'Fewer than five' Zika cases in Northern Ireland since 2015
Several people have been diagnosed with Zika virus in Northern Ireland in the last year.
The Public Health Agency (PHA) said there had been fewer than five cases since 2015 and all patients had travelled to affected areas.
Ulster Unionist MLA Jo-Anne Dobson, the party's health spokeswoman, has described the findings as "extremely worrying".
In a statement the PHA said: "Zika does not occur naturally in the UK. However, since 2015, the Public Health Agency (PHA) can confirm that there have been less than five cases of Northern Ireland residents diagnosed with Zika virus.
"All have a history of travel to Zika-affected areas."
The infection, which began in Brazil last year, is primarily transmitted by Aedes mosquitoes.
While it often occurs without symptoms, the Zika virus can cause a mild illness including a fever, headache, rash, joint and muscle pain, and conjunctivitis.
Earlier this year the World Health Organisation declared the virus's link to microcephaly found in babies born to infected mothers a public health emergency.
Health warnings have also been issued to people travelling to affected areas such as the Caribbean, Central and South America, Oceania and some parts of Asia.
The PHA said there was no specific medical treatment for Zika.
The statement said: "For those with symptoms, Zika virus tends to cause a mild, short-lived (two to seven days) illness.
"There is no specific treatment for Zika virus disease other than supportive measures (such as analgesics and hydration) for those who have symptoms and patients affected are advised to rest and drink plenty of fluids."
Mrs Dobson said she would be raising the issue when Stormont's health scrutiny committee convenes on Thursday.
She said: "This news is an extremely worrying development and the fact that this virus has been linked to thousands of babies being born with underdeveloped brains will be disturbing for local people.
"I am concerned that despite being in the Assembly chamber answering questions yesterday, and having the opportunity to update the public on this development, the Health Minister Michelle O'Neill chose silence over providing clarity.
"I would urge the minister to inform at-risk groups about the risks and how to protect themselves.
"The Minister must also ensure that her department closely monitors developments in both managing and understanding the virus as work is ongoing across the world to develop treatment and testing regimes."