Coronavirus Disease 2019 (COVID-19) Outbreak, Update # 20
On August 7, 2020, NH DHHS issued health alert COVID-19 outbreak update #20 regarding updates on antigen testing.
Key Points and Recommendations:
- NH DPHS recommends that outpatient and ambulatory care facilities look to bring on point-of-care antigen testing for SARS-CoV-2 in order to facilitate rapid testing of patients with symptoms of COVID-19, preferably with the more sensitive test platform (i.e., the Quidel Sofia SARS Antigen test).
- There are currently two point-of-care SARS-CoV-2 antigen tests that have received FDA Emergency Use Authorization (EUA) and are able to provide rapid results (within 15 minutes) when testing a symptomatic person for COVID-19:
- When compared with usual RT-PCR testing, the Quidel Sofia Antigen FIA showed a positive percent agreement (PPA) of 96.7% and a negative percent agreement (NPA) of 100%; the BD Veritor System showed a PPA of 84% and an NPA of 100%.
- Both tests need to be performed within 5 days of symptom onset
- These antigen tests are intended for people with symptoms of COVID-19, and should not be used to test asymptomatic persons or for asymptomatic screening
- Because of the improved reported sensitivity of the Quidel Sofia Antigen FIA, negative results do NOT need to be confirmed with PCR testing as long as the test is performed within 5 days of symptom onset.
- The BD Veritor System has a lower sensitivity; therefore, negative test results are still considered “presumptive negative” and need PCR confirmation
- NH DPHS continues to recommend that any patient presenting with even mild symptoms of COVID-19 be tested for COVID-19.
- With the start of the school year approaching, NH DPHS recommends that students or staff with any new or unexplained symptoms of COVID-19 be excluded from school and tested for COVID-19; this is consistent with recommendations in other settings. Students and staff can be allowed to return to school when either of the following criteria are met:
- Person has tested negative using one of the approved testing methods below, AND the person’s symptoms are improving and is fever-free for at least 24 hours off any fever-reducing medications. Approved tests include:
- A RT-PCR test (molecular test)
- Quidel Sofia antigen test conducted within 5 days of symptom onset
- Person has met criteria for discontinuation of isolation if they test positive or do not undergo testing (person will be out of school for a minimum of 10 days after onset of symptoms)
- These antigen-based tests can be conducted on anterior nares collected specimens (a nasopharyngeal specimen can also be tested on the Quidel). Therefore, ambulatory care practices should consider how to facilitate outpatient point-of-care testing for their patients by implementing patient collected (or parent/guardian collected) anterior nares swabs in order to minimize healthcare contact and PPE use.
- See CDC guidance for respiratory specimen collection instructions
- For improved sensitivity, anterior nares specimen collection should involve a single swab which has sampled both nostrils (10-15 seconds per nostril)
- Patient or parent/guardian self-collection should be monitored, and person collecting the specimen should be provided instructions
- Healthcare providers should review our prior HAN, Update #18 for current personal protective equipment (PPE) recommendations, which have not changed. In the outpatient setting for evaluation of patients with suspect COVID-19 (including for specimen collection), we continue to recommend a surgical mask in addition to other PPE (gown, gloves, and eye protection).
- Remdesivir continues to be available to hospitals who previously identified as having the capacity to manage this medication under the U.S. Food and Drug Administration (FDA) Emergency Use Authorization (EUA). Remdesivir is being distributed directly to hospitals through AmerisourceBergen (see Remdesivir for the Commercial Marketplace). However, NH DPHS has a small supply of Remdesivir in case of emergent need. If a hospital needs Remdesivir urgently for patient care, please contact us at: 603-271-4482.
Communication and Partner Engagement:
• Webinar for long-term care facilities (LTCFs) and congregate living settings every Wednesday from 12:00 – 1:00 pm:
• Webinar for healthcare providers and local partners every Thursday from 12:00 – 1:00 pm:
• Webinar for school partners every Friday from 12:00 – 1:00 pm: