The area around Bishan Street 12 was yesterday identified as a potential Zika cluster, and the authorities are set to step up anti-mosquito efforts there.

The number of confirmed Zika cases in Singapore reached 275 as of noon yesterday, after 17 new cases were detected. Ten of them were linked to the Aljunied Crescent/ Sims Drive/Paya Lebar Way/Kal- lang Way cluster. Six had no known links to any cluster, while one was in Bishan Street 12, adding to another case found there previously.

The other confirmed Zika clusters are in Bedok North and Joo Seng, although no new cases were detected in those areas yesterday.

Bishan-Toa Payoh GRC MP Chong Kee Hiong told The Straits Times that residents have been expressing their concerns. He said that the ward was stepping up anti- mosquito efforts, adding: "Everyone has to do their own part. Fogging alone is not the solution. There are so many corners to check, and everyone has to take care of their own compounds."

From today, most people showing clear signs of a Zika infection, and with a doctor's referral, will pay a subsidised rate of $60 to be tested. Private patients will have to pay the full $150.

The test is free for all pregnant women who meet the criteria, given how the virus can cause foetuses to be born with microcephaly - a condition in which the head is much smaller than usual.

Unless pregnant, a Zika infection typically results in mild symptoms such as fever and rash, joint and muscle aches or red eyes, which last for between four days and a week.

That is why many whom The Straits Times spoke to yesterday said they will think twice before forking out $60 for a Zika test, even if they are suspected of carrying the virus.

"I am not pregnant, so I am not worried," said Madam Dorothy Lee, 57, who works in accounts. "Only pregnant women need to be worried."

Others said they would get the test, at least to confirm that they do not have a more serious condition.

"I would be curious to know if I had Zika," said 19-year-old student Chloe Leong.

Mr Ganayur Rahaman, a 48-year- old owner of a convenience store in Aljunied Crescent, added: "It's better to get the test. If not, you won't know why you're sick."

Previously, the test was free for people living or working in Zika clusters, and suspected of having an infection. On Monday, the Health Ministry explained why it was adjusting its strategy.

The previous consideration was based on the assumption that most cases were still clustered in the affected areas. But more cases have been found in other parts of Singapore. Unless a patient is pregnant, testing for Zika also does not impact treatment, since this is focused on relieving symptoms.

Dr Ann Tan, an obstetrician and gynaecologist at Mount Elizabeth Hospital, believes that unless one is pregnant, there is no pressing need to get tested for Zika, even for the purpose of charting where the virus is popping up on the island.

"People travel and mosquitoes fly around," she said.

Infectious diseases expert Leong Hoe Nam of Mount Elizabeth Novena Hospital said allowing pregnant women who meet the criteria to get free tests was important. "It allows them to clear their doubts by taking away cost as a consideration."

MacPherson MP Tin Pei Ling meanwhile revealed yesterday that she has compiled a list of 104 expectant mothers living in her ward and has been reaching out to them.

"The mums-to-be are coping well, worried but determined, and taking active precautions," she posted on Facebook, encouraging Singaporeans to "gambatte" - or not to give up - in the fight against mosquitoes, "for their sake and ours".

•Additional reporting by Nadia Chevroulet