This article comes from WeChat public account: fruit shell (ID: Guokr42) , author: Xie nini
When will the new coronavirus pneumonia epidemic end? This is probably an issue that everyone is currently paying attention to.
This epidemic is occasionally compared to SARS 17 years ago. SARS coronavirus landed in Guangdong, China in November 2002. After detonating China, it quickly spread to neighboring countries such as Vietnam and Singapore, and eventually spread to 29 countries and regions around the world. According to the World Health Organization’s (World Health Organization, WHO) , as of July 2003, there were a total of 8096 confirmed diagnoses worldwide, of which 774 died. .
How much do you remember about SARS 17 years ago? Photo by Ren Chenming / Phoenix.com
So, how did SARS disappear that year?
When does SARS come and go?
On February 11, 2003, the WHO received a report from the Ministry of Health of China describing an acute respiratory syndrome. The report states that 305 cases have occurred in Guangdong Province, of which 5 have died. Retrospective studies suggest that the first case occurred on November 16, 2002. People don’t know about this disease, only can be determined that this is not some kind of flu, and the patient’s symptoms are atypical pneumonia (SARS is actually “atypical pneumonia” Of one) .
The first publicly reported SARS patient was a 64-year-old Guangdong doctor. The patient traveled to Hong Kong before February 21, 2003 and checked into Hotel M. When he was in Guangdong five days ago, he felt slightly unwell. After visiting Hong Kong for a day while playing, the patient’s symptoms worsened and he was sent to the intensive care unit for respiratory failure. He had previously treated patients with atypical pneumonia in Guangdong, and he told doctors that he was worried that he had contracted a “very fatal disease.”
SARS then became a pandemic in Hong Kong due to a sexual outbreak among family members in contact with him, tourists in the same hotel, and medical workers who treated him. Tourists from the same hotel came from all over the world, and they inadvertently brought SARS to Canada, the United States, Singapore, Vietnam, and Ireland. (Figure 1) . In the end, SARS cases occurred in 29 countries and regions around the world.
Hotels that SARS Coronavirus “connects the world” M ｜ Reference [1]
Global Outbreaks
In mid-March 2003, WHO defined the main symptoms of the disease, including high fever, cough, shortness of breath or difficulty, and named it severe acute respiratory syndrome. (severe acute respiratory syndrome) , also known as SARS. At the same time, the WHO issued a global alert announcing that SARS has become a “global health threat” and that it is necessary to join the health departments of multiple countries to curb the disease epidemic. Before further clarifying the pathogen, WHO recommends isolating SARS patients. In view of the SARS epidemic in China, Singapore, and Canada, WHO recommends that airlines perform health checks on passengers on routes departing from the outbreak area; in April, the WHO issued a number of travel recommendations.
No new flight-related cases have been reported after health screening of passengers | Pixabay
Although Chlamydia infection was found in 2 deaths in Guangdong, Chlamydia was once considered to be the cause of SARS, but with more and more cases, researchers have gradually locked in the “true murder”. On April 16, after completing the sequencing of the genome, they announced that this is a brand-new coronavirus: SARS-CoV -at this point, the new coronavirus of that year finally showed its true face. In addition, in a study published on May 23, researchers detected a virus highly related to the SARS virus in civets at the game market; plus more than one-third of previous cases were in the catering industry. This study further advances the relationship between SARS outbreaks and food wildlife.
The SARS epidemic peaked in early May. April 23, total global reportsOver 4,000 cases were reported, reaching 5,000 on April 28, more than 6,000 on May 2, and more than 7,000 on May 8—an average of about 200 new cases per day. Subsequently, the rate of new infections slowed; by June, the number of new infections had been reduced to a few cases per day.
Curve of SARS cases (orange) and death cases (red) based on WHO data | Phoenix7777 / Wikimedia Commons
At the same time, WHO has successively removed multiple cities from the list of “regions where local spread has occurred recently” . On June 24, for Beijing, where the outbreak was most severe, WHO cancelled travel advice for Beijing and deleted it from the list of local transmission areas; at this time, the last confirmed patient from Beijing was isolated and has passed more than 20 days. After removing Toronto, Canada, and Taiwan, China from the list of local transmission areas, on July 5, 2003, the WHO announced that SARS outbreaks had been controlled globally, but vigilance still needed.
Small-scale outbreak
The large-scale SARS epidemic ended in the second half of 2003 and the first half of 2004. But four small-scale outbreaks still occurred . Three of them were related to the coronavirus laboratory, and one was related to contact with the intermediate host (if raccoon) . Therefore, strict control of disease-causing virus strains and control of possible animal intermediate hosts is extremely important to prevent the recurrence of SARS.
No new SARS cases have been reported worldwide since mid-2004.
Conjecture about the disappearance of SARS
From November 2002 to July 2003, SARS took a full 9 months from its inception to almost extinction. Why did SARS eventually disappear? After 17 years, there is still no definitive answer to this question. However, the following factors and speculations can provide us with a lot of inspiration.
