Changes of cytomegalovirus infection in neonates before and after the COVID19 pandemic in Zhengzhou, China.

Recently, the findings of Li et al.1Li T. Li X. Gao K. Dong G. Yang J. Changes in pathogen distribution in the blood culture of neonates before and after the COVID-19 pandemic, Henan, China.J Infect. 2022; ([published online ahead of print, 2022 Nov 10]) (S0163 -445300644-2)https://doi.org/10.1016/j.jinf.2022.11.003Abstract Full Text Full Text PDF Scopus (1) Google Scholar in the Journal of infection have caused our attention, which showed that the number of pathogens detected in the blood of neonates decreased during the COVID-19 pandemic. The impact of COVID-19 pandemic on the prevalence of other pathogens were also reported. Li et al.2Li Y. Guo Y. Duan Y. Changes in Streptococcus pneumoniae infection in children before and after the COVID-19 pandemic in Zhengzhou, China.J Infect. 2022; 85 (e80-1 Sep)https://doi.org/10.1016/j.jinf.2022.05.040Abstract Full Text Full Text PDF Scopus (18) Google Scholar and Zhou et al.3Zhou J. Zhao P. Nie M. Gao K. Yang J. Sun J. Changes of haemophilus influenzae infection in children before and after the COVID-19 pandemic, Henan, China.J Infect. 2022; (Oct 20)https://doi.org/10.1016/j.jinf.2022.10.019Abstract Full Text Full Text PDF Scopus (14) Google Scholar reported a decline in Streptococcus pneumoniae and Haemophilus influenzae infection in children under the influence of COVID-19 pandemic. However, there are no data or studies on the changes in cytomegalovirus (CMV) infection in neonates before and after the COVID-19 pandemic. Human CMV belongs to the herpesvirus family, is one of the most common viruses of intrauterine infection, and is also the most common cause of sensorineural hearing loss and intellectual disability in neonates.4Lim Y. Lyall H. Congenital cytomegalovirus - who, when, what-with and why to treat?.J Infect. 2017; 74 (Suppl): S89-S94https://doi.org/10.1016/S0163-4453(17)30197-4Abstract Full Text PDF PubMed Scopus (28) Google Scholar In addition, CMV can adversely affect the immune system of infants. Infants with cytomegalovirus infection in the first year of life are at high risk of subsequently developing tuberculosis disease.5Martinez L. Nicol M.P. Wedderburn C.J. et al.Cytomegalovirus acquisition in infancy and the risk of tuberculosis disease in childhood: a longitudinal birth cohort study in Cape Town, South Africa.Lancet Glob Health. 2021; 9 ([published correction appears in Lancet Glob Health. 2021 Nov 17;:]): e1740-e1749https://doi.org/10.1016/S2214-109 X(21)0 0407-1Crossref PubMed Scopus (0) Google Scholar Groups with low immune function, such as neonates are prone to congenital infection caused by vertical transmission between mother and infant, and postnatal acquired infection through breastfeeding, close contact with virus carriers. According to infection time, neonatal CMV infection can be divided into congenital infection and postnatal acquired infection. Congenital infection refers to CMV pathogen detection positive within the first 3 weeks of life. If CMV pathogen is negative within 3 weeks of birth and positive after 3 weeks of birth, it belongs to postnatal infection. The incidence rate of congenital CMV infection in neonates varies from 0.15% to 2.50% in different regions.6Kenneson A. Cannon M.J. Review and meta-analysis of the epidemiology of congenital cytomegalovirus (CMV) infection.Rev Med Virol. 2007; 17: 253-276https://doi.org/10.1002/rmv.535Crossref PubMed Scopus (1173) Google Scholar Understanding the situation of neonatal CMV infection in different countries or regions and taking targeted preventive measures are essential for controlling neonatal CMV infection. In response to COVID-19, many countries have implemented strict interventions, such as large-scale and long-term regional lockdown, wearing masks, keeping social distance, restricting gathering and outdoor activities. These control measures seriously affect people's lifestyle, which may also affect the epidemiology of pathogens. Hence, analyzing the changes of cytomegalovirus infection in neonates before and after