key: cord-302180-sgg8pvm8
authors: Blain, Hubert; Rolland, Yves; Tuaillon, Edouard; Giacosa, Nadia; Albrand, Mylène; Jaussent, Audrey; Benetos, Athanase; Miot, Stéphanie; Bousquet, Jean
title: Efficacy of a Test-Retest Strategy in Residents and Health Care Personnel of a Nursing Home facing a COVID-19 Outbreak
date: 2020-06-11
journal: J Am Med Dir Assoc
DOI: 10.1016/j.jamda.2020.06.013
sha: 
doc_id: 302180
cord_uid: sgg8pvm8

Abstract Objective To assess the American Testing Guidance for Nursing Homes (NHs) - updated May 19, 2020 - with a new COVID-19 case. Design Case investigation. Setting and Subjects: All 79 residents and 34 Health Care Personnel (HCP) of a NH. Methods 7 days after identification of a COVID-19 resident, all residents and HCP underwent rRT-PCR testing for SARS-CoV-2 with nasopharyngeal swabs. This was repeated weekly in all previously negative subjects until the testing identified no new cases and in all positive subjects until the testing was negative. COVID-19 infection prevention and control (IPC) measures were implemented in all residents and HCP with positive testing or with COVID-19 symptoms. Standard IPC was also implemented in all HCP. Six weeks after initial testing, all residents underwent testing for ELISA-based IgG antibodies directed against the SARS-CoV-2. Symptoms were serially recorded in residents and HCP. Results 36 residents had a positive RT-PCR at baseline and two at day 7. Six HCP had a positive RT-PCR at baseline and two at day 7. No new COVID-19 cases were diagnosed later. Among the SARS-CoV-2-positive cases, six residents (16%) and three HCP (37%) were asymptomatic during the 14 days before testing. Twenty-five residents (92.3%) and all 8 HCP (100%) with a positive RT-PCR developed IgG antibodies against SARS-CoV-2. Among the residents and HCP always having tested negative, 2 (5%) and 5 (11.5%) developed IgG antibodies against SARS-CoV-2. These 2 residents had typical COVID-19 symptoms before and after testing and 2/5 HCP were asymptomatic before and after testing. Conclusions and Implications This study shows the validity of the updated American Testing Guidance for Nursing Homes (NHs). It suggests implementing COVID-19 IPC in both residents and HCP with positive testing or COVID-19 symptoms and warns that asymptomatic HCP with repeated negative RT-PCR testing can develop antibodies against SARS-CoV-2.

A wide testing strategy is effective in detecting asymptomatic COVID-19 residents and HCP in a NH facing COVID-19 outbreak. Symptomatic residents and HCP as well as asymptomatic HCP with negative testing may also play a role in the virus spread within the NH. later. Among the SARS-CoV-2-positive cases, six residents (16%) and three HCP (37%) were 20 asymptomatic during the 14 days before testing. Twenty-five residents (92.3%) and all 8 HCP 21 (100%) with a positive RT-PCR developed IgG antibodies against SARS-CoV-2. Among the 22 residents and HCP always having tested negative, 2 (5%) and 5 (11.5%) developed IgG 23 antibodies against SARS-CoV-2. These 2 residents had typical COVID-19 symptoms before 24 and after testing and 2/5 HCP were asymptomatic before and after testing. 25 Seroconversion with SARS-CoV-2 antibodies generally occurs rapidly in adult subjects. 5 The 45

immune response to viruses may be influenced by aging, and seroconversion in frail older 46 subjects is uncertain. It is unclear whether residents and HCP with repeated negative testing 47 may develop antibodies against SARS-CoV-2. 48

A study was carried out on all residents and HCP of a NH facing a COVID-19 outbreak. The 49 aim was to assess clinical and serological parameters for the efficacy of infection prevention 50 and control (IPC) measures adapted to (i) symptoms and (ii) results of repeated testing. 51

Participants: From March 3 rd to 6 th , 2020, three NH residents were hospitalized for severe 54 non-respiratory COVID-19 symptoms. All three developed respiratory symptoms (cough with 55 fever and dyspnea) 7 to 10 days after admission, and RT-PCR following nasopharyngeal swab 56 test confirmed COVID-19. Seven days after the first diagnosis, all residents or HCP were 57 enrolled in the study. 58

