Clusters of patients who had initial negative RT-PCR then converted to positive COVID-19

Introduction: Diagnosing SARS-CoV-2 infection is essential in stopping the spread of COVID19, yet we have to take into account that onset of symptoms often vary among our exposed patients. Objectives: Investigate the probable causes of conversions among the clusters of patients with negative RT-PCR COVID19 results upon admission who converted to positive PCR after 2-18 days in one of the acute care hospitals in New Jersey, USA. Methods: A descriptive study was conducted to identify cases, trace exposed contacts, and identify the probable causes of conversion. A confirmed case was defined as a positive reverse-transcription polymerase reaction test for SARS-COV-2. COVID19 cases were categorized as community-acquired, and or hospital-acquired. Hospital-acquired is defined as an occurrence of a positive PCR result or onset of symptoms on or after 7 days post admission. Results: There were 18 patients admitted, all tested negative, and were not place on isolation. Within 7 days post admission 11 (61%) tested positive. Review of records showed that 14 (78%) were community- acquired infection and 4 (22%) were HAIs. Symptomatic upon admission 11 (61%) and asymptomatic 7 (39%). Twelve (67%) with 2 or more comorbidities and the rest none. During their stay 5 patients (28%) required high flow oxygenation, 1 required intubation. Thirteen (72%) on nasal cannula/room air. Five (28%) expired, 12 recovered/discharged, and 1 still in the hospital. Conclusion: The conversions among these patients could be due to full reliance on the diagnostic RT-PCR and not considering clinical conditions, breaches in infection control, and gaps in identifying exposed patients from the community prior to admission. Thus, strict infection control measures were implemented which included enhanced surveillance screening through RT-PCR on day 1, day 3 and day 5;more rigid environmental terminal cleaning even in non-Covid units where most of the conversion occurred;increased awareness among physicians and staff for any subtle changes in clinical condition to place in isolation and repeat testing, dedication of staff and equipment, and refresher courses on the use of personal protective equipment.