Time to negative PCR in various disease categories of COVID-19 infection in Pakistani population.

Objectives: To identify association of epidemiological characteristics, presence of underlying pre-morbidities and disease severity with time to first negative PCR in Corona virus disease 2019.

Methods: Total 842 Corona Virus Real Time Polymerase-Chain-Reaction positive patients were included in this cross-sectional study. Patients were admitted to Department of Medicine at KRL Hospital Islamabad from April to August 2020. Age, gender, symptoms, pre-morbidities and disease severity were recorded. Outcome (recovered versus died) was documented. World Health Organization categories to classify disease severity (asymptomatic, mild, moderate and severe) were used. Time to negative PCR was documented as time between first positive PCR to first negative PCR.

Results: The mean age of patients was 39.04 ± 11.32 years with 99.8 % being males. Majority of patients (78.4%) were asymptomatic. Amongst symptoms, fever was the most common symptom. Diabetes mellitus and hypertension were the most commonly recorded co-morbidity. Mean time to negative PCR was 8.8 ± 3.1 days. A large proportion of patients recovered (99.9%). Significant positive correlation (p value < 0.05) was found between age, gender, presence of underlying pre-morbidities and disease severity categories with time to first negative PCR.

Conclusion: The underlying epidemiological factors, pre-morbidities and disease severity are associated with time to negative PCR and hence affect frequency of recovery samples.