Category: Antiviral

The following information was released at a recent press conference on COVID-19:

Previous tracing results of Putuo cases showed that

Gene sequencing analysis was performed in the laboratory of Municipal Center for Disease Control and Prevention

The Novel coronavirus infection of the cases in this outbreak is

Omicron mutant

The citizens found that

The number of asymptomatic cases in Shanghai has increased recently

Is omicron weak?

· The characteristics of the Omicron variant cause many infected people to show "asymptomatic" symptoms.

National COVID - 19 medical treatment expert group members, zhongshan hospital affiliated to fudan university professor bi-jie hu director infection diseases and infection management section, told reporters that the mutation strains pathogens has its own change, in general, people infected with lower respiratory tract infection rate decreased significantly, some people have a headache, fever percentage drops hot symptoms also have no, morbidity.

Experts further analyzed that the characteristics of the pathogen were closely related to the clinical manifestations of the infected. At the beginning of the COVID-19 epidemic, the mutant pathogen was prone to lower respiratory tract infection, which showed imaging changes and was accompanied by fever and cough. Asymptomatic infections were rare. Back in 2003, the SARS virus was also a coronavirus, a pathogen that causes severe illness. The omicron variant in the current epidemic has mild or no symptoms, which is one reason why many infected people are asymptomatic.

· Related to immunization

Professor Wu Fan, a member of the Shanghai Public health expert group on epidemic prevention and control and vice president of Shanghai Medical College of Fudan University, previously mentioned that in addition to the mutation, the proportion of asymptomatic infections will also increase due to mass immunization and enhanced immunity of the population.

Bi-jie hu said, after the vaccination built a "immune wall" in the crowd, the crowd resistance increased, this means that the virus will not thrive, once the virus concentration increases, vaccine, antibody response, although viral load will test (positive), but I can't play out virulence (no symptoms).

· It is also possible that the disease is at an early stage and has not yet shown symptoms

In the interview, experts also mentioned that asymptomatic infected persons do not exclude a situation: that is, they are in the early stage of the disease and have not yet shown symptoms, but may show symptoms after a period of time. At present, Shanghai is under the double pressure of "preventing imported cases from abroad and rebounding from within", and the investigation and screening of cases are very meticulous.

Asymptomatic infected persons in Shanghai are being quarantined for 14 days in strict accordance with national standards. After the 14-day quarantine, asymptomatic infected persons can be released from quarantine only after two consecutive nucleic acid tests are negative.

The omicron variant faced with "off the charts" transmission power

Are regular masks still effective?

Will it be reinfected?

Dr. Shi Qingfeng of infection management department of Zhongshan Hospital affiliated to Fudan University gave answers to several questions of public concern.

· Are regular masks still effective?

According to experts, the novel Coronavirus mutation has enhanced transmission mainly because it can infect more respiratory cells in a short period of time, leading to the early onset of clinical symptoms. However, the mode of transmission is still mainly based on respiratory droplets, so the standard wearing of qualified masks is still one of the most effective prevention and control measures. Before wearing a mask, we need to confirm the inside and outside of the mask, and then wrap the rubber band behind the ear, and open the mask. Remember to press the nose clip along the bridge of the nose. Wash hands thoroughly after removing the mask.

· There is no need to worry if the pathogenicity is weak?

Although omicron is highly contagious, it mainly infects the nasopharynx, the upper respiratory tract, and can become severe once the virus reaches the lungs. Recently, tens of thousands of people in Hong Kong are infected every day, and more than 100 new deaths occur every day. Low pathogenicity does not mean no pathogenicity. Therefore, the public should not take Omicron lightly.

· If you have been infected with other COVID-19 strains, will you be re-infected with Omicron?

Although some immunity can be acquired after COVID-19 infection, Omicron is a relatively new mutant, and antibodies previously obtained may not fully neutralize omicron. Of the 3,582 new positive cases tested in the UK in January, two thirds had been infected with the Novel Coronavirus in the past. Therefore, people who have been infected with COVID-19 in the past should not think that they can rest easy, let alone take personal protection lightly in daily life.

· "Omicron" is the flu?

Shi Qingfeng is clear: this comparison is not appropriate. Although it has mild symptoms, it is much more contagious than influenza. In terms of sequelae, foreign data show that COVID-19 has far more sequelae than influenza. In addition, the infection rate among family members was 15.8 percent, higher than delta's 10.3 percent and much higher than influenza. Therefore, the public should not treat Omicron with the mentality of dealing with flu.

During repeated outbreaks in China

How can people strengthen self-protection?

Shanghai Health Promotion Center today also issued a reminder:

When people come back from going out,

Wash your hands after touching public objects, sneezing or coughing.

In particular, the municipal Health Promotion Center points out that wearing gloves daily is not a substitute for hand hygiene; If people do not have running water outside, they can use hand sanitizer to clean their hands. However, hand sanitizer cannot replace hand washing. The best method is "running water + hand sanitizer/soap".

Adhere to the "epidemic prevention of three sets", keep in mind the "five protection", which is the most effective, the most convenient, the most economical way to prevent infectious diseases.

