Usefulness of national respiratory virus surveillance data for clinicians who manage adult patients

Dual respiratory virus detection in adult patients with acute respiratory illness

BACKGROUND

Nonrandom multiple respiratory virus (RV) detection provides evidence for viral interference among respiratory viruses. However, little is known as to whether it occurs randomly.

METHODS

The prevalence of dual RV detection (DRVD) in patients with acute respiratory illnesses (ARIs) at 4 academic medical centers was investigated; data about the prevalence of 8 RVs were collected from the Korean national RV surveillance dataset. Linear regression analysis was performed to assess the correlation between observed and estimated prevalence of each type of DRVD.

RESULTS

In total, 108 patients with ARIs showing DRVD were included in this study between 2011 and 2017. In several types of regression analysis, a strong correlation was observed between the observed and estimated prevalence of each type of DRVD. Excluding three DRVD types (influenza/picornavirus, influenza/human metapneumovirus, and adenovirus/respiratory syncytial virus), the slope of the regression line was higher than that of the line of random occurrence (1.231 > 1.000) and the 95% confidence interval of the regression line was located above the line of random occurrence.

CONCLUSIONS

Contrary to the results of previous epidemiologic studies, most types of DRVD occur more frequently than expected from the prevalence rates of individual RV, except for three underrepresented pairs above.

Impact of social distancing on the spread of common respiratory viruses during the coronavirus disease outbreak

During the coronavirus disease (COVID-19) pandemic, social distancing was effective in controlling disease spread across South Korea. The impact of national social distancing on the spread of common respiratory virus infections has rarely been investigated. We evaluated the weekly proportion of negative respiratory virus polymerase chain reaction (PCR) test results and weekly positive rates of each respiratory virus during the social distancing period (10th-41st weeks of 2020) and the corresponding period in different years, utilizing the national respiratory virus surveillance dataset reported by the Korean Center for Disease Control and Prevention. The proportions of negative respiratory virus PCR test results increased up to 87.8% and 86.1% during level 3 and level 2 of the social distancing period, respectively. The higher the level of social distancing, the higher the proportion of negative respiratory virus PCR test results. During the social distancing period, the mean weekly positive rates for parainfluenza virus, influenza virus, human coronavirus, and human metapneumovirus were significantly lower than those during the same period in 2015-2019 (0.1% vs. 9.3%, P <0.001; 0.1% vs. 7.2%, P <0.001; 0.4% vs. 2.3%, P <0.001; and 0.2% vs. 5.3%, P <0.001, respectively). The mean positive rate for rhinovirus/enterovirus during level 3 social distancing was lower than that in the same period in 2015-2019 (8.5% vs. 19.0%, P <0.001), but the rate during level 1 social distancing was higher than that in the same period in 2015-2019 (38.3% vs. 19.4%, P <0.001). The national application of social distancing reduced the spread of common respiratory virus infections during the COVID-19 pandemic.

Usefulness of national respiratory virus surveillance data for clinicians who manage adult patients

The Korean Centers for Disease Control and Prevention (KCDC) provides weekly respiratory virus (RV) surveillance reports on its website (the KCDC data). Clinicians in clinical settings wherein the use of PCR for RVs is not a routine laboratory test for adult patients with acute respiratory illness (ARI) may question the clinical utility of such a national RV surveillance dataset in predicting RV outbreaks among their adult patients. We compared the KCDC data to the RV PCR data of adult patients who visited a tertiary care center. During a period of 108 weeks, a total of 6955 (5598 pediatric and 1257 adult) patients underwent RV PCR tests for ARI; most of these tests were administered while the patients were admitted (n = 6,920; 99.5%). From the KCDC website, we collected the RV PCR test results of 22 540 patients. Three graphs of weekly positivity rates were made for adults, children, and the KCDC data per each RV, and these graphs were then compared with one another. Whereas RV outbreaks were coincident between the KCDC and the adult graph with respect to influenza virus, respiratory syncytial virus, human metapneumovirus, and human coronavirus, the same was not true for human bocavirus, parainfluenza virus, rhinovirus, and adenovirus. However, a negative predictive value of the KCDC data in the prediction of the occurrence of an outbreak in the adult graph was high for the respective eight RVs (85‐100%). A national RV surveillance dataset may be useful in identifying RV outbreaks in adult patients with severe ARI.