Common cold
The common cold, also known as the common cold, runny, or constipation, is a viral infectious disease Common upper respiratory tract infection involving the nose, sinuses, pharynx, and larynx. It is mainly caused by rhinoviruses, is self-limiting, and can affect people of all ages. The virus is spread through contact with the infected person's nasal secretions or inhalation of their saliva droplets. Symptoms appear one to two days after contact.
Symptoms usually include runny nose, runny nose, nasal obstruction, sore throat, sneezing, malaise, low-grade fever, and cough; they reach their greatest intensity between the first and third day of evolution and last from seven to ten days, although occasionally they can persist for up to three weeks. Fever occurs more often in children. As one advances in age, the incidence of the common cold is lower.
The common cold is a type of upper respiratory infection different from influenza, a more serious viral infection of the respiratory tract that differs by being a generalized disease, with more intense symptoms, especially in the respiratory tract, which are often complicated at the level of the bronchi or lungs. Likewise, the flu can simultaneously or successively affect the brain, the meninges, the heart, the digestive tract and the musculature. However, many people confuse both terms.
Epidemiology
This is a highly prevalent type of upper respiratory infection of viral origin, which affects adults two to six times and children six to ten times a year. Even though it is not a serious illness, colds account for 40% of work absenteeism and 30% of school absenteeism.
Healthcare personnel, including dental personnel, have a risk, at least potential, of acquiring a respiratory disease such as the common cold in the exercise of their profession.
The best ways to avoid colds are to avoid contact with infected people and keep your immune system in optimal condition: getting enough sleep to feel rested, reducing stress, eating a proper diet and avoiding excessive alcohol consumption.
Risk factors
Spending time indoors with infected people or in close contact with an infected person increases the risk of catching a cold. The common cold is a droplet-borne infection, which means it is transmitted primarily through the inhalation of small particles that an infected person emits when they cough, sneeze, or exhale.
Low humidity increases viral transmission rates. One theory is that dry air causes the evaporation of water, allowing small virus droplets to disperse farther and remain airborne for a longer period of time.
Habits
Smoking extends the duration of illness by an average of three days. Sleeping less than seven hours a day has been associated with a three-fold increased risk of developing an infection when such a subject is exposed to a rhinovirus, in compared to those who sleep more than eight hours a night.
Decreased levels of vitamin D in the blood plasma are associated with an increased risk of contracting the common cold. Whether this association is causal has yet to be determined.
Hygiene
Touching contaminated eyes, nose, or mouth with contaminated fingers often transmits the virus. This behavior somewhat increases the likelihood of transfer of viruses from the surface of the hands, where the viruses are harmless, to the upper respiratory tract, where they can infect nasal tissues. Some studies show that frequent hand washing and decreasing touching of mucous membranes can reduce the likelihood of catching a cold in adults.
Cold environment
Although common colds are seasonal, with more cases occurring in winter, there is no scientific evidence that short-term exposure to cold increases susceptibility to infection, which may mean that seasonal variation is caused by a change in temperature. behavior, such as spending more time indoors, in close contact with others.
A study showed that exposure to cold causes symptoms of constipation to appear in 10% of people so exposed, and that subjects who experience this effect more frequently report the onset of colds in general than those not affected by colds. exposure to cold.
Regarding the cause of the symptoms, research at the Cardiff University Common Cold Center led to a study to "test the hypotheses that acute chilling of the feet causes the onset of cold symptoms." common.” The study found that subjects had more cold symptoms after 5 days, probably because constriction of the blood vessels in the nostrils can lead to reduced immune capacity in the upper respiratory tract.
On the other hand, it is known that in winter the accelerated rhythmic movement of the nasal cilia decreases in the presence of the autumn-winter cold, which would give more time for viruses and bacteria to pass through the mucus and achieve infect body cells.[citation needed]
In addition to the fact that migratory birds, important vectors of viruses from the other hemisphere, leave a trail of viruses in the air, favoring the appearance of epidemics.[citation required]
Etiology
The common cold is an infection of the upper respiratory tract caused by viruses. In total, more than 200 serologically different viral types cause constipation. The most frequently implicated virus is rhinovirus (24-52% of clinical cases or 52-76% of infections with an identified pathogen), which has 99 known serotypes.