The new rabies virus is basically a bat host. Since the outbreak of the novel Coronavirus pandemic, the study of pathogens in bats around the world has entered a new stage, and further advances the study of rabies virus in bats. This paper is a summary of the research results in this field, introduces the potential threat to public health posed by the new lysa virus, and puts forward some suggestions for future research.
This blog will introduce the main content of this article in succession.
Contents of this article:
Abstract

1. Introduction
2. The growing diversity of Lisha virus
3. Are Miniopterus bats the source of genetically diverse Lissa viruses?
4. Batlysa virus found in Lleida, France
5. West Caucasus bat virus found in Italy
6. Matlo Batlysa virus, Republic of South Africa
7. Bat host association analysis
8. Availability of a bat-lysa virus vaccine
9. Newly emerging Lisha virus
   Conclusion 10.
   reference
10. Increasing Diversity of Lisha virus (1)
    Lysha virus is classified in the family Rhabdoviridae, order Mononegavirales. Within The Genus Lyssavirus, The International Committee on Taxonomy of Viruses (ICTV) has identified 17 distinct species of Lyssavirus. Based on genome sequences, they are classified as separate species, including: Aravan Lyssavirus (ARAV); Australian bat Lyssavirus (ABLV); Bokeloh bat Lyssavirus (BBLV); Duvenhage Lyssavirus (DUVV); European Bat 1 Lyssavirus (EBLV-1); European Bat 1 Lyssavirus (EBLV-2); Gannoruwa bat Lyssavirus (GBLV); Ikoma Lyssavirus (IKOV); Irkut Lyssavirus (IRKV); Khujand Lyssavirus (KHUV); Lagos bat Lyssavirus (LBV); Lleida bat Lyssavirus (LLEBV); Mokola Lyssavirus (MOKV); Rabies Lyssavirus (RABV, the most common classic Rabies virus); Shimoni bat Lyssavirus (SHIBV); Taiwan bat Lyssavirus (TWBLV); West Caucasian bat Lyssavirus (WCBV).
    Another novel lyssavirus virus, Kotalahti bat Lyssavirus (KBLV), was detected in a Species of Brandt's mouse-eared bat (Myotis Brandtii) from Finland. There is also a potential novel Lyssavirus virus, tentatively named Matlo bat Lyssavirus (MBLV), two sequences of which have been reported but remain tentative until fully identified. In addition to classification by species, these viruses can be classified into distinct genetic lineages (phylogroups) based on genetics, using nucleoprotein genes, phylogenetic and antigenic data.
    At least two genetic lineages can be identified by phylogenetic topological analysis (Figure 1). The phylogenetic tree of genetic lineage I is divided into two main branches (branche), One clade includes species from the Palearctic and Indo-Malay regions (ARAV, BBLV, EBLV-2, KBLV, ABLV, GBLV and KHUV); The other branch is composed of EBLV-1, DUVV, IRKV and TWBLV. Genetic lineage II consists of African Lisha viruses: LBV, MOKVm and SHIBV. The most genetically differentiated Lysa viruses were provisionally classified into genetic lineage III and subdivided into two clades, which were collected from Europe to Africa, including WCBV-MBLV and Ikov-LleBV respectively.
    In terms of sequence similarity, the mean nucleotide sequence similarity of viral glycoprotein genes in genetic lineage II was the highest (71.5%), and that of viruses in genetic lineage I was 70.3%. The average nucleotide sequence similarity of the viruses preliminarily classified as genetic lineage III was 58.2%, indicating that these viruses were quite different. The mean nucleotide sequence similarity of viruses in genetic lineage III was lower than that of viruses in genetic lineage I and GENETIC lineage II (54.1% and 54.5%, respectively).
    Similar to evolutionary and genetic data, antigenic analysis has identified several antigenic groupings comparable to genetic lineages (Figure 1). The degree of differentiation in these genetic lineages can be used to predict the degree of cross-protection that existing rabies vaccines based on RABV, the most common classic rabies virus, may provide. Although different individuals have different immune responses to vaccines, it is generally believed that conserving viral neutralizing antibody (VNA) levels equal to or greater than 0.5 international units (IU/mL) are positively associated with serum transformation after RABV vaccination. With the exception of RABV, approved rabies vaccines appear to offer largely protective immunity against lyssa virus of genetic lineage I, with the least protection against IRKV. In conclusion, the level of VNA required for protection against non-RABV Lyssa viruses is unclear.

