OVERVIEW

What is COVID-19?

The "novel coronavirus" is a newly discovered, highly contagious coronavirus first identified in Wuhan, China, in late 2019. Coronaviruses are named for their crown-like appearance under electron microscopy. The International Committee on Taxonomy of Viruses designated it as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), also known as the novel coronavirus (2019-nCoV).

"COVID-19" refers to the disease caused by infection with the novel coronavirus. The virus can cause pathological changes in multiple organs, including the lungs, spleen, heart, blood vessels, liver, gallbladder, and kidneys, particularly damaging the lungs and causing inflammation—hence the name "novel coronavirus pneumonia," abbreviated as COVID-19.

According to the "Diagnosis and Treatment Protocol for COVID-19 (Trial Version 9)," guidelines from the World Health Organization (WHO), and other countries, treatments include antiviral therapy, immunotherapy, psychological intervention, and general symptomatic care^[1-6]. Daily prevention is crucial.

Is COVID-19 common?

Yes. As reported by the WHO, as of June 19, 2022, over 536 million confirmed cases and more than 6.3 million deaths have been recorded globally^[1]. These numbers continue to rise.

Does COVID-19 infection always lead to pneumonia?

Not necessarily. Some cases may be mild and resolve within about a week.

Most COVID-19 patients recover well, but a small percentage may progress to critical illness or even death.

Is COVID-19 contagious? How does it spread?

Yes, it is highly contagious.

• Respiratory droplets and close contact are the primary transmission routes.
• Contact with virus-contaminated objects can also cause infection.
• Aerosol transmission is possible in enclosed environments with prolonged exposure to high concentrations of aerosols. Additionally, contaminated items, as well as patients' feces and urine, may contribute to environmental transmission via contact or aerosols^[2,3].

Can COVID-19 spread between people?

Yes.

Infected individuals and asymptomatic carriers can transmit the virus during the incubation period, with higher infectiousness 1–2 days before and after symptom onset. Transmission occurs mainly through respiratory droplets and close contact^[2,3].

The virus's genome continuously mutates during outbreaks (e.g., Delta and Omicron variants in 2021), with some variants showing significantly increased transmissibility.

What is contact transmission in COVID-19?

Contact transmission includes direct and indirect contact.

• Direct contact: Exposure to an infected person's bodily fluids (e.g., sputum, feces, urine) without intermediary objects.
• Indirect contact: Transmission via contaminated objects (e.g., bedding, toys, utensils, clothing) touched by hands, followed by contact with mucous membranes (nose, mouth, eyes). Thus, handwashing, proper mask use, and maintaining distance are key preventive measures.

What are droplet and aerosol transmission in COVID-19?

• Droplet transmission: Droplets can travel 1–2 meters and reach susceptible mucous membranes. Talking, coughing, or sneezing near others can spread droplets. If near a suspected case, wear a mask and maintain a 2-meter distance. Dispose of masks properly and wash hands thoroughly after contact.
• Aerosol transmission: Droplets mix with air, forming aerosols (<5 μm in diameter) that remain infectious over long distances and durations, floating and spreading widely.

Are older adults more susceptible to COVID-19?

All age groups are generally susceptible.

However, older adults often have weaker immunity and underlying conditions (e.g., cardiovascular disease), leading to more severe illness, rapid progression to critical cases, or death, requiring extra caution.

What are "suspected exposures" and "close contacts" in COVID-19?

Suspected exposures: Contact with infected individuals, wildlife, or contaminated environments/items without proper protection (e.g., masks).

Close contacts: Individuals with any of the following exposures to suspected or confirmed cases:

• Living, studying, working, or having close contact in the same space.
• Healthcare workers, family members, or others in close contact without protection during diagnosis, care, or visits.
• Other patients or caregivers in the same ward.
• Those in close contact on the same transport.
• Others deemed eligible by investigators.

Close contacts must undergo home medical observation: avoid work/public outings, monitor health, and follow up with community doctors.

Can recovered COVID-19 patients be reinfected?

Reinfection is possible.

Recovered patients test negative twice, indicating no active viral replication, and develop antibodies. However, these antibodies are not lifelong, and reinfection may occur.

