The Scoop on Sentinel Surveillance Testing

As Hawai‘i cautiously reopens its economy, the Hawai‘i Department of Health’s Disease Outbreak Control Division (DOCD) is keeping an eye on detecting flu and COVID-19 in the community through its Sentinel Surveillance Program. The program conducts random testing to gain a pulse on respiratory illness in the state by partnering with outpatient healthcare providers and private laboratories.

Influenza Epidemiologist Han Ha Youn gave us the inside scoop on sentinel surveillance testing.

What is sentinel surveillance and how does it work?

Han Ha: In partnership with the Department of Health, selected physicians in outpatient settings and health care centers throughout the state are collecting nasal swab samples from patients with symptoms of respiratory illness who test negative for flu and have no travel history outside of the state. These samples are tested for COVID-19 and can provide valuable information on possible spread of the disease in Hawaii. The system can give us an early warning sign for cases in the community or unusual flu-like illness activity, especially in rural areas where it can be difficult to find healthcare and testing.

Why is sentinel surveillance testing being conducted by DOCD?

Han Ha: As part of a multi-layered approach, Sentinel surveillance is being performed at select outpatient sites to determine if there is community transmission of COVID-19. We use this systematic testing method to detect new infections in the community using a broad sampling from all areas of the state.

Sentinel surveillance relies on specimens and reporting from various outpatient providers (i.e., sentinel providers) who have volunteered to be part of the network. Specimens are collected from patients with COVID-like or influenza-like illness symptoms and sent to the State Laboratories. We use this systematic method to detect any new infections in the community quickly and ensure their contacts are traced to contain transmission as early as possible. We also select specimens meeting testing criteria from those submitted to the clinical laboratories for COVID/flu testing to ensure a broad sampling from all areas of the state.

Why is this systematic testing important to monitoring COVID-19 disease activity?

Han Ha: It’s a more strategic way to test broadly across the population through local healthcare providers and private labs so we can actively identify the virus. Sentinel surveillance involves testing people across the community including those who seem well, in order to discover unseen transmission.

What is Hawaii currently seeing in terms of community spread of COVID-19?

Han Ha: Currently, we are seeing few cases and local geographic spread in Hawaii’s communities. What is most amazing to see is the low levels of respiratory diseases overall throughout the state. Influenza-like illness in Hawaii is at an all-time low, well below historical levels.

How are community mitigation measures working to reduce spread of COVID-19 and the flu, and influenza-like illnesses (ILI)?

Han Ha: Both COVID-19 and the flu are respiratory pathogens that spread person-to-person via respiratory droplets from someone’s cough or sneeze. Physical distancing measures, wearing masks, sanitizing high-touch surfaces, staying home when sick, and washing hands all have worked to dramatically decrease the disease caused by both viruses. The combination of these prevention measures is what is working to prevent spread in our community.

What do you like most about this work and your role at the Department of Health?

Han Ha: I enjoy being able to work with the dedicated and hardworking staff in DOCD to improve public health in Hawaii’s communities.