Epidemiological Brief Nº5: 17 May – 23 May, 2021
A regular brief edited by: (1) Pilar 3 & Pilar 5 of the Ministry of Health (as part of the Task Force for the Prevention and Mitigation of Covid-19 Outbreak, Integrated Centre for Crisis Management, Situation Room); (2) Intituto Nasional de Saúde;
- Menzies School of Health Research; (4) AusMAT; (5) CoMo Consortium (6) National Centre for Immunisation Research and Surveillance; (7) WHO.
Cumulative cases: 5,637 (1,167 cases since last report).
Data current as at 23 May 2021.
1. Epidemic curve
The epidemic curve shows the total case numbers for each day, in the green bars (measured against the y-axis on the left hand side of the graph). The blue line shows the cumulative total case numbers (measured against the y-axis on the right hand side of the graph), which have risen now to 5,637 since the beginning of the global pandemic (as at 23 May, 2021). In the past week, the curve has not been as steep, compared to previous weeks.
There has been an increase in cases in Bobonaro Municipality in the last week with a number of healthcare workers notified with infection. The epidemic curve of cases reported cases in Bobonaro is below and shows the number of cases reported per day (green bars) and the cumulative cases of COVID-19 (represented by blue line).
2. Hospitalisations and mortality
Approximately 8% of cases diagnosed in Timor-Leste between 17 May 2021 and 23 May 2021 were symptomatic. Since 1 March 2021, there have been 135 people with COVID-19 who have required hospitalisation. Hospitalisation numbers only include those with moderate, severe and critical disease, who need treatment in specialised healthcare facilities for COVID-19.
This graph shows the cases that have needed hospitalisation since March 2021 in green bars. The blue line shows the cumulative number of people who have needed hospitalisation.
There have been 13 people who have died with COVID-19 including 3 who died since the last report.
The case fatality rate measures what proportion of people who are known to have COVID-19, die with COVID-19. In Timor-Leste, the case fatality rate, based on known cases of COVID-19 and reported deaths, is 0.2%. This means that for every one thousand cases diagnosed, there have been 2 deaths. This is a lower case fatality rate than has been seen in other countries including Australia (3.0%), China (4.7%), Indonesia (2.8%) and Portugal (2.0%). It is a higher case fatality rate than has been seen in Singapore (0.05%). Countries with a low case fatality rate have had outbreaks
of infection that have mostly affected younger people, with a large proportion of cases identified through testing asymptomatic people. Countries with higher case fatality rates usually have seen large numbers of deaths in older people with COVID-19. In the past week in Timor-Leste, 78% (906/1167) of the diagnosed with COVID-19 were aged less than 40 years.
3. Incidence rate estimates
The incidence rate measures the number of confirmed cases in a population, per day, and is usually measured as cases per 100,000 people per day. The average daily notification rate for Timor-Leste over the past 7 days (17 May – 23 May, 2021) was
12.7 cases per 100,000 population per day, compared to 13.3 cases per 100,000 population per day in the previous reporting period.
The rate of infection in all municipalities over the last 7 days is reported in the table below.
|Rate per 100,000 population per day, from 17-23 May 2021
4. Prevalence estimates
Over the last week, the proportion of tests that were positive was 17% (compared to 19% in the previous reporting period). The prevalence of COVID-19 in Dili can be estimated, based on the proportion of people who test positive for COVID-19 when they are tested before travelling to leave the sanitary fence. In the seven days from the 17 May – 23 May 2021, there were 3,820 people tested for this purpose; 601 (15.7%) were positive. This can be used to estimate prevalence, and a calculation of 95% confidence intervals, suggests the current prevalence of COVID-19 in Dili is between 14.6% and 16.9%. This is similar to last reporting period.
