Laboratory testing trends for respiratory syncytial virus, 2007-2011

Respiratory syncytial virus (RSV) remains a significant cause of respiratory illness, particularly in infants and elderly populations. Traditional diagnostic methods have relied heavily on antigen detection tests, which are widely used in clinical settings. However, these tests have limitations in sensitivity and specificity, potentially leading to underdiagnosis. Recent advancements in molecular diagnostics have introduced polymerase chain reaction (PCR) as a more sensitive alternative. Despite growing interest in PCR for RSV detection, its adoption in U.S. hospital laboratories has not been well documented. Prior studies have shown PCR's potential to improve diagnostic accuracy, but real-world usage trends remain unclear. This gap motivated a study to track RSV diagnostic test types over several seasons. No prior work had resolved how PCR adoption might impact surveillance accuracy. Understanding these trends is essential for public health planning and diagnostic strategy development.

The study aimed to track changes in RSV diagnostic test types used in U.S. hospital-affiliated laboratories between 2007 and 2011. Specifically, the focus was on the adoption and prevalence of PCR testing. Researchers sought to determine whether PCR was replacing traditional antigen detection and viral culture methods. They also wanted to assess how these changes might affect RSV surveillance systems. The motivation stemmed from the need to understand how evolving diagnostic practices could influence public health data accuracy. By analyzing test type proportions over time, the study aimed to provide insights into laboratory trends. The goal was to inform future diagnostic and surveillance strategies for RSV. This approach allows for better alignment of clinical practice with public health monitoring needs.

The study collected data from a convenience sample of U.S. hospital-affiliated laboratories each RSV season from 2007 to 2011. Weekly reports of RSV test types were gathered from 480 to 666 laboratories across 50 states, the District of Columbia, and Puerto Rico. Data collection occurred from November to April, the typical RSV season. The types of tests reported included antigen detection, viral culture, and PCR. Weekly proportions of each test type were calculated to track trends. The total number of tests performed was also reported each season. Kendall τ rank correlation was used to assess the relationship between time and test type proportions. This descriptive analysis allowed for the identification of increasing or decreasing trends in diagnostic test usage.

PCR tests accounted for 2%, 3%, 16%, and 21% of weekly RSV tests conducted in the 2007–2008 through 2010–2011 seasons, respectively. The proportion of laboratories reporting at least one PCR test increased from 4% to 16% over the same period. Antigen detection and viral culture showed declining proportions during the same timeframe. The total number of RSV tests ranged from 381,068 to 481,654 across the four seasons. These findings suggest a shift in diagnostic preference toward PCR. The increase in PCR use was statistically significant according to Kendall τ analysis. Antigen detection remained the most commonly reported test type in early seasons. By 2011, PCR had become a major contributor to RSV diagnostic testing in U.S. hospitals.

The study found that PCR testing for RSV increased significantly from 2007 to 2011 in U.S. hospital laboratories. Antigen detection remained the most commonly used test type, but its proportion declined over time. The authors suggest that PCR adoption may improve diagnostic accuracy and surveillance completeness. They note that relying solely on antigen detection results may miss a growing proportion of RSV cases. These findings highlight the importance of incorporating PCR data into RSV surveillance systems. The increase in PCR use indicates a shift in laboratory diagnostic practices. The authors emphasize that surveillance systems must adapt to include new diagnostic technologies. This trend supports the need for updated public health monitoring strategies.