What is Delta Virus and what are its symptoms, and how virulent is the Delta strain?

Recently, the epidemic has rebounded in some areas. We thought that the new coronavirus was about to be controlled by us, but it mutated again. The transmission ability of the new coronavirus was previously like "hitting a few people", but now the new coronavirus mutated virus - Delta strain may be "released to a large number of people". Delta virus generally refers to Delta (the mutated new coronavirus first discovered in India). How toxic is the new coronavirus mutated virus Delta strain? Below, let's take a look at the relevant knowledge of Delta virus with Encyclopedia Knowledge Network.

Contents of this article

1. What is Delta virus?

2. What are the signs of Delta virus infection?

3. How toxic is the Delta strain?

4. How does the Delta strain spread?

5. How to protect yourself?

6. Important reminders for epidemic prevention

What is Delta Virus

What is Delta Virus

Delta virus generally refers to Delta (the mutated new coronavirus first discovered in India)

Delta is a variant of the novel coronavirus. It was first discovered in India in October 2020. In May 2021, the World Health Organization named the novel coronavirus variant B.1.617.2, which was first discovered in India, as the "Delta" variant. The variant was identified as one of the driving factors of India's second wave of the epidemic.

On June 15, 2021, it was reported that the "Delta" variant further mutated to derive the "Delta+" or "AY.1" variant. On July 2, the WHO held a routine press conference on the new crown pneumonia. WHO Director-General Tedros Adhanom Ghebreyesus said that the Delta variant is becoming the main epidemic strain in many countries. The Delta variant has appeared in at least 98 countries and regions and continues to mutate and evolve. On September 15, Zhong Nanshan and his team accurately described the Delta transmission chain for the first time. The study revealed that the Delta variant has the characteristics of a short incubation period, fast transmission speed, high viral load, long nucleic acid conversion time, and is more likely to develop into critical illness.

As of September 22, 2021, Delta variant infections have been reported in 185 countries and regions.

On December 11, the Joint Prevention and Control Mechanism of the State Council held a press conference to report that the National Health Commission's virology research results confirmed that the viral genome sequences of recent local cases in Zhejiang (including Ningbo) and the epidemic cases in Shanghai and Jiangsu were highly homologous, indicating that they were from the same related epidemic. After the third-generation sequencing of the case specimens from the Ningbo Center for Disease Control and Prevention, the results were the Delta variant (AY.4 evolutionary branch) Warsaw strain.

What are the signs of Delta virus infection?

There are some signs of delta virus infection. If you have headache, dry throat, fever, phlegm, soft and weak, these symptoms may be symptoms of delta virus infection, and you should get tested as soon as possible. So we can judge whether you may be infected with delta virus based on these symptoms and whether you have been to high-risk areas of the epidemic.

How virulent is the Delta strain?

1. Fast transmission speed:

It is spreading across provinces, and currently at least 20 cities in my country have been affected; the Delta strain of the new coronavirus variant has spread to about 100 countries and is the most contagious new coronavirus variant discovered so far.

2. Highly contagious:

There was a case of virus transmission in 14 seconds without contact in Guangzhou, Guangdong; the UK Department of Public Health released data saying that the number of confirmed Delta cases reported in the UK in the past week increased by 46% compared with the original number, and the Delta variant virus currently accounts for 99% of new cases in the UK.

The Delta variant has a total of 13 mutations, which may cause changes in the structure of the S protein. Research data show that these mutations affect the virus's transmissibility and its ability to be neutralized by antibodies.

3. Short incubation period:

Academician Zhong Nanshan said that the incubation period of the Delta virus in the body is relatively short, and the disease will occur in two or three days, and some may even develop within 24 hours. Some Delta viruses have five generations of transmission within 10 days.

4. Atypical symptoms:

Patients infected with the Delta strain may only show symptoms such as fatigue, olfactory impairment, and mild muscle aches in the early stages; this is unlike the symptoms of the new coronavirus before it mutated: fever, fatigue, dry cough, and may also experience symptoms such as itchy throat, sore throat, nasal congestion, runny nose, diarrhea, abnormal taste, and loss of smell.

5. Long treatment time:

Judging from the results of current observations, the Delta strain of the new coronavirus mutant has a longer treatment cycle and is more likely to develop into severe illness than those infected before the mutation.

6. Redefinition of close contacts:

In the past, it was believed that close contacts were those who worked in the same office as the patient’s family or had meals or meetings together within one meter two days before the onset of the disease. These were called close contacts.

Based on the characteristics of the Delta virus, the definition of close contacts of the Delta strain of the new coronavirus variant has been modified. Those who have been in the same space, the same unit, the same building, and have been with the patient for 4 days before the onset of the disease are considered close contacts.

How does the Delta strain spread?

Transmission through respiratory droplets: Respiratory droplets sprayed out by sneezing, coughing, or even talking carry the virus and can cause infection to people who are in close contact with it. This is the main way.

Transmission through contact with contaminants: Respiratory droplets and secretions contaminate the surface of objects, and the virus can survive for a period of time. Other people touch the contaminated surface with their hands and become infected with the virus when they touch their mouth, eyes, and nose.

Aerosol transmission: In a small, poorly ventilated space indoors, if an infected person coughs or sneezes, very fine respiratory secretion particles will be formed, which can hover in the air and be inhaled by others, causing infection. Even after the person who excreted the virus leaves the space, the virus will still remain in the air for a certain period of time, causing infection when other people enter.

How to protect yourself?

Adhere to normal epidemic prevention and control measures: wear masks scientifically, wash hands frequently, ventilate frequently, and try not to go to crowded places with poor air circulation. Consciously abide by epidemic prevention measures, and cooperate in wearing masks, code verification, temperature measurement, one-meter line and other prevention and control measures in public places.

Reduce unnecessary gatherings: It is not advisable to hold or attend gatherings with a large number of people, avoid gatherings in confined spaces, keep activities as short as possible and pay attention to opening windows for ventilation.

Actively get vaccinated against the new coronavirus: Vaccination is the most effective measure to prevent diseases.

Important reminders for epidemic prevention

At present, my country faces the dual challenges of the Delta and Omicron strains of the imported epidemic. The Spring Festival travel rush is about to begin, and the flow and gathering of people will increase significantly, and the epidemic prevention and control situation is severe. In areas where the epidemic occurs, it is necessary to speed up screening, flow investigation, and isolation, find and control risk personnel as early as possible, and block the transmission route as soon as possible; promote the implementation of regional joint investigations, and strictly prevent the spillover and spread of the epidemic. We must do everything possible to ensure the supply of materials and basic medical needs of the people, and ensure that the people's demands can be responded to and resolved in a timely manner.