Kira is now speaking out to raise awareness of the deadly virus — just days after Leo died on August 19 — and is calling for herpes tests to become obligatory for all mums-to-be.
She said: "I've always wanted to be a mum so being able to bring Leo home was just a dream come true, everything was finally perfect and everyone was happy.
"But as Leo was laid there in hospital with doctors and nurses surrounding him, it was a mother's worst nightmare.
"I was physically sick when the herpes test came back positive, as I had done everything humanly possible to give my son the best start in life.
"I could have contracted it before or during the pregnancy, as it can be dormant for months or years so there's no way of telling.
"I had no knowledge I had the virus, as there were no symptoms other than thrush, and if I had been offered a test during my pregnancy all this heartache could have been avoided.
"I'm now urging men and women to get tested. That's my message to everyone — not just pregnant women.
"I hope sharing Leo's story will save other lives."
Herpes has two strains, which are both dangerous to babies as their immune systems are yet to have fully developed to fight off the virus.
Type 1 can cause cold sores, while Type 2 typically causes genital herpes, and the virus can be passed on to newborn babies during vaginal delivery.
As Leo fought for his life in hospital, medics told Kira her son's odds of surviving were dropping by the minute.
Unable to hold her baby boy, Kira and her mum had to look on helplessly as doctors fought to save his life.
But on the Sunday morning — just hours after he was first rushed into hospital — doctors told her his liver and kidneys were failing and that they would have to put him on a dialysis machine in order to keep him alive.
Leo was then moved to a private room as Kira was told it was time to get her baby boy baptised.
Soon after, Kira and her mother were given the devastating news that medical staff had found a clot and swelling on Leo's brain and that all his organs were failing.
It was then that Kira decided that her brave boy had suffered enough and she made the heartbreaking decision to turn off his life support machines.
Kira said: "As Leo lay in hospital, all I wanted to do was to hold and to kiss him and to tell him that everything would be all right.
"I told my baby boy to fight and that we were all on his side, and how much I loved him and wanted to return home with him."
"Leo's baptism was a nice moment to know I could bless him before he passed.
"I wanted to get him christened at Christmas, but obviously his time came a lot sooner.
"The consultant then told us his condition had worsened.
"Once I knew the status of Leo's health, I knew it was time for me as his mother to say 'enough is enough'.
"Once I'd decided that, I was then allowed to be next to him and be by his side.
"I fell asleep with my head on his incubator and held his hand and when it was time to stop the machines, they let me hold him.
"It was heartbreaking, as he took his last breaths in my arms, I held his hand and held him so close, and told him how proud I was of him.
"The doctors then left the room, and let me and my family have our time alone and a chance to say goodbye."
Despite his short life, Kira is adamant her son touched the lives of everyone he met.
After Leo's death, the heartbroken mum was forced to return home, surrounded by the clothes and toys she had prepared for the tot just weeks before.
But she is now channelling her grief into campaigning for all mums-to-be to undergo mandatory screening for all types of the herpes virus.
She said: "Leo was the calmest, happiest baby you'd ever meet.
"He was a dream. I say to everyone he was born an angel.
"He never cried until that night.
"His death has been even harder because I came back to a house with all his things here.
"I can see all the things here that would have been."
• Kira is raising money for Royal Manchester Children's Hospital.
In Australia, RANZCOG guidelines on antenatal care suggest only screening for syphilis at the first visit for all women, and chlamydia for in those in at-risk groups. No other STIs are usually tested for if there's no history of them.