The mechanism of package disinfection is to destroy the protein of the virus, denaturate it and lose its ability to spread, rather than decompose the nucleic acid -- so the package can still detect the nucleic acid virus after disinfection, but the virus has no infectious ability at this time. In March 6, zhejiang province epidemic prevention and control work press conference, provincial center for Disease Control and Prevention and environmental health deputy director Lu Ye said. To express the disinfection, he said, according to the existing scientific evidence that conform to the level of medical health disinfector, of which will be coronavirus variants are inactivated effect, will be coronavirus is composed of protein, nucleic acid, chemical disinfection way is mainly to virus inactivated, mechanism is destroy the virus protein, make its degeneration loses its ability to spread, It doesn't break down nucleic acids. "So that's why sometimes we can sterilize the package and still detect nucleic acid fragments, but the virus is no longer infectious." He expresses, to the public, choose to disinfect a product to basically see outer package whether to mark "sanitization license of disinfect product" these a few words. Secondly, choose the product instruction label for environmental object surface disinfection, you can pile up express and express and its place for environmental object surface disinfection. Lu Ye reminds, everybody don't forget to unpacking, transport tools, such as a cart and to use in the process of sign after receiving STH of pen and phone also need disinfected, "charge express a look is a little thing, but there are a lot of details in relation to the prevention of each of us, hope you fine point, everyone to do a good job of epidemic prevention, guard against all kinds of possible risk factors."

As a clinician in the department of hepatology, this is one of the questions I often hear when I communicate with patients with hepatitis B: Dr. Fang, I am taking antiviral drugs, but I accidentally got pregnant. Can I still have this child?

Before we answer that question, let's take a look at some common sense about drug safety in pregnancy.

Before 2015, the United States Food and Drug Administration (FDA) divided drugs into five grades according to their safety during pregnancy, namely: Class A, no harm to embryos was found in animal experiments and clinical application before the drug was put on the market; Grade B: no harm to embryos has been observed in animal experiments, but the safety for fetuses has not been proved clinically; Grade C: it has been proved to have teratogenic or injurious effects on embryos only in animal experiments, but lacks corresponding data for human beings; Grade D: It has been confirmed clinically that it is unsafe for human embryos, but the drug has certain clinical efficacy for pregnant women and no safe drug can replace it, so it should be used after weighing the advantages and disadvantages; X level: clearly prove to have harm to embryo, gestation period is forbidden. In fact, only 0.7 percent of class A drugs are classed as CLASS B, and most drugs are classed as CLASS C.

Because preclinical drug doses used in animal trials are often dozens or even hundreds of times higher than those used in post-clinical trials, the results of animal trials do not prove the same for humans. Class C pregnancy drugs do not mean that they cannot be used during pregnancy, the FDA notes. Doctors, pregnant women and their families often overestimate the risks of drugs to fetal development during pregnancy. The drug may be used if the assessed benefits outweigh the risks to the pregnant woman.

In recent years, the classification of pregnancy safety of drugs has aroused a lot of controversy, and it is believed that such classification is not reasonable and may cause misunderstanding of drugs by doctors, pregnant women and their families. Therefore, since 2016, THE US FDA has no longer made equal classification of pregnancy safety of newly marketed drugs. The results or data on the use of drugs in animals or humans during pregnancy are simply written in instructions for doctors to use.

Clinical anti-hepatitis B virus drugs have two types: oral antiviral drugs and interferon injection. With the passage of time, some oral antiviral drugs with large clinical side effects, poor antiviral effect and easy drug resistance are gradually replaced by drugs with small side effects, good efficacy and low incidence of drug resistance. At present, there are three kinds of first-line oral antiviral drugs recommended by domestic and foreign guidelines: entecavir, tenofovir fumarate, and propofol tenofovir fumarate, as well as polyethylene glycol interferon injections.

Below, I will introduce the pregnancy safety of these antiviral drugs for hepatitis B mothers one by one in combination with the latest version of hepatitis B prevention and treatment guidelines in our country:

1. Entecavir (ETV)

It was the first first-line oral anti-hepatitis B drug to hit the market (2015), and was classified as a class C drug for pregnancy by THE US FDA at the time of marketing, which is not recommended for use during pregnancy. The reason why entecavir is listed as C and drug is that in pre-market animal experiments, when the large dose (tens of times higher than the human dose), entecavir is observed to have certain harm to the embryo development of some animals. At doses ranging from three to 40 times the human dose, the incidence of lung tumors increased in mice. At present, entecavir has been clinically used for more than 10 years, and it is the most widely used anti-hepatitis B drug in clinic. No adverse pregnancy reaction cases have been found clinically, nor has there been a clear literature report of harm to fetal development. According to the latest guidelines for the Prevention and Treatment of Chronic Hepatitis B released in 2019, pregnant women who become pregnant unexpectedly during antiviral treatment are not required to terminate their pregnancy if they are being treated with entecavir, and it is recommended to change to Tenofovir fumarate and continue treatment.

2. Tenofovir fumarate (TDF)

It was listed in 2008 and has been in clinical application for more than 10 years. In animal experiments before TDF was marketed, it was found that the effects on animal embryo development could also be found when the dose was tens of times larger than human body. Due to the lack of data on the safety of human pregnancy, TDF was classified as a class B pregnancy drug by THE US FDA when it was marketed. Because TDF was first used for the treatment of AIDS, there have been a large number of data on the safety of AIDS pregnant women in clinical practice, and it is found to be safe for pregnancy. Existing large amounts of data also confirmed in pregnant women who applied to hepatitis b is safe for fetal development, and for taking TDF, is rare in the breast milk (only about 0.03% of the therapeutic dose), and the low bioavailability of TDF in breast milk, so such traces of TDF content in milk for newborn almost negligible influence growth and development. At present, TDF is recommended by domestic and foreign guidelines as the preferred anti-hepatitis B drug during pregnancy. It can be used before, during and after pregnancy, and hepatitis B mothers can breastfeed while taking the drug.

