what is the covid-19
Coronaviruses are a family of viruses that can cause diseases such as the common cold, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). In 2019, a new coronavirus was identified as the cause of a disease outbreak that originated in China.
This virus is now known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease it causes is called coronavirus disease 2019 (COVID-19). In March 2020 the World Health Organization (WHO) declared that this COVID-19 outbreak is a pandemic.
Public health organizations, including the United States Centers for Disease Control and Prevention (CDC) and WHO are monitoring the pandemic and posting updates on their websites. These groups have also published recommendations to prevent and treat this disease.
Signs and symptoms of Coronavirus Disease 2019 (COVID-19) may appear two to 14 days after exposure to the virus. This period between exposure and the onset of symptoms is called the incubation period. Common signs and symptoms may include:
Other symptoms can be:
Shortness of breath or difficulty breathing
Loss of sense of taste or smell
This list does not include all possible signs and symptoms. Other less common symptoms, such as nausea, vomiting, and diarrhea, have been reported. Children have symptoms similar to those of adults, and generally have a mild illness.
The severity of COVID-19 symptoms can be very mild to extreme. Some people have only a few symptoms, and others have none. Older adults or people who have certain chronic conditions, such as heart or lung disease, diabetes, extreme obesity, chronic kidney or liver disease, or who have a compromised immune system, may be at higher risk of becoming seriously ill. This is similar to what is seen with other respiratory diseases, such as influenza (flu).
Some people may have worsening symptoms, such as more trouble breathing and pneumonia, about a week after symptoms start.
When to see the doctor
If you have symptoms of COVID-19, or have been in contact with someone diagnosed with COVID-19, immediately contact your doctor or clinic for advice. Before going to the appointment, talk to your healthcare team about your symptoms and possible exposure to the virus.
If you have emergency signs and symptoms of COVID-19, such as trouble breathing, chest pain or pressure, confusion, or your face or lips turn blue, seek medical help immediately.
If you have airway symptoms but are not and have not been in an area with continued spread of the virus in the community, contact your doctor or clinic for advice. Tell your doctor if you have other chronic health conditions, such as heart or lung disease. As the pandemic progresses, it is important to ensure that there is medical care for those who need it most.
Infection with the novel coronavirus (severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2), causes coronavirus disease 2019 COVID-19).
The virus seems to spread easily from person to person, and over time more is being discovered about how it spreads. The data shows that it is spread from person to person among those who are in close contact (within about 6 feet, or 2 meters). It is transmitted by respiratory droplets that are released when someone with the virus coughs, sneezes, or speaks. A person nearby can inhale these droplets, or the drops can fall into his mouth or nose.
It can also spread when a person touches a surface where the virus is found and then touches his mouth, nose, or eyes.
Risk factors for COVID-19 seem to include:
Travel to or recent residence in an area where COVID-19 community transmission continues, as determined by CDC or WHO
Close contact (less than 6 feet or 2 meters) with someone who has COVID-19, or who has been coughed or sneezed by an infected person very close
Although most people with COVID-19 have mild to moderate symptoms, the disease can cause serious medical complications and, in some people, lead to death. Older adults or people with chronic conditions are at increased risk of becoming seriously ill with COVID-19.
Some of the complications can be:
Pneumonia and trouble breathing
Multiple organ failure
Acute kidney injury
Additional viral and bacterial infections
Although there is no vaccine to prevent COVID-19, you can take steps to reduce the risk of infection. (WHO) and (CDC) recommend taking these precautions to avoid COVID-19:
Avoid crowded events and crowded gatherings.
Avoid close contact (less than 6 feet or 2 meters) with anyone who is sick or has symptoms.
Stay home as much as possible and keep distance between yourself and others (6 feet or 2 meters) if COVID-19 is spreading in your community, especially if you are at higher risk of serious illness. Keep in mind that some people can have COVID-19 and spread it to others, even if they don’t have symptoms or know they have COVID-19.
Wash your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer that contains at least 60% alcohol.
