bronchoscopy demonstrated severe necrotizing tracheobronchitis, and CT imaging demonstrated multiple patchy and cavitation formation in both lungs. Next-generation sequencing (NGS) and bronchoalveolar lavage fluid (BALF) culture supported the co-infection of influenza B and MRSA. We also found T lymphocyte and NK lymphocyte functions were extremely suppressed during illness exacerbation. The patient was treated with antivirals and antibiotics including vancomycin. Subsequent bronchoscopy and CT scans revealed significant improvement of the airway and pulmonary lesions, and the lymphocyte functions were restored. Finally, this patient was discharged successfully.ConclusionNecrotizing tracheobronchitis should be suspected in patients with rapid deterioration after influenza B infection. The timely diagnosis of co-infection and accurate antibiotics are important to effective treatment.

Risk factors for pneumonia among children with coinfection of influenza A virus and Mycoplasma pneumoniae.

To investigate the clinical characteristics and risk factors for pneumonia in children co-infected with influenza A virus (IAV) and Mycoplasma pneumoniae (MP). Children who were diagnosed with IAV and MP infection between January and December, 2023 were enrolled and divided into a non-pneumonia group and a pneumonia group. Univariate analysis and logistic regression analysis were used to evaluate each index, and the risk factors for pneumonia caused by coinfection in the two groups were explored. A total of 209 patients were enrolled, of which 107 and 102 patients were in the pneumonia and non-pneumonia groups, respectively. The patients in the pneumonia group were older and had a longer duration of fever (P < 0.05). Univariate analysis revealed that the median age, duration of fever, and CD3+, CD4+, CD8+ and IL-10 levels were significantly correlated with pneumonia (P < 0.05). Multivariate logistic regression analysis revealed that the median age, duration of fever, and CD4+, CD8+ and IL-10 levels were independent risk factors for pneumonia. Area under the curve of the five combined indicators in the ROC (receiver operator characteristic) analysis was 0.883, was higher than single factor. Children with IAV and MP infection whose age older than 6.08years, had a fever longer than 4days, had a CD4+ count < 22.12%, had a CD8+ count < 35.21%, had an IL-10 concentration > 22.08 ng/ml were more likely to develop pneumonia.

SARS-CoV-2 and Influenza Co-Infection: Fair Competition or Sinister Combination?

The COVID-19 pandemic remains a serious public health problem globally. During winter influenza seasons, more aggressive SARS-CoV-2 infections and fatalities have been documented, indicating that influenza co-infections may significantly impact the disease outcome of COVID-19. Both influenza and SARS-CoV-2 viruses share many similarities in their transmission and their cellular tropism for replication in the human respiratory tract. However, the complex intricacies and multi-faceted dynamics of how the two pathogens interact to ensure their survival in the same lung microenvironment are still unclear. In addition, clinical studies on influenza co-infections in COVID-19 patients do not provide conclusive evidence of how influenza co-infection mechanistically modifies disease outcomes of COVID-19. This review discusses various viral as well as host factors that potentially influence the survival or synergism of these two respiratory pathogens in the infected lung microenvironment.

Bifunctional neuraminidase inhibitory and simultaneously anti-Mycoplasma pneumoniae of flavan-3-ols and flavanones: Combined molecular docking, virtual screening, ADMET, and synthesis prediction

After lifting COVID-19 restrictions, pneumonia caused by influenza A virus coinfection with Mycoplasma pneumoniae bacteria emerges as a matter of concern. Only a few reports have recently proposed natural compounds for treating the coinfection of influenza A virus and M. pneumoniae, especially resistant strains. Hence, this study demonstrated in silico investigation of two natural classes (flavan-3-ol and flavanone) that could become future inhibitors for bifunctional neuraminidase and anti-M. pneumoniae. Combining the molecular docking with based-virtual screening strategies for over 900 ligands with neuraminidase protein of oseltamivir-resistant virus strain at H274Y mutation (PDB ID: 3CL0), 03 flavan-3-ols and 46 flavanones interacted with both the active site and the adjacent 430-cavity, and showed lower binding energies than laninamivir (−8.1 kcal/mol). The four most suitable candidates (FL22, FN166, FN316, and ChEMBL1779463) also exhibited potential characteristics for inhibiting M. pneumoniae through some vital targets (30S Ribosome-binding factor A (PDB ID: 1PA4) and immunodominant protein P40/P90 complex (PDB ID: 6TLZ)). Furthermore, the total-synthesis strategy of ChEMBL1779463 was successfully proposed using commercial reagents and modern techniques. Our results will offer potential insights for future methods to identify biflavonoids, especially biflavanone, to simultaneously suppress the resistant strains of influenza A virus and M. pneumoniae.

