{"doi":"10.1093/ageing/afab081","title":"Are presymptomatic SARS-CoV-2 infections in nursing home residents unrecognised symptomatic infections? Sequence and metadata from weekly testing in an extensive nursing home outbreak","abstract":"BACKGROUND: Sars-CoV-2 outbreaks resulted in a high case fatality rate in nursing homes (NH) worldwide. It is unknown to which extent presymptomatic residents and staff contribute to the spread of the virus. AIMS: To assess the contribution of asymptomatic and presymptomatic residents and staff in SARS-CoV-2 transmission during a large outbreak in a Dutch NH. METHODS: Observational study in a 185-bed NH with two consecutive testing strategies: testing of symptomatic cases only, followed by weekly facility-wide testing of staff and residents regardless of symptoms. Nasopharyngeal and oropharyngeal testing with RT-PCR for SARs-CoV-2, including sequencing of positive samples, was conducted with a standardised symptom assessment. RESULTS: 185 residents and 244 staff participated. Sequencing identified one cluster. In the symptom-based test strategy period, 3/39 residents were presymptomatic versus 38/74 residents in the period of weekly facility-wide testing (P-value < 0.001). In total, 51/59 (91.1%) of SARS-CoV-2 positive staff was symptomatic, with no difference between both testing strategies (P-value 0.763). Loss of smell and taste, sore throat, headache or myalga was hardly reported in residents compared to staff (P-value <0.001). Median Ct-value of presymptomatic residents was 21.3, which did not differ from symptomatic (20.8) or asymptomatic (20.5) residents (P-value 0.624). CONCLUSIONS: Symptoms in residents and staff are insufficiently recognised, reported or attributed to a possible SARS-CoV-2 infection. However, residents without (recognised) symptoms showed the same potential for viral shedding as residents with symptoms. Weekly testing was an effective strategy for early identification of SARS-Cov-2 cases, resulting in fast mitigation of the outbreak.","journal":"Age and Ageing","year":2021,"id":175375,"datarank":0.47032413238937254,"base_score":3.1354942159291497,"endowment":3.1354942159291497,"self_citation_contribution":0.47032413238937254,"citation_network_contribution":0.0,"self_endowment_contribution":0.47032413238937254,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":22,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9637,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":231812,"name":"Reina S. Sikkema","orcid":"0000-0001-7331-6274","position":1,"is_corresponding":false},{"id":717259,"name":"Fleur Koene","orcid":null,"position":2,"is_corresponding":false},{"id":716435,"name":"Laura W. van Buul","orcid":"0000-0001-8753-3464","position":3,"is_corresponding":false},{"id":231800,"name":"Bas B. Oude Munnink","orcid":"0000-0002-9394-1189","position":4,"is_corresponding":false},{"id":717260,"name":"Ine Frénay","orcid":null,"position":5,"is_corresponding":false},{"id":717261,"name":"René te Witt","orcid":null,"position":6,"is_corresponding":false},{"id":107146,"name":"Marion Koopmans","orcid":"0000-0002-5204-2312","position":7,"is_corresponding":false},{"id":716436,"name":"Cees M.P.M. Hertogh","orcid":"0000-0003-3081-1245","position":8,"is_corresponding":false},{"id":716437,"name":"Bianca M. Buurman","orcid":"0000-0001-7139-6178","position":9,"is_corresponding":false},{"id":716434,"name":"Judith H. van den Besselaar","orcid":"0000-0001-6066-1503","position":0,"is_corresponding":true}],"reference_count":29,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-18T23:47:15.431199Z","pmid":"33963830","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}