3. Propofol Tenofovir dipivoxil (TAF)

TAF was introduced into the market in 2016. Compared with entecavir and Tenofovir fumarate, TAF was put on the market later, because both TDF and TAF were decomposed into tenofovir (TFV) in vivo to play a role. Therefore, TDF was used for reproductive toxicity in animal experiments before marketing. TAF is safer because the dose is much smaller than TDF. At the end of 2021, researchers from the First Affiliated Hospital of Zhengzhou University conducted a multicenter prospective study to evaluate the efficacy and safety of TAF in the treatment of 103 pregnant women with chronic hepatitis B and the prevention of mother-to-child transmission of HBV. The results showed that: For pregnant women with active chronic hepatitis B and their infants, TAF is safe and effective to be administered throughout pregnancy or early in pregnancy. Therefore, TAF will also become a drug with good safety during pregnancy.

4. Polyethylene glycol interferon (PEG-IFN)

Peginterferon has been on the market since 2005 and has been contraindicated in pregnant women because of reproductive toxicity found in pre-marketing animal tests. "Peg-ifn can be used before pregnancy to complete treatment within the first six months of pregnancy, and reliable contraceptive measures should be taken during the treatment for patients with antiviral therapy indications," the 2019 version of China's Guidelines for the Prevention and Treatment of Chronic Hepatitis B states. According to limited literature reports, interferon pregnancy harms are mainly abortion, fetal growth retardation, low weight children, etc., but there are no reports of teratogenicity, so, China's guidelines also point out: "If a pregnant woman has an unintended pregnancy during peG-IFN antiviral therapy, it is recommended that she and her family be fully informed of the risks, and that she decide whether to continue the pregnancy or switch to TDF treatment if she continues the pregnancy." Guidelines in the United States and Europe are similar, suggesting changing medications and not terminating a pregnancy. Therefore, for older pregnant women, in this case, it is necessary to fully consider the patient's reproductive age, the risk of abortion and the impact of abortion on future fertility, and then decide whether to terminate pregnancy after weighing the advantages and disadvantages.

5. Other antiviral drugs

These included prior use of lamivudine, adefovir dipivoxil, tibivudine, and common interferon. Lamivudine and tibivudine have been classified as pregnancy B drugs by FDA in the past, and their use during pregnancy has been found to be safe in clinical practice. There are few data on the safety of adefovir dipivoxil in pregnancy, and there are reports that there is no effect on fetal growth and development when adefovir dipivoxil is used in pregnancy. The pregnancy safety of common interferon is the same as peg-interferon. These drugs are not recommended as first-line antiviral drugs at present because of their efficacy, side effects and drug resistance.

As mentioned above, the effect of anti-hepatitis B drugs on hepatitis B mothers is not as serious as people think, and the effect on hepatitis B fathers is even less. Therefore, hepatitis B mothers and hepatitis B fathers, do not worry too much about the safety of antiviral drugs for the fetus, the most important thing is to find a specialist before pregnancy to check and evaluate, timely safe and effective intervention when needed, in order to block the occurrence of vertical transmission of hepatitis B virus from mother to child, to avoid the transmission of hepatitis B virus to the next generation.

The COVID-19 outbreak in early 2020 has changed too many lives. The COVID-19 pandemic has been raging worldwide for a year, but it is still going strong, infecting more than 91 million people worldwide and killing nearly 2 million as of January.

The economic losses were even greater and incalculable. The continuing pandemic triggered a widespread economic recession and dealt a blow to the already booming wave of globalization. The United States, the only superpower, has fallen in front of the Novel Coronavirus pandemic, which further aggravates the domestic political turmoil and division and exposes its economic, social and institutional vulnerability.

Historically speaking, the Black Death, smallpox and cholera were the deadliest and most terrifying super plagues in human history, killing hundreds of millions of people. These devastating infectious diseases can change the fate of a nation or even the course of human history. To date, only smallpox has been completely eradicated by humans, with only partial samples of the smallpox strain remaining in the laboratory for scientific research. Plague has occasionally spread in small scale around the world, while cholera remains a risk in areas with poor sanitation and a lack of safe water.

Of the three pandemics, the Black Death had a huge impact on Europe. The Black Death, mainly from 1348 to 1451, killed tens of millions of people and nearly halved Europe's population. It was the worst plague pandemic in human history. At that time, it was found that those who were infected with the plague would have many black spots on their skin, and then the whole body would become black, delirium, high fever, and finally painful death, so this particular plague was called "black Death" by the Europeans.

Plague is a natural epidemic disease widely prevalent in wild rodents. Ancient China had already called it "plague" and had already carried out anti-rodent measures to effectively prevent it. In the middle Ages, Europeans were completely ignorant of the disease caused by plague bacteria, and Europe at that time could be said to be the paradise of rats. At that time, Europe had extremely poor public health conditions and people did not pay attention to hygiene. They defecated, urinated and littering everywhere in cities, providing a good living environment for rats. In addition, at that time, the Catholic Church in Europe thought absurdly extreme, that the cat is the angel of the devil, the servant of the witch, so the cat was killed. Lacking natural predators and good living conditions, rats in Europe thrived in cities. Contamination of the environment by rats and their fleas caused the spread of plague.