Interaction and antiviral treatment of coinfection between SARS-CoV-2 and influenza in vitro

BackgroundThe pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has lasted for three years. Coinfection with seasonal influenza may occur resulting in more severe diseases. The interaction between these two viruses for infection and the effect of antiviral treatment remains unclear. MethodsA SARS-CoV-2 and influenza H1N1 coinfection model on Calu-3 cell line was established, upon which the simultaneous and sequential coinfection was evaluated by comparing the viral load. The efficacy of molnupiravir and baloxavir against individual virus and coinfection were also studied. ResultsThe replication of SARS-CoV-2 was significantly interfered when the influenza virus was infected simultaneously or in advance (p < 0.05). On the contrary, the replication of the influenza virus was not affected by the SARS-CoV-2. Molnupiravir monotherapy had significant inhibitory effect on SARS-CoV-2 when the concentration reached to 6.25 μM but did not show any significant anti-influenza activity. Baloxavir was effective against influenza within the dosage range and showed significant effect of anti-SARS-CoV-2 at 16 μM. In the treatment of coinfection, molnupiravir had significant effect for SARS-CoV-2 from 6.25 μM to 100 μM and inhibited H1N1 at 100 μM (p < 0.05). The tested dosage range of baloxavir can inhibit H1N1 significantly (p < 0.05), while at the highest concentration of baloxavir did not further inhibit SARS-CoV-2, and the replication of SARS-CoV-2 significantly increased in lower concentrations. Combination treatment can effectively inhibit influenza H1N1 and SARS-CoV-2 replication during coinfection. Compared with molnupiravir or baloxavir monotherapy, combination therapy was more effective in less dosage to inhibit the replication of both viruses. ConclusionsIn coinfection, the replication of SARS-CoV-2 would be interfered by influenza H1N1. Compared with molnupiravir or baloxavir monotherapy, treatment with a combination of molnupiravir and baloxavir should be considered for early treatment in patients with SARS-CoV-2 and influenza coinfection.

Coinfection of Influenza A and B and Human OC43 Coronavirus in Normal Human Bronchial Epithelial Cells.

Influenza viruses and seasonal coronaviruses are pathogens transmitted via an airborne route that can cause respiratory diseases in humans that have similar symptoms such as fever, cough, and pneumonia. These two viruses can infect similar human tissues, such as the respiratory tract and nasal, bronchial, and alveolar epithelial cells. Influenza virus and seasonal coronavirus coinfections are poorly understood. Here, we coinfected normal human bronchial epithelial (NHBE) cells with influenza A/California/04/09 (IAV) or B/Victoria/504/2000 (IBV) strains and the seasonal human beta-coronavirus OC43 and evaluated viral replication capacities. We also examined changes in the expression of various cytokines/chemokines by qPCR and Luminex assay. We observed that the replication of IAV and IBV was not affected by coinfection with OC43. However, coinfection reduced OC43 titers (~3-fold) compared with infection with OC43 alone. Select cytokine/chemokine expression was increased in coinfected cells compared with all single infections with greater differences seen between coinfected cells and cells infected with OC43 alone compared with IAV- or IBV-infected cells. In addition, IL-8 and IL-1RA showed the highest expression among a panel of 22 cytokines by Luminex. As the rate of influenza and seasonal coronavirus coinfection continue to increase, our findings may help set guidelines for the treatments of the individuals coinfected with both viruses.

Influenza and COVID-19 co-infection and vaccine effectiveness against severe cases: a mathematical modeling study.

