Key Facts You Need To Know About Coronavirus According To CDC
Disclaimer: Not medical or professional advice.
The course of COVID-19 disease is very different from that of the flu.
In COVID-19 patients, interferons (immune proteins) are released as they approach the second week of illness. The immune response is triggered when the virus population has already grown and made its way into the lower airways.
The main and primary mode of infection transmission is airborne.
A talking person releases over 200 virus particles in a single exhale. The most active virus replication occurs in the nasopharynx during the first week of illness.
The incidence rate depends on the weather.
Exposure to cold temperatures and humidity can lead to hypothermia, making the body more vulnerable to infections.
COVID-19 patients are usually most contagious about 2 days before the symptom onset and on the first day of illness.
On average, coronavirus shedding is highest 3-4 days (or rarely – 7 days) before symptoms appear in the first 5 days of illness. Patients in the late stage of the disease are unlikely to spread the virus to others.
Disease progression patterns may vary from patient to patient.
Some people infected with the coronavirus may maintain a normal body temperature or experience a short-term sub febrile rise in temperature (up to 38°C) within 1-2 days. Some patients may develop catarrh symptoms (cough and runny nose) early on. While in others, COVID-19 appears as fatigue and muscle aches, with cough and/or shortness of breath emerging on the second week (but absent during the onset of disease).
Wearing a mask is the most simple and effective way to prevent COVID-19.
A mask helps to stop the infected people from spreading the virus. It also protects the wearer from inhaling virus particles.
The severity of illness depends on the amount of virus entering the body.
That's why everyone should be wearing masks. Despite the mask's inability to filter out 100% of virus particles, it still helps to reduce their amount considerably.
Scientists made assumptions about people who are more likely to have a mild or asymptomatic case of COVID-19.
A certain proportion of the population has so-called cross-reactive T cells primed against SARS-CoV-2 antigens. It is believed to be the result of prior infection with seasonal coronaviruses (common cold). Such pre-existing "immunity" to coronavirus allows for a strong T cell response to the infection. This could explain why people with cross-reactive T cells may show milder symptoms, no symptoms at all, or be immune to the virus.
Testing positive for coronavirus doesn't always mean you are contagious.
PCR testing (nasal and/or nasopharyngeal swab) detects the virus's genes (particles) but doesn't allow determination of whether the virus is viable. However, to ensure others' safety and prevent the spread of the virus, everyone who has positive PCR results should self-isolate.
Myths about COVID-19
COVID-19 remains a relatively novel and unresearched disease. No wonder that it gives rise to many myths and speculations which can be dangerous to human health.
Does recovery mean you’re not contagious anymore?
One of the common misconceptions about the coronavirus is that people who recovered from COVID-19 can’t spread the infection anymore and can disregard safety precautions suggested by doctors and the government. While in fact, these individuals pose the most danger to others in terms of the coronavirus spread.
A person who had COVID-19 and recovered continues to release virus particles, though fewer than while being sick. The virus stays in the upper respiratory tract and can be transmitted via airborne routes through even talking.
Mask provides the only barrier that helps to prevent the infection from spreading.
Do antibodies equal immunity?
There is no evidence that a person, after initial infection with COVID-19, becomes immune to the virus and is protected from reinfection. Even if the lab test has confirmed the presence of antibodies specific to this virus in their blood. Many believe that antibodies equal immunity, and such people are protected from the second infection. However, doctors refute this opinion.
The trick is that immunity against SARS-CoV-2 does not last forever. Research has already proven that antibodies may protect against coronavirus infection only for several months. It is also indicative that some people are catching the virus twice.
There is one more trick. According to CDC, antibodies are not created equal, and their presence does not confer immunity. Doctors determine how many antibodies are present: a low amount means that the risk for reinfection is very high.
Besides, four similar coronaviruses cause mild URI. A patient may have cross-reactive antibodies, which can recognize both these common coronaviruses and SARS-CoV-2. But they won’t protect against COVID-19.
Does the absence of symptoms mean you’re not spreading the infection?
There is another common and extremely dangerous myth backed by the World Health Organization, among others. Until quite recently, the WHO claimed that asymptomatic COVID-19 carriers are harmless and unlikely to pass the disease to others.
However, in a little while, it became evident that the agency’s experts had erred. After all, the disease is still novel. The WHO confirmed that there’s a fair share of coronavirus carriers among asymptomatic patients. But most people remained deaf to their message.
The infection spread depends on due observance of safety precautions suggested by health experts and the government: mask and glove regime and social distancing.