Influence of novel coronavirus prevention and control measures on common upper respiratory tract pathogen infection in children in Guangzhou

Objective: To understand the epidemiological changes of children infected with 8 respiratory viral pathogens under the protection strategy of the new coronavirus epidemic in Guangzhou. Methods: A total of 13 606 children diagnosed with upper respiratory tract infection from January 2019 to December 2020 were retrospectively analyzed. Children were divided into four groups: infant group, toddler group, preschool group and school age group. Indirect immunofluorescence assay (IFA) was used to detect eight major respiratory virus pathogens, including: adenovirus (ADV), respiratory syncytial virus(RSV), influenza A virus (IV-A), influenza B virus (IV-B), parainfluenza virus (PIV), Chlamydia pneumonia(CP), Legionella pneumophila (LP) and Mycoplasma pneumonia (MP). Results: Sinc ethe outbreak of COVID-19, the positive rates of eight respiratory pathogens had decreased, especially influenza A and B. The positive rate of IV-A showed significant decrease from 30.126% to 12.930%, and the positive rate of IV-B from 25.597% to 19.268%, the defferences were statistically significant (X2=52.849, 369.778, all P < 0.05). Among different age groups, the positive rates of IV-A and ADV infection in each group decreased significantly, especially in infant group and toddler group. The positive rate of IV-A showed significant decrease from 4.588% to 1.979%, and the positive rate of ADV from 43.007% to 21.240%, the defferences were statistically significant(X2=18.910, 197.714, all P < 0.05). Before and after the outbreak of COVID-19, the differences in ADV, IV-A, IV-B, MP and PIV between the male and female groups were statistically significant (P < 0.05). Conclusion: Novel coronavirus protective measures were effective in preventing some common respiratory diseases in children.

Age-related seroprevalence trajectories of seasonal coronaviruses in children including neonates in Guangzhou, China.

OBJECTIVES: Four seasonal coronaviruses, including human coronavirus (HCoV)-229E and HCoV-OC43, HCoV-NL63, and HCoV-HKU1 cause approximately 15-30% of common colds in adults. However, the full landscape of the immune trajectory to these viruses that covers the whole childhood period is still not well understood. METHODS: We evaluated the serological responses against the four seasonal coronaviruses in 1886 children aged under 18 years by using enzyme-linked immunosorbent assay. The optical density values against each HCoV were determined from each sample. Generalized additive models were constructed to determine the relationship between age and seroprevalence throughout the whole childhood period. The specific antibody levels against the four seasonal coronaviruses were also tested from the plasma samples of 485 pairs of postpartum women and their newborn babies. RESULTS: The immunoglobulin (Ig) G levels of the four seasonal coronaviruses in the mother and the newborn babies were highly correlated (229E: r = 0.63; OC43: r = 0.65; NL63: r = 0.69; HKU1: r = 0.63). The seroprevalences in children showed a similar trajectory in that the levels of IgG in the neonates dropped significantly and reached the lowest level after the age of around 1 year (229E: 1.18 years; OC43: 0.97 years; NL63: 1.01 years; HKU1: 1.02 years) and then resurgence in the children who aged older than 1 year. Using the lowest level from the generalized additive models as our cutoff, the seroprevalences for HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1 were 98.11%, 96.23%, 96.23% and 94.34% at the age of 16-18 years. CONCLUSION: Mothers share HCoV-specific IgGs with their newborn babies and the level of maternal IgGs waned at around 1 year after birth. The resurgence of the HCoV-specific IgGs was found thereafter with the increase in age suggesting repeated infection occurred in children.

Age-related seroprevalence trajectories of seasonal coronaviruses in children including neonates in Guangzhou, China

Background Four seasonal coronaviruses, including HCoV-229E and HCoV-OC43, HCoV-NL63 and HCoV-HKU1 cause approximately 15–30% of common colds in adults. However, the full landscape of the immune trajectory to these viruses that covers the whole childhood period are still not well understood. Methods We evaluated the serological responses against the four seasonal coronaviruses in 1886 children who aged under 18-year-old by using Enzyme-linked immunosorbent assay (ELISA). The O.D values against each human coronavirus were determined from each sample. Generalized addictive models (GAM) were constructed to determine the relationship between the age and seroprevalence throughout the whole childhood period. The specific antibody levels against the four seasonal coronaviruses were also tested from the plasma samples of 485 pairs postpartum women and their newborn babies. Results The IgG levels of the four seasonal coronaviruses in mother and the newborn babies were highly correlated (229E: r=0.63;OC43: r=0.65;NL63: r=0.69;HKU1: r=0.63). The seroprevalences in children showed a similar trajectory that the levels of IgG in the neonates dropped significantly and reached to the lowest level after the age of around 1 year (229E: 1.18 years;OC43: 0.97 years;NL63: 1.01 years;HKU1: 1.02 years) and then resurgence in the children who aged older than 1 year old. Using the lowest level from the GAMs as our cutoff, the seroprevalences for HCoV-229E, HCoV-OC43, HCoV-NL63 and HCoV-HKU1 were 98.11%, 96.23%, 96.23% and 94.34% at the age of 16-18 years. Conclusion Mothers share HCoV-specific IgGs with their newborn babies and the level of maternal IgGs waned at around one year after birth. Resurgence of the HCoV-specific IgGs were found thereafter with the increase of the age suggesting repeated infection occurred in children.