Differential Kinetics of Cycle Threshold Values during Admission by Symptoms among Patients with Mild COVID-19: A Prospective Cohort Study

Teppei Sakano, Mitsuyoshi Urashima, Hiroyuki Takao, Kohei Takeshita, Hiroe Kobashi and Takeo Fujiwara
Additional contact information
Teppei Sakano: Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
Mitsuyoshi Urashima: Division of Molecular Epidemiology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
Hiroyuki Takao: Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
Kohei Takeshita: Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
Hiroe Kobashi: Infectious Disease Department, Team Medical Clinic, Tokyo 105-0003, Japan
Takeo Fujiwara: Department of Global Health Promotion, Tokyo Medical and Dental University, Tokyo 113-8510, Japan

IJERPH, 2021, vol. 18, issue 15, 1-16

Abstract: In the coronavirus disease 2019 (COVID-19) pandemic, more than half of the cases of transmission may occur via asymptomatic individuals, which makes it difficult to contain. However, whether viral load in the throat during admission is different between asymptomatic and symptomatic patients is not well known. By conducting a prospective cohort study of patients with asymptomatic or mild COVID-19, cycle threshold (Ct) values of the polymerase chain reaction test for COVID-19 were examined every other day during admission. The Ct values during admission increased more steadily in symptomatic patients and febrile patients than in asymptomatic patients, with significance ( p = 0.01 and p = 0.004, respectively), although the Ct values as a whole were not significantly different between the two groups. Moreover, the Ct values as a whole were higher in patients with dysosmia/dysgeusia than in those without it ( p = 0.02), whereas they were lower in patients with a headache than those without ( p = 0.01). Patients who were IgG-positive at discharge maintained higher Ct values, e.g., more than 35, during admission than those with IgG-negative ( p = 0.03). Assuming that viral load and Ct values are negatively associated, the viral loads as a whole and their changes by time may be different by symptoms and immune reaction, i.e., IgG-positive at discharge.

Keywords: coronavirus disease 2019; COVID-19; SARS-CoV-2; mild; asymptomatic; febrile; afebrile; PCR; Ct; cycle threshold (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2021
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1660-4601/18/15/8181/pdf (application/pdf)
https://www.mdpi.com/1660-4601/18/15/8181/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jijerp:v:18:y:2021:i:15:p:8181-:d:607058

Access Statistics for this article

IJERPH is currently edited by Ms. Jenna Liu

More articles in IJERPH from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().