No ethics committee was required as this is an observational study. 59 followed daily for 6 weeks. 62

Nasopharyngeal testing for SARS-CoV-2 using rRT-PCR was performed in all residents and 63 HCP. It was repeated weekly in all previously negative subjects until no new cases were 64 identified and in all positive subjects until testing was negative. 65 COVID-19 IPC measures were applied in all residents and HCP with positive testing or with 66 new COVID-19 symptoms, including diarrhoea, delirium, or falls. 67

Six weeks after initial testing, all residents and HCP underwent blood testing for IgG 68 antibodies directed against the SARS-CoV-2 nucleocapsid protein using an ELISA CE-IVD 69 marked kit (ID screen ® SARS-CoV-2-N IgG indirect ID. Vet, Montpellier, France). 5 70

Residents 72

Among the 79 residents, 38 (48%) had a positive RT-PCR (Table 1) . 36 were diagnosed at 73 baseline and two at day 7. The residents who tested positive were distributed throughout the 74 4 floors of the NH (10, 9, 10, 9). 75

The mean age of residents was similar in positive and negative RT-PCR groups. Diabetes and 76 renal disease were more common in RT-PCR positive residents. 77

Thirteen residents died two to seven days after testing due to respiratory symptoms. Twelve 78 (7 men) had a positive RT-PCR. Six RT-PCR-positive residents (16%) were asymptomatic 79 before testing. 80

Six weeks after initial testing, seven residents still had at least one typical COVID-19 81 symptom (particularly fever or cough) or a significant functional impairment. Among them, 5 82 (83%) were RT-PCR-positive. 83

The RT-PCR test became negative 14, 21, or 28 days after initial positive testing in 2 (14%), 84 7 (27%), and 12 (46%) residents. In the 5 (19%) who still had positive RT-PCR 28 days after 85 initial testing, one recovered completely and 4 had long-lasting symptoms (fever and 86 hypothermia; shortness of breath; dry cough; impaired health status). All residents and HCP were tested and there was no selection bias. This study was conducted 101 before any other COVID-19 cases had been detected in the county. The presence of 102 antibodies in residents and HCP is therefore almost certainly linked with the COVID-19 103 outbreak in that NH. 104

In the present study, 16% of residents and one third of HCP with positive RT-PCR were 105 asymptomatic in the 14 days before testing. This confirms that all residents and HCP should 106 be tested if there is a confirmed case of COVID-19, whatever the symptoms. 4 Two residents 107 and two HCP who tested negative at baseline were tested positive for COVID-19 7 days after 108 baseline. This suggests that a repeated weekly testing of all previously negative residents and 109 HCP until no new COVID-19 cases are identified is also essential in preventing the SARS-110

CoV-2 spread. 4 111 Positive RT-PCR was associated with a severe prognosis (death in 32%), especially in men 112 (death in 58%), confirming previous studies. 1,2 Among the 22 negative RT-PCR residents 113 presenting COVID-19 symptoms, one died and the others recovered completely, suggesting 114 that severe COVID-19 outcomes could be generally, but not always, predicted by positive 115 testing.

One remained positive for 8 weeks, indicating that NHs facing a COVID-19 outbreak should 118 be prepared to maintain prolonged protective measures in residents tested positive for SARS-119

CoV-2. In accordance with our regional guidelines 6 , this NH was considered to be COVID-120 19-free when none of the residents and HCP were diagnosed within the 14 days after the last 121 positive result. COVID-19 free NHs apply regional recommended measures to prevent any 122 further COVID entrance and spread. In our Occitanie region, these measures include 6 

174 Epidemiology of Covid-19 in a Long-Term Care Facility in King County

CoV-2 Infections and Transmission in a Skilled Nursing Facility. 178

Interpreting Diagnostic Tests for SARS-CoV-2

Interim Testing Guidance in Response to Suspected 182 or Confirmed COVID-19 in Nursing Home Residents and Healthcare Personnel. Centers 183 for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19)

CoV-2 antibodies using commercial assays and seroconversion patterns in hospitalized 187 patients

COVID-19 Strategy for Prevention in Older Subjects. French Occitanie County Health 189

Agency [COVID19. Stratégie de Prévention des Personnes Agées. Agence Régionale de 190 la Santé Occitanie

Acknowledgements -The authors thank Anna Bedbrook for editorial assistance and all residents and health care personnel of the nursing home.