‘Take a coat’: the cold can cause the flu and colds? The doctors explain – 05/18/2022

A cold wave is hitting several states in Brazil this week. THE dawn in the south was marked by snow, negative thermal sensations and incidents caused by strong winds in the middle of Cyclone Yakecan, which reached more than 100 km/h, covering a hospital in Tramandaí (RS) and overturning a truck in Serra do Rio do Rastro (SC).

The city of São Paulo had a average temperature of 8°C all nightbut the cold went further, with negative thermal sensations in certain areas, such as the district of M’Boi Mirim, in the south, where 8 ºC seemed to be 1 ºC, and the airport area of ​​Congonhas, also in the south, where the Observed temperature was 8 ºC with a sensation of -2 ºC.

This type of cold always raises health concerns and a question that children and grandchildren historically ask themselves: after all, who is cold without clothes, can you catch the flu, catch a cold or have a runny nose? ?

The “million dollar question” has a simple answer: yes. The cold, according to an expert heard by the report of VivaBem, can facilitate viral infections. The explanation is given by the immunologist Fábio Castro, Professor of Clinical Immunology and Allergy at USP (University of São Paulo) and Supervisor of the Clinical Immunology and Allergy Service of the Hospital das Clínicas de Sao Paulo.

The flu is caused by the virus flu. A runny nose can be a sign of a cold, which is also a respiratory disease and is often mistaken for the flu. The image is caused, however, by different viruses. The most common, according to the Department of Health, are rhinoviruses, parainfluenza viruses and respiratory syncytial virus. The difference between them lies primarily in the symptoms and the duration of the disease.

According to the doctor, the cold does not act directly on the immune system, but it can act as an important trigger. In addition, that tidy coat that only comes out of the closet can possibly have the opposite effect of the expected protection, if it has not been properly disinfected.

“This time of year, fall, is even worse than winter. Several factors are important: sudden changes in temperature; the confinement and overcrowding of people; dry and cold air; the increase in pollution and this is when people take their coats and blankets out of the closet, full of dust mites. It is therefore also very harmful for people with rhinitis and Asma“, he says.

Fábio Castro says that there is a constant fight between the human organism, through the immune system, against the aggressors of the external environment: which are the microorganisms (fungi, viruses and bacteria); allergens and environmental pollutants (chemical agents). In most cases, the USP professor points out, the body wins this battle.

“When it loses, comes disease. The immune system is made up of cells, proteins, different substances that interact by regulating, activating and inhibiting, in short, controlling our defenses. The first defense is the skin and mucous membranes (respiratory, digestive, genito-urinary). Any rupture of this barrier already allows the entry of these aggressive agents. An example: the inflammation of the bronchial mucosa in allergic asthma can facilitate the infection and a viral infection can facilitate the aggravation of asthma”, he underlines.

For the immune system to function properly, he adds, good nutrition, hydration, moderate physical activity and rest are essential. In this case, the expert points out that even if you catch a cold or reproachthe person will have a self-limited evolution of three to five days because the immune system has organized a more elaborate defense response.

“Repeated infections suggest a defect in the immune response and should be investigated. They are called immunodeficiencies. Fortunately, they are not that common and can appear in children and adults.”

I’m always cold. And now?

The brothers João Neto, 3, and Giovana, 1, are far from having the autonomy to face the cold of the street alone, and it is not yet time to hear this old seasonal advice from their parents: “Children, take your coats because the weather is getting colder”.

However, despite being careful with all the protections, the children of educator Priscila Cavalcanti, 39, almost change the cycles of the flu. Priscila says the problem has arisen since little João Neto started going to school.

“These are symptoms that keep recurring. During the second week of the course, he already came back with a runny nose. Then cough, phlegm… And a few days later it went to Giovana who still doesn’t go to school We were both cured About 15 days later he came back with the flu and his sister caught it again.

This sequenced contagion, explains Fábio Castro, inevitably occurs when little ones come into contact with other children in daily school life. This daily life increases the possibility of contact with the virus and of developing recurrent flus and colds.

“Which, in a way, even strengthens the immune defense. Obviously, some children may have weak immunity, so in the event of repeated infections, expertise is important,” he warned.

Philip Prohaska, head of infectious disease screening at HUOC (Hospital Oswaldo Cruz), a unit linked to UPE (University of Pernambuco), explains that when a person has the first viral infection, immunity drops. And what happens next?

“It makes it easier for other infections to enter. It opens the door to other infections, other viruses, other fungi. The cold can bring you harm as well as the heat, which causes a lot of dehydration. cause a greater number of respiratory symptoms But it’s not just the cold. Some situations make you sick. The sudden change in temperature, thermal shock: you leave a hot environment for a cold environment, for example”, specifies- he.

agglomeration and viruses

The infectiologist recalls that in the cold season, people accumulate in greater numbers in closed places, which can have additional heat. This causes more virus transmission.

“Covid-19 has shown us that overcrowding increases the transmissibility of respiratory diseases. That is why in this cold season we have the most circulating viruses, because there are more often agglomerations. The virus has a lot to do with contact with people and the lack of hand hygiene. When you heat an environment, it ends up not having contact with the outside environment. And then this air accumulates. If someone continues to sneeze or cough in this environment, the viruses accumulate inside”, he underlined.

According to Marcus Villander, president of the Pernambuco Society of Clinical Medicine, which works directly on autoimmune diseases and immunodeficiencies, it is because of this set of aspects that the vaccines of the reproach are applied in campaigns made before winter.

“I was born in the countryside (of Pernambuco) and there they call the cold the serene night. There is a popular knowledge that the cold can cause reproach. It’s just that certain cold-related factors can actually increase your risk of viral infections. More agglomerations, closed environments, but there are other causes. For example, during cold and dry periods, the mucous membranes produce less secretion, which is a natural protective barrier of the immune system. There are other studies that say that cold can further stabilize the viral membrane and make its exposure longer,” he explains.

Villander points out that viral infections are more common in cold weather, not necessarily because the virus weakens the immune system, because the HIV for example, but because indirect causes, such as greater agglomeration and drier environments, ensure contamination by the virus and facilitate the breakdown of the body’s first defense barrier, which is the mucous membranes.

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