RSV Infection Tops List of SARI in Infants!

On July 31st, the latest national acute respiratory infectious disease sentinel surveillance report (Week 30, 2025) released on the Chinese CDC website showed that starting from Week 24 (June 9th-15th, 2025) to Week 30, Respiratory Syncytial Virus (RSV) has consistently ranked first among severe acute respiratory infection (SARI) cases requiring hospitalization in infants and young children aged 0-4 years. Among hospitalized SARI cases, RSV infection has also ranked first for multiple consecutive weeks in southern provinces. What are the characteristics of RSV? How can infection be avoided in daily life? What is the situation in Nanjing?... With these questions, a reporter interviewed Dr. Cheng Jia, Deputy Chief Physician of Pediatrics at Nanjing Maternity and Child Health Care Hospital.

It is undeniable that RSV is highly contagious, primarily spreading through respiratory droplets and contact transmission, with an average infected person capable of spreading it to 4-5 others. Data shows that over 84% of infants are infected with RSV before their first birthday, and nearly all young children become infected at some point. "Due to climate and environmental conditions, its peak season varies across different regions of China. Based on outpatient clinic observations, the peak infection period in the Nanjing area is mainly winter and spring," said Dr. Cheng Jia.

Initial symptoms of RSV infection may include fever, nasal congestion, and other upper respiratory symptoms. In some children, it can rapidly progress to lower respiratory symptoms like rapid breathing and wheezing, developing into bronchitis or pneumonia. Dr. Cheng Jia told the reporter that while most RSV infections have a good prognosis, infants and young children may experience recurrent wheezing, airway hyperreactivity, or asthma after infection, requiring long-term follow-up. "If a child develops persistent high fever, difficulty breathing, or severe wheezing, it is crucial to seek medical attention immediately. RSV infection has consistently been a leading cause of hospitalization for lower respiratory tract infections in infants and young children."

Currently, there is no specific antiviral drug to cure RSV infection; treatment mostly relies on symptomatic relief and supportive care. "Comparatively, prevention of RSV infection is more important," emphasized Dr. Cheng Jia. She recommended reducing visits to public places during the peak season, wearing masks outdoors, frequent handwashing, ensuring good ventilation by opening windows, regularly disinfecting commonly used items, and strengthening personal protection. Secondly, Nirsevimab is used to prevent infection during an infant's first RSV season, while Palivizumab is suitable for high-risk infants (such as premature babies or those with underlying medical conditions). For babies born before the RSV season (May-October), vaccination is recommended to be completed in October-November; for babies born during the RSV season (November-April of the following year), the injection can be administered shortly after birth. This can effectively reduce the rates of medical visits and hospitalizations due to RSV lower respiratory tract infection, protecting newborn babies as they safely pass through the RSV epidemic season.

The REACHLINE RSV Rapid Test is an in vitro immunochromatographic assay for the qualitative detection of respiratory syncytial antigens in nasopharyngeal swab specimens collected from patients with signs and symptoms of respiratory infection.This test is intended for use as an aid in the differential diagnosis of respiratory syncytial viral Infections in humans in conjunction with clinical and epidemiological risk factors.

Test Principle

The RSV Rapid Test is an immunochromatographic membrane assay.In the test procedure,a specimen is collected and placed for one minute into the Extraction Well of the test device containing extraction solution,during which time antigen is extracted from disrupted virus particles.The test device is then raised,tapped and laid back down onto a level surface to allow the solution in the Extraction Well to migrate through the pads containing lyophilized detector antibodies conjugated to gold dye and then through the test membrane.

The RSV antigen test uses highly sensitive monoclonal antibodies to detect RSV antigen in

nasopharyngeal swab specimensThese antibodies and a control protein are immobilized onto a membrane support as two distinct lines and are combined with other reagents/pads to construct a Test Strip.The RSV antigen test has one test lines and one control line.If Test line appears in the test result window,together with the Control line, the test result is positive for RSV.