Later, Europe implemented the strictest quarantine system, isolating patients, villages, people and goods, and eventually, European countries have emerged from the shadow of the Black Death. People learned to control the epidemic of plague effectively through deratization, disinfection and strict isolation measures.

Europe in the Middle Ages was decimated by the Black Death. However, the black Death also completely shook the traditional social structure of Europe, weakened the power of feudal and ecclesiastical aristocrats, led to the revival of humanism and indirectly contributed to the later Renaissance and religious Reform. In the following two or three hundred years, Europe led the world trend, taking a leading position in science and technology, military affairs and economy, thus ushering in the era of global colonial expansion in the 19th century.

The infectious disease that had a profound impact on Chinese history was smallpox. Smallpox was a deadly virus, and it struck quickly. As early as the Jin Dynasty (220-2jin dynasty), the philosopher Ge Hong described the symptoms of smallpox in detail for the first time in his work "Urgent Prescription of Elbow Reserve". Later, with the deepening of medical understanding, song and Yuan dynasties, there have been many doctors began to prevent and treat smallpox through the kind of "human pox", "human pox" is used to blow the scab powder of the patients with pox self-healing into the nasal cavity of the inoculated, which is the most effective smallpox prevention method before the invention of "vaccinia". By the Ming Dynasty, most adults in the Central Plains had certain immunity to tianhua, and only children had a higher incidence. Therefore, in each dynasty before Ming Dynasty, although smallpox always existed, the epidemic scale was not large, and it did not have a significant impact on the whole society and political situation.

Smallpox, however, had a major impact on the fate of the last authoritarian dynasty, the Qing. Smallpox played a decisive role in the succession and power game of the Qing Dynasty.

The Jurchen nationality lived in the northeast area outside Serbia, where the climate was cold and dry. Their lifestyle was mainly nomadic and hunting, and they had little contact with the Han people in the south, so smallpox virus was rarely spread in these areas. At the beginning of the qing army's entry into the pass, the number of smallpox patients in the eight Banners increased with each passing day because of the increased contact with han people due to accultation with the soil and water.

Three of the twelve Emperors of the Qing dynasty died of smallpox. They were Huangtaiji and Shunzhi in the early Qing Dynasty and Tongzhi in the late Qing Dynasty. Another one that could not be ignored was the powerful "Auxiliary Prince Shu Deyu" in the early years of Shunzhi in the early Qing Dynasty.

Dodor, the brother of dourgun, the regent of the emperor's father, also died of smallpox.

The sudden death of these three emperors and an auxiliary prince had a great impact on the political situation of the Qing Court at that time.

Huang Taiji died of smallpox a year before the Qing army entered the Pass. At that time, The disease developed rapidly and he died suddenly before he could stand up. As a result, fu Lin's succession to the throne was an unexpected result of the power struggle. Although Fu Lin, Huangtaiji's ninth son, succeeded to the throne, the highest power was in the hands of duergun, the regent.

In the eighth year of shunzhi, fu Lin, the fourteen-year-old Shunzhi emperor, was in power. Although he only reigned for ten years, he died of smallpox at the age of twenty-four. But it was also because of smallpox that Shunzhi came to power. Shunzhi six years, the Second person in the Qing Court, power second only to the regent Duergun "assistant Prince Shudeyu" Duduo died suddenly of smallpox. The following year, Duoergun died suddenly, opening the way for Shunzhi.

On the seventh day of the first lunar month in the 18th year of Shunzhi, emperor Shunzhi died of smallpox in the Hall of Mental Cultivation. Although he had eight sons, four of them died young (thought to have been caused by smallpox), and the eldest was the second son, who was only nine years old. Finally, eight-year-old Xuanye, the third son of the emperor, was chosen by Shunzhi as his successor, the later Kangxi Emperor. The reason for choosing him was simple: Xuanye had smallpox and was immune for life, so he did not have to worry about premature death.

In the late Qing Dynasty, emperor Tongzhi also died of smallpox at the age of 19. Tongzhi's sudden death, although there was no power struggle, caused political turmoil, but his mother Cixi continued to hold the power of the Qing dynasty, objectively played a role in helping. As a result, smallpox had a profound impact on modern Chinese history.

Cholera, on the other hand, is a disease that is still prevalent in areas with poor sanitation. Cholera is an acute diarrheal infectious disease caused by ingestion of food or water contaminated with vibrio cholerae. Cholera peaks in summer and can cause diarrhea, dehydration and death within hours. The World Health Organization estimates there are 3 million to 5 million cholera cases worldwide each year, with 100,000 to 120,000 deaths, and Africa accounts for more than 90 percent of the world's cholera cases.