Achievements in quarantine and prevention
From the perspective of infectious diseases, infection has three elements: the source of infection, the route of transmission, and the susceptible population. In the case where there is no vaccine to protect the susceptible population, only strict isolation of the SARS patient as the source of infection and cut off the transmission route ( For example, wearing surgical masks or N95 masks, gloves, protective clothing, hand washing, etc.) can control the spread of the virus.
Before the WHO Global Alert was issued in March 2003, Singapore’s first SARS case was hospitalized. Because there was no early warning, the patient was admitted to a general ward without isolation, and more than 20 contacts were infected in the hospital. After the hospital adopted strict infection control, there was no transmission of SARS in the hospital.
Isolation and prevention are also important for this epidemic | Pixabay
It is worth noting that once the hospital ’s infection control is relaxed, SARS can recur, and the second SARS outbreak in Canada is related to this. A hospital for SARS patients in March 2003Due to inadequate infection control, failure to detect and isolate all SARS patients, a fracture patient in the same hospital was infected with the SARS virus. The unknown patient was subsequently transferred to another hospital in May, triggering a cluster infection in another hospital. Strict and continuous infection control, especially isolation and protection in densely susceptible places such as hospitals, is essential to control SARS.
The virus itself has weaknesses
In the early stage of SARS infection, the virus’s ability to spread was weak; when the respiratory symptoms were severe 6 to 11 days after the onset of symptoms, the amount of SARS virus in the respiratory secretions of the patients also reached a peak, and the virus was highly infectious. This is why it is easier for medical staff to (especially for ENT and anesthesiologists who undergo tracheal intubation) .
But at the same time, SARS virus has the characteristics of low infectivity in the early stage of infection and high infectivity when the disease gets worse. It is helpful for medical staff to identify patients as soon as possible and take precautionary measures before the infectivity increases / strong> to prevent and control SARS infection. If the SARS coronavirus becomes more cunning, it is more infectious in the early stage. In this case, early patients are likely to be difficult to identify because of atypical symptoms, and the virus will quickly spread to the vulnerable population silently .
Coronavirus under electron microscope | Dr. Fred Murphy / CDC
In addition, after the second-generation cases of SARS virus are transmitted, it is rare to pass 3 to 4 generations. This may be because the pathogenicity of the virus will gradually decrease with the intergenerational transmission . Otherwise, with a SARS mortality rate of 9.6%,After the world pandemic, countless families may experience tragedies in their homes.
Seasonal Coronavirus
Coronaviruses are almost ubiquitous, but only a few of them can infect humans and even cause public health emergencies.
In temperate zones, respiratory infections caused by coronaviruses occur mainly in winter. (Of course, there are small peaks of disease in autumn or spring) Looks like the result of a particular climate. In reality, however, coronavirus infections can occur in any season. Only in the winter, everyone gathered in the house for heating, and the movement of people at various festivals was more conducive to the spread of the virus. Every winter, patients with respiratory infections in the hospital’s respiratory department and various departments are at high levels throughout the year.
Thus, there is also speculation that the SARS coronavirus abruptly stopped in the summer due to the warmer weather. However, the temperature is gradually increasing and the number of patients is gradually decreasing. It is unknown whether the two are causal; We need more observations to determine whether there are other disturbances factor.
The SARS Monument in Shenzhen Central Park | Sparktour / Wikimedia Commons
The virus is more ancient than human beings. We do n’t know where it came from or why it went away. All that human beings can win in the gambling of viruses and life is knowledge and memory. Although the SARS virus is different from this new crown virus, early detection of the outbreak, strict isolation and control, research on the characteristics of the virus, and tracking the onset of the pathogen, these 17 years of experience are also valuable assets this winter.
I hope that no winter is insurmountable, and no high summer will not come.
References:
1. Christian MD, Poutanen SM, Loutfy MR, et al. Severe acute respiratory syndrome. Clin Infect Dis 2004; 38: 1420.
2. Tsang KW, Ho PL, Ooi GC, et al. A cluster of cases of severe acute respiratory syndrome in Hong Kong. N Engl J Med 2003; 348: 1977. 3.Acute respiratory syndrome in Hong Kong Special Administrative Region of China / Viet Nam. Https://www.who.int/csr/don/2003_03_12/en/.
4. Rota PA, Oberste MS, Monroe SS, et al. Characterization of a novel coronavirus associated with severe acute respiratory syndrome. Science 2003; 300: 1394.
5. Lim PL, Kurup A, Gopalakrishna G, et al. Laboratory-acquired severe acute respiratory syndrome. N Engl J Med 2004; 350: 1740. < / p>
6. Severe Acute Respiratory Syndrome (SARS) Epidemiology Working Group. Consensus document on the epidemiology of SARS. Global Meeting on the Epidemiology of SARS 2003.
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8. Update 83 – One hundred days into the outbreak https://www.who.int/csr/don/2003_06_18/en/
9. Update 95-SARS: Chronology of a serial killer https://www.who.int/csr/don/2003_07_04/en/
This article comes from WeChat public account: fruit shell (ID: Guokr42) , author: Xie nini