Q&A on HRSV

Human respiratory syncytial virus (HRSV) belongs to the Pneumoviridae HRSV, which has only one serotype and is divided into two subtypes: A and B. At present, the ON1 genotype of subtype A and the BA9 genotype of subtype B are the dominant genotype in the global epidemic, and also the main genotype in China in recent years.

 

the incubation period is usually 2-8 days after the infection of HRSV. 

The clinical manifestations are mainly respiratory tract infection symptoms. The early HRSV infection shows the clinical manifestations such as nasal congestion, runny nose and cough. Most of the symptoms of children with HRSV infection will disappear within 1-2 weeks, and a small part of them will develop into lower respiratory tract infection. The clinical symptoms include coughing, wheezing. The serious cases can develop into respiratory failure, which can affect external organs of the respiratory system, and even lead to death.

 

People of all ages can be infected with HRSV, but the high-risk groups of HRSV infection are mainly concentrated in children, the elderly and people with low immune function. 

HRSV can cause outbreaks in specific places and populations, such as nursing homes, maternity centers, pediatric wards, neonatal intensive care units and other places where people with low immune function gather. 

 

Both symptomatic HRSV infected persons and asymptomatic infected persons can transmit the virus:

(1) Contact transmission: It is the most common way of transmission, mainly through the contact of nasopharyngeal mucosa or eye mucosa with virus-containing secretions or pollutants;

(2) Drops and aerosols can also cause transmission, such as coughing or sneezing in close contact with patients.

 

Since 2016, WHO has carried out HRSV monitoring in 14 member countries based on the Global Influenza Surveillance and Response System (GISRS), including the United Kingdom, Russia, Brazil, Canada, South Africa, India. The United States, Japan and other countries have also carried out HRSV monitoring.

 

It is reported that the positive rate of HRSV detection in Canada was significantly higher than that in the same period of previous years in the autumn and winter of 2022. According to the data released by the US CDC, the positive rate of HRSV nucleic acid detection in the United States increased significantly in the autumn and winter of 2022, with the peak ahead of previous years. 

 

China is one of the countries with high prevalence of HRSV in the world. The study shows that the pathogen composition of acute respiratory infection cases in China from 2009 to 2019: influenza virus, HRSV and human rhinovirus are the top three viral pathogens in the detection rate of the whole population, with the constituent ratio of 28.5%, 16.8% and 16.7% respectively.

 

The diagnosis of HRSV infection can be based on clinical symptoms and signs, laboratory tests and whether it is epidemic season. At present, the laboratory detection methods mainly used for clinical HRSV diagnosis include antigen detection and nucleic-acid detection.

 

At present, there is no HRSV vaccine at home and abroad. In the case of no vaccine available, infection can also be prevented by strengthening personal protection, including avoiding going to the crowd gathering place as much as possible during the epidemic season of HRSV.

Pay attention to hand hygiene in any place, wash hands frequently, and do not touch eyes, mouth and nose after touching public goods; Children's personal protection should be done well in medical institutions such as children's hospitals to prevent cross-infection.

 

If the symptoms are mild, try to isolate and rest at home, and avoid entering public places; Wear a mask when going out; Cover your mouth and nose when coughing or sneezing; Avoid sharing cups and tableware with others; Wash hands often with soap and running water. 

In case of serious symptoms such as persistent cough, shortness of breath and dyspnea, go to the hospital in time andseek for medical treatment.