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Frequently Asked Questions on Coronavirus Disease 2019 (COVID-19)

Frequently Asked Questions on Coronavirus Disease 2019 (COVID-19)
2022-06-29
  1. What is novel infectious disease?
  2. What is a novel coronavirus?
  3. What is Coronavirus Disease 2019 (COVID-19)?
  4. What are the symptoms of COVID-19?
  5. What is the mode of transmission of COVID-19?
  6. What is incubation period? How long is it for COVID-19?
  7. What is the treatment for COVID-19?
  8. Is the death rate very high for COVID-19?
  9. Will there be no symptom for COVID-19? Will patients die suddenly on the street?
  10. Will COVID-19 disappear spontaneously when the weather becomes warm?
  11. How to prevent COVID-19?
  12. What preventive measures should be taken when travelling outside Hong Kong?
  13. What is the function of a mask?
  14. Can young children wear a face mask?
  15. What are the other measures to prevent respiratory tract infection other than wearing a mask?
  16. After cleaning the hands with water and liquid soap, how should the faucet be turned off?
  17. If there is no water and liquid soap, can I use alcohol-based handrub instead?
  18. What are cough manners?
  19. Why is it important to properly maintain drainage pipes and regularly re-fill U-traps?
  20. Is ozone disinfection effective?
  21. Should consumers sanitise food packaging?
  22. What to take note of when using disinfectants?
  23. Why a mobile phone number that can receive local SMS and phone calls is important?

1. What is novel infectious disease?

Novel infectious disease is an infectious disease that has newly appeared in a human population. It may be caused by any infectious agents such as virus, bacteria or parasites which the human population has low or no pre-existing immunity. It may result in mortality and morbidity of different severity and may cause sustained community outbreak or proceed to a pandemic.

2. What is a novel coronavirus?

Coronaviruses are a large family of viruses found in both animals and humans. Some infect people and are known to cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS).

3. What is Coronavirus Disease 2019 (COVID-19)?

"Coronavirus disease 2019 (COVID-19)" is the disease caused by a new coronavirus called “SARS-CoV-2”.

4. What are the symptoms of COVID-19?

The most common symptoms of COVID-19 include fever, dry cough and fatigue. Other symptoms include loss of taste or smell, nasal congestion, conjunctivitis, sore throat, headache, muscle or joint pain, skin rash, nausea or vomiting, diarrhoea, chills or dizziness. Some people may only have very mild or non-specific symptoms, while some may develop severe symptoms like shortness of breath, chest pain or confusion.

Complications may include respiratory failure, acute respiratory distress syndrome (ARDS), sepsis and septic shock, thromboembolism, and/or multi-organ failure including injury of the heart, liver or kidneys. There are reports that children and adolescents with COVID-19 may develop a rare but serious condition known as multisystem inflammatory syndrome in children (MIS-C), leading to multi-organ failure and shock.

People of older age and those with underlying medical problems (e.g. hypertension, heart and lung problems, diabetes, obesity or cancer) are at higher risk of developing serious illness.

According to the information from the World Health Organization (WHO), approximately 10-20% of people may continue to experience mid- and long-term effects of COVID-19, including fatigue, respiratory and neurological symptoms. According to the WHO, these effects are collectively known as “Post COVID-19 condition,” or “Long COVID”. Although it is still unclear how long the symptoms may last, current research suggests that patients can improve with time.

5. What is the mode of transmission of COVID-19?

Mode of transmission includes through respiratory droplets, contact of contaminated surfaces or objects, short-range aerosol or short-range airborne transmission. The virus can also spread in poorly ventilated and/or crowded indoor settings.

6. What is incubation period? How long is it for COVID-19?

The "incubation period" means the time between catching the virus and beginning to have symptoms of the disease. Most estimates of the incubation period range from 1 to 14 days, and some variants, such as the Omicron variant, may have even shorter incubation period of around 3 days.

7. What is the treatment for COVID-19?

Treatment includes supportive therapy, symptomatic treatment, antiviral agents and Chinese medicine.

8. Is the death rate very high for COVID-19?

Please refer to :“Provisional Data Analysis on Reported Death Cases”.

COVID-19 vaccines are effective to protect people against COVID-19 disease, in particular severe illness and death.

On the other hand, both Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), are respiratory tract disease caused by coronavirus. The former carries a death rate of about 9.6% while that of the latter exceeds one third.

