We present the case of an 81-year-old man, who was immunocompetent, who was admitted to the hospital with symptoms of fever and dyspnea suspected to be caused by COVID-19. Further examination revealed a triple coinfection, as determined by multiplex polymerase chain reaction testing, caused by the respiratory syncytial virus, human coronavirus OC43, and rhinovirus. Upon auscultation, diffuse wheezing without crackles was detected. After ruling out the possibility of acute heart failure with pulmonary edema, the patient was treated with nebulization of terbutaline for a period of 72 hours. This case serves to demonstrate the potential dangers of lifting barrier measures, such as mandatory face masks in high-risk areas, during the fall-winter season. In addition, it highlights the challenges that may arise in the post-COVID-19 era because reliance on flu vaccinations alone may not be sufficient.

There are hundreds of coronaviruses, most of which circulate among animals, yet there are seven types that infect humans. Three of them can cause severe acute respiratory illness-SARS-CoV, SARS-CoV-2, and MERS-CoV. Other HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1 usually cause only mild to moderate upper respiratory tract infections. These four coronaviruses are called seasonal, because they are continuously circulating among human population and are responsible for up to 30% of all respiratory tract infections. Genetically, these low-pathogenic types are related to SARS-CoV-2. That is why questions concerning the cross-reactivity and cross-neutralization between antibodies against different types of coronaviruses have been raised. We addressed these questions by using enzyme-linked immunosorbent assays and targeted next-generation sequencing (NGS). We established the upper respiratory infection etiology for three patients who had been vaccinated with Sputnik V and tested positive on anti-SARS-CoV-2 antibodies. The symptoms included sore throat, nasal congestion, and myalgia. Their blood serum was analyzed for anti-SARS-CoV-2 antibodies in dynamics: before vaccination, and after the first and second dose of the vaccine. After the second dose, all patients were positive for IgG antibodies against SARS-CoV-2. The targeted NGS panel sequencing data analysis showed that these patients were infected with common coronavirus HCoV-OC43. These results suggest that S protein-targeted vaccine-induced antibodies against SARS-CoV-2 are not protective against seasonal coronavirus HCoV-OC43.

Neurologic manifestations of COVID-19 include anosmia, ageusia, encephalopathy, agitation, confusion, ischemic strokes, Guillain-Barré syndrome, seizures, and hemorrhagic encephalitis. Although mechanisms of central nervous system (CNS) injury are likely diverse, direct viral invasion of the CNS has been demonstrated in case reports. Neurotropism of human coronaviruses (HCoVs) is therefore of great interest in the context of the COVID-19 pandemic. Here we present an autopsy-proven case of fatal human coronavirus (HCoV)-OC43 encephalitis in an infant with aplastic thymus and chronic T-cell lymphopenia. Clinicians should remain alert to the possibility of direct CNS invasion by human coronaviruses, including the novel pandemic SARS-CoV-2.

OBJECTIVE: There are limited data on the pathogen-related and host-related factors in the pathogenesis of febrile seizures (FS). We designed a controlled study to compare the role of different respiratory viruses and febrile response in FS.
METHODS: In a prospective cohort study of 1899 pediatric emergency room patients aged 6 months-6 years with a positive respiratory virus multiplex PCR, we identified 225 patients with FSs. We first compared the distribution of respiratory viruses in age-stratified patients with FSs with that in other patients. In an embedded case-control study, we compared the febrile response in patients with FSs with that in the controls matched for age, season and the same respiratory virus.
RESULTS: The relative risk for FS was the highest for coronavirus OC43, 229E, and NL63 infections [RR: 3.2, 95 % confidence interval (CI): 1.4-7.2) and influenza A and B [RR: 2.5, 95 % CI: 1.4-4.7] as compared to those with other respiratory viral infections. The patients with FSs had a stronger febrile response of 39.2 °C (difference: 0.8 °C, 95 % CI: 0.5-1.2) later during hospitalization after acute care than the controls matched for the same respiratory virus.
CONCLUSIONS: Influenza and coronaviruses caused relatively more FS-related emergency room visits than other respiratory viruses. Furthermore, the febrile response was stronger in the patients with FSs than in the controls matched for the same respiratory virus. The results suggest that the pathomechanism of FSs includes modifiable pathogen-related and host-related factors with possible potential in the prevention of FSs.

BACKGROUND: Information regarding the clinical features and outcomes of pneumonia due to an infection with human coronavirus (HCoV)-OC43 in children with cancer is rare. This report presents the clinical features in terms of chest CT scan images which may be used to identify cases of HCoV-OC43 infection induced pneumonia in immunocompromised children.
UNASSIGNED: We report here a girl with acute lymphoblastic leukemia who developed respiratory symptoms during febrile neutropenia. Rapid clinical progression and nodular lesions on her chest X-ray and computed tomography scans were suggestive of a pulmonary fungal infection.
METHODS: A series of tests eventually confirmed the exclusive presence of HCoV-OC43 by the FilmArray Respiratory Panel from a throat swab sample.
METHODS: After the diagnosis was confirmed, the antimicrobial agents initially administered were discontinued.
RESULTS: Although the chest CT scan images looked severe, the clinical course of the infection induced pneumonia was benign. The respiratory status of the patient was completely resolved in 2 weeks.
CONCLUSIONS: This report highlights the importance of early identification of respiratory viruses, via the realization of their clinical characteristics, which helps reduce the duration of administration of antimicrobial agents in this setting.