Severe Acute Respiratory Syndrome Coronavirus 2 and Respiratory Virus Sentinel Surveillance, California, USA, May 10, 2020-June 12, 2021

Abstract

State and local health departments established the California Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Respiratory Virus Sentinel Surveillance System to conduct enhanced surveillance for SARS-CoV-2 and other respiratory pathogens at sentinel outpatient testing sites in 10 counties throughout California, USA. We describe results obtained during May 10, 2020‒June 12, 2021, and compare persons with positive and negative SARS-CoV-2 PCR results by using Poisson regression. We detected SARS-CoV-2 in 1,696 (19.6%) of 8,662 specimens. Among 7,851 specimens tested by respiratory panel, rhinovirus/enterovirus was detected in 906 (11.5%) specimens and other respiratory pathogens in 136 (1.7%) specimens. We also detected 23 co-infections with SARS-CoV-2 and another pathogen. SARS-CoV-2 positivity was associated with male participants, an age of 35-49 years, Latino race/ethnicity, obesity, and work in transportation occupations. Sentinel surveillance can provide useful virologic and epidemiologic data to supplement other disease monitoring activities and might become increasingly useful as routine testing decreases.

Keywords: COVID-19; California; SARS-CoV-2; United States; coronavirus disease; coronaviruses; respiratory infections; respiratory viruses; sentinel surveillance; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.

Figure 1

Total specimens tested for SARS-CoV-2, by county of sentinel site, California, USA, from specimens collected through the California SARS-CoV-2 and Respiratory Virus Sentinel Surveillance program during May 10, 2020–June 12, 2021 (N = 8,662). SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 2

Weekly specimens tested and percent positive for SARS-CoV-2 and for >1 other respiratory pathogen, California, USA, from specimens collected through the California SARS-CoV-2 and Respiratory Virus Sentinel Surveillance program during May 10, 2020–June 12, 2021 (SARS-CoV-2 tested, n = 8,662; other respiratory pathogen tested, n = 7,851). SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 3

Percentage of persons tested for SARS-CoV-2 compared with percentage of persons in California by demographic group, California, USA, from specimens collected through the California SARS-CoV-2 and Respiratory Virus Sentinel Surveillance program during May 10, 2020–June 12, 2021 (SARS-CoV-2 tested, n = 8,662. NHPI, Native Hawaiian/Pacific Islander; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 4

Percentage positive for SARS-CoV-2 and for >1 other respiratory pathogen, by demographic group, California, USA, from specimens collected through the California SARS-CoV-2 and Respiratory Virus Sentinel Surveillance program during May 10, 2020–June 12, 2021 (SARS-CoV-2 positive, n = 1,373; other respiratory pathogen positive, n = 1,002; total N = 7,476). Results included are not mutually exclusive; there were 23 co-infections between SARS-CoV-2 and another respiratory pathogen included. Included are only participants with test results for SARS-CoV-2 and for other respiratory pathogens. NHPI, Native Hawaiian/Pacific Islander; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Figure 5

Percentage of participants who had each collected symptom and meeting clinical case definitions for influenza-like illness and COVID-like illness among persons infected with SARS-CoV-2 and select respiratory panel pathogens, California, USA, from specimens collected through the California SARS-CoV-2 and Respiratory Virus Sentinel Surveillance program during May 10, 2020–June 12, 2021 (SARS-CoV-2 positive, n = 1,350; other respiratory pathogen positive, n = 973; total, N = 7,447). Results included are mutually exclusive: a SARS-CoV-2‒positive person was negative for all other respiratory pathogens and vice versa. Co-infections between SARS-CoV-2 and other respiratory pathogens (n = 23) and multiple respiratory pathogen infections (n = 7) were excluded. Included are only participants with test results for SARS-CoV-2 and for other respiratory pathogens. Non–COVID-19 coronavirus, coronaviruses other than SARS-CoV-2; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.