Epidemiological surveillance of respiratory viral infections in SARS-CoV-2-negative samples during COVID-19 pandemic in Iran.

BACKGROUND: To improve the patient care, public health surveillance, and infection control, it is crucial to identify the presence and frequency of the common respiratory infections in individuals with COVID-19 symptoms but tested negative for SARS-CoV-2. This study aimed to shed light on this during the COVID-19 pandemic in Iran. METHODS: In this cross-sectional study, a total of 1,002 patients with acute respiratory infection who had negative SARS-CoV-2 test results and referred to Valfajr Health Center, the National Collaborating Laboratory of Influenza and COVID-19 National Reference Laboratory at Pasteur Institute of Iran were recruited between January 2020 and January 2022. Nasopharyngeal and oropharyngeal swab samples were collected to detect 17 common respiratory viruses via TaqMan one-step real-time multiplex PCR. Demographic and clinical data of the participants were obtained from their electronic medical records. RESULTS: In total, 218 samples (21.8%) were tested positive for at least one respiratory virus infection. Most of the common investigated respiratory viruses belonged to the years 2020 and 2022. The number of investigated patients in 2021 was few, which highlights the impact of health measures following the COVID-19 pandemic in Iran. Influenza A was the most common virus (5.8%), while adenovirus had the lowest prevalence (0.1%). Although the rate of respiratory virus infection was higher in men (24%) compared to women (19.3%), this difference was not statistically significant (P = 0.069). The prevalence of respiratory viruses had an inverse association with increasing age, with the highest rate (55.6%) observed in the age group below 2 years and the lowest rate (12.7%) in those above 65 years. CONCLUSION: Our findings underscore the significance of adopting a comprehensive approach to respiratory infections detection and management. These results can be employed for the development of syndromic surveillance systems and implementation of the effective infection control measures. Furthermore, the results contribute to better understanding of the dynamics of respiratory viruses, both during pandemic periods and in non-pandemic contexts.

Comparison of a Multiplex Real-Time PCR Technique with Oxford Nanopore Technologies Next-Generation Sequencing for Identification of SARS-CoV-2 Variants of Concern.

INTRODUCTION: The rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and their potential to endangering the global health has increased the demand for a fast-tracking method in comparison to the next-generation sequencing (NGS) as a gold standard assay, particularly in developing countries. This study was designed to evaluate the performance of a commercial multiplex real-time PCR technique (GA SARS-CoV-2 OneStep RT-PCR Kit, Iran) for identification of SARS-CoV-2 variants of concern (VOCs) compared to the Oxford Nanopore NGS assay. METHODS: A total of 238 SARS-CoV-2-positive respiratory samples from different waves of COVID-19 in Iran were randomly selected in this study. To determine the SARS-CoV-2 VOC, the samples were analyzed via the commercial triple target assay, GA SARS-CoV-2 OneStep RT-PCR Kit, and NGS as well. RESULTS: The results revealed good concordance between GA SARS-CoV-2 OneStep RT-PCR Kit and NGS for identification of SARS-CoV-2 VOCs. GA SARS-CoV-2 OneStep RT-PCR Kit identified Wuhan, Alpha, and Delta variants with 100% relative sensitivity and specificity. Regarding Omicron subvariants of BA.1, BA.2, and BA.4/5, the relative sensitivity of 100%, 100%, and 81.5% and the relative specificity of 95.3%, 93.5%, and 100% were observed. CONCLUSION: Overall, GA SARS-CoV-2 OneStep RT-PCR Kit can be used as a rapid and cost-effective alternative to NGS for identification of SARS-CoV-2 VOCs.

SARS-CoV-2 re-infection rate in Iranian COVID-19 cases within one-year follow-up.

Since the COVID-19 pandemic initiation, the possibility of re-infection has been unclearly present. Although herd immunity has a potential reliance through natural infection, human corona viruses has the ability to subvert immunity and re-infection happens for seasonal corona viruses. Currently, the frequency of SARS-CoV-2 re-infection incidence is not exactly defined. In this study we aimed at determination of SARS-CoV-2 re-infection rate in Iranian population. In a total of 5696 COVID-19 suspicious individuals, RT-PCR was applied to diagnose the infection. The confirmed patients were followed for 12 months and serology tests were applied to measure the specific antibodies. Among 1492 confirmed COVID-19 cases, five individuals experienced the subsequent infection. The re-infection/reactivation incidence rate was totally 0.33% after one year of follow-up. The interval ranged from 63 to 156 days. All the cases had viral mutations in the second episode of the infection. All of them were symptomatic cases with moderate severity. The estimated rate of SARS-CoV-2 in Persian population is therefore rare and natural infection seems to induce good protection against re-infection which clarifies that mass vaccination can hugely affect the society.