Additionally, some may test positive again after recovery. Recovered patients must undergo 7-day home health monitoring due to residual transmission risk^[4].

Why must close contacts undergo medical observation?

COVID-19's incubation period is 1–14 days (typically 3–7 days^[4]), though cases with 20–40 days have been reported.

Most infected individuals show symptoms within this period. If none appear, they are likely uninfected. However, delayed symptoms may occur post-observation, requiring prompt medical attention if fever, cough, or muscle pain develops.

SYMPTOMS

What are the symptoms of COVID-19 patients?

After being infected with the novel coronavirus, there is an incubation period ranging from 1 to 14 days, with an average of 3 to 7 days^[4].

Common symptoms of COVID-19 include fever, fatigue, dry cough, changes in taste and smell, and gradually developing difficulty breathing. Some patients may have mild initial symptoms or even no obvious fever.

Severe symptoms include acute respiratory distress syndrome, septic shock, difficult-to-correct metabolic acidosis, and coagulation dysfunction. Based on current case reports, most patients have a good prognosis, while a few are critically ill or may even die.

In addition to the above symptoms, some cases may present with "atypical" symptoms, such as:

• Digestive symptoms as the first manifestation: mild loss of appetite, fatigue, poor mental state, nausea, vomiting, diarrhea, etc.;
• Neurological symptoms as the first manifestation: headache;
• Cardiovascular symptoms as the first manifestation: palpitations, chest tightness, etc.;
• Ophthalmic symptoms as the first manifestation: conjunctivitis;
• Mild muscle soreness in the limbs or lower back^[4].

What are the specific manifestations of dry cough, one of the symptoms of COVID-19?

Dry cough is a type of cough characterized by no phlegm or sticky, scanty phlegm that is difficult to expel.

Common colds and acute bronchitis can also cause dry cough, as can other respiratory infections such as acute sinusitis, acute rhinitis, acute tonsillitis, acute pharyngitis, and acute exacerbation of chronic bronchitis. Additionally, inhaling irritants like gases or dust can trigger acute dry cough.

Coughing is a protective reflex of the respiratory system, helping to clear secretions and harmful substances. When these secretions or irritants are expelled through coughing, phlegm is produced. Coughing and phlegm usually indicate respiratory irritation or an underlying illness.

What symptoms in suspected COVID-19 patients require prompt medical attention?

If symptoms such as fever, fatigue, muscle pain, cough, phlegm, shortness of breath, diarrhea, conjunctival congestion, or changes in taste and smell occur, seek medical attention immediately. Inform the doctor of any travel history or contact history in the two weeks prior to symptom onset to facilitate rapid diagnosis.

CAUSES

What causes COVID-19?

It is caused by infection with the SARS-CoV-2 coronavirus. The WHO named the disease caused by SARS-CoV-2 infection as COVID-19. Since most infections can lead to pneumonia, it is referred to as novel coronavirus pneumonia or COVID-19.

The main sources of infection are patients infected with the novel coronavirus and asymptomatic carriers. The virus is contagious during the incubation period and is most infectious within 5 days after the onset of symptoms^[2,3,5,6].

What is the transmission distance of the novel coronavirus? What distance is recommended to maintain from others?

The novel coronavirus can spread through respiratory droplets, which can travel 1-2 meters and enter the mucous membranes of susceptible individuals. Therefore, when in contact with suspected cases, in addition to wearing a mask, it is best to maintain a distance of two meters.

DIAGNOSIS

Which department should suspected COVID-19 patients visit if they develop symptoms?

Fever clinic.

For patients with fever, fatigue, or cough, many hospitals have separate fever clinics where they can go directly. Before the consultation, doctors will conduct an epidemiological investigation, such as asking about travel history or contact with suspected infected individuals.

If pneumonia is suspected, the doctor will collect specimens such as throat swabs or sputum and send them to the CDC or qualified hospital laboratories for COVID-19 testing. A positive nucleic acid test result, along with positive IgM and IgG antibodies in unvaccinated individuals, confirms the diagnosis, and the patient will be isolated for treatment. Those not diagnosed with COVID-19 will receive treatment based on their specific condition, either hospitalized or sent home.

How is COVID-19 diagnosed?

