Traditional Culture Encyclopedia - Weather forecast - Weather and SARS

Weather and SARS

In the early reports of SARS, there is a widespread saying that SARS virus can only survive for 3-4 hours in the ordinary environment after leaving the host. The question is what kind of environment is this: the air, the surface of objects, or the excrement of SARS patients?

Unlike bacteria, viruses lack an independent metabolic mechanism, so they cannot replicate themselves. They can only use the metabolic mechanism of the host cell, through nucleic acid replication and protein synthesis, and then assemble and proliferate in living cells. Therefore, after leaving the host cell, the survival time of the virus is limited.

However, according to the latest data provided by many laboratories published by the World Health Organization, the viability of SARS virus is far beyond people's imagination and much more tenacious than the data originally publicized.

These laboratories are the Government Virus Laboratory under the Department of Health of Hong Kong, the Queen Mary Hospital under the University of Hong Kong, the National Institute of Infectious Diseases of Japan and Marburg University.

Experiments show that the SARS virus on the plastic surface can survive for at least 2 days at room temperature and for at least 4 days in the feces of SARS diarrhea patients. A remarkable feature of SARS virus is that it is not afraid of heat or cold. Whether at minus 80 degrees Celsius or at 4 degrees Celsius, the SARS virus survives for at least 4 days (Japanese data) or even as much as 2 1 day (German data). However, at 37 degrees Celsius, the SARS virus will not live for 4 days; At 56 degrees Celsius, the survival time of SARS virus does not exceed 30 minutes.

These data imply the fact that the excrement of SARS patients is a very important source of infection, which may be more important than the well-known droplets. Therefore, it is very important to disinfect the excreta of SARS patients.

Another important hint of these data is that good personal hygiene habits, frequent hand washing and bathing with hot water and detergent are effective measures to prevent SARS.

The third implication of these data is that with the gradual increase of temperature, the SARS epidemic will gradually ease or even disappear. Exposing bedding and clothing to strong sunlight in summer can effectively kill SARS virus.

SRAS virus has strong resistance, but it does have the characteristics of not being able to withstand drying and heat. The virus can survive for 4-6 hours on absorbent materials such as wood and cloth. It can survive for 2 days on non-absorbent materials such as glass, metal and plastic. They selected several common temperatures in people's daily life to measure and found that SARS virus is very sensitive to heat. When the temperature reaches 56 degrees Celsius, the virus cannot survive for 30 minutes. SARS virus can survive for a long time in cold weather, and its activity will be weakened around 3. 5℃.

Data 2: According to related research, SARS virus can maintain its vitality for a long time in three common excreta and blood: phlegm, feces and urine. At 24℃, SARS virus can survive for about 5 days in sputum and feces, 15 days in urine and 15 days in blood. Under indoor conditions, surfaces such as filter paper, cotton cloth, wood block, soil, metal, plastic and glass can survive for 3 days.

The evaluation results of several disinfectants and disinfection methods used at present show that chlorine-containing disinfectants and peracetic acid can completely kill SARS virus in feces and urine in a few minutes according to the concentration recommended by the Ministry of Health. When the distance is 80 ~ 90 cm and the intensity is greater than 90 μ w/cm2, ultraviolet irradiation for 30 minutes can kill SARS virus in vitro. Simulating the natural conditions of sunny days in Beijing in May 10 am, the ultraviolet intensity is 4 ~ 5 μ w/

Cm2, which can kill SARS virus in 3 hours in vitro. It is also found that SARS virus is sensitive to temperature, and its survival rate decreases obviously with the increase of temperature. Under the condition of serum-free culture, SARS virus can survive for 4 days at 37℃, and can be inactivated when heated to 56℃ for 90 minutes or 75℃ for 30 minutes.

Summary: SARS virus is not resistant to dryness and high temperature, and its survival time is less than 30 minutes when the temperature exceeds 75 degrees. This virus is not easy to survive in the environment of high ultraviolet radiation. Peroxyacetic acid and chlorine-containing disinfectant can quickly kill the virus.

The above information is quoted, so let's pay tribute to the medical staff and scientists who have been and have been fighting the virus! !

SARS

Atypical pneumonia (SARS) refers to pneumonia in which the exact source of disease has not been found and the pathogen has not been clearly defined. At present, it refers to the SARS epidemic in China in 2003.

In 2003, there were some twists and turns in the naming of SARS in China because the medical department could not find a clear cause. At first, the medical staff gave it a temporary name-"unexplained pneumonia" (UP). For diseases with unknown causes, this diagnosis is permissible and common in clinic. Later, due to the further understanding of the epidemiology and pathology of the disease, it was known that it was an infectious pulmonary parenchymal inflammation that first occurred outside the hospital, so the diagnosis of "community acquired pneumonia" (CAV for short) was put forward. Finally, according to the clinical manifestations of patients, bacteria can't be cultured, and common antibiotics are ineffective. The diagnosis of "atypical pneumonia" finally surfaced and became the most authoritative statement in many media. However, some experts tend to think that SARS is the pneumonia caused by mycoplasma and chlamydia in the past. Because this pneumonia in Guangdong has basically ruled out the infection caused by mycoplasma and chlamydia, it can't be called atypical pneumonia, but should be called "atypical pneumonia" or "atypical pneumonia" to show the difference.

[atypical pneumonia]

Atypical pneumonia is relative to atypical pneumonia, and is usually caused by common bacteria such as pneumococcus. Typical symptoms, such as fever, chest pain, cough and expectoration. Laboratory tests show that white blood cells increase and antibiotic treatment is effective. Atypical pneumonia itself is not a newly discovered disease, it is mostly caused by viruses, mycoplasma, chlamydia, rickettsia and other pathogens. Symptoms, lung signs and blood test results are not as obvious as SARS infection, and some viral pneumonia antibiotics are ineffective.

SARS refers to a group of diseases caused by the above atypical pathogens, not a definite diagnosis. Its clinical characteristics are that the onset is hidden, mostly dry cough, occasional hemoptysis, and less positive signs of auscultation in the lungs; X-ray chest film mainly shows interstitial infiltration; Its pathogenesis is usually mild, and patients rarely die because of it.

The name of atypical pneumonia originated at the end of 1930, which corresponds to typical pneumonia, mainly lobar pneumonia or bronchopneumonia caused by bacteria. In 1960s, Mycoplasma pneumoniae was considered as the main pathogen of atypical pneumonia, but other pathogens were later discovered, especially Chlamydia pneumoniae. At present, it is believed that the main pathogens of atypical pneumonia are mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Legionella and Rickettsia (causing Q fever pneumonia), especially the first two, which account for almost 1/3 of hospitalized adults with community-acquired pneumonia every year. Most of these pathogens are intracellular parasites without cell walls, so broad-spectrum antibiotics (mainly macrolides and tetracyclines) that can penetrate into cells are effective for their treatment, while β -lactams are ineffective. Antibiotics are ineffective for SARS caused by virus.

[epidemiological history]

June, 2002165438+1October, 65438+June, Foshan First People's Hospital admitted a patient with special pneumonia. Two or three cases were found in Foshan. Since then, similar cases have appeared in Heyuan, Zhongshan, Jiangmen, Guangzhou and Shenzhen.

From June 5438 to February 65438 to May 2002, Huang Kechu and Guo Ducheng of Zijin County were admitted to Heyuan People's Hospital successively. The five medical staff I have seen have the same symptoms as the patients. Panicked people lined up in front of the major pharmacies in Heyuan. At that time, people flocked to pharmacies, but they didn't know what to buy. They just followed the trend and snapped up some antiviral drugs. Someone bought 10 boxes at once. Soon, the pharmacies in the whole city were out of stock, and people who couldn't buy medicine were even more afraid. Until 9 pm, many pharmacies closed and people were waiting in line. Some parents are rushing to school to take their children home to avoid "disaster".

On June 2, 2003, Zhongshan City admitted a similar patient. Due to the lack of understanding of this disease, medical staff did not take timely protection, and seven or eight staff members in a hospital in Zhongshan City were infected. Since 65438+ 10/6, rumors of "pneumonia epidemic" have spread in Zhongshan, and citizens have gone to pharmacies to buy medicines just in case. Some people buy dozens of boxes at a time. The reporter learned that a box of ordinary roxithromycin costs more than 10 yuan, and a better box of roxithromycin costs several hundred yuan for most citizens. The person in charge of Relay Pharmacy, the largest pharmaceutical chain in Zhongshan City, said that the number of people who came to the pharmacy to buy roxithromycin began to increase on 16, and reached a peak on 17, and half of its eight chain stores were out of stock.

On February 6, 2003, the incidence of atypical pneumonia reached its peak in Guangdong Province, with 2 18 cases found in the whole province, with a sudden increase of 45 cases, which greatly exceeded the previous one-day increase. These cases are mainly concentrated in Guangzhou, and a considerable number of them are medical personnel. "First, the staff inside the hospital sent reminders to relatives and friends, and then these relatives and friends passed them on to more social groups. From the eighth day of the first month to the tenth day of the first month, it spread widely. In Guangdong, quite a few citizens own two mobile phones. " According to the statistics of short message traffic of Guangdong Mobile, its users have sent1260,000 short messages in three days, which is fast catching up with the short message traffic from New Year's Eve to New Year's Day. The extreme flood of information has brought about disastrous social panic. From February 10 to February 1 1, the streets of Guangzhou showed a gloomy scene, with hotels, restaurants and various entertainment places deserted. On June 5438+02, even pharmacies in Beijing adopted the regulation of restricting the purchase of Radix Isatidis (two boxes of Tong Ren Tang and five boxes of other brands).

[epidemiology]

Air droplets spread at close range, and family members and medical staff may be infected when they contact with patients' secretions.

Epidemiological law: there is no difference between men and women, and young adults account for 70% to 80% in age, which is different from the frail old and young patients with respiratory infectious diseases in the past; Due to the lack of protective measures in the early stage of the disease, medical staff are at high risk of atypical pneumonia, but after taking measures, the infection rate of medical staff has dropped from about 33% to about 24%. There are cluster infections in families and hospitals.

[Clinical manifestations]

The current incubation period is 1- 14 days, with a median of 4 days.

Most people get sick four days after infection, with fever as the first symptom, and their body temperature lasts for several days above 39℃. Some people may be accompanied by headache, chills, fatigue, joint pain, body aches and diarrhea. Respiratory symptoms are obvious, with dry cough, little phlegm and occasional bloodshot phlegm. In severe cases, symptoms of dyspnea such as accelerated breathing and breath holding occurred five days later, and very few patients developed respiratory failure. If you delay the diagnosis and treatment, you may die.

The above symptoms are similar to upper respiratory tract infection, so there are four conditions for a high degree of suspicion of atypical pneumonia, namely, a recent history of being in an epidemic area of the disease or having close contact with patients; White blood cells are lower than 1000, or even decrease progressively; The chest film has different degrees of shadow; The effect of antibacterial drugs is not obvious.

Common atypical patients had close contact with similar patients two weeks before onset, or had clear evidence of being infected by others, or lived in epidemic areas, or had been to areas where atypical pneumonia was prevalent two weeks before onset. Their main clinical symptoms are fever (> 38℃), cough, rapid breathing, shortness of breath or respiratory distress syndrome, lung rales or more than one sign of lung consolidation. Laboratory examination showed that the white blood cell count in the early stage did not decrease, and pulmonary imaging examination showed patchy, patchy and infiltrating shadows or reticular changes in the lungs to varying degrees, and antibacterial drugs had no obvious effect. The patient is accompanied by headache, joint pain, general pain, fatigue, chest pain and diarrhea. Medical institutions at all levels should pay attention to exclude primary bacterial or fungal pneumonia, tuberculosis, lung tumor, non-infectious interstitial lung disease, pulmonary edema, atelectasis, pulmonary embolism, pulmonary eosinophilic infiltration, pulmonary vasculitis and other lung diseases with similar clinical manifestations.

The Beijing Municipal Government has opened an emergency telephone hotline 120. If citizens find themselves, their family members or friends with any of the following symptoms, please call the emergency number 120, 120 to provide an ambulance to the hospital for treatment.

1. fever (higher than 38℃); At the same time accompanied by headache, joint pain, general pain, fatigue.

2. Dry cough with little phlegm, occasional bloodshot sputum, rapid breathing, shortness of breath and respiratory distress.

3. There is no obvious effect after taking antibacterial drugs.

[therapy]

If you have symptoms of respiratory infection, you should consult a doctor as soon as possible. The earlier treatment, the higher the chance of recovery. The disease can be cured by timely treatment.

Before the cause is unknown, Gopra suggested that it is best to use the traditional Chinese medicine treatment method of strengthening the body resistance and eliminating evil. Or by stimulating and mobilizing the immune function of patients.

[prevention]

Avoid going to densely populated places.

Good ventilation: keep the indoor air circulating and often open the window for ventilation. Buses or taxis should be ventilated with windows.

Pay attention to personal hygiene: wash your hands frequently, keep them clean, wash your hands correctly, and wash your hands with soap and tap water for more than 30 seconds. Wash your hands after being soiled by respiratory secretions (such as sneezing). Avoid contact with eyes, nose and mouth. Wash your hands first if you need to touch them.

Pay attention to a balanced diet, exercise regularly, have enough rest, reduce stress and avoid smoking, so as to enhance the body's resistance.

Articles that are often used or contacted in public places are regularly soaked and wiped with disinfectant for disinfection.

You can wear 16 gauze mask in public places where there are many people. But there is no need to wear a mask when moving in an open place or walking on the street.

Avoid visiting patients.

Cover your nose when sneezing or coughing.

Gopra suggested that a good mood and mentality are more important than strict preventive measures. Whether you can stay away from the disease depends on your own immune ability. It is not entirely impossible to get infected with some viruses properly. The infectivity of SARS is not as terrible as people think.

What measures should I take if I have contact with SARS patients?

If a family member or friend is diagnosed as a patient with atypical pneumonia, the following measures should be taken to ensure the health of the patient's family members, contacts and others:

Under the guidance of local disease prevention and control institutions, disinfect patients' homes or places where patients have been stranded recently, including air, furniture, clothing and other items.

In order to control the epidemic situation, close contacts of patients should cooperate with disease control institutions for medical observation or relative isolation. The cycle is generally 2 weeks, try to rest at home, do not participate in group activities, and do not travel far. If you feel unwell, please see a doctor as soon as possible and take the initiative to inform you that you have had close contact with similar patients.

Avoid visiting patients. When you need to visit, you must wear a mask. Pay attention to physical condition, personal hygiene and wash your hands frequently.