It is estimated by Saving Lives, an HIV awareness charity, that 110 people are HIV-positive and working in the NHS. It can only be estimated of course, because some – we don't know how many – don't know themselves or prefer not to tell anyone about it.

Perhaps that seems selfish? Perhaps you feel that patients have a right to know when the person treating them is carrying a life-threatening virus? Perhaps that person shouldn't be treating anyone at all?

If this is your view, you need better information. Today, the truth is that it is virtually impossible to catch HIV from someone who is HIV-positive and receiving treatment. "People living with HIV who are on stable effective treatment will have undetectable levels of virus in their blood," says Dr Steve Taylor, an HIV specialist at Birmingham Heartlands hospital and medical director of Saving Lives. "That means the risk of their blood infecting another person through a needle-stick injury is almost nothing. There have only been four cases worldwide of people being infected by a healthcare worker and those cases were in the early days before treatment was available. The risk of transmission of HIV to healthcare professionals is infinitely higher."

This is why the guidelines changed last week, finally allowing NHS staff with HIV to work in any area of the health service that they like. The news is going to change the lives of real people – including many patients, who will get some excellent medics back. Two nurses explain what the new rules will mean to them.

Shamin Onyango Odera, 35, nurse

I always wanted to become a doctor. But in Kenya some bureaucrat somewhere told me that being a doctor was a man's job, so I was allocated a place to be a nurse. I accepted it and thought I'd do nursing, then convert later to be a doctor.

When I was 23, I gave birth to a baby boy back in the UK, where I had been born. The pregnancy was fine, but when he was six months old he started getting sick. At nine months, he had to be admitted, and then tested positive for HIV 1 and 2, which meant that I had it too. He died a couple of weeks after that. We had been infected without knowing it by my first husband. This also meant that I wasn't allowed to train to be a doctor, and I was told I couldn't do midwifery either. It was a blow, but I was getting used to dealing with bad news.

Instead, I worked as an acute medical nurse, and finally got into A&E. When patients come in, of course, we don't know what they have. They keep bleeding and vomiting all over you, but we all take care. Some of my colleagues don't know about my HIV status, but some do and are fine with it.

One time, in a previous job, I was on the ward and developed a high fever, so I had to go down to the medical assessment unit, where they take a full medical history. When she heard, the doctor looked at me as though she couldn't believe it. One of the charge nurses, bless him, felt he needed to save me the embarrassment of everybody knowing I was HIV-positive, so he erased me from the computer system. A while later, I was walking with one of the other nurses and she said: "A couple of weeks ago there was this nurse who came into medical assessment unit, and she was HIV-positive …" So I told her: "Actually that was me." She looked really surprised, like I should be covered with boils or something. I just added: "And I'm fine."

It's too late for me to become a doctor now. I had two children after I got married again, and if I went back into training I'd have to survive on a bursary, which is hard with a family. I might try for midwifery, though.

Eric Hofheinz, 48, student nurse

It all started 19 years ago, when my mother passed away. She was ill for about a year and a half, in and out of the Royal Marsden. The care was excellent, and I sat there and I thought: "I could do this." I'd never thought about a medical career before. I was working in business travel, making reservations for corporate clients, but that experience planted the seed for nursing.

I was diagnosed with HIV in 2001. It was a very dark period of my life. I'd just come out of a four-year relationship, but it only takes having unsafe sex once to contract HIV – and for me that was the case. Receiving my diagnosis was very, very scary. I still had that image of the 1980s in my head, and that's still the stigma today.

But I've been lucky. The HIV is still there, but it's not a big part of my life. One pill in the morning, two in the evening: remembering to take the pills is the most annoying part, to be honest. There's no effect on the body for me.

Four years ago I was made redundant from my travel-industry job, and I thought: "Goodness, what am I going to do?" My partner at the time said, "Why don't you try nursing?" After all, I'd been going on about it for years. Being HIV-positive, though, I thought I wouldn't be allowed to. Looking into it, I