Timing of onset of symptom for COVID-19 from publicly reported confirmed cases in Uganda

Abstract

INTRODUCTION: Incubation period for COVID-19, 2 to 14 (average 5 to 6) days. Timing of onset of COVID-19 signs and symptoms amongst cases in Uganda is however, not known. METHODS: we utilized data on real-time reverse transcription polymerase chain reaction (RT-PCR) confirmed cases to investigate symptom onset timing, from 21st March to 4th September 2020. Since timing of COVID-19 symptom onset is highly likely to be an interval rather than a point estimate, we generated 3-tertile categories: 1st, 2nd and 3rd tertile denoting symptom presentation within 3, 4 to 6 and at least 7 days. We considered all signs and symptoms in the database and analysed using Chi-square test and multinomial logistic regression, controlling for age and sex. RESULTS: we analysed a total of 420 symptomatic case-patients; 72.0% were males, median age of 33 years. Common symptoms were cough (47.6%), running nose (46.2%), fever (27.4%), headache (26.4%) and sore throat (20.5%). We utilized 293 cases with clinical symptom onset date recorded. Most of the patients, 37.5%, presented symptom within 3 days, 31.4% had symptom in the 2nd and 31.4% in 3rd tertile, denoting 4 to 6 days and at least 7 days after exposure. Running nose (RRR=0.45, 95%CI:0.24-0.84) and chest pain (RRR=0.64, 95%CI:0.09-0.72) were more likely to occur in 3rd tertile than 1st or 2nd tertile. Cases aged 20 yrs were less likely to have symptoms in the 1stand 2nd tertile compared to 20 years (p=0.05). CONCLUSION: our study provides empirical evidence for epidemiological characterization of cases by signs and symptoms which complements current proposals for the length of active monitoring of persons exposed to SARS-CoV-2.

Keywords

• covid-19
• sars-cov-2
• incubation period for coronavirus
• uganda