The Most Massive Corona Virus Development Occurs Before Symptoms Appear
JAKARTA - A study released on Wednesday, April 15 revealed that the people who can transmit COVID-19 the most are those who have not shown any symptoms.
According to CNN, Friday, April 17, research published in Nature Medicine has evidence to suggest that apparently healthy people spread the virus. Researchers carried out swabs on 94 COVID-19 patients treated at the Guangzhou People's Hospital in China who were treated from January 21 to February 14.
The amount of viral genetic material peaks rapidly after the onset of symptoms, then decreases for about 21 days. The results suggest that viral production may be strongest early in the infection before the immune system starts killing the virus and producing symptoms.
"We looked at the highest viral load in throat swabs at the time of incipient symptoms and concluded that the infection was contagious at or before the onset of symptoms," the researchers wrote in the journal.
In addition, the researchers also found that the shedding of the virus, or when one person can infect another, can start two to three days before symptoms appear. The amount of virus shed appeared to decrease after people started feeling sick.
Researchers provide clear warnings in addition to their research. Because people may be spreading the virus before they develop symptoms, public health interventions such as contact tracing are essential.
Contact tracing not only needs to identify those exposed to the person with symptoms, but they also need to look in order of who had contact while the person was still feeling well.
"More inclusive criteria for contact tracing to capture potential transmissions two to three days before the onset of symptoms should be considered immediately for effective outbreak control," write the investigators.
This research does have its limitations. That is, it relies on the patient's memory of when their symptoms first appeared, which can be vague and uncertain. Hand washing and social distancing for everyone may also be needed to control the pandemic as long as there is no COVID-19 treatment or vaccine available, the researchers said.
Based on growing evidence, the United States recommends that healthy people keep wearing masks outside to reduce the risk of infecting others.