COVID-19 Quick Facts
Hello I'm Dr Leong. Today's talk will be on COVID-19.
A Suspected Case of COVID-19 needs to fulfil 2 criteria. One is the Clinical Criteria and the other is the Epidemiological Criteria. In the clinical criteria one has to have an acute fever and cough OR an acute illness with two or more of the following: fever, cough, general malaise, fatique, headache, myalgia, sore throat, coryza, dyspnea, anorexia, nausea, vomiting, diarrhea or altered mental status.
In the Epidemiological Criteria the suspected case needs to have been in the following places within the last 14 days prior to symptoms and signs. The case needs to have 1. stayed or worked in an area of high risk of transmission like in a close residentials example a nursing home or institutions like prison or immigration detention depot 2. stayed or travelled in an area with community transition or 3. worked in any healthcare setting.
A confirmed case is one who is tested positive RTK- Ag in areas of prevalence greater than 10% or cases tested positive with a molecular test, namely RT-PCR or a rapid molecular test.
This graph shows the probability of detection of SARS CoV2 over time. The incubation period of SARS Co V2 is about 5 days. Most infected persons will show symptoms or signs within 11 days of infection. During the onset of symptoms, RT- PCR testing will usually be positive. Before symptoms onset, RT-PCR testing can be negative even though the person is infective because of viral shedding. After the onset of symptoms, the RT-PCR test can be positive for up to 3 weeks. Commonly the infected person will no longer be infective to others after 14 days of symptom onset, even though the RT-PCR is still positive as the nasopharyngeal swabs contain detectable non-viable viral material. The infected person begins to develop antibodies to the virus after a week of symptom onset and the antibodies will be detectable at about the 2nd week. RT-PCR will likely be negative after the 3rd week of symptom onset.
SARs CoV2 mutation and variants. This chart shows the variants of concern. The Alpha, Beta, and Delta variants are present in Malaysia. The delta variant is of special concern as there is information suggesting increased transmissibility of the virus. There is also some suggestion of reduced neutralization of the virus by antibodies produced in our bodies by vaccination. But it is too early to say if vaccines are compromised.
Dr Noor Hisham reported in the Malay Mail that the variants of concern like beta and delta are already present in Malaysia.
Clinical stages of COVID-19 infection. There are five categories. Category 1 – asymptomatic. Category 2 - symptomatic but no pneumonia. Category3 - symptomatic with pneumonia. Category 4 - symptomatic with pneumonia and requiring oxygen. Category 5 – the critically ill with multi-organ involvement. Persons in Category 1 and 2 maybe opt for home quarantine. Whereas persons in Category 3 to 5 will need hospital admission.
Category 2 can be divided into mild and moderate. The moderate cases who have RED FLAG symptoms may need to be admitted to hospital for observation. The RED FLAG symptoms are - persistent or new onset fever, exertional dyspnea, chest pain, unable to tolerate orally, worsening lethargy, unable to ambulate without assistance, worsening or persistent symptoms such as cough, nausea, vomiting, or diarrhea, reduce level of consciousness. or reduced urine output in the last 24 hours.
Confirmed cases of COVID-19 can undergo home quarantine or be admitted to hospital for observation. Persons in Category 1 and 2, with mild symptoms, can undergo home quarantine. However should the Category 2 status change with RED FLAG symptoms they better be observed in hospital. Persons in Category 3 - 5 should be admitted to hospitals.
A person may undergo home quarantine if he fulfills the following criteria: For adults the person should be less than 40 years and without comorbidities; like diabetes, cardiovascular disease, chronic lung disease, chronic kidney disease, hypertension, or obesity. The person needs to be able to ambulate without any assistance and also be able to self-administer medication. The person should have no ongoing clinical needs, like hemodialysis, not pregnant and is not immunocompromised.
For pediatric patients, who are in Category 1, they should not have any comorbidity and with a suitable caregiver. Children in Category 2 with mild symptoms should be more than two years old, with no comorbidities and with suitable caregivers.
The home condition should be suitable and the person must be able to adhere strictly to SOP.
Caregivers who are suitable should not be more than 60 years old, are not pregnant, without comorbidities, are not immunocompromised and with no disease considered high risk by health personnel.
The home should be suitable. A telephone should be available at all times. The isolation room should preferably have an attached bathroom. The other occupants in the house are not immunocompromised and appropriate caregivers should be present in the house.
