A patient whose husband works in Singapore has been found to be the first pregnant woman in Malaysia infected with the Zika virus.

The 27-year-old Chinese woman is about four months pregnant with her first child and lives in Johor Baru, Malaysian Health Minister Subramaniam Sathasivam told reporters yesterday.

Her husband, who commutes to work in Geylang each day, has been tested, he said, but the results are not out yet so it is not known definitively whether she contracted the virus from him.

"She showed signs and symptoms before the husband," said Datuk Seri Subramaniam. "She was tested earlier and found positive."

Men infected with the Zika virus should avoid sex or use protection for at least six months, he said. Women should avoid becoming pregnant and practise safe sex for eight weeks after infection.

Dr Subramaniam also said the Health Ministry will hospitalise all pregnant Zika patients for treatment by specialists and that pregnant women who show no symptoms but have partners confirmed to be infected will also be tested for the virus.

Zika infections during pregnancy have been linked to a higher chance of babies being born with microcephaly, a severe birth defect in which the head and brain of the child are undersized, and other brain abnormalities.

The Health Minister clarified that Malaysia is not spraying incoming vehicles at the land checkpoints with disinfectant and insect repellent as a safety precaution.

Instead, the authorities are asking drivers to spray their vehicles before entering Malaysia, though he acknowledged that it is impossible for enforcement officers to ensure that all vehicles have been disinfected.

But body temperature checks at entry points into the country are continuing.

"Taking into account the proximity to Singapore, we have projected the likelihood of increasing cases in Johor Baru. Protection from mosquito bites is crucial in high-risk areas like Johor," he told a press conference.

Control measures have been increased in Johor Baru, especially around the house of the patient in Taman Desa Harmoni, he said.

Around 400 houses have been examined and 450 premises fogged since Zika was discovered in Johor.

Dr Subramaniam announced that the Cabinet had decided that an "environmental cleanliness" council will intensify and coordinate control activities. It will be chaired by Deputy Prime Minister and Home Minister Ahmad Zahid Hamidi.

The pregnant woman came down with a rash, fever and body aches last Friday, and visited a hospital to seek treatment on Monday.

Tests revealed that she was positive for Zika on Tuesday.

She is known to have travelled to Singapore in the past six months. Her husband, who also exhibited symptoms, has also been confined to the hospital.

The pregnant woman is Malaysia's third confirmed case of Zika.

The other cases were detected in Klang, Selangor, and in Kota Kinabalu, Sabah, last week.

The country's Health Ministry said the blood and urine tests of 30 other suspected victims were found to be negative for the virus.