Phan Trong Lan, director of the Pasteur Institute in Ho Chi Minh City, Vietnam’s premier epidemiology center, said the Delta variant, or B.1.167.2, which was first discovered in India, was classified as highly transmissible by the World Health Organization and able to reduce the effectiveness of the available Covid-19 vaccines.
Previously in 2020, one infected person could spread the virus to two to four others and up to seven of the alpha or British strain that emerged earlier this year. The Delta variant should meanwhile be 40-60 percent more transferable than the Alpha.
The gene sequencing results show that the delta variant is dominant in infections in the ongoing outbreak in Vietnam, particularly in cases recorded in central and southern locations, including Ho Chi Minh City.
Because of this exposure, the southern region has seen many cases where Covid-19 symptoms developed or tested positive a day after contact with an infected person, Lan said.
“It is still uncertain whether the Delta variant causes more severe Covid-19 symptoms, although the increased number of cases has overloaded the health system, which can lead to a higher mortality rate,” he said.
In the fourth wave of Covid-19 that broke out in Vietnam on April 27, the Delta tribe was first discovered in northern Yen Bai Province before spreading to the epicenter of Bac Giang Province in the north.
Currently, more than 15,200 cases have been registered in 52 of 63 cities and provinces.
Le Quoc Hung, director of the tropical diseases department at Cho Ray, a leading hospital in South Vietnam, said if a new strain of coronavirus emerges there will be groups with high and low virulence levels.
In particular, the higher virulence group will see early symptoms, allowing early detection of Covid-19 patients for early isolation and treatment.
Meanwhile, people with lower virulence often see no or only mild symptoms, which makes detection difficult.
This leads to infections in the community and gives the virus a chance to spread and multiply, he noted.
Hung said the more infectious Delta variant retained the basic core of the virus, with the only difference found at virus spikes.
The number of spikes in this strain is higher, resulting in a greater ability to attach to cells in the throat, making it easier to invade the body and cause infection.
“For example, earlier strains may have fewer virus spikes and simply swallow them to remove them from the oropharynx to avoid infection,” said Hung.
Nguyen Tri Dung, director of the Center for Disease Control in Ho Chi Minh City, agreed when addressing a city meeting on June 25.
He said that after being transmitted over many generations, the new coronavirus would either mutate and increase its virulence or stay the same and decrease its virulence.
Although the virulence may decrease, the transmission would persist, albeit with no or mild symptoms. Hence, the virus would quietly spread throughout the community without anyone knowing.
Nguyen Huy Nga, former head of the General Department of Preventive Medicine at the Ministry of Health, said the Delta Tribe made this outbreak more complex.
About 80 percent of patients have no or mild symptoms, making it difficult to determine who is carrying the virus into the community and posing a high risk of infection.
The infected may not know they have contracted the virus and so can easily pass it on to others. Even if patients recovered thanks to a healthy immune system, the virus would already have been transmitted, Nga said.
“So it is necessary to track down all infections in the community, but given the ongoing situation, it seems impossible.”
With HCMC making up the second most common infections in the community in this wave so far, HCMC has been running a mass test campaign since June 26 to collect up to five million samples in 10 days to detect possible Covid-19 cases in the community.
The city and other infected locations have cordoned off infected areas and imposed social distancing measures to help curb the spread of the infection.
source https://dailyhealthynews.ca/delta-variant-threatens-to-overload-vietnams-healthcare-system-experts/
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