There have been seven recorded cholera pandemics. In the century-plus years from 1817 to 1923, when the first cholera epidemic began, six pandemics took an incalculable toll, killing more than 38m people in India alone. The seventh cholera pandemic began in 1961. This time it started in Indonesia, then spread to other Asian countries and Europe, and in 1970 it arrived in Africa, where it has been a scourge ever since.

In the 1990s, cholera cases began to rise again. The resurgence of cholera after many years is mainly related to environmental deterioration, poor sanitation facilities, lack of clean drinking water, malnutrition and other factors in poor areas. Cholera hit Latin America in 1991, sickened 400,000 people and killed 4,000 in a single year.

As we have now begun to vaccinate against COVID-19, the spread of the Novel coronavirus virus will be brought under control, just as we have conquered other plagues. Thanks to modern medicine, the novel Coronavirus mortality rate seems to be much lower than those of these three infectious diseases, especially compared with plague and smallpox. But the Novel Coronavirus will undoubtedly go down in history as highly effective, stealthily infectious, with its wide spread and far-reaching impact on the global economy.

A new, more virulent and transmissible form of HIV has been discovered in Europe, infecting at least 109 people.

On February 3, academic journal science specialized papers to introduce the new HIV variants, the university of Oxford and the university of Amsterdam in the Netherlands, researchers in institutions such as named VB mutant strains, said its viral load is 3.5 to 5.5 times of ordinary after HIV infection, CD4 cells decreased for two times, in the case of the untreated, Intermediate stage of HIV infection is about 9 months after infection, compared with about 3 years for normal HIV infection.

The VB mutant may have existed for more than 30 years and is caused by de novo mutation of the virus rather than gene recombination. Its origin, virulence and infectivity… There are still plenty of mysteries to be solved.

The virus has been around for 30 years

In a previous study, researchers found that 17 hiv-infected people, 15 from the Netherlands, were infected with a new and unknown HIV mutation. When the study was expanded, 92 additional cases of infection with the new mutant strain were found.

Let's start with some data on the VB mutant.

Without treatment, CD4 cells decreased to 350 cells/mm³ in patients with the VB mutant in about 9 months, compared with 36 months in patients with conventional HIV. And enter the commonly recognized onset of AIDS, VB mutant infection about 2 to 3 years, routine infection about 6 to 7 years.

To explain the surge in virulence, the researchers looked at the mutant genome of the VB strain for clues. The report shows that the VB mutant carries a variety of mutations, with significant changes in its genome affecting nearly 300 amino acids. However, the genetic causes of increased virulence cannot be determined at a specific point due to their dispersion.

The mortality rate after treatment was similar to that of conventional HIV infection. This is because existing antiretroviral drugs, the standard treatment for HIV, are not less effective against VB mutant strains. At the same time, this may be one of the reasons why the VB mutant strain has not completely replaced conventional HIV.

In short, the virulence of the VB mutant and the duration of treatment are mutually affected. Due to the virulence of the VB mutant strain, both morbidity and mortality increase when untreated. However, due to the stronger virulence and shorter incubation period of VB mutant strain, the time for patients to show symptoms is faster, which accelerates the timely intervention of medical treatment.

How is the VB mutant produced? The researchers have yet to draw a definitive conclusion.

Unlike the emergence of drug-resistant bacteria as a result of antibiotic overuse, it is not a result of "survival of the fittest", as existing AIDS drugs remain sensitive to the VB mutant. Researchers have tentatively concluded that the mutation is likely due to the fact that the original infected person did not receive treatment for a long time.

Using statistical models of the data, the researchers found that the VB mutant was likely to have appeared in the Netherlands as early as the 1980s and had been spreading faster than other mutants in the early 2000s, but the rate of spread slowed significantly after 2010.

For similar reasons, rapid detection and intervention also reduced the risk of high-risk transmission of HIV infection, while screening and treatment were not fully available.

"Possible more deadly Novel Coronavirus variant"

"Is it 'sleep on brushwood and taste gall', or short high-gloss burning?" In an accompanying editorial, Professor Joel Wertheim, an expert on viral evolution at the University of California, San Diego, said the less virulent HIV is and the lower its viral load, the longer its host lives but the less able it is to spread. On the contrary, the host enters the onset stage more quickly and is more transmissible, but the transmission time is shorter.

Naturally, viruses tend to choose the middle ground. However, medical intervention has made the factors more complicated, and the selective drivers behind the evolution of HIV are still not fully explained.

The scientists hope to clarify the balance between virulence, infectivity and treatment. Previous studies have tried to determine the best time to treat HIV. One idea is that:

Without treatment, HIV is less likely to mutate into a more virulent form because the host becomes ill quickly, limiting transmission opportunities. And once too early, too wide spread treatment, may accelerate the emergence of highly virulent HIV.

The simple answer is, "If you're going to be blocked, you might as well be more virulent."

Credit: Cavallini James/BSIP/Science Photo Library

But the VB mutant was created before drugs were widely available, and this time the researchers suggest a different conclusion: widespread treatment helps prevent new virulent variants, because treatment reduces the progression of transmission, regardless of virulence.

In other words, if viruses can't replicate, they can't mutate.