Doctors typically diagnose COVID-19 based on epidemiological history, clinical manifestations, and a positive nucleic acid test result^[4].

1. Epidemiological history:

   • Travel or residence in a community with reported cases within 14 days before symptom onset;
   • Contact with a confirmed or asymptomatic COVID-19 case within 14 days before symptom onset;
   • Contact with a fever or respiratory symptom patient from a community with reported cases within 14 days before symptom onset;
   • Cluster infections (two or more fever and/or respiratory symptom cases in small settings like households, offices, schools, or classes within two weeks).

2. Clinical manifestations:

   • Fever and/or respiratory symptoms related to COVID-19;
   • Characteristic COVID-19 imaging findings;
   • Normal or decreased white blood cell count and normal or reduced lymphocyte count in early stages.

3. Laboratory tests: Early-stage peripheral blood tests may show normal or reduced white blood cell counts and decreased lymphocytes. Some patients may exhibit elevated liver enzymes, lactate dehydrogenase, creatine kinase, myoglobin, troponin, or ferritin. Most patients have elevated CRP and ESR, with normal procalcitonin. Severe cases may show increased D-dimer, progressive lymphopenia, and elevated inflammatory markers.

4. Pathogen testing: SARS-CoV-2 nucleic acid can be detected in nasopharyngeal swabs, sputum, lower respiratory secretions, blood, feces, or urine. Lower respiratory specimens (sputum or airway extracts) are more accurate.

5. Serological testing: Positive SARS-CoV-2-specific IgM and IgG antibodies, though positivity rates are low within the first week of illness.

6. Chest imaging features: Early-stage shows multiple small patchy shadows and interstitial changes, mainly in the lung periphery, progressing to bilateral ground-glass opacities or infiltrates. Severe cases may develop lung consolidation, but pleural effusion is rare^[4].

How should healthcare workers respond to COVID-19?

Since some COVID-19 patients lack typical symptoms like fever, healthcare workers must remain vigilant for atypical signs such as poor appetite, fatigue, muscle pain (even mild), or lethargy and conduct timely screenings.

Detailed patient histories should be taken, especially regarding contact with suspected or confirmed cases or fever within the past two weeks.

For "atypical" cases, perform blood tests, respiratory pathogen tests, and chest CT scans if possible, while maintaining clear communication with patients and families.

If abnormalities are detected, further coronavirus testing should be conducted.

Chest X-rays are not recommended due to the risk of missing early-stage lesions.

How are suspected and confirmed COVID-19 cases distinguished?

Suspected cases: Meet any one criterion in epidemiological history and any two clinical manifestations, OR (without clear epidemiological history) meet any two clinical manifestations with positive SARS-CoV-2 IgM antibodies, OR meet all three clinical manifestations.

Confirmed cases: Suspected cases with one of the following:

• Positive SARS-CoV-2 nucleic acid via RT-PCR;
• Viral gene sequencing highly homologous to known SARS-CoV-2;
• Positive SARS-CoV-2-specific IgM and IgG antibodies;
• SARS-CoV-2 IgG seroconversion or a fourfold increase in convalescent IgG titers^[4].

How are severe COVID-19 cases diagnosed?

Warning signs in adults:

• Progressive hypoxemia or respiratory distress;
• Worsening tissue oxygenation or rising lactate;
• Progressive lymphopenia or elevated inflammatory markers (e.g., IL-6, CRP, ferritin);
• Markedly elevated coagulation markers (e.g., D-dimer);
• Rapid progression on chest imaging.

Warning signs in children:

• Increased respiratory rate;
• Lethargy or poor responsiveness;
• Rising lactate;
• Elevated inflammatory markers (CRP, PCT, ferritin);
• Bilateral/multilobar infiltrates, pleural effusion, or rapid progression on imaging;
• Underlying conditions (e.g., congenital heart disease, immunodeficiency, malnutrition) or neonatal status^[4].

Can COVID-19 be detected during the incubation period?

Yes. Nucleic acid testing of patient samples can detect SARS-CoV-2 early, even during the incubation period.

How to avoid missing COVID-19 cases without typical symptoms?