Other viruses that can cause the common cold are coronaviruses (10-15%), influenza viruses (5-15%), human parainfluenza viruses, and respiratory syncytial virus, among others of lesser incidence.
Rhinoviruses
Rhinoviruses are the main cause of the common cold. The virus replicates between 33 and 37 °C temperatures. The incubation period is approximately two days.
Coronavirus
Coronaviruses are the viruses most particularly implicated in adult colds. Of the total of more than 30 identified coronaviruses, 3 or 4 are those that cause infections in humans, but are difficult to culture in the laboratory, so their meaning remains poorly understood. The coronaviruses that cause the common cold are types 229E and OC43; they can occasionally cause pneumonia in the elderly, neonates, and immunocompromised patients.
Influenza Viruses
Influenza viruses can also cause mild constipation. Influenza virus infection occurs after the transfer of respiratory secretions from an infected person to an immunologically susceptible person. If the virus is not neutralized by secretory antibodies, it invades the cells of the respiratory tract. Once inside the host cells, cellular dysfunction and degeneration occurs, along with viral replication and the release of viral progeny. Unlike the flu, the influenza virus causes the common cold when there are no systemic symptoms resulting from inflammatory mediators in the body. The incubation period varies from 18 to 72 hours.
Adenoviruses
Adenoviruses are DNA viruses, first isolated in the 1950s from cultured adenoid cells (hence the name), and cause 5% of cases of the common cold. Adenoviruses are a common cause of infection asymptomatic respiratory tract.
Pathogenesis
Caused by numerous viruses (mainly rhinoviruses, coronaviruses, and also certain echoviruses and coxsackieviruses) that infect the upper respiratory tract. Several hundred viruses that cause the common cold have been described. The variety of causative agents makes any type of vaccination very ineffective. They are transmitted from person to person through small droplets of saliva that are expelled when coughing, speaking or sneezing. Droplets are directly inhaled or, more frequently, are transmitted from hand to hand through handshakes or objects such as doorknobs, handles, railings, etc. and then enter the nasal passages when the hand touches the nose, mouth, or eyes.
The virus enters cells in the lining of the nose and throat and multiplies rapidly within them. Symptoms begin 1 to 2 days after infection. They are the result of the body's defense mechanisms: sneezing, runny nose and coughing to expel the invader, and inflammation to attract and activate immune cells. The virus takes advantage of sneezing and coughing to infect the next person before being cleared by the body's immune system. A sick person is most infectious within the first three days of illness.
After a common cold, the patient develops some immunity to the particular virus that has affected him. However, because the immunity generated is not very strong and the large number of different cold viruses that exist, this immunity is limited and a person can easily become infected with another cold virus (or even with the same virus weeks-months). later) and start the process again.
Clinical picture and diagnosis
The common cold usually begins with a single symptom such as a feeling of eye irritation or a dry throat, which is quickly followed by other symptoms such as sneezing, runny nose, headache, stuffy or blocked nose, eyes watery, itchy or sore throat, dysphonia, cough, tiredness, fever and feeling of general malaise. A combination of these symptoms and signs can last for a week or more. The diagnosis is established by the presence of a variable set of these signs and symptoms, ruling out the diagnosis if only one exists or predominates over the others, preferring in this case the name of the affected territory (pharyngitis, laryngitis, rhinosinusitis, etc.).
Treatment
In general, people have little scientific knowledge regarding the common cold, both its causes and its treatment, therefore, health professionals should seek to educate and reassure the patient, offer options for symptom relief and avoid the use of antibiotics or other medications that have not been shown to be effective.