9. Will there be no symptom for COVID-19? Will patients die suddenly on the street?

The most common symptoms of COVID-19 include fever, dry cough and fatigue. Some people may only have very mild or non-specific symptoms, while some may develop severe symptoms like shortness of breath, chest pain or confusion. When having respiratory symptoms, wear a surgical mask, refrain from work or attending class at school, avoid going to crowded places and seek medical advice promptly.

10. Will COVID-19 disappear spontaneously when the weather becomes warm?

A study found that coronaviruses typically survive longer and stay active longer at lower temperatures in a dry environment.

11. How to prevent COVID-19?

COVID-19 vaccination

  • COVID-19 vaccines are effective to protect people against COVID-19 disease, in particular severe illness and death.
  • Vaccination is one of the tools in the overall public health response to COVID-19. The combination of non-pharmaceutical interventions (NPIs) with vaccination will allow for maximum protection against the virus.
  • With COVID-19 vaccines deployed, there is a need to continue NPIs, including social distancing, good hand hygiene and wearing a mask in public, to reduce the risk of virus transmission. NPIs should continue to be followed by vaccinated individuals, as well as those who have not yet been vaccinated.
  • For details on COVID-19 vaccination, please refer to thematic website for COVID-19 Vaccination Programme: www.covidvaccine.gov.hk

Health advice

Members of the public are urged to go out less and reduce social activities such as meals gatherings or other gatherings, and maintain appropriate social distance with other people as far as possible.

To maintain at all times strict personal and environmental hygiene is key to personal protection against infection and prevention of the spread of the disease in the community:

  • Well-fitted surgical mask can prevent transmission of respiratory viruses from ill persons. It is essential for persons who are symptomatic (even if having mild symptoms) to wear a well-fitted surgical mask;
  • Wear a surgical mask when taking public transport or staying in crowded places. It is important to wear a mask properly, including hand hygiene before wearing and after removing a mask;
  • Avoid touching your eyes, mouth and nose before washing hands;
  • Perform hand hygiene frequently, especially before touching one's mouth, nose or eyes; before eating; after using the toilet; after touching public installations such as handrails or door knobs; or when hands are contaminated by respiratory secretions after coughing or sneezing;
  • Cover your mouth and nose with tissue paper when sneezing or coughing. Dispose of soiled tissues into a lidded rubbish bin, then wash hands thoroughly;
  • Wash hands with liquid soap and water, and rub for at least 20 seconds. Then rinse with water and dry with a disposable paper towel. When the hands are cleaned, do not touch the water tap directly again (for example, using a paper towel to wrap the faucet before turn it off). If hand washing facilities are not available, or when hands are not visibly soiled, performing hand hygiene with 70 to 80% alcohol-based handrub is an effective alternative;
  • After using the toilet, put the toilet lid down before flushing to avoid spreading germs; and
  • When having respiratory symptoms, wear a surgical mask, refrain from work or attending class at school, avoid going to crowded places and seek medical advice promptly.
  • Maintain good indoor ventilation;
  • Home should be cleaned thoroughly at least once per week with 1 in 99 diluted household bleach (mixing 10 ml of bleach containing 5.25% sodium hypochlorite with 990 ml of water), leave for 15 - 30 minutes and then rinse with water. For metallic surface, disinfect with 70% alcohol;
  • If places are contaminated by respiratory secretions, vomitus or excreta, use strong absorbent disposable towels to clean up the visible matter. Then disinfect the surface and the neighbouring area with appropriate disinfectant. For nonmetallic surface, disinfect with 1 in 49 diluted household bleach (mixture of 10ml of household bleach containing 5.25% sodium hypochlorite solution with 490ml of water), leave for 15 - 30 minutes, and then rinse with water. For metallic surface, disinfect with 70% alcohol;
  • Maintain drainage pipes properly and regularly (about once a week) pour about half a litre of water into each drain outlet (U-traps) to ensure environmental hygiene;
  • Build up good body resistance and maintain healthy lifestyle. This can be achieved through balanced diet, regular exercise and adequate rest and
  • Do not smoke and avoid alcohol consumption.

