According to foreign news agency BGR, a new study says the spread of asymptomatic patients with new crowns may be much rarer than most experts believe — and the more severe coVID-19 patients are, the more likely they are to infect others. Researchers from Southern Medical University in China have written a study in the Journal of the Aneurysm that says asymptomatic transmission is rare.
The researchers analyzed the “renewal rates” of COVID-19 infections in each group. This is the possibility of a person spreading the disease to their close contacts. They found that patients who experienced more severe symptoms of COVID-19 were more likely to infect their close contacts than in mild cases. The researchers found that “asymptomatic cases are least likely to infect their close contacts”.
The study also noted that the risk of transmission through public transport and health care is lower than that of households. This is because people are less likely to wear masks at home, which is mandatory in many public places. Over the early two months of the pandemic, the researchers looked at about 3,410 close contacts of 391 index cases. “Our results suggest that patients with more severe symptoms of COVID-19 have higher transmission capacity, while asymptomatic cases have limited transmission capacity,” the researchers wrote. “This supports the View of the World Health Organization that asymptomatic cases are not the main driver of the overall outbreak dynamics.”
“This mechanism may be that more severe cases of COVID-19 may carry a higher SARS-CoV-2 viral load and therefore have greater transmission capacity,” they said. That’s the first major limitation of the study. Researchers may have observed different strains of the virus than are now raging around the world. Some researchers believe that the new crown virus mutation makes the virus stronger and more contagious, although it is not more deadly than before, such as the D614G mutation, which is now returning to Asia.
Second, while the study does agree with WHO that asymptomatic cases are not the main driver of the disease, the organization made a clear distinction in the COVID-19 transmission update a few weeks ago. WHO says people without symptoms can also be transmitted to others, dividing those without COVID-19 symptoms into two categories. We are concerned about the real asymptomatic people who have never shown any SYMPTOMAD-19 symptoms and can only be diagnosed with PRC testing;
Early data from China suggest that asymptomatic people can infect others. In order to better understand the spread of asymptomatic infections, it is important to distinguish between the spread of infected persons who have never had symptoms (asymptomatic transmission) and the transmission of infected persons who have been infected but have not yet developed symptoms (pre-symptom transmission). This distinction is important in the development of public health strategies to control transmission.
The same updated report notes that the extent of truly asymptomatic transmission in the community remains unknown, and details other studies of asymptomatic and pre-symptom transmission. The list includes a modeling study that estimates that up to 44% of transmission may occur in pre-symptomatic patients.