The researchers also stressed that because the VB mutant is more harmful to the body's immune system, early diagnosis and early treatment are crucial.

In addition, this research is further extended to the field of novel Coronavirus. Scientists believe the finding points to the risk of a more deadly novel Coronavirus variant.

"The emergence of Omicron contributes to the idea that novel Coronavirus is becoming less lethal, but that is not how novel Coronavirus has evolved." Dr Emma Hodcroft, a molecular epidemiologist at the University of Bern in Switzerland.

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Professor Chris Wymant, one of the authors of the paper, said the discovery of the VB mutant was a warning: "We should not underestimate the evolutionary potential of viruses or be overconfident that they will only evolve in milder, less virulent directions."

"Since the first AIDS discovery in the United States in 1981, the viral load of patients at diagnosis has increased every decade, both before and after treatment became widely available." Professor Joel Wertheim said it was unclear how the virus would evolve in the future in response to human "siege".

But he also stressed that the emergence of a more virulent and contagious FORM of HIV was not a public health crisis and that existing methods of screening and treatment could still be effective.

Greece has reported 11,124 new cases of COVID-19 in the past 24 hours, bringing the total number of confirmed cases to 1,920,992, the Country's national Public Health Organization announced on Monday evening. A total of 23,372 people have died, with 97 new deaths reported.

A paper published recently in the Annals of Internal Medicine, a leading international scientific journal, has reportedly mentioned the possibility of re-infection in novel Coronavirus patients. Stavrola Paschu, Dioradora Pasaldobulu and Sanos Dimopoulos, professors at the University of Athens School of Medicine, summed up the main points of the paper.

The scientists involved in the study compared the risk of reinfection after infection with the Novel Coronavirus with the risk of infection in previously uninfected individuals when exposed to the Novel Coronavirus. The results showed that people who recovered after infection had an 80 to 98 percent lower risk of contracting the primary or alpha-variant of the virus compared to people who had not been vaccinated and had never been infected.

People who were previously infected had an 87 percent lower risk of reinfection, according to an analysis of the data. Meanwhile, infected people can maintain an 80% response rate to antibodies for seven months.

The results of the study did not cover patients infected with Delta or Omicron, and the scientists said further studies would be carried out on the efficacy and validity of antibodies in patients infected with the mutated strain.

Can antibiotics kill viruses as well as bacteria?

A: No, antibiotics can only kill bacteria, not viruses.

Why aren't antibiotics antiviral? Because viruses have no cell wall, they are a class of tiny, non-cellular microorganisms that contain a single nucleic acid (DNA or RNA) type and must host and replicate in living cells. There are four mechanisms of bactericidal action of antibiotics: inhibition of bacterial cell wall synthesis, interaction with cell membrane, interference with protein synthesis and inhibition of nucleic acid transcription and replication. In layman's terms, antibiotics are drugs used to treat various bacterial infections or to suppress infections by disease-causing organisms.

Israel has reported its first case of Florona, or simultaneous infection with novel coronavirus and influenza viruses, according to media reports on 2 January. The potentially dangerous case was found in an unvaccinated young pregnant woman in Israel.

"On arrival she was diagnosed with both influenza and novel coronavirus infections. We tested again and the results were still positive." The patient's symptoms were 'mild' and she was discharged Thursday, said Dr. Arnon Vizhnitser, director of obstetrics and gynecology at the hospital.

"Last year, we had no flu cases in pregnant women or women giving birth. Now, we are seeing an increase in both novel coronavirus infections and influenza cases, with more and more pregnant women contracting influenza." "It's a huge challenge, dealing with a woman who has a fever during childbirth, and you don't know if it's coronavirus or flu," Says Wiznitser. Because the symptoms of influenza and novel coronavirus infections are very similar, the virus is currently attacking the upper respiratory tract."

Israel's Ministry of Health is reportedly evaluating the case to determine whether the combination of the two viruses could cause more severe illness. Health officials estimate that there may be many patients with dual infections who are not diagnosed.

Israel has seen a new wave of outbreaks as the Omicron variant swept through. According to projections, the number of new infections could peak at more than 50,000 a day during the current wave of the epidemic.

Nahla Abdul Wahab, a doctor at Cairo University Hospital, said the dual infection of the Novel coronavirus and influenza viruses could indicate that the patient's immune system has broken down because the body is letting in both viruses at the same time.

At the same time, as the global spread of Omicron accelerates, scientists are assessing the potential risk of various combinations of virus and novel Coronavirus variants. Paul Burton, chief medical officer of vaccine maker Moderna, warned last month that a combination of the Delta and Omicron variants could create new, more dangerous viruses.

What is the mode of transmission of novel Coronavirus?

Virus is a kind of non-cellular microorganism without complete cell structure, and must live in the cell parasitical, thereby duplicating and developing. From a scientific point of view, viruses are narrowly defined as "living organisms" that, once out of their host cells, quickly fail to adapt to their environment and die. So in order to survive, the virus has to infect. Unfortunately, this time the human body is one of the Novel Coronavirus infectious organisms.

