COVID-19 transmission highest within a week of symptom onset: study

ROC Central News Agency

05/02/2020 07:52 PM

Taipei, May 2 (CNA) The viral transmission of COVID-19 has been found to be highest within a week of the onset of symptoms, according to a medical study authored by a Taiwanese research team published by the American Medical Association Friday.

The research paper "Contact Tracing Assessment of COVID-19 Transmission Dynamics in Taiwan and Risk at Different Exposure Periods Before and After Symptom Onset" was authored by six medical researchers for the Taiwan COVID-19 Outbreak Investigation Team and published in the monthly peer-reviewed medical journal JAMA Internal Medicine.

The paper, which collected data from Jan. 15 to March 18 with a final follow up date on April 2, followed Taiwan's first 100 confirmed patients and 2,761 of their close contacts to determine transmissibility of the coronavirus before and immediately after symptom onset.

The findings indicated that the infection rate was higher among contacts whose exposure to index cases started within five days of symptom onset compared with those who were exposed later.

Contacts with exclusive pre-symptomatic exposure were also at risk, the paper showed.

The infection rate was higher among household and non-household family contacts relative to health care settings, the paper showed, adding that the rates were also higher among those aged 40 or older.

At a daily Central Epidemic Command Center press briefing, Cheng Hao-Yuan (鄭皓元), one of the authors of the study, said the results matched similar studies conducted overseas despite the different data sets used.

"We can now make the judgment that a few days before and a week after the onset of symptoms results is the period of highest transmission for COVID-19," Cheng said.

The high transmissibility of COVID-19 before and immediately after symptom onset suggests that finding and isolating symptomatic patients paired with more generalized measures such as social distancing is required to contain the disease, Cheng said.

Taiwan has been praised by the international community for its efforts to prevent the spread of the virus and has also helped countries combat the disease with donations of medical supplies and sharing valuable medical skills.

As of Saturday Taiwan has had a total of 432 confirmed COVID-19 cases, of which only 55 have been classified as domestic.

United States Secretary of Health and Human Services Alex Azar II held a bilateral virtual meeting with Taiwan Health Minister Chen Shih-chung (陳時中) earlier this week to discuss the need for Taiwan's inclusion in the World Health Organization.

Globally, COVID-19 has infected 3,381,839 people in 186 countries and regions, including 1,120,092 in the U.S., 215,216 in Spain, 207,428 in Italy, 200,137 in France, and 177,454 in the United Kingdom, with a total of 238,040 fatalities, according to CECC statistics as of Saturday.

(By William Yen)

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