Increase in the estimated number of adults aged 50 years and older that visited their GP for an RS-virus infection in the Netherlands per season

The RS-virus can be dangerous for children. However, older adults can also become seriously ill from the acute respiratory infection that can be caused by the RS-virus. Little is known about the burden of disease caused by this virus among older adults in the Netherlands, partly because testing for the RS-virus is not routinely performed in primary care. In this study, estimates were calculated for the number of older adults in the Netherlands that visited their GP with an RS-virus infection per season. From season 2011/2012 to 2018/2019, this number appears to increase in adults aged 50 years and older. This research was conducted by research institute Nivel and the National Institute for Public Health and the Environment (RIVM).

Because symptoms of the RS-virus are very similar to other acute respiratory infections, such as flu, it is difficult to determine the number of older adults with acute respiratory infections caused by the RS-virus. Therefore, the number of adults aged 50 years and older that visited their GP with an RS-virus infection was estimated. For this study, data on the number of persons with a registered acute respiratory infection from Nivel Primary Care Database was combined with virological data collected by the Nivel sentinel practices which were analysed by the RIVM. The results of this study are important for policy makers. These results can help them in making scientifically based decisions on the introduction of preventive measures in the future.

Estimated number of new RS-virus infections among adults aged 50 years and older appears to increase

A respiratory season in this study consisted of the period from the beginning of October until mid-May (weeks 40-20). Among adults aged 50 years and older who were registered at a general practice, an estimated 2.8 per 1,000 persons had an RS-virus infection in season 2011/2012. In season 2018/2019, this estimate was 9.3 per 1,000 persons. These results were used to estimate the total number of adults aged 50 years and older who visited their GP with an RS-virus infection in the Netherlands. The estimated number ranged from 17,000 persons in season 2011/2012 to 64,100 persons in season 2018/2019.

Number of GP contacts for an RS-virus infection was relatively small in adults aged 50 years and older

The average number of contacts with the GP for an RS-virus infection was 13 per 1,000 persons for seasons 2011/2012 to 2018/2019. For all acute respiratory infections the total contacts with the GP was on average 169 per 1,000 persons during this study period. The proportion of contacts that were attributed to the RS-virus was relatively small.

More RS-virus infections in adults of 50 years and older with chronic pulmonary disease

Adults aged 50 years and older with chronic pulmonary disease, such as asthma or COPD, were estimated to be more likely to have a new RS-virus infection than persons with diabetes mellitus, chronic heart disease, or other diseases that may increase the risk of an RS-virus infection. It was estimated that an infection with the RS-virus was more common among persons aged 75 years and older who were registered at a GP compared to persons aged 50 to 74 during seasons 2011/2012 to 2018/2019.

More people were at higher risk to visit their GP with an RS-virus infection

Adults aged 50 years and older with one or more specific diseases were at increased risk of visiting their GP with an RS-virus infection. These diseases were diabetes mellitus, chronic heart disease, a compromised immune system, chronic lung disease, liver disease or kidney disease. The total number of adults aged 50 years and older with these diseases increased slightly from season 2011/2012 to 2018/2019. On average, around 2.8 million persons were at increased risk of visiting their GP for a new RS-virus infection during this period.

Fragment from Respiratory syncytial virus (RSV) incidence estimates in primary care among adults aged 50 years and older in the Netherlands; 2011-2019: The estimated RS-virus infections per 1,000 persons per season appeared to increase in adults aged 50 years and older who were registered at a GP. Season 2016/2017 had the highest estimate of new RS-virus infections.

About this study

For this study data of the Nivel Primary Care Database and virological data of the Nivel sentinel practices were used. The estimates for new RS-virus infections were derived from the total number of persons with a registered acute respiratory infection in primary care (based on data from Nivel Primary Care Database), combined with the number of adults aged 50 years and older with an acute respiratory infection that tested positive for the RS-virus (based on data from Nivel sentinel practices). This study was funded by GlaxoSmithKline (GSK) and conducted in collaboration with the RIVM. RIVM did not receive funding for this study.