Treatment for colds consists of symptom relief, which leads to the frequent use of both prescription and over-the-counter medications, and home remedies. Codeine is effective in treating nonproductive cough, as it decreases the brain response that triggers the cough. Dextromethorphan, although chemically related to opiates, does not act on the same receptors, it may be beneficial in adults with cough, but its effectiveness has not been demonstrated in children and adolescents. Although hydrocodone is indicated for patients with colds and has been shown to which is effective for coughs in other illnesses, has not been well studied in patients with colds. Oral and intranasal nasal decongestants have been shown to rapidly relieve nasal symptoms and can be used in adolescents and adults for up to three days. Antihistamines and combination antihistamine/decongestant therapies may modestly improve symptoms in adults, however benefits must be weighed against potential side effects.[citation needed] Antihistamines Newer non-sedatives are not effective against coughs. Topical ipratropium relieves nasal symptoms in older children and adults. Antibiotics have not been shown to improve symptoms or shorten the duration of the disorder. Certain complementary and alternative therapies, including the use of Echinacea and zinc, are not recommended for the treatment of symptoms of the common cold. Contrary to popular belief, vitamin C does not reduce or prevent the symptoms of the disease. The common cold is considered an endemic disease.
There is no cure for the common cold, that is, there is no treatment that directly fights the virus. Only the body's immune system can effectively destroy the invader. A cold can be made up of several million viral particles, and usually within a few days the body begins to mass-produce a more suitable antibody that can stop the virus from infecting more cells, as well as white blood cells that destroy the virus through phagocytosis and infected cells to prevent further replication of the virus.
Therefore, the available treatments focus on relieving the symptoms, and also on helping the body to develop its defenses.
For some people, colds are relatively minor inconveniences, and they can go about their daily activities with tolerable discomfort. This discomfort must be weighed against the price and possible side effects of the remedies.
Common treatments include: pain relievers such as aspirin, acetaminophen, or paracetamol, as well as localized versions for the throat (often prescribed in lozenge form), nasal decongestants that reduce inflammation of the nasal passages, constricting the vessels local blood drugs, cough suppressants (which work like a narcotic, suppressing the brain's cough reflex or thinning the mucus in the lungs), and first-generation antihistamines, such as brompheniramine, chlorpheniramine, and clemastine (which reduce secretion of mucosa in the corresponding gland and thus combat runny nose and nasal congestion, although they also cause drowsiness as a side effect). Second-generation antihistamines do not have useful effects on colds. Research has been done on the adjuvant action in respiratory diseases of electrolyzed superoxidation solutions with neutral pH, due to their broad spectrum against bacteria, viruses and fungi present in the nostrils, being successful in reducing the inflammatory process and improving congestion symptoms. Another strategy in managing symptoms is to use combinations with different active principles, under the therapeutic principle of performing sum synergism, that is, taking advantage of the effect of drugs with different mechanisms of action, an example is the use of acetaminophen or paracetamol combined with chlorpheniramine to improve discomfort and rhinorrhea, thus there are multiple combinations in a single presentation.
Staying in a warm, dry environment and drinking plenty of fluids, especially hot liquids, will relieve symptoms somewhat.[citation needed]
Antibiotics are ineffective against the common cold and also against any other viral infection. They are useful for treating any secondary bacterial infections, but antibiotic treatment before these co-infections develop is counterproductive, as it can lead to drug resistance.
Do not forget that all medications are for symptomatic relief and do not prevent the spread of infection to those around us and we must think about the number of people we will infect if we continue with our daily rhythm and therefore, it would be recommended that people with colds wear surgical masks.[citation needed] Only after our body reacts, generates defenses against the infection and eliminates the symptoms naturally, we stop be carriers of the infection.[citation needed]
Complications
Bacteria normally present in the respiratory tract can take advantage of a weak immune system during a common cold and cause a co-infection. Middle ear infection (in children) and bacterial sinusitis are common coinfections.
Prevention
The best way to avoid a cold is to avoid close contact with current patients, wash your hands thoroughly and regularly, and avoid touching your face. Antibacterial soaps have no effect on cold viruses - it is the mechanical action of hand washing itself that removes the virus particles. Alcohol hand rubs are recommended as an effective method to reduce the concentration of infectious viruses on the hands. However, like hand washing, alcohol gels do not provide any residual protection against another infection.
In some countries like Japan, constipated people don surgeon's masks as a courtesy to others. In Spanish-speaking countries, there are people who cover their mouth and nose with their sweater, t-shirt, scarf or handkerchief when coughing, to capture the emitted microparticles.[citation required]
Due to the wide variety of viruses that cause the common cold, vaccination is not feasible.