Introduction
Respiratory syncytial virus (RSV) is
one of the most important pathogens leading to severe lower respiratory
tract infection in children. It causes 2.7–3.8 million hospitalizations
and 94,600–149,400 deaths in children under five years of age each
year[1]. It can also result in severe respiratory
infections in high-risk adults or elderly healthy persons. Therefore,
RSV has been raising concern[2] and RSV
surveillance is being conducted in many countries. The United States has
included RSV in the National Respiratory and Enteric Virus Surveillance
System since 1989[3, 4]. Japan has used the
National Epidemiological Surveillance System for Infectious Diseases to
monitor RSV since 2003[5]. The European Union has
initiated RSV surveillance using the existing influenza surveillance
network since 2003[6, 7]. The United States also
launched the Global Disease Detection project in 2004, which monitored
influenza virus and RSV in several countries
world[8]. Likewise, the World Health Organization
began monitoring RSV using the global influenza network in
2017[9]. However, so far, a nationwide RSV
surveillance network has not been established in China.
China has a heavy burden of RSV
infection. Several studies have reported that the RSV detection rate in
pneumonia cases in Chinese children could reach 17%–33% during the
RSV epidemic season[10, 11]. However, these
studies rarely cover RSV infections in adults (particularly in elderly
persons). Given that China is the most populous country globally and its
aging population problem is becoming more serious, we can speculate that
the proportion of Chinese elderly adults with RSV should not be small.
Therefore, more attention should be paid to RSV infections among Chinese
adults, especially Chinese elderly adults.
Up to now, there is no licensed RSV vaccine available. Palivizumab is
the only prophylaxis biological product approved by the Food and Drug
Administration in the USA for use in infants at high risk of severe RSV
infection[12], but it is expensive and was not
approved by the Chinese Food and Drug Administration. In addition, there
is still no specific therapy drug for RSV, and only symptomatic and
supportive treatments for RSV infection are available. Thus, it is
urgent to establish an effective RSV surveillance system that covers all
age groups (particularly the population with a high risk of severe
respiratory infection) in China, which would contribute to a better
understanding of the epidemiological and clinical characteristics of RSV
infection in different ages groups, a better controlling the RSV
epidemic and a better administration of severe RSV infection cases.
Our research team has established
the Respiratory Pathogen
Surveillance System (RPSS) in Beijing since 2014, which consists of 17
Centers for Disease Control and Prevention (CDCs) and 30 sentinel
hospitals. Using this surveillance system, we have monitored the 11 most
common respiratory pathogens, including RSV, influenza virus, and
adenovirus. In this study, we systematically investigated the prevalence
of RSV in Beijing for four consecutive years from March 2015 to February
2019, and compared the clinical characteristics of RSV infection among
people of different age groups, with a focus on children under five
years of age and elderly adult over 60 years of age.
Population and Methods1.1 Ethics statement
This study was approved by the Ethics Committees at Beijing Center for
Disease Prevention and Control. Enrollees (or their guardians if
appropriate) were told the nature, purpose, procedures, and potential
health impact regarding this study, and written informed consent was
obtained from each one. Patients were required to provide consent by
themselves if their age and medical condition were appropriate.