Surveillance of endemic coronaviruses during the COVID-19 pandemic in Iran, 2021-2022.

Background: Human coronaviruses (HCoVs) 229E, OC43, HKU1, and NL63 are common viruses that continuously circulate in the human population. Previous studies showed the circulation of HCoVs during the cold months in Iran. We studied the circulation of HCoVs during coronavirus disease 2019 (COVID-19) pandemic to find the impact of pandemic on the circulation of these viruses. Methods: As a cross-sectional survey conducted during 2021 to 2022, of all throat swabs sent to Iran National Influenza Center from patients with severe acute respiratory infection, 590 samples were selected to test for HCoVs using one-step real-time RT-PCR. Results: Overall, 28 out of 590 (4.7%) tested samples were found to be positive for at least one HCoVs. HCoV-OC43 was the most common (14/590 or 2.4%), followed by HCoV-HKU1 (12/590 or 2%) and HCoV-229E (4/590 or 0.6%), while HCoV-NL63 was not detected. HCoVs were detected in patients of all ages and throughout the study period with peaks in the cold months of the year. Conclusions: Our multicenter survey provides insight into the low circulation of HCoVs during the COVID-19 pandemic in Iran in 2021/2022. Hygiene habits and social distancing measures might have important role in decreasing of HCoVs transmission. We believe that surveillance studies are needed to track the pattern of HCoVs distributions and detect changes in the epidemiology of such viruses to set out strategies in order to timely control the future outbreaks of HCoVs throughout the nation.

A delayed resurgence of respiratory syncytial virus (RSV) during the COVID-19 pandemic: An unpredictable outbreak in a small proportion of children in the Southwest of Iran, April 2022.

The global outbreak of coronavirus disease 2019 (COVID-19), an emerging disease caused by severe acute respiratory syndrome virus-2 (SARS-CoV-2), and strict restrictions implemented to control the infection have impacted the circulation and transmission of common seasonal viruses worldwide and subsequently the rate of hospitalizations in children at young ages. Respiratory syncytial virus (RSV) surprisingly disappeared in 2020-2021 in many countries due to lockdown and precautions were taken because of the COVID-19 pandemic. Herein, we showed a notable change in the rate of hospitalization and reported an unpredictable outbreak of RSV in a small proportion of children admitted to a children's hospital in Dezful (a city in Southwest Iran) in the early spring of 2022. We performed a descriptive study of hospitalized young children (aged ≤ 5 years) with acute respiratory infections. Together with clinical information, 30 nasopharyngeal swabs were prospectively collected and 3 important respiratory viruses (RSV, influenza viruses, and SARS-CoV-2) were tested through the real-time polymerase chain reaction (real-time PCR) method. The age distribution of 30 hospital-admitted children was 1 month to 5 years old and males were the most included subjects 18/30 (60%) in this study. Although the viral genome of SARS-CoV-2 and influenza viruses was not detected, the presence of RSV was confirmed in 16/30 (53.33%) patients. Results showed that the majority of RSV-infected cases were males 10/16 (62.5%), within 12 months of life, and had changes in parameters of the complete blood count. Almost all patients with RSV infection had a cough as the most common clinical manifestation and had no history of past medical conditions as a risk factor. The presented study is the first investigation that documented an outbreak of RSV infection in young children reported since the onset of the COVID-19 outbreak in Iran. Our cases highlight the potential threats of important but neglected pathogens during the ongoing pandemic as described here for RSV, which would be challenging by easing the preimposed restrictions.