Cover your face with a cloth mask when you are in public places, like the store or the supermarket, where it is difficult to avoid close contact with others, especially if you are in an area where contagion continues at the community level. Use only cloth masks that are not for medical use – surgical masks and N95 respirators should be reserved for healthcare providers.
Cover your mouth and nose with your elbow or disposable tissue when you cough or sneeze. Discard the used disposable tissue.
Avoid touching your eyes, nose, and mouth.
Avoid sharing plates, glasses, bedding, and other household objects if you are sick.
Clean and disinfect frequently touched surfaces daily, such as door latches, light switches, electronic devices, and countertops.
Stay home and don’t go to work, school, or public places if you are sick, except for medical attention. Avoid public transportation, taxis, and ridesharing if you are sick.
If you have a chronic health condition and may be at higher risk for serious illness, talk to your doctor about other ways to protect yourself.
Complications included acute respiratory distress syndrome (positive result for real-time RT-PCR in the plasma sample), acute heart injury, and secondary infection. Thirteen patients (32%) were admitted to an ICU and six died (15%). In a clinical commentary from the same journal, a comparison of the clinical presentation against other emerging coronaviruses (SARS and MERS) is presented; Among other clinical data in the cases studied at the moment, it should be noted that the symptoms of the upper respiratory tract are notably infrequent (for example, no patient had a sore throat) .91
The most frequent complications are pneumonia and multi-organ failure that sometimes cause death.32 92
Clinical research found that a high concentration of cytokines is detected in the plasma of critically ill patients infected with SARS-CoV-2, suggesting that cytokine storm was associated with disease severity.93
Additionally, COVID-19 may predispose to arterial and venous thromboembolic disease due to excessive inflammation, hypoxia, immobilization, and disseminated intravascular coagulation (DIC). Surprisingly, thrombotic complications have hardly been described. Accurate knowledge of the occurrence of thrombotic complications in patients with COVID-19 is important for decision-making regarding the intensity of thromboprophylaxis, especially in patients admitted to the intensive care unit (ICU) who are at risk. highest thrombotic. In a study published on April 11, 2020, it was evidenced that there were 31% of thrombotic complications in patients with COVID-19 hospitalized in the ICU.94
Among the first 41 cases of COVID-19 that were treated in Wuhan hospitals, thirteen (32%) required intensive care and six (15%) died.79 Many of those who died had previous pathologies such as high blood pressure, diabetes or cardiovascular disease that weakened their immune systems.95
In these early cases that ended in death, the median duration of the disease was fourteen days and the total range was from 6 to 41 days.96 Of the confirmed cases, 80.9% were classified as mild cases.97 98
Case fatality rate
According to a study of COVID-19 deaths in China’s Hubei province, out of a total of 72,314 patient records, 44,672 (61.8%) were confirmed as COVID-19 cases. Among them, 1,023 deaths were registered, which supposes a mortality rate of 2.3% .97 This figure, however, may be an overestimate of the real mortality because many people may have been infected but have no symptoms. , and therefore have not been accounted for. Other studies indicate that the apparent mortality was higher in the early stages of the outbreak (17.3% for symptomatic cases between January 1 and 10), and that it decreased over time to 0.7% for patients with onset of symptoms after February 1, 2020.1
South Korea, which is the only country in the world where systematic analyzes of large population groups were carried out since the beginning of the pandemic (about 10,000 a day, with 210,000 counted until March 10), a rate was found much lower mortality.99
As of March 3, 2020 globally, 3,110 of the 90,892 reported cases of COVID-19 had died (3.4%), according to figures indicated by the WHO director. 100 101
Effect according to age and previous pathologies
Case fatality rates in Italy (until March 17) and China (until February 11) 102
Age (years) Case fatality in Italy (%) Case fatality in China (%)
0–9 0 0
10–19 0 0.2
20–29 0 0.2
30–39 0.3 0.2
40–49 0.4 0.4
50–59 1.0 1.3
60–69 3.5 3.6
70–79 12.8 8.0
80 or older 20.2 14.8
In Italy as of March 31, 2020, it was found that the median age of those killed by COVID-19 was 79 years. 69% of the deceased were men and only 2% were in good health (that is, absence of previous pathologies) before infection.103
In China, it was also observed that mortality increased with age and is higher among men than women (4.7% vs. 2.8%). While patients without previous pathologies had a mortality rate of 1.4%, those who did had died at much higher rates: 13.2% for cardiovascular diseases, 9.2% for diabetes, 8.4% for hypertension , 8.0% for chronic respiratory disease and 7.6% for cancer.1
In a study published online in the journal Pediatrics, researchers looked at 2,143 cases of children under the age of 18 who were reported to the CCDC until February 8, 2020. About half of the children had mild symptoms, such as fever, fatigue , dry cough, congestion, and possibly nausea or diarrhea. About 39% became moderately ill, with additional symptoms
Mai article: Evidence of COVID-19
tomography image of pneumonia in both lungs caused by COVID-19
On January 5, 2020, a team from the Shanghai Public Health Clinical Center managed to sequence the RNA of the new virus. This achievement was kept secret until, six days later, researchers leaked it to various websites. This act allowed the international community to start developing tests and vaccines for the virus, and those responsible were punished with the closure of their laboratory.