Influenza A virus have a distinctive ability to exacerbate SARS-CoV-2 infection proven by in vitro studies. Furthermore, clinical evidence suggests that co-infection with COVID-19 and influenza not only increases mortality but also prolongs the hospitalization of patients. COVID-19 is in a small-scale recurrent epidemic, increasing the likelihood of co-epidemic with seasonal influenza. The impact of co-infection with influenza virus and SARS-CoV-2 on the population remains unstudied. Here, we developed an age-specific compartmental model to simulate the co-circulation of COVID-19 and influenza and estimate the number of co-infected patients under different scenarios of prevalent virus type and vaccine coverage. To decrease the risk of the population developing severity, we investigated the minimum coverage required for the COVID-19 vaccine in conjunction with the influenza vaccine, particularly during co-epidemic seasons. Compared to the single epidemic, the transmission of the SARS-CoV-2 exhibits a lower trend and a delayed peak when co-epidemic with influenza. Number of co-infection cases is higher when SARS-CoV-2 co-epidemic with Influenza A virus than that with Influenza B virus. The number of co-infected cases increases as SARS-CoV-2 becomes more transmissible. As the proportion of individuals vaccinated with the COVID-19 vaccine and influenza vaccines increases, the peak number of co-infected severe illnesses and the number of severe illness cases decreases and the peak time is delayed, especially for those >60 years old. To minimize the number of severe illnesses arising from co-infection of influenza and COVID-19, in conjunction vaccinations in the population are important, especially priority for the elderly.

Avian influenza overview December 2023-March 2024.

Between 2 December 2023 and 15 March 2024, highly pathogenic avian influenza (HPAI) A(H5) outbreaks were reported in domestic (227) and wild (414) birds across 26 countries in Europe. Compared to previous years, although still widespread, the overall number of HPAI virus detections in birds was significantly lower, among other reasons, possibly due to some level of flock immunity in previously affected wild bird species, resulting in reduced contamination of the environment, and a different composition of circulating A(H5N1) genotypes. Most HPAI outbreaks reported in poultry were primary outbreaks following the introduction of the virus by wild birds. Outside Europe, the majority of outbreaks in poultry were still clustered in North America, while the spread of A(H5) to more naïve wild bird populations on mainland Antarctica is of particular concern. For mammals, A(H5N5) was reported for the first time in Europe, while goat kids in the United States of America represented the first natural A(H5N1) infection in ruminants. Since the last report and as of 12 March 2024, five human avian influenza A(H5N1) infections, including one death, three of which were clade 2.3.2.1c viruses, have been reported by Cambodia. China has reported two human infections, including one fatal case, with avian influenza A(H5N6), four human infections with avian influenza A(H9N2) and one fatal case with co-infection of seasonal influenza A(H3N2) and avian influenza A(H10N5). The latter case was the first documented human infection with avian influenza A(H10N5). Human infections with avian influenza remain rare and no sustained human-to-human infection has been observed. The risk of infection with currently circulating avian H5 influenza viruses of clade 2.3.4.4b in Europe remains low for the general population in the EU/EEA. The risk of infection remains low to moderate for those occupationally or otherwise exposed to infected animals.

Differentiating Viral from Bacterial Pneumonia in Children: The Diagnostic Role of Lung Ultrasound-A Prospective Observational Study.

This prospective observational study aimed to investigate the utility of lung ultrasound (LUS) in diagnosing and managing pediatric respiratory infections, specifically focusing on viral, bacterial, and SARS-CoV-2 infections. Conducted over a period of 1 year and 8 months, this research involved 85 pediatric patients (showcasing a median age of 14 months) recruited based on specific criteria, including age, confirmed infection through multiplex PCR tests, and willingness to undergo LUS imaging. This study employed a 12-area scoring system for LUS examinations, utilizing the lung ultrasound score (LUSS) to evaluate lung abnormalities. The PCR examination results reveal diverse respiratory pathogens, with SARS-CoV-2, influenza, and bacterial co-infections being prominent among the cases. As an observational study, this study was not registered in the registry. Distinct LUS patterns associated with different pathogens were identified, showcasing the discriminatory potential of LUS in differentiating between viral and bacterial etiologies. Bacterial infections demonstrated more severe lung involvement, evident in significantly higher LUSS values compared with viral cases (p < 0.0001). The specific abnormalities found in bacterial superinfection can be integrated into diagnostic and management protocols for pediatric respiratory infections. Overall, this research contributes valuable insights into optimizing LUS as a diagnostic tool in pediatric pneumonia, facilitating more informed and tailored healthcare decisions.

