By Ellalyn De Vera-Ruiz
A study by the University of the Philippines (UP) COVID-19 Pandemic Team found that the Luzon-wide enhanced community quarantine (ECQ) has been so far effective in containing the spread of the disease.
However, its implementation over a wide area may not be sustainable beyond April 30.
The study, led mostly by mathematicians across different UP campuses, showed that the number of confirmed cases now takes a little longer to double in number.
"What took three days for the total number of cases to double now takes about six days to happen," the study found.
Its estimate is that the number of COVID-19 cases by the end of April will be between 9,000 to 44,000. "In general, this indicates the relative success of the ECQ along with other interventions in containing the spread of the virus."
Another benchmark used in the study to test the effectiveness of the ECQ was the case fatality rate.
Based on the data as of April 10, the study reported an estimated case fatality rate of 5.38 percent and a reproduction number of 0.6398, pointing out that "the ECQ has been effective."
The goal is to keep bringing the reproductive number down to lower than 1 through continued medical and non-medical interventions, the researchers said.
"Quantifying the effectiveness of the ECQ, however, is highly dependent on efforts in discovering new cases. Specifically, there are situations in which countries were able to bring their reproduction numbers down close to 1, but later testing pulled the number up, such as the case of Singapore.
"In the case of Korea, consistent increased testing coupled with contact tracing facilitated the detection and management of the epidemic, lowering the reproduction number of COVID-19," the researchers added.
While it seemed successful, the UP team pointed out that an ECQ covering a wide area may not be sustainable over the long run.
"Prolonged restriction on the movement of goods and services over a large area, i.e. region-wide, can unnecessarily paralyze local economies," they said.
The team proposed a graduated activation of the ECQ after April 30.
"Under this set-up, provinces or even lower-level LGUs (local government units) may be put under ECQ depending on how close or far they are to an estimated outbreak threshold," the team said.
"This suggestion is made based on our analysis on the trajectory of spread and the severity of its impacts across LGUs, which varies depending on the onset of local transmission, population density, and age-group distribution," it explained.
The team also explored epidemiological approaches in disease mapping at the provincial level using population density as proxy measure of "outbreak spread potential."
'By getting the ratio of the number of cases against the estimated outbreak threshold, we can determine which level of community quarantine to implement," it said.
It gave as an example a province whose number of cases is at least equal to the estimated outbreak threshold should implement ECQ measures.
Meanwhile, a province whose number of cases is less than 75 percent of the estimated outbreak threshold may not declare a community quarantine at all, but only need to sustain information campaign efforts, general physical distancing, testing and contact tracing, home quarantine for probable cases, and hospitalization for patients needing care and treatment.