During the global pandemic of COVID-19 accurate diagnosis of the infection by demonstrating SARS-CoV-2 viral RNA by PCR in specimens is crucial for therapeutic and preventative interventions. There have been instances where nasal and throat swabs have been negative despite the patient having typical clinical and radiological findings compatible with the disease. We report a case of a man in his late 50s, brought to the hospital following a cardiac arrest and prolonged unsuccessful resuscitation. The history was typical for COVID-19 with fever for 10 days and worsening shortness of breath. His throat and nasal swabs (after death) were negative for SARS-CoV-2. A limited diagnostic autopsy was performed after 27 days, and lung swabs confirmed presence of SARS-CoV-2. This case highlights the importance of lung swabs when initial upper respiratory tract swabs are negative and proves that the virus can be detected from dead human tissue almost a month later.

Background SARS-CoV-2 outbreaks are difficult to recognise and control due to its high infectivity and the wide range of clinical manifestations of the infection. An outbreak at Watford general hospital provided an opportunity to recognise the complexity involved in a COVID-19 outbreak investigation. Methods An outbreak control team (OCT) was convened. The terms outbreak, a case and a significant exposure were defined as per Public Health England (PHE) Guidance and in the context of the local outbreak. Root cause analyses (RCAs) were carried out on cases to identify possible causes, possible route of transmission and any learning points. All contact patients and staff were screened with RT PCR and genomic sequencing was performed on a set of positive specimens. In addition to active contact tracing, screening and cohorting of patients and staff, standard and transmission-based precautions were reinforced to control the outbreak. Findings Fifteen patients and four staff members were identified in this outbreak investigation. With contact tracing, screening and through strict infection control measures the outbreak was brought under control. Conclusion We could successfully contain the spread of this outbreak following PHE outbreak control guidelines and our local guidelines. We recognised several challenges in investigating a COVID-19 outbreak in a hospital setting. Problems arising from variable sensitivity of the tests, difficulty in differentiating COVID-19 related symptoms from underlying diseases, problems related to establishing the route of transmission, issues with contact tracing are discussed. Additionally, the importance and limitations of genomic studies in COVID-19 are discussed.