The Health Ministry on Tuesday (Sept 13) reported two more cases of locally transmitted Zika infections in the central Philippine city of Iloilo, 600km south of the capital Manila.
Health Minister Paulyn Ubial said the mosquito-borne virus was found in two people living in the same house as the 45-year-old woman who tested positive for Zika on Sept 5. The woman, who is married but not pregnant, was the first confirmed case of locally transmitted Zika in the Philippines this year.
The Philippines have reported four other cases since January, but these involved an American and three Korean travellers. The cases were considered travel-related rather than locally transmitted.
The two new cases in Iloilo bring to eight the total number of Zika infections reported in the country since 2012.
A confirmed case of locally transmitted Zika in the Philippines was reported in May 2012, involving a 15-year-old male in Cebu city, 572km south of Manila.
All three patients in Iloilo have since recovered, but they remain under home quarantine, Dr Ubial said.
The ministry had sent a team to Iloilo to check for more Zika cases there.
Dr Ubial said 88 houses were inspected, and 12 people who had skin rashes and fever were tested for the virus.
The United States-based Centres for Disease Control and Prevention (CDC) said earlier in a bulletin that a strain of the mosquito-borne virus might have been introduced in the Philippines before 2012, and that it probably remained undetected.
Zika resembles a mild case of flu and its symptoms can be treated with over-the-counter medication.
Patients infected with Zika seldom go to clinics, and doctors often associate symptoms with other illnesses, usually dengue or chikungunya.
CDC bulletins showed Zika infections in the Philippines and Indonesia were detected only after targeted surveillance following outbreaks of dengue or chikungunya, or during long-term studies over specific areas.