The person should be able to adhere strictly to SOP. The person should stay at home, maintain physical distance with other household members and there should be no visitors. The person must wear a mask, wash hands regularly and practice cough etiquette. The person must be able to report health status to health care providers through MySejahtera App. The eating utensils, tableware should be used exclusively for the person.
The national COVID-19 immunization program is on a voluntary basis, is free for all Malaysians and non-Malaysian residing in the country. It is for everyone of age 18 years and above. Currently the age has been extended to cover 12 years and above using the Pfizer vaccine. The immunization target is to cover 80% of the Malaysian population. We are currently in Phase 3 of the program. The immunization program will be completing sometime at the end of this year.
Portfolio of Vaccine in Malaysia are from the following manufacturers: Pfizer, SinoVac, Astra Zeneca, Johnson and Johnson and CanSino.
The Pfizer vaccine uses the mRNA technology. The Astra Zeneca, Jansen, CanSino vaccines use the viral vector technology. SinoVac is of the inactivated virus technology.
As of June the registration for immunization has reached almost 60% of the population in Malaysia. From the graph you can see the accelerated growth for vaccination. There is an increase in demand by the population and vaccine roll out by the government.
Selangor, Sarawak, Kuala Lumpur and Putrajaya will reach vaccination target in August. Labuan will reach vaccination target earlier in July. Perak will reach the 50% target in September and full target by year end.
Vaccine adverse events are very uncommon. Of note with mRNA vaccines is heart inflammation (myocarditis and pericarditis) This adverse event occurs several days after vaccination. It mostly affect males, adolescent and young adults of 16 years and above. The presenting symptoms are chest pain, difficulty breathing and palpitation. The Pfizer vaccine is a mRNA vaccine. The occurrence of the adverse event is about 2 per 100,000 population, aged between 16- 39 years.
Another adverse event of concern is Thrombosis with Thrombocytopenia Syndrome. (TTS). It occurs 4 to 30 days post vaccination. TTS may present as cerebral venous sinus thrombosis. The illness presents with severe headache, worse by lying down or bending over, and is associated with blurred vision, nausea and vomiting, difficulty with speech, weakness, drowsiness, or even seizures.
There may even be unexplained bruising or bleeding. Some may experience shortness of breath, chest pain, leg swelling or persistent abdominal pain.
The Astra Zeneca and Jansen vaccines are viral vector vaccines. These adverse events are very rare with 2 - 4 events per million vaccinated.
The national recovery plan has 4 Phases. There are 3 conditions to be met under each phase. The conditions include 1. the number of daily cases 2. ICU bed availability and 3. The percentage of population vaccinated.
In Phase 1 only essential services are allowed. In Phase 2, some economic sectors to reopen while the social sector remains closed. In Phase 3, more economic sectors to reopened, the social sector is reopened gradually, Parliament and schools to reopened as well. In Phase 4, there is full reopening of the economy. Phase 4 is projected to occur sometime in November and December this year.
This chart shows the number of observed and forecast cases in the month of April and June. R0 is the basic reproduction number of an infection. The rate of infection rises when the R0 is greater than 1 and declines when the R0 is less than 1. We currently have a R0 of less than 1 with declining number of cases.
As you can see from this chart, there has been an increasing number of hospitals managing COVID-19 cases. The number of ICU beds and ventilators have also increased.
As such, with deceasing number of cases and increased number of ICU beds we can expect ICU bed utilization will decrease.
More than 10% of the population is already vaccinated. We shall soon reach our 40% and 60% target soon and will help speed up our National Recovery Plan.
There is a very low risk of viral transmission from surfaces and outdoor activities. However there is a very high risk of viral transmission from gatherings in enclosed spaces, like in offices, religious places, cinema halls, gyms and theaters.
The COVID virus is mainly transmitted via droplets and contact routes. However airborne transmission is possible for example while performing aerosol generating procedures. There has been no report of faecal- oral transmission to date.
A viral dose of about 1000 virus particles is needed before a person becomes infected. During normal breathing about 20 vp are shed in a minute. While speaking about 200 vp. Coughing and sneezing expel about 200 million vp into the air and these vp can remains in the air for hours in poorly ventilated environments.
The infectious dose is dependent on the number of virus particles multiplied by time.