the COVID-19 pandemic will provide efficient clinical management strategies. To evaluate the impact of COVID-19 on the epidemiological characteristics of CMV infection in neonates, laboratory data were collected and analyzed for neonates with CMV PCR in urine samples in Henan Children's hospital from January 2018 to November 2022. The diagnosis of both symptomatic and asymptomatic CMV infection can be made with detection of positive CMV PCR in urine samples. A total of 11,260 neonates was included (n = 2538 in 2018, n = 2738 in 2019, n = 1698 in 2020, n = 2304 in 2021 and n = 1982 in 2022) (Fig. 1A). The total number of CMV infection cases was 1024 (n = 300 in 2018, n = 293 in 2019, n = 138 in 2020, n = 150 in 2021 and n = 143 in 2022). Both the total number of neonates and CMV infection cases, were found a significant decrease in 2020 (the first year of the COVID-19 pandemic), which increased in 2021 and 2022, while the cases were still lower than that in 2018 and 2019. The positive rate of CMV infection showed a decreasing trend from 2018 to 2021 (from 11.8 to 6.5%, Fig. 1B). In 2022, there was a slight increase in the incidence of CMV infection (7.2%), but it was still lower than that before COVID-19. These results indicated significant impact of COVID-19 pandemic on the epidemiological characteristics of CMV infection in neonates. Further, the incidence of two main infection types including the congenital CMV infection and postnatal acquired CMV infection were analyzed before and after the COVID-19 pandemic (Fig. 2). The cases with congenital CMV infection decreased from 2019 to 2021. The cases with postnatal acquired CMV infection were more than the cases with congenital CMV infection. The positive rate of postnatal acquired CMV infection decreased from 10.9% in 2018 to 5.9% in 2021, which increased to 6.5% in 2022. From January 2020 to the first half of 2021, Zhengzhou has implemented a strict lockdown, which has changed people's way of life. Reduced daycare attendance, smaller class sizes, increased hand hygiene and disinfection, these measures may also prevent the transmission of CMV among children. Because close contact with children infected with CMV, especially those under 2 years of age, is a particular risk factor for maternal CMV infection.7Rawlinson W.D. Boppana S.B. Fowler K.B. et al.Congenital cytomegalovirus infection in pregnancy and the neonate: consensus recommendations for prevention, diagnosis, and therapy.Lancet Infect Dis. 2017; 17: e177-e188https://doi.org/10.1016/S1473-3099(17)30143-3Abstract Full Text Full Text PDF PubMed Scopus (424) Google Scholar The main route of postnatal acquired CMV infection is breast feeding. During the COVID-19 epidemic, the opportunities of NICU visits were significantly reduced, accompanied by a decrease in neonatal fresh breast feeding, and increased use of frozen breast milk and breast milk substitutes. Infants who were fed frozen breast milk from CMV positive mothers had lower rates of acquiring CMV.8Lanzieri T.M. Dollard S.C. Josephson C.D. Schmid D.S. Bialek S.R. Breast milk-acquired cytomegalovirus infection and disease in VLBW and premature infants.Pediatrics. 2013; 131 ([published correction appears in Pediatrics. 2014 Apr;133(4):755]): e1937-e1945https://doi.org/10.1542/peds.2013-0076Crossref PubMed Scopus (121) Google Scholar Besides, with the mitigation of control measures for COVID-19, the incidence rate of CMV infection increased slightly in 2022. In summary, our data indicated that the epidemiological characteristics of neonates with CMV infection including the CMV infection cases, the incidence rates of CMV infection, and the time of CMV infection were affected by COVID-19. With the ease of the COVID-19 pandemic, the infection of CMV may increase. Hence, continuous observations are required to reveal the epidemiology information and to provide clues for the prevention and control of CMV infection during pregnancy and among neonates. The authors declare no conflict of interests. This work was supported by grant from the Medical Science and Technology Projects of Henan Province (2018020655).