Recently, many places across the country have entered the "steaming and baking" mode
Even if you hide indoors or in a shady place
I also feel unbearably hot
In the coming July
High temperatures will become the norm
In the face of days of high temperatures
Do you have air conditioning in your house?
But be careful
If the air conditioner has been idle for a long time, it can be used directly without cleaning
It can be harmful to your health!
Let's take a look at the health hazards in the air conditioner↓↓↓
Happen one after another! Be careful when blowing air conditioners in summer
Recently, Changsha Central Hospital has admitted two patients with Legionella pneumonia one after another, and the cause of the illness is related to air conditioning.
Ms. Yao (pseudonym), a 32-year-old citizen of Ningxiang City, has not cleaned the air conditioner at home for more than half a year, some time ago the heat was unbearable, she used the air conditioner at home for two days, but she did not expect to have cough, phlegm, high fever, chills and other symptoms, after initial treatment did not work, the condition worsened and transferred to the respiratory and critical care medicine department of Changsha Central Hospital. After asking about her medical history, the doctor learned that Ms. Yao's immunity had been low due to a pre-existing illness. Combined with the results of physical examination and related auxiliary examinations, the patient was preliminarily judged to have severe community-acquired pneumonia. However, after general anti-infective treatment, the patient's condition did not improve, but gradually worsened, with recurrent high fever and abnormal function of multiple organs. The doctor finally diagnosed severe Legionella pneumonia by analyzing the patient's orange-red sputum, intrapulmonary and extrapulmonary manifestations, and improving the etiological examination. After targeted adjustment of medication, the patient's condition improved rapidly, the body temperature gradually returned to normal, and various indicators gradually recovered.
Source: Changsha Central Hospital subscription number
Ms. Yao was admitted to the hospital at about the same time as Mr. Zhou (pseudonym), a citizen of Changsha. Mr. Zhou had previously traveled by car. Because of the hot weather, he turned on the car air conditioner, which had not been cleaned for a long time, and spent more than ten hours in the car every day, and after returning he had fever, cough and other symptoms similar to "cold". Therefore, he was admitted to the Department of General Medicine of Changsha Central Hospital for treatment. During the examination, the doctor found that Mr. Zhou had a serious infection in his lungs. Antibiotic anti-infective treatment was ineffective, and the patient continued to have fever and abnormal manifestations of apathy. After learning about the medical history, the doctor judged that Mr. Zhou might be infected with Legionella bacteria, and then completed the bronchoscopy, took a sample of alveolar lavage fluid, and finally found the pathogen: Legionella pneumophila, and made a clear diagnosis of Legionella pneumonia. The doctor immediately adjusted the treatment plan and switched to a first-line drug that can cover Legionella pneumophila to fight the infection, and the patient's body temperature gradually decreased, and the body temperature returned to normal the next day, and he was discharged from the hospital after follow-up treatment.
Source: Changsha Central Hospital subscription number
In fact, it is not new to be "blown into" the hospital by an air conditioner that has not been cleaned for a long time. In 2021, Mr. Li, a 37-year-old in Yichang, Hubei Province, was also admitted to the ICU because of a bacterial infection caused by not cleaning the air conditioner before using it, and even used life support equipment such as ECMO (artificial lung), hemodialysis machine, and ventilator.
Source: Weibo
How dirty is an uncleaned air conditioner?
If your air conditioner has been used for many years but has never been cleaned, then now you open the air conditioner cover, find its filter, and touch it with your hands, is it a thick layer of dust? If the years are a little longer, not only the filter, but also the air outlet may be dusty.
This dirt is not only made of dust, but also mixed with mites, bacteria, viruses and other microorganisms. This is because after the air conditioner is used for a period of time, the tiny dust and microorganisms in the air will pass through the filter screen, enter the inside of the air conditioner, and adhere to the condensate on the heat sink and collect on the heat sink. Not only that, the humid environment inside the air conditioner also provides good conditions for these microorganisms to reproduce. Blowing such an air conditioner for a long time, it is easy to get sick.
Image source: "Analysis of Microbial Species and Temperature and Humidity Control of Air Conditioning System"
Previously, the Indoor Environment and Health Branch of the Chinese Society of Environmental Sciences conducted a household survey on household air conditioners in Beijing and Shenzhen, and found that 88% of air conditioners had a total number of bacteria in their radiators, and the bacterial content per square centimeter reached 288~1200CFU (CFU, colony forming unit), and the bacterial content was more than 60 times that of the toilet!
How dangerous is Legionella infection? Severe can be fatal!