The guidelines published on February 6 by the Zhongnan Hospital of Wuhan University recommended diagnostic methods based on epidemiological risk and clinical characteristics. This included identifying patients who had recently traveled to Wuhan or had contact with someone infected, in addition to two or more of the following symptoms: fever, radiological signs of pneumonia, normal or low white blood cell count (leukopenia), and lymphopenia.
The WHO subsequently published several protocols for diagnosing the disease for Japan. The test of choice was real-time RT-PCR (or reverse transcription followed by quantitative polymerase chain reaction), performed on samples respiratory or blood. The results were available, as of January 30, in a few hours or days. However, Chinese pulmonologist Wang Chen reported that this RT-PCR test method would give false positives in 50-70% of cases
COVID‑19 is a new disease, and many of the details of its spread are still under investigation. It spreads between people very efficiently and sustainably—easier than influenza but not as easily as measles. This occurs mainly when people are in close contact (two metres or six feet) via small droplets produced during coughing, sneezing, or talking. Contaminated droplets exhaled by infected people are then inhaled into the lungs, or settle on other people’s faces to cause new infection. The droplets are relatively heavy, usually fall to surfaces, and do not travel far through the air. People can transmit the virus without showing symptoms, but according to the WHO and ECDC, it is unknown how often this happens. One summary of available studies estimated the number of those infected who are asymptomatic to be 40%.
People are most infectious when they show symptoms (even mild or non-specific symptoms), but may be infectious for up to two days before symptoms appear (pre-symptomatic transmission). They remain infectious an estimated seven to twelve days in moderate cases and an average of two weeks in severe cases.
When the contaminated droplets fall to floors or surfaces they can, though less commonly, remain infectious if people touch contaminated surfaces and then their eyes, nose or mouth with unwashed hands. On surfaces the amount of active virus decreases over time until it can no longer cause infection, and surfaces are thought not to be the main way the virus spreads. It is unknown what amount of virus on surfaces is required to cause infection via this method, but it can be detected for up to four hours on copper, up to one day on cardboard, and up to three days on plastic (polypropylene) and stainless steel (AISI 304). Surfaces are easily decontaminated with household disinfectants which kill the virus outside the human body or on the hands. Disinfectants or bleach are not a treatment for COVID‑19, and cause health problems when not used properly, such as when used inside the human body.
Sputum and saliva carry large amounts of virus. Although COVID‑19 is not a sexually transmitted infection, kissing, intimate contact, and faecal-oral routes are suspected to transmit the virus. Some medical procedures are aerosol-generating and result in the virus being transmitted more easily than normal.
Estimates of the number of people infected by one person with COVID-19 (the R0) have varied widely. The WHO’s initial estimates of the R0 were 1.4-2.5 (average 1.95), however a more recent review found the basic R0 (without control measures) to be higher at 3.28 and the median R0 to be 2.79.
video’s informativos del covid-19
by: jeyson contreras