For individuals with recent travel to epidemic areas or contact with confirmed cases, watch for atypical symptoms, including:

• Digestive symptoms: Poor appetite, fatigue, nausea, vomiting, diarrhea;
• Neurological symptoms: Headache;
• Cardiovascular symptoms: Palpitations, chest tightness;
• Ophthalmic symptoms: Conjunctivitis;
• Mild muscle aches in limbs or back^[4].

Such patients may visit non-respiratory departments (e.g., gastroenterology, neurology), increasing misdiagnosis risks.

What diseases should COVID-19 be differentiated from?

Per China’s COVID-19 Diagnosis and Treatment Guidelines (Trial 9th Edition), differentiate from^[4]:

1. Other viral upper respiratory infections;
2. Influenza, adenovirus, RSV, or Mycoplasma pneumoniae infections (use rapid antigen/PCR tests for common pathogens);
3. Non-infectious diseases (e.g., vasculitis, dermatomyositis);
4. Kawasaki disease in children with rash/mucosal lesions;
5. Even if common respiratory pathogens are positive, test for SARS-CoV-2 in close contacts of COVID-19 patients.

How does SARS-CoV-2 differ from SARS virus?

SARS-CoV-2, SARS-CoV, and MERS-CoV belong to the same coronavirus family, sharing genetic similarities but not identical. Its transmissibility compared to SARS remains uncertain, and current data suggest lower lethality, though mutations may alter this.

How do COVID-19, flu, and common cold symptoms differ?

COVID-19: Fever, fatigue, dry cough, taste/smell changes; some have nasal congestion, diarrhea. Pneumonia may occur without fever early (CT shows infiltrates). Severe cases develop dyspnea/hypoxemia after ~1 week, progressing to ARDS, shock, or multiorgan failure. Mild cases recover in ~1 week. Children may present atypically (e.g., vomiting, lethargy). Elderly and those with comorbidities face higher mortality.

Flu: High fever (39–40°C), headache, myalgia, fatigue, sore throat, dry cough. Self-limiting in 3–4 days, but cough/fatigue may persist. Complications include pneumonia, myocarditis, or shock.

Common cold: Mainly nasal congestion/runny nose; rarely causes pneumonia.

TREATMENT

What to do if body temperature slightly exceeds 37°C during a COVID-19 infection?

What we commonly refer to as a fever is actually a body surface temperature (e.g., armpit) exceeding 37.3°C. However, due to changes in time and environment, normal body temperature can also fluctuate. Measurements taken at different times may vary, but the fluctuation range should not exceed 1°C.

If the temperature is slightly above 37.3°C but there are no other discomforts, you can monitor the situation at home first. If the temperature gradually returns to normal and other symptoms lessen, it indicates gradual recovery.

Similarly, experiencing breathing difficulties or chest tightness alone can have many causes and does not necessarily indicate COVID-19. Unless you have chronic conditions such as diabetes, hypertension, hyperlipidemia, heart disease, or COPD, it is advisable to seek immediate medical attention.

If there are no underlying health issues, try relaxing, opening a window for fresh air, and breathing deeply. If chest tightness persists, seek medical attention.

What should you pay attention to when going to the hospital if you suspect a COVID-19 infection?

• Wear a proper mask, preferably an N95, on the way to the hospital.
• Inform the doctor if you have recently visited epidemic areas or high-risk regions or had contact with suspected or confirmed cases.
• Cooperate with the doctor for relevant laboratory tests to help assess the condition.

Are there any effective drugs for COVID-19? Can COVID-19 be prevented?

According to the Diagnosis and Treatment Protocol for COVID-19 (Trial Version 9), antiviral drugs include:

1. PF-07321332/Ritonavir (Paxlovid)
Indicated for adults and adolescents (12-17 years old, ≥40kg) with mild or moderate symptoms within 5 days of onset and at high risk of progressing to severe illness. Dosage: 300mg PF-07321332 with 100mg ritonavir taken together every 12 hours for 5 days. Read the instructions carefully before use. Do not combine with drugs like pethidine or ranolazine that are highly dependent on CYP3A for clearance, as elevated plasma concentrations may cause severe or life-threatening adverse reactions.

