RESUMO
Long covid (persistent COVID-19) is a new disease with contested aetiology and variable prognosis. We report a 2-year ethnography of UK long covid clinics. Using a preformative lens, we show that multidisciplinary teams (MDTs) built working knowledge based on shared practices, mutual trust, distributed cognition (e.g. emails, record entries), relational knowledge of what was at stake for the patient, and harnessing uncertainty to open new discursive spaces. Most long covid MDTs performed the working knowledge of 'rehabilitation', a linked set of practices oriented to ensuring that the patient understood and strove to 'correct' maladaptive physiological responses (e.g. through breathing exercises) and pursued recovery goals, supported by physiotherapists, psychologists and generalist clinicians. Some MDTs with a higher proportion of doctors (e.g. cardiologists, neurologists, immunologists) enacted the working knowledge of 'microscopic damage', seeking to elucidate and rectify long covid's underlying molecular and cellular pathology. They justified non-standard investigations and medication in selected patients by co-constructing an evidentiary narrative based on biological mechanisms. Working knowledge was ontologically concordant within MDTs but sometimes discordant between MDTs. Overt ontological conflict occurred mostly when patients attending 'rehabilitation' clinics invoked the working knowledge of microscopic damage that had been generated and circulated in online support communities.