Clinical features and outcomes of influenza and RSV coinfections: a report from Canadian immunization research network serious outcomes surveillance network

BackgroundInfluenza and RSV coinfections are not commonly seen but are concerning as they can lead to serious illness and adverse clinical outcomes among vulnerable populations. Here we describe the clinical features and outcomes of influenza and RSV coinfections in hospitalized adults.MethodsA cohort study was performed with pooled active surveillance in hospitalized adults ≥ 50 years from the Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) during the 2012/13, 2013/14, and 2014/15 influenza seasons. Descriptive statistics summarized the characteristics of influenza/RSV coinfections. Kaplan-Meier estimated the probability of survival over the first 30 days of hospitalization.ResultsOver three influenza seasons, we identified 33 cases of RSV and influenza coinfection, accounting for 2.39 cases per 1,000 hospitalizations of patients with acute respiratory illnesses. Adults aged 50 + years commonly reported cough (81.8%), shortness of breath (66.7%), sputum production (45.5%), weakness (33.3%), fever (27.3%), and nasal congestion (24.2%) as constitutional and lower respiratory tract infection symptoms. The mortality rate was substantial (12.1%), and age, comorbidity burden, and frailty were associated with a higher risk for adverse clinical outcomes.ConclusionsOlder adults are at higher risk for complications from influenza and RSV coinfections, especially those over 65 with a high comorbidity burden and frailty.

Risk factors for hospitalization and pneumonia development of pediatric patients with seasonal influenza during February-April 2023.

In China influenza remains a low activity for continuous 3 years due to COVID-19 controls. We here sought to study the clinical characteristics and risk factors of the influenza infection among children after the mandatory COVID-19 restrictions were lifted. We included 1,006 pediatric patients with influenza A virus (IAV) infection, enrolled in one tertiary hospital in Zhenjiang, Jiangsu Province, China, during February to April 2023. Patients were divided into the outpatient (n = 798) and inpatient (n = 208) groups, and their baseline characteristics were compared between two groups to conclude the risk factors for pediatric hospitalization. Separately, pediatric inpatients (n = 208) were further divided into the pneumonia and non-pneumonia groups with comparison of their clinical characteristics, including their laboratory test results and representative radiological features, to derive the key determinants for pneumonia development after hospitalization. Compared to outpatients, IAV-infected pediatric inpatients exhibited younger age, higher female: male ratio, more co-infection of influenza B virus (IBV) and hematological abnormality. Multivariate regression analysis determined the independent risk factors of hospitalization to be the clinical symptom of abdominal pain (OR = 2.63, [95% CI, 1.05-6.57], p = 0.039), co-infection of IBV (OR = 44.33, [95% CI, 25.10-78.30], p = 0.001), elevated levels of lymphocytes (OR = 2.24, [95% CI,1.65-3.05], p = 0.001) and c-reactive proteins (CRPs) (OR = 1.06, [95% CI, 1.03-1.08], p = 0.001) upon hospital admission. Furthermore, the cough symptom (OR = 17.39, [95% CI, 3.51-86.13], p = 0.001) and hospitalization length (OR = 1.36, [95% CI, 1.12-1.67], p = 0.002) were determined to be risk factors of pneumonia acquirement for pediatric inpatients. While the abdominal pain, viral co-infection and some hematological abnormality mainly contribute to hospitalization of pediatric patients with IAV infection, the length of hospital stay and clinical sign of coughing upon hospital admission constitute the key determinants for nosocomial pneumonia development.

Nucleic acid sensing Toll-like receptors 3 and 9 play complementary roles in the development of bacteremia after nasal colonization associated with influenza co-infection.