2. Monoclonal Antibodies: Bamlanivimab/Etesevimab Injection
Used in combination for treating mild or moderate cases at high risk of severe progression in adults and adolescents (12-17 years old, ≥40kg). Dosage: 1000mg of each drug, diluted separately in 100ml saline and administered intravenously at ≤4ml/min, with a 100ml saline flush between infusions. Monitor patients during infusion and observe for at least 1 hour afterward.

Current consensus suggests that potential antiviral drugs should be used early in the course of the disease, particularly for patients with high-risk factors or a tendency toward severe illness.

On January 24, 2020, The Lancet published a study stating that no drugs could prevent COVID-19^[5]. For viral diseases, except for a few like influenza, there are generally no specific treatments.

However, China’s inactivated COVID-19 vaccine was officially approved for emergency use on July 22, 2020. Booster shots can reduce the likelihood of infection and the risk of severe illness after infection.

Can COVID-19 be cured?

Yes, it can be cured. Following the Diagnosis and Treatment Protocol for COVID-19 (Trial Version 9), WHO guidelines, and other national recommendations can help patients test negative.

Treatment methods include antiviral therapy, immunotherapy, symptomatic treatment, and psychological support^[4].

How is COVID-19 treated?

Patients should be isolated and treated in hospitals with proper quarantine and protective measures. Critical cases should be admitted to the ICU as early as possible.

General Treatment:

• Bed rest, supportive care, and maintaining fluid and electrolyte balance.
• Regular monitoring of vital indicators.
• Oxygen therapy based on blood oxygen saturation levels.

Antiviral Treatment: Currently, two officially approved oral drugs are available: Merck’s Molnupiravir and Pfizer’s Paxlovid (Nirmatrelvir/Ritonavir). Paxlovid was conditionally approved for import by China’s NMPA in February 2022^[8].

Immunotherapy: Convalescent plasma, intravenous COVID-19 immunoglobulin, and Tocilizumab may be used clinically.

Corticosteroid Therapy: For patients with worsening oxygenation, rapid imaging progression, or hyperinflammatory responses, short-term (3-5 days, not exceeding 10 days) corticosteroid use may be considered^[4].

Antibacterial Treatment: Avoid unnecessary or excessive use of antibiotics, especially broad-spectrum combinations^[4,6].

Is high-dose hormone therapy needed for COVID-19 treatment?

For patients with deteriorating oxygenation, rapid imaging progression, or excessive inflammatory responses, short-term high-dose corticosteroids (3-5 days, not exceeding 10 days) may be used.

What are the discharge criteria for COVID-19 patients?

• Normal body temperature for at least 3 days.
• Significant improvement in respiratory symptoms.
• Marked improvement in acute exudative lesions on lung imaging.
• Two consecutive negative nucleic acid tests (sampling interval ≥24 hours).

Patients meeting these criteria can be discharged. For those meeting the first three criteria but testing positive for over four weeks, further assessment of infectivity (e.g., antibody tests, viral culture) is recommended before discharge^[4].

DIET & LIFESTYLE

How to Properly Disinfect Your Home During the COVID-19 Pandemic?

The novel coronavirus can be killed at 56°C for 30 minutes. For heat-resistant items, boiling (100°C) for 15 minutes can be used for disinfection^[4].

• Alcohol: Alcohol denatures bacterial proteins. Use 75% medical alcohol for skin disinfection.
• Steaming: 20 minutes of boiling achieves disinfection, suitable for tableware, clothing, and gauze.
• Boiling: 100°C also denatures bacterial proteins. Items must be fully submerged. Suitable for tableware, certain toys, and bedding.
• Air Cleaning: Maintain indoor air cleanliness by frequent ventilation, especially in cold seasons.
• Potassium Permanganate Solution: A 5‰ solution can disinfect tableware, vegetables, and fruits. Soak for 1 minute, then rinse with clean water.
• Bleach: Bleach deactivates bacterial enzymes. Use 1–3% bleach solution (mixed with water) to wipe surfaces like tables, beds, floors, and walls.
• Disinfectants: Chlorine-based disinfectants (e.g., 84 Disinfectant) are effective. Dilute and apply, but avoid contact with food and utensils. Suitable for surfaces.

Is the Novel Coronavirus Sensitive to 84 Disinfectant?

Yes.

