Useful Information on Covid 19 Infection Caused by SARS-CoV2
Covid 19 infection caused by the SARS-CoV 2 virus has become a global pandemic. It started in China in late December 2019 and has rapidly spread to many countries across the world. As of now, the overall trends show an increase in the total number of cases as well as deaths, especially in Europe and USA. There is a real possibility of Covid 19 escalating to alarming levels, if we do not take appropriate precautions now. Today, there is information overload, especially on social media sites, many of which are not authentic and are inaccurate. This leads to misinformation. In this write up, I wish to share the current information regarding Covid 19 in the form of questions and answers, with references of reliable sources as needed.
Q: Is there a specific country or region, which is immune to Covid 19 infection?
A: Covid 19 does not spare any particular country; region and it has already spread to all regions.
Q: Will countries with warmer climates be spared from Covid 19 outbreaks?
A: As of now, there is no evidence of that. Viruses multiply within human body and human-to-human transmission can continue in countries with warmer climates too. Moreover, at room temperature, the viruses can survive for several days.
Q: Would Covid 19 transmission stop in summer or in warmer climates?
A: No. Covid 19 transmission will not stop in summer or warmer climates. Transmission rates are lower in warmer and more humid climates, as compared to cooler and more dry climates. However, after a temporary dip, the case numbers of Covid 19 are likely to go up as winter approaches, if other precautions (social distancing, isolation, etc) are discontinued. (Ref: Center for Communicable disease dynamics, Harvard)
Q: Are there any age or gender-related differences?
A: Children below 10 have milder infections, with extremely low mortality. On the other hand, older people especially those aged 80 and above have more severe infections. They have a greater need for ICU care & mechanical ventilation and have a higher mortality. Women have less severe infections and lesser death rates, as compared to men.
Q: What are the common symptoms of Covid 19 infection?
A: Common symptoms are fever, cough and difficulty in breathing.
Q: What is known about Covid 19 infection in children?
A: It is reassuring to note that infections in children are milder and often asymptomatic. The mean age of affected children is 6-7 years. Severe infections occur in fewer children and less than 2% require mechanical ventilation. Death rate is <1%. (Ref: NEJM, Mar 18, 2020)
Q: How does the Covid 19 infection spread?
A: 1. It can spread by inhalation of droplets released from the sneeze of infected persons. Viruses can survive for at least a few hours in air in the form of aerosols.
2. These droplets can remain on surface (fomites) and viruses can survive for several days on them. When a person touches those surfaces with hands, the hands get infected. Infection can spread if the person touches eyes, nose or mouth with those hands. They survive longer on stainless steel and plastic, as compared to cardboard and copper. (Ref: NEJM, Mar 17, 2020)
Q: What precautions can one take to avoid the spread of infection?
A: 1. Those with a travel history to covid 19 infections should be quarantined for 14 days, so that they do not expose others to the infection.
2. Those with respiratory symptoms (such as cough, fever, sore throat, etc) should also self-isolate themselves at home.
3. Those who are asymptomatic or have no travel history should follow the following: washing hands frequently with soap & water or alcohol-based sanitizer, avoid touching eyes, nose & mouth with hands, avoid crowded areas, avoid going out as much as possible. Social distancing (maintaining 3 feet or one meter distance from each other) is also important.
Q: Are some people more prone to acquire Covid 19 infection?
A: Yes, the following groups of people are more people to acquire Covid 19 infection. These groups also have a more severe form of infection and higher death rates than others. These include: Older people, people with heart disease, diabetes, hypertension and cancer, people on immunosuppressive drugs (after transplant, for rheumatological or immunological disorders, etc)
Q: Are masks mandatory for everyone?
A: No, everyone need not wear masks. Healthcare professionals who are taking care of patients suffering from Covid 19 or other respiratory infections require masks. Persons who are suffering from a respiratory infection should also wear masks in order to prevent spread of infections.
Q: Can a person without any symptoms (asymptomatic people) spread Covid 19 infection?
A: Yes. Virus shedding begins even before symptoms show up. So, a person can transmit the infection to others 2-4 days prior to the day, when symptoms first show up. (NEJM, Mar 5, 2020)
Q: Is there a vaccine or tablet one can take to prevent Covid 19 infection?
A: No. There are multiple vaccines undergoing clinical trials. Hydroxychloroquine (HCQ) is also being tested to see whether it can prevent Covid 19 infection in a person not previously infected. So, at present no vaccine or tablet can be recommended to prevent the infection.
Q: Are there any treatments available for Covid 19 infection?
A: There are several treatments being tried and initial reports have been encouraging. However, these are small studies and data available is not very strong.
- Chloroquine (500 mg twice daily for 10 days) was compared with hydroxychloroquine (400 mg twice daily on day 1 followed by 200 mg twice daily from days 2 to 5). HCQ was found to be more potent and less toxic. HCQ has anti-inflammatory properties and stops the cytokine storm that occurs in advanced stages of covid 19 infection. (Clin Infect Dis, Mar 9, 2020). Both chloroquine and HCQ can cause prolongation of QT interval (on ECG), especially in people with hepatic or renal disease. HCQ is safe in pregnancy.
- HCQ along with azithromycin: Combination of HCQ and azithromycin is more effective than HCQ alone. HCQ dose: 200 mg thrice daily for 10 days. Azithromycin dose: 500 mg on day 1, 250 mg from days 2 to 5. Limitation was that this was tested on a small number of patients: 14 on HCQ alone, 6 both HCQ and azithromycin, 16 controls (no medicines). Treatment resulted in clearing the nasopharyngeal region from virus as early as on day 3 of treatment (normally viral shedding may continue for 20 days). (Ref: International Journal of Antimicrobial Agents, 17 Mar, 2020)
- Remdesivir: It is a broad spectrum antiviral drug that inhibits viral replication through premature termination of RNA transcription. For patients in US, they can get this as part of clinical trials. Patients with pneumonia, who are not a part of clinical trials, can request remdesivir for compassionate use from manufacturers (firstname.lastname@example.org (Ref: CDC website)
- Lopinavir-Ritonavir along with standard care was NOT BETTER than standard care alone in 199 adults on whom they were tested. (Ref: NEJM, Mar 18, 2020)
In conclusion, these treatments are still not fully proven. These should be taken only after prescription from a doctor and should not be self-prescribed.
Q: Who should be tested for Covid 19 infection?
A: All cannot and need not be tested for two reasons. 1. Testing is expensive and not widely available, 2. Treatment is mild in a majority and patients recover on own (testing would not change the outcome). The following groups of people should be tested for Covid 19 infection:
Current testing strategy (as per ICMR, 20th March, 2020)
- All asymptomatic individuals who have undertaken international travel in the last 14 days:
- They should stay in home quarantine for 14 days.
- They should be tested only if they become symptomatic (fever, cough, difficulty in breathing)
- All family members living with a confirmed case should be home quarantined
2. All symptomatic contacts of laboratory confirmed cases.
3. All symptomatic health care workers.
4. All hospitalised patients with Severe Acute Respiratory Illness (fever AND cough and/or shortness of breath).
5. Asymptomatic direct and high-risk contacts of a confirmed case should be tested once between day 5 and day 14 of coming in his/her contact.
Dr Sudhir Kumar MD DM
Apollo Hospitals, Hyderabad, India