Metro Manila (CNN Philippines, March 9) — Coronavirus cases in the Philippines more than doubled to 24 overnight on Monday.

President Rodrigo Duterte announced in a press briefing after his meeting with the task force on emerging infectious diseases four new cases of the new virus that causes coronavirus disease, officially known COVID-19, just hours after the Health Department reported 10 new patients.

Duterte said the four new cases were reported in West Crame, San Juan, Sta. Maria, Bulacan, and Project 6, Quezon City.

All the new cases earlier announced by the Health Department are Filipinos, three of whom have no travel history outside of the country, while two have been exposed to someone with COVID-19, the disease caused by the novel coronavirus.

Four of them have travelled to the United Arab Emirates, Australia, Taiwan and Japan, respectively.

Health authorities have yet to determine whether one of the new patients, a 24-year-old man who began coughing on March 1, has a history of travel outside of the country.

He, along with a 56-year-old man, a 34-year-old man and a 46-year-old woman, are currently admitted at the Makati Medical Center.

A 70-year-old man and a 69-year-old woman are admitted at UniHealth Parañaque Hospital, while a 41-year old man, and a 46-year-old woman are admitted at Tricity Medical Center in Pasig City.

A 72-year-old man is admitted at The Medical City in Pasig, while a 48-year-old man is admitted at the Research Institute for Tropical Medicine in Muntinlupa City.

Nearly all of the new cases exhibited symptoms including coughing, fever and colds, except a 46-year-old woman whose onset of symptoms are still under investigation.

Health Assistant Secretary Maria Rosario Vergeire attributed the sudden spike in new cases to better surveillance of COVID-19 by the Health Department.

Vergeire said that despite a spike in coronavirus cases, there is still not enough evidence to say that there is community transmission of the virus in the country.

"The main determinant para masabing may community transmission ka kapag ang mga kaso mo ay hindi na linked to each other," she said.

[Translation: The main determinant for us to say that there is community transmission is if your cases are no longer linked to each other.]

The Philippines confirmed its first case of local transmission of the new virus last Friday after a 62-year-old man from Cainta, Rizal without a history of travel outside of the country tested positive for it. His wife, 59, also tested positive.

A 57-year-old man from Quezon City who has not traveled outside of the Philippines had also been infected. He claimed that he had been exposed to someone with the disease, but health officials are still verifying his account.

Two of the confirmed cases have earlier recovered and have been discharged. Another died early last month.

Contact tracing

The Health Departmennt said it has traced 468 people who have come in contact with the previous six cases of coronavirus. Of them, six are classified as patients under investigation and have been placed under isolation at unspecified health facilities.

The department added that 107 of those who have been contacted have been placed under home quarantine.

It is also appealing to the public to cooperate with their surveillance teams in their contact tracing activities.

Those who have been exposed to someone positive for coronavirus or traveled to areas with local transmission and are experiencing mild symptoms like fever, dry cough, phlegm, sore throat and headache are advised to quarantine themselves in their homes for 14 days.

Meanwhile, those with severe and critical symptoms should be admitted to health facilities, the Health Department said.

All those who fall under the abovementioned criteria should get in touch with the Health Department at (02) 86517800 local 1149-1150.

President Rodrigo Duterte has declared a state of public health emergency, which can allow the government to declare price freezes for medicine, get additional funding for its response to the coronavirus, and impose a mandatory quarantine.

Some lawmakers have been calling for Metro Manila to be placed on lockdown. The Health Department said this may happen if it decides to raise Red Alert Sub-level 2.