The virus is heat-sensitive and can be killed at 56°C for 30 minutes. Chlorine-based disinfectants, alcohol, iodine, and peroxides are also effective. Use 75% alcohol or iodine for skin disinfection. For home disinfection, 84 Disinfectant, bleach, or other chlorine-based products (≥500 mg/L) can be used. Heat-resistant items can be boiled for 15 minutes.

Is the Novel Coronavirus Sensitive to All Disinfectants? Can Hydrogen Peroxide Be Used?

No. According to UpToDate, common disinfectants like PCMX, benzalkonium chloride, and chlorhexidine are ineffective against coronaviruses.

Hydrogen peroxide works, but commercial solutions vary in concentration. Medical-grade is typically 3%. High concentrations can damage skin—avoid direct contact.

What to Do If Someone Nearby Is Infected with COVID-19?

If you suspect infection, wear a mask, maintain >2 meters distance, and advise the person to seek medical care. If confirmed:

• Report to local authorities and follow guidelines.
• Avoid spaces visited by the infected person.
• Wash hands, disinfect, and ventilate frequently.

Can Suspected or Confirmed COVID-19 Cases Self-Isolate at Home?

No.

Confirmed/suspected cases and asymptomatic carriers must be isolated or treated at designated facilities to minimize transmission. Close contacts should undergo centralized quarantine or monitored home isolation^[9].

Is Disinfecting Keys and Phones Necessary During the Pandemic?

Yes.

COVID-19 spreads via contact. Disinfecting frequently touched items (keys, phones, outerwear) reduces infection risk.

Can Bathing or Saunas Kill the Virus?

No.

Viruses die at 56°C for 30 minutes, but bathing/saunas don’t reach this threshold. Still, regular hygiene lowers infection risks.

Can I Open Windows Near a Fever Clinic?

Yes.

Hospital designs ensure safe distances. Residential buildings nearby remain safe.

Can I Open Windows If a Neighbor Is in Home Quarantine?

Yes.

Risk is negligible unless windows are adjacent and the neighbor coughs directly toward yours.

Can Central Air Conditioning Be Used During the Pandemic?

Depends on the setting.

Home systems are safe unless someone is isolated indoors. Public/commercial systems (hotels, malls) may spread viruses if contaminated—evaluate after disinfection.

Can Air Purifiers Replace Ventilation?

Partially, but don’t rely solely on them.

Purifiers filter droplets carrying viruses but don’t disinfect. Ventilation remains superior.

How Should Pregnant Women Manage Checkups and Delivery?

Continue hospital visits with precautions:

• Wear surgical/N95 masks.
• Avoid lingering post-appointment.
• Discard masks properly; wash hands thoroughly.
• Seek fever clinics if symptoms arise.

Dietary Advice During the Pandemic?

Avoid sick animals; buy chilled poultry from reliable sources. Cook thoroughly. Separate raw/cooked food tools; wash hands between handling.

Is Takeout Safe?

Yes.

Cooking heat minimizes risk. Choose reputable vendors, opt for contactless delivery, disinfect packaging, and wash hands before eating.

Infection Risk on Public Transport After a Carrier?

Low but not zero.

Close contact defines exposure, but rare cases of indirect transmission exist.

How to Ventilate in Cold Weather?

Open windows 15–30 minutes (morning/noon/evening) when outdoor air is clean. Reduce frequency if pollution is high.

Should You Exercise During the Pandemic?

Yes. Follow three principles:

• Comprehensive training: Target all body parts and systems.
• Gradual progression: Increase intensity slowly.
• Consistency: Make it a lifelong habit.

PREVENTION

Can COVID-19 infection be prevented? How to prevent it?

Vaccination is an important method to provide immunity and prevent severe illness and death. Currently, there are no effective drug-based preventive measures.