Streptococcus pneumoniae can cause mortality in infant, elderly, and immunocompromised individuals owing to invasion of bacteria to the lungs, the brain, and the blood. In building strategies against invasive infections, it is important to achieve greater understanding of how the pneumococci are able to survive in the host. Toll-like receptors (TLRs), critically important components in the innate immune system, have roles in various stages of the development of infectious diseases. Endosomal TLRs recognize nucleic acids of the pathogen, but the impact on the pneumococcal diseases of immune responses from signaling them remains unclear. To investigate their role in nasal colonization and invasive disease with/without influenza co-infection, we established a mouse model of invasive pneumococcal diseases directly developing from nasal colonization. TLR9 KO mice had bacteremia more frequently than wildtype in the pneumococcal mono-infection model, while the occurrence of bacteremia was higher among TLR3 KO mice after infection with influenza in advance of pneumococcal inoculation. All TLR KO strains showed poorer survival than wildtype after the mice had bacteremia. The specific and protective role of TLR3 and TLR9 was shown in developing bacteremia with/without influenza co-infection respectively, and all nucleic sensing TLRs would contribute equally to protecting sepsis after bacteremia.

The dynamics of influenza and COVID-19 coinfection with vaccination: stability and sensitivity

The dynamics of influenza and COVID-19 coinfection with vaccination: stability and sensitivity

Prevalence and trends in mono- and co-infection of COVID-19, influenza A/B, and respiratory syncytial virus, January 2018-June 2023.

This study aimed to determine the impact of the COVID-19 pandemic on the overall prevalence and co-infection rates for COVID-19, influenza A/B, and respiratory syncytial virus in a large national population. We conducted a retrospective review of 1,318,118 multi-component nucleic acid amplification tests for COVID-19, influenza A/B, and RSV performed at Labcorp® sites from January 2018 to June 2023, comparing positivity rates and co-infection rates by age, sex, and seasonality. In 2021-2023, 1,232 (0.10%) tested positive for COVID-19 and influenza A/B, 366 (0.03%) tested positive for COVID-19 and RSV, 874 (0.07%) tested for influenza A/B and RSV, and 13 (0.001%) tested positive for COVID-19, influenza A/B, and RSV. RSV positivity rates were particularly higher in Q2 and Q3 of 2021 and in Q3 of 2022. Higher influenza A positivity proportions were found in Q4 of 2021 and again in Q2 and Q4 of 2022. Influenza B positivity had been minimal since the start of the pandemic, with a slight increase observed in Q2 of 2023. Our findings highlight the need for adaptability in preparation for upper respiratory infection occurrences throughout the year as we adjust to the COVID-19 pandemic due to the observed changes in the seasonality of influenza and RSV. Our results highlight low co-infection rates and suggest heightened concerns for co-infections during peaks of COVID-19, influenza, and RSV, which may perhaps be reduced.

Co-circulation and co-infection of COVID-19 and influenza in China: challenges and implications.

Co-circulation and co-infection of COVID-19 and influenza in China: challenges and implications.

Late diagnosis of respiratory syncytial virus and influenza co-infection during coronavirus disease 2019 pandemic: a case report

BackgroundRespiratory syncytial virus (RSV)-induced disease is one of the important causes of flu-like illness in older adults and can cause serious disease in those who are at high-risk medical conditions. During coronavirus disease 2019 (COVID-19) pandemic, because of overlapping symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection with other respiratory infections, diagnosing diseases based on clinical and radiological findings was challenging and could cause misdiagnosis.Case presentationAn 87-year-old Persian man was admitted to the hospital due to loss of consciousness, respiratory distress, tachypnea, and oliguria. He had previously hospitalized because of cough, fever, loss of appetite, and fatigue. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) test was performed which was negative; however, based on ground glass opacity on his chest computed tomography (CT) scan and being on the outbreak of COVID-19, he fulfilled case definition of COVID-19; therefore, he received protocol’s treatment (remdesivir) for COVID-19 and relatively recovered and discharged. In our center, we requested brain and chest CT scans, blood tests, and multiplex PCR. Multiplex PCR revealed co-infection of influenza virus and RSV. Although we had started pneumonia and sepsis treatment, old age, weak immune system and the delay in initiation of right antibiotic and antivirus therapy altogether led him to die.ConclusionAs a takeaway lesson of this case report, it is necessary to pay attention to viruses that show similar symptoms during future specific virus pandemics, especially in patients with old age and weak immune systems.