5. Vaccination update
As at 22 May 2021, there have been over 55,000 doses of COVID-19 vaccine given in Timor-Leste. Following the second shipment of AstraZeneca vaccines, phase 2 of the rollout which started on 10 May 2021 and has seen over 28,500 more people in Dili municipality vaccinated with their first dose. Approximately 21% of people aged 18 years and above in Dili have received their first dose of COVID-19 vaccine. The current vaccination phase is especially targeting older people (aged over 60 years) and adults with underlying health conditions as these people are most at risk of suffering from severe COVID-19. While phase 2 of the rollout has commenced first in Dili, because the incidence of COVID-19 is highest there, the vaccination campaign will continue in Dili and other municipalities, firstly targeting older adults, those with underlying health problems, essential frontline workers, and then all other people aged 18 years and above. Vaccination using the 20,000 doses which arrived from Australia last Wednesday 19th May will continue this week in Dili municipality.
6. Epidemiological modelling
Epidemiological modelling is a way of trying to predict what might happen using available data and mathematical formulae. Modelling by the COVID-19 International Modelling (CoMo) Consortium has been updated using recent data from Vigilânsia Epidemiológica and the Laboratorio Nacional da Saude to revise predictions. The modelling shows that rapid rollout of COVID-19 vaccines and continuing public health measures like face masks, hand hygiene and physical distancing, can significantly reduce the impact of COVID-19 in Timor-Leste, reducing the number of cases, the burden on the health system, and the number of deaths.
Modelling is most useful in setting with established community transmission. In Dili, where there is community transmission already, the following graphs show the difference that a rapid rollout of vaccination can make in Dili. The green curve (baseline) shows the number of reported cases (dark green) and unreported cases (light green) expected in Dili if the vaccine rollout proceeds slowly, and public health measures are eased in June. The blue curve (hypothetical scenario) shows the number of reported cases (dark blue) and unreported cases (light blue) expected if the vaccine
rollout proceeds quickly over the next two months, with ongoing adherence to public health measures like face masks, hand hygiene and physical distancing.
If the sanitary fences in place for municipalities with higher incidence of COVID-19 are removed, there is a significant risk of spread to other municipalities, resulting in community transmission through the country. The following graphs, based on a situation of community transmission in the whole country, show the impact of rapid vaccination and ongoing adherence to public health measures in the whole country.
The green curve (baseline cases) shows the number of reported cases (dark green) and unreported cases (light green) expected if the vaccine rollout proceeds slowly, and public health measures are eased. The blue curve (hypothetical scenario 2) shows the number of reported cases (dark blue) and unreported cases (light blue) expected if the vaccine rollout proceeds quickly over the next two months, with ongoing adherence to public health measures like face masks, hand hygiene and physical distancing.
In the baseline scenario, approximately 60% of people in Timor-Leste are predicted to get COVID-19. But if the vaccines could be rolled out quickly in the next two months as demonstrated in the hypothetical scenario, approximately 37.5% of people in Timor-Leste are predicted to get COVID-19, with numbers of hospitalisations and deaths less than half of what is predicted for the baseline scenario.
7. Recommendations and public health actions
The low case fatality rate in Timor-Leste is largely because most diagnosed cases of COVID-19 have been in young people. There is a significant risk of increasing numbers of deaths if COVID-19 affects more people who are older and those with comorbidities like hypertension, diabetes and heart disease.
People who are over 60 years of age, and people who have comorbidities should be vaccinated as soon as possible, to protect them from COVID-19 and reduce their risk of severe disease or death. The COVID-19 vaccine is safe to give to people with hypertension, diabetes and heart disease. It can also be offered to women who are breastfeeding and to those who are pregnant if they are at high risk of COVID-19 disease.
It is important that people who are unwell with respiratory symptoms seek medical care. With good treatment that can be provided in Ministry of Health COVID-19 treatment facilities, the outcome of COVID-19 infection will be good for most people. If people with symptoms of COVID-19 infection stay at home and avoid medical care, there is a risk of poor outcomes including death at home, and a risk of transmission of COVID-19 to others in the community, including those who are most at risk.
Maintaining the sanitary fence helps to identify asymptomatic cases and prevent transmission from municipalities where the incidence is high, to municipalities with lower incidence. Application of a sanitary fence should be considered for other municipalities with a high incidence of COVID-19 cases.
Transmission rate can be reduced by effective public health and social measures, including the use of masks, hand washing and physical distancing. Measures which limit physical interactions, travel and mass gatherings, have been shown to be effective in many countries around the world in reducing the transmission of COVID- 19.
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