1. Droplet transmission: droplets from coughing, sneezing and talking enter the surface of susceptible mucosa;
2. Contact transmission: Touching your mouth or nose after touching something that an infected person has touched can lead to transmission of the virus.
3. Airborne transmission: pathogens can remain infectious even after being spread over long distances;
4. Fecal-oral infection: that is, rotavirus exists in the feces of patients, and often pollutes water, food, clothing, toys, utensils, etc., after discharge. When healthy people come into contact with these items, they will enter the human body through the hand and mouth way, causing digestive tract lesions.

How does the Novel Coronavirus infect us?

We can think of the lung as a tree. Trees have trunks, branches, branches, and leaves. Lungs also have windpipes, bronchi, and alveoli. In trees, the leaves photosynthesize, sending nutrients back to the whole tree;

In the lungs, air passes through the various levels of the trachea, and eventually the alveoli allow oxygen to enter the blood.

The alveoli are not single, but in clusters, covered with blood vessels. It is these blood vessels that carry carbon dioxide to the alveoli (and eventually exhaled) and carry oxygen from the alveoli to the heart, where it flows throughout the body.

The so-called "COVID-19" is pneumonia caused by the Novel coronavirus infection. If your hand is caught in a door, swelling can quickly develop. This is also inflammation, which is essentially a lot of protein-rich fluid seeping into tissue space. When you clamp your hand, the fluid enters the tissue space of your finger and makes it swell up. In COVID-19, these fluids permeate between the alveoli and blood vessels, blocking the membrane of respiration and infiltrating the alveoli, blocking the normal exchange of oxygen. This is why some infected people experience swelling in their lungs when they press on them. For critically ill novel coronavirus infections, there is inflammation all over the lungs, blocking most of the hundreds of millions of alveoli, leaving the body starved of oxygen and unable to breathe. In severe cases, respiratory failure can occur, and ARDS can occur.

That is the working principle of ARDS, the novel Coronavirus critical death principle.

How important is immunity to preventing Novel Coronavirus?

Immunity is like an army in the body. It recognizes foreign objects (viruses, bacteria, etc.) when they invade and "fights" them when necessary. A small cut or common cold can heal itself over time.

Academician Zhang Boli also said, "In fact, we get this disease because it is the result of the game and struggle between the virus and the immune system of the human body. When the virus wins, it often gets sick. Therefore, if the resistance is improved, it is not easy to be infected, even if the infection is mild. So, in the same environment, people with low immunity are more likely to get sick than those with strong immunity!

So at this particular time of the epidemic,

How do we "activate" the body's immunity

Against Novel Coronavirus?

5 tips teach you to enhance immunity!

Eat healthy: Get enough nutrition

Staying at home, "healthy eating" is particularly easy to overlook: some people eat more casual, often full meal hungry meal, meal time irregular; Others eat with open stomach; Because the person buys vegetable inconvenient, and eat everyday more onefold, the choice that does not notice food and match, and caused nutrition partial waste. But in the face of the epidemic, we should pay more attention to the reasonable collocation of food, in order to ensure adequate nutrition intake, for the immune system to provide adequate material support!

The normal synthesis and operation of immune cells in our body are inseparable from the support of a variety of nutrients, so through dietary approaches, follow the relevant healthy dietary principles, with high-quality nutrition supply, can also help the body better enhance immunity!

Sleep regularly to prevent your immune system from weakening

Regularly skimping on sleep can lead to a sharp drop in the number of immune cells your body produces. Researchers at the University of Chicago found that people who slept only four hours a night had 50 percent less flu antibodies in their blood than those who slept seven to eight hours.

Action: Not getting enough sleep can lower your immune system, but it doesn't have to be eight hours, just waking up feeling rested in the morning.

Moderate exercise: stimulate the improvement of immunity

Epidemiological studies have shown that people who exercise regularly and moderately have a significantly lower risk of respiratory infections than those who sit for long periods of time. Foreign studies of runners show that they have significantly fewer colds per year and fewer total cold days.

Exercise can affect many aspects of the immune system to help boost immunity. Moderate exercise stimulates immunity, but if you exercise too much, will also lower immunity, so exercise must be moderate. For special periods, indoor exercise is recommended.

Be normal: Don't let panic overwhelm you

The outbreak of the epidemic, causing many people to panic, keep a good state of mind, can also improve our immunity. Studies at home and abroad show that if the mind is often in a state of anxiety, then autoimmune will be relatively low.

Experts point out that long-term emotional stress, will make the body become weak, and weak people are prone to infection. Because this kind of emotion can have a bad effect on the immune system, causing a series of brain reactions. We should actively prevent infection, pay attention to the emotional, psychological and behavioral reactions of ourselves and even our families, maintain a normal mind and stabilize our emotions.

Do not abuse drugs: induce bacterial drug resistance

Experts say there is no medical proof that antibiotics and anti-flu drugs protect against COVID-19. Self-medication is not recommended. Antibiotics do not kill or inhibit viruses, while abuse of antibacterial drugs will cause adverse drug reactions and induce bacterial resistance, and reduce human immunity, but will harm the health of the body.

Of course, usually love to drink often smoke have bad life habits should also try to avoid oh ~