12. What preventive measures should be taken when travelling outside Hong Kong?

Members of the public are strongly urged to avoid non-essential travel outside Hong Kong. If it is unavoidable to travel to countries/areas outside Hong Kong, they should take heed of the health advice below:

  • Complete COVID-19 vaccination before travel according to the latest recommendations to effectively protect against COVID-19 disease (For details on COVID-19 vaccination, please refer to thematic website for COVID-19 Vaccination Programme: www.covidvaccine.gov.hk);
  • Avoid visiting crowded places and maintain appropriate social distance with other people as far as possible;
  • Wear a surgical mask and maintain at all times strict personal and hand hygiene;
  • Perform hand hygiene frequently, wash hands with liquid soap and water, and rub for at least 20 seconds, then rinse with water and dry with a disposable paper towel; If hand washing facilities are not available, or when hands are not visibly soiled, performing hand hygiene with 70 to 80% alcohol-based handrub is an effective alternative;
  • Adhere to food safety and hygiene rules such as avoiding consuming raw or undercooked animal products, including milk, eggs and meat, or foods which may be contaminated by animal secretions, excretions (such as urine) or contaminated products, unless they have been properly cooked, washed or peeled;
  • If feeling unwell when outside Hong Kong, especially if experiencing respiratory symptoms, wear a surgical mask and seek medical advice at once; and
  • After returning to Hong Kong, consult a doctor promptly if experiencing any symptoms, take the initiative to inform the doctor of any recent travel history, and wear a well-fitted surgical mask to help prevent spread of the disease.

13. What is the function of a mask?

Face mask provides a physical barrier to fluids and large particle droplets. Surgical mask is a type of face mask commonly used. Choose an appropriate size to completely cover nose, mouth and chin without gaps. Attain good seal with the face by minimising air leak from edges.

Most surgical masks adopt a three-layer design which includes an outer fluid-repelling layer, a middle layer serves as a barrier to germs, and an inner moisture-absorbing layer. Mask without the above functions is not recommended as it cannot provide adequate protection against infectious diseases transmitted by respiratory droplets. Masks with exhalation valve or vents which allow exhaling air to escape should not be used due to the fact that exhaled air are unfiltered and may pose a risk to surrounding people if the wearer is infected with COVID-19 or other respiratory infectious diseases.

The general indications for wearing a surgical mask include:

  • To protect ourselves: When taking care of person with respiratory infection; or visiting hospitals or clinics during peak season for respiratory infectious diseases;
  • To prevent the spread of infection to others: When having respiratory symptoms, e.g. fever, runny nose, cough or sneeze.

14. Can young children wear a face mask?

Choose the appropriate mask size. Child size is available for selection as indicated:

  • Face mask (including surgical masks and cloth face coverings) is not recommended for children under the age of 2 years without supervision;
  • For newborns and young children under 2, there would be a chance of suffocation or other health risks if face mask is not properly used. In addition, young children like to touch or pull the mask on their face which increase the chance of infection;
  • Parents are advised to let infants and young children stay at home as much as possible and avoid bringing them to unnecessary social gathering or playgrounds. If there is a need to go out, choose less crowded places and remember to keep the social distance between children and other people, avoid touching things around or perform hand hygiene immediately after touching;
  • Caretaker should ensure their own hygiene before handling young children. Keep your hands clean and wear mask when feeding your baby.

15. What are the other measures to prevent respiratory tract infection other than wearing a mask?

The following preventive measures, apart from wearing a well-fitted surgical mask, should be emphasised:

  • Hand hygiene is the single most important measure of reducing the spread of diseases. Members of the public should perform hand hygiene properly and frequently, especially before touching eyes, nose and mouth; before eating or preparing food; after using the toilet; when hands are contaminated by respiratory secretions, e.g. after coughing or sneezing; and after touching public installations or equipment, such as escalator handrails, elevator control, panels or door knobs.
  • Wash hands with liquid soap and water when hands are visibly soiled or likely contaminated with blood and body fluid. When hands are not visibly soiled, hands could be cleaned with 70 to 80% alcohol-based handrub;
  • Maintain respiratory etiquette and cough manners;
  • Stay at home if got sick and minimise contact with others;
  • Stay away from possible sources of infection and avoid contact with the infected persons by minimizing unnecessary social contacts and avoid visiting crowded places or shorten the length of stay whenever possible, especially for persons at a high risk of having infection-related complications, e.g. pregnant women or persons with chronic illnesses

16. After cleaning the hands with water and liquid soap, how should the faucet be turned off?

When the hands are cleaned, do not touch the water tap directly again. For example, one may use a paper towel to wrap the faucet before turn it off.

17. If there is no water and liquid soap, can I use alcohol-based handrub instead?

If your hands are not visibly soiled, you can use 70 to 80% alcohol-based handrub. It can effectively prevent cross transmission of infectious diseases via hands.