To prevent COVID-19 infection, the following measures should be taken:

• Avoid high-risk areas. If you have visited medium- or high-risk regions, report it promptly, avoid false or concealed reporting, and undergo testing and self-isolation.
• Avoid crowded places, minimize the use of public transportation and taxis, and stay away from enclosed, poorly ventilated public spaces or gatherings, especially for children, the elderly, and immunocompromised individuals. Wear a mask when going out and maintain a safe social distance of at least one meter from others.
• Ventilate rooms at least twice a day for no less than 30 minutes each time to improve air circulation and reduce respiratory infections.
• Maintain personal hygiene. Wash hands frequently with soap and running water or use alcohol-based hand sanitizer. Cover your mouth and nose with a tissue or elbow when sneezing or coughing—avoid using your hands directly.
• Avoid sharing personal items such as dishes, glasses, or bedding with others.
• Seek medical attention promptly if symptoms like fever (especially persistent high fever), cough, or shortness of breath occur. Wear a mask and visit a healthcare facility immediately.
• High-risk individuals should consider getting vaccinated against COVID-19^[4,9].

How to choose a mask during the COVID-19 pandemic?

Wearing a mask is an effective way to block respiratory droplet transmission. Common masks available include medical protective masks (e.g., N95), surgical masks, and standard disposable medical masks. Additionally, there are cloth masks, sponge masks, and other "trendy masks" often worn by celebrities.

For daily protection, surgical masks are sufficient. N95 masks offer better protection but are less breathable and uncomfortable for prolonged wear.

How to use masks properly during the COVID-19 pandemic?

• Disposable medical masks: Recommended for the public in non-crowded public areas.
• Surgical masks: Recommended for public transport staff, sanitation workers, taxi drivers, and service personnel in public places.
• N95/KN95 particulate respirators: Recommended for frontline workers conducting investigations, sampling, or testing, or for the public in highly crowded areas.
• Medical protective masks: Recommended for healthcare workers in isolation wards or during confirmed patient transfers.

How to wear a mask correctly during the COVID-19 pandemic?

Fully unfold the mask, covering the mouth, nose, and chin, then press the nose clip to ensure a snug fit against the face.

Wash hands before wearing a mask or avoid touching the inner side while putting it on. Identify the inside (light-colored side) and outside (dark-colored side) of the mask, with the metal strip (nose clip) on top. Replace masks regularly—do not wear them inside out or reuse them alternately.

Can expired masks be used during the COVID-19 pandemic?

Expired masks are generally not recommended for use.

Surgical masks are sterilized, and expired ones may harbor bacteria. Under special circumstances, check if the packaging is dry, undamaged, and free of mold, odor, or discoloration before use as a backup.

Can masks be skipped in uncrowded areas during the COVID-19 pandemic?

Masks are necessary in crowded or poorly ventilated places where virus exposure is possible. They are also required if you have symptoms like coughing or fever to prevent infecting others.

Can masks be reused during the COVID-19 pandemic?

Surgical masks should not be reused.

N95 masks are also meant for single use, but due to shortages, they may be reused up to five times if no fever or respiratory symptoms (runny nose, sneezing, congestion) are present. However, reuse carries risks.

Handwashing is crucial—wash hands with soap and water for at least 20 seconds to kill pathogens and prevent transmission via touching the face.

What precautions should be taken after returning from a high-risk area during the COVID-19 pandemic?

Monitor your health and avoid public places if you have visited high-risk areas. Seek medical attention immediately if symptoms like fever, fatigue, dry cough, muscle pain, or shortness of breath occur. Disclose your travel and contact history to healthcare providers.

How to wash hands effectively during the COVID-19 pandemic?

Wash hands before meals, after using the toilet, returning home, handling garbage, or touching animals. Use soap and running water, scrubbing for at least 20 seconds. Follow the seven-step technique: palms, back of hands, fingers, knuckles, thumbs, fingertips, and wrists.

1. Palm to palm.
2. Palm to back of hand.
3. Fingers interlaced.
4. Knuckles bent and scrubbed.
5. Thumbs rotated in palms.
6. Fingertips rubbed in palms.
7. Wrists cleaned.

Use alcohol-based hand sanitizer if hands are not visibly dirty, and avoid touching the eyes, nose, or mouth with unwashed hands.

What dietary precautions should COVID-19 patients take?

Follow the Dietary Guidelines for Chinese Residents for balanced nutrition. Eat a variety of foods, including whole grains, lean proteins, fresh fruits, and vegetables. Stay hydrated and avoid unverified remedies claiming to treat COVID-19. Seek medical care at designated hospitals if symptoms appear.