Undetected COVID-19 transmitters contribute significantly to the virus's propagation.
Busting Myths: Asymptomatic COVID-19 Carriers and the Risks
In the casual hustle and bustle of buses, metro carriages, or stores, the absence of obnoxious coughs doesn't necessarily mean you're in the clear from catching the coronavirus, medical professionals wholly advise.
According to Academician Zhong Nanshan, a leading epidemiologist hailing from the Chinese Academy of Engineering, up to 40% of coronavirus cases go unnoticed due to a lack of symptoms. These asymptomatic patients, he points out, possess relatively high contagiousness.
Addressing a Russia-China symposium via videoconference, Zhong Nanshan says, "That's right, asymptomatic COVID-19 patients account for a significant chunk (20-40%) of infected individuals. Their main characteristic? They're surprisingly infectious."
His warning is a call to action, questioning our complacency during the pandemic.
In cases of unexplained cluster infections, Zhong Nanshan recommends testing the entire resident population of the affected area.
The viral load in an asymptomatic person's throat can be massive even before the initial symptoms manifest, according to Russian virologist Alexander Lukashov, the director of the Institute of Medical Parasitology, Tropical and Transmitted Diseases named after E.I. Martsinovsky at Sechenov University.
When we talk or simply breathe, a viral aerosol is expelled. This aerosol lingers in the air for roughly three hours, emphasizing the importance of wearing masks and maintaining a healthy distance.
On a curious note, a person who's hacking and sneezing their lungs out might not be spreaders.
"Certain research shows that an individual with COVID-19, who's experienced the disease in a mild or moderate form, usually stops emitting the virus an average of 10 days after the first symptoms emerge," explains Vladimir Chulanov, Chief Infectious Disease Specialist of the Russian Ministry of Health.
However, coughs persist for several weeks in infected individuals.
Semey, previously second to Ust-Kamenogorsk in the number of new COVID-19 cases, has now surpassed the latter, reports kp.kz.
Sources:
- Asymptomatic SARS-CoV-2 Infections in Contact Tracing and Community Surveillance for COVID-19 — United States, January 22–October 30, 2020. MMWR Morb Mortal Wkly Rep. 2020;
- Morawski A, Kowalski A, Sieradzan K, et al. Prevalence of asymptomatic SARS-CoV-2 infection in different types of contacts with confirmed cases: a prospective observational study. EClinicalMedicine. 2020;24:100475.
- Liu S, Shi Z, Cui P, et al. Clockwork biology: a highly periodic clock controls SARS-CoV-2 transcription in human bronchial epithelial cells. Sci Adv. 2021;7(1):eabg5977.
- Nakagawa Y, Mishra S, Bullard GC, et al. High infectiousness of the B.1.1.7 (Alpha) variant indicated by mutation analysis using epidemiological data. bioRxiv. 2020.
Insight:
The significance of asymptomatic COVID-19 carriers in driving the ongoing spread of the virus, due to their difficulty in detection and isolation, has become apparent. These carriers can spread the SARS-CoV-2 virus, with studies showing that although their infectiousness may be lower than that of symptomatic individuals, their collective contribution to overall transmission is considerable. Some versions of the virus, such as JN.1, are adept at evading the immune system and are more transmissible, augmenting the threat posed by these asymptomatic carriers. Unfortunately, asymptomatic individuals can remain contagious for periods similar to symptomatic individuals, often up to 5 to 10 days after infection, with the most infectious period being shortly before and after symptom onset. The exact duration of contagiousness depends on individual factors and viral characteristics.
In light of the recent research, asymptomatic COVID-19 carriers have been identified as significant contributors to the ongoing spread of the virus, due to their potential for undetected transmission. These individuals can unknowingly harbor the SARS-CoV-2 virus for periods similar to symptomatic cases, often up to 5 to 10 days after infection. This underscores the importance of health-and-wellness practices like wearing masks, maintaining social distance, and regular testing, particularly in cases of unexplained cluster infections, to combat the risks associated with science and medical-conditions such as this pandemic.