The hand rubbing technique of using alcohol-based handrub is similar to hand washing. Use sufficient amount, around 3 to 5 ml of alcohol-based handrub to cover all surfaces of your hands. Rub our palms, back of hands, finger webs, back of fingers, thumbs, finger tips, and wrists. Rub hands for at least 20 seconds until your hands are dry. Let the alcohol dry on your hands, do not wipe it off with paper towel. Check the expiry date of alcohol-based handrub before using.

18. What are cough manners?

Cover your mouth and nose with tissue paper when sneezing or coughing. Dispose of soiled tissues into a lidded rubbish bin, then wash hands thoroughly. If tissue paper is not available, you can cover your mouth and nose with your blouse or upper sleeve.

19. Why is it important to properly maintain drainage pipes and regularly re-fill U-traps?

U-traps serve to stop foul smells and unhygienic substances (including bacteria and viruses) in the drainage system from entering living areas. Defective or dried U-traps could negate this important function.

Pour half a litre of water into each drain outlet every week. Besides, one should regularly inspect their drainage pipes, U-traps and sanitary fittings and arrange immediate repair if damage is found.

20. Is ozone disinfection effective?

Ozone irritates the eyes and respiratory tract. It can cause serious damage to the lung if inhaled in high concentrations.

If used at concentrations that do not exceed public health standards, ozone applied to indoor air does not effectively remove viruses, bacteria, mold, or other biological pollutants.

21. Should consumers sanitise food packaging?

The risk of acquiring the novel coronavirus through food packaging is very low. In fact, contaminated hands play a significant role in facilitating indirect contact transmission by transferring the infectious virus from one surface to another and even into one’s body. Instead of food packaging, transmission is more likely to happen in contact with certain high-touch points, such as door handles, handles of the shopping trolleys and water taps – the more frequently being touched by different people the higher the risk that it becomes contaminated. Therefore, while some people may still opt to disinfect food packaging surfaces with common household disinfectants such as alcohol-based wipes or sprays if needed, it is more important for people to wash their hands thoroughly, especially before touching eyes, nose and mouth, after returning home from grocery shopping, and after handling and storing purchased products.

Points to note if disinfection of packaging would be performed:

  • Disinfectant should (i) Be proofed to be effective against SARS-CoV-2; (ii) Compatible to the packaging material; (iii) Used according to the manufacturer recommendations.
  • Perform hand hygiene after cleaning and disinfection of the packaging.

22. What to take note of when using disinfectants?

Disinfectant and relevant equipment should be used properly. Improper use may lead to adverse health effects and environmental contamination.

Follow the manufacturer’s instructions to ensure that disinfectant and relevant equipment are handled and used safely and effectively. Pay particular attention to information about application and safety, such as the recommended use, concentration and contact time, items and surfaces compatible with the disinfectant, stability of the product, hazard warning, storage method and personal protective equipment required when using the product. Keep disinfectant out of reach of children and pets. To prevent accident, do not pour disinfectants into other containers with different labels.

Improper use of disinfectant and relevant equipment may lead to adverse health effects to users. The adverse health effects caused by disinfectants are dependent on several factors, such as chemical ingredients of disinfectant, exposure duration and concentration, route of exposure, the individual state of health, and environmental conditions. In general, direct contact to disinfectant may cause irritations on eye, skin and respiratory tract. It may affect the lung if inhaled, or even fatal if used incorrectly.

Keep well ventilated while using disinfectant.

Spraying of people with disinfectants is not recommended. This practice could be harmful to health and would not reduce an infected person’s ability to spread the virus.

In indoor spaces, routine application of disinfectants to environmental surfaces via spraying is generally not recommended because it is ineffective at removing contaminants outside of direct spray zones and can cause eye, respiratory, and skin irritation and other toxic effects. If disinfectants are to be applied, these should be via a cloth or wipe which is soaked in the disinfectant.

23. Why a mobile phone number that can receive local SMS and phone calls is important?

When you are staying in Hong Kong, you need a valid mobile phone number that can receive SMS and phone calls locally in Hong Kong. Otherwise, you may not be able receive important messages regarding COVID-19 testing results, quarantine, isolation and COVID-19 vaccination. These messages are very important for you to comply with relevant regulations and protect yourself. This phone number is also very useful for contact tracing purpose when positive cases are identified.