Legionella is an aerobic gram-negative bacillus that is widely found in nature in natural water sources such as rivers and lakes, in humid environments such as soil, and can also multiply in man-made water systems such as hot and cold water pipes. The first outbreak of Legionella infection occurred in 1976 at the Philadelphia Veterans Convention, and once the infection is usually severe, 50% of patients need to be admitted to the intensive care unit for treatment, and the case fatality rate can be as high as 30%.
The air-conditioning cooling water system in the central air conditioner has a suitable water temperature and a large amount of organic matter, which provides a suitable environment and nutrients for the growth of Legionella. Therefore, 90% of Legionella bacteria are easy to hide in the microecological environment formed by the accumulation of sediments in the air-conditioning cooling water system, forming a bacterial colony containing biofilm and growing in an attached manner. In household vertical or wall-mounted air conditioners, filters and radiators are the most suitable living environment and potential source of Legionella growth. In the process of air conditioning air supply, Legionella bacteria can be dispersed into the air in the form of aerosols, which can be inhaled by the human body and cause disease, resulting in a series of atypical pneumonia symptoms.
What are the manifestations of Legionella infection?
The main clinical symptoms of Legionella infection are mainly lung lesions, but it can also cause damage to multiple organs such as digestive system, urinary system, muscular system and nervous system, so it increases the difficulty of Legionella diagnosis.
β-lactams and aminoglycosides cannot penetrate cell membranes, so the treatment effect is poor, and the commonly used drugs for Legionella infection are quinolones, macrolides, doxycycline, tigecycline, cotrimoxazole and rifampicin.
Rapid detection and rational use of drugs can effectively inhibit the production of drug-resistant strains, and the course of treatment should not be too short, as it is easy to cause recurrence, and it is generally recommended to carry out 2 weeks to 3 weeks of treatment according to the body's immune status.
Hypersensitivity pneumonitis caused by blowing air conditioners is equally common
Every summer is the season with a high incidence of hypersensitivity pneumonia, which is also closely related to the daily use of air conditioners. The air conditioning filter that has not been cleaned for a long time is easy to accumulate a large amount of dust and dust mites, and the humid air conditioning environment is easy to breed a large number of bacteria, etc., which are allergens for the human body, and the human body can easily lead to the occurrence of lung allergies after inhaling the lungs.
Hypersensitivity pneumonitis is mainly manifested by cough, fever, and in severe cases, dyspnea. Symptoms can appear 3~6 hours after human inhalation of allergens, and symptoms generally improve within a few hours after acute patients get rid of allergens, but it takes several weeks to fully recover, and repeated attacks can lead to pulmonary fibrosis. Symptoms persist for days to weeks in subacute patients, and hospitalization is required in those with progressive disease. Chronic patients can have symptoms such as cough and dyspnea for months to years, and in severe cases, respiratory failure can develop.
If you want to prevent hypersensitivity pneumonitis, you should regularly clean and disinfect the air conditioner in your home and workplace, open windows frequently for ventilation, and insist on physical exercise to enhance your body's immunity, maintain a good mental state, and drink more water, which can greatly reduce the occurrence of hypersensitivity pneumonitis.
How often is the best time to clean an air conditioner?
Zeng Xiaopeng, director of the Beijing Municipal Center for Disease Control and Prevention, reminded everyone that the air conditioner should be cleaned before use, the central air conditioner should be tested regularly, and professional disinfectants should be used to prevent respiratory tract infections caused by germs and mites accumulated in the air conditioner.
In the process of using the air conditioner, it is best to take out the filter and clean it every half a month, and wipe the air outlet clean. Even if you want to save trouble, the filter should be cleaned at least twice a year, that is: once a year before the air conditioner is turned on for the first time, and then once after the air conditioner decides not to use it again. For fins, the air conditioner can be cleaned every 2~3 months.
If you've already used it before you clean it, it's too late to clean it. Whether it is wall-mounted, vertical cabinet or central air conditioning, we can choose professional air conditioner cleaning and home cleaning. If you want to clean yourself, there are three areas to focus on: the air outlet, the filter, and the fins (i.e. the heat sink).
The air outlet is exposed, its cleaning is very simple, take a soft cloth dipped in detergent, gently wipe it clean, and if you can't wipe it, you can change a soft-bristled toothbrush to wipe it.
But the filters and fins are installed inside the air conditioner, and to wipe them down, it involves removing the air conditioner. It should be noted that the fins are relatively fragile, and wiping them too hard may cause the fins to deform, so it is not recommended to wipe them with a rag, and you can choose to purchase a "fin brush" to sweep the dust off the fins.
It is comprehensively compiled from Popular Science China, Learning Power, Changsha Central Hospital Subscription Number, Jiangxi Chest Hospital, Beijing Daily, "Analysis of Microbial Species in Air Conditioning System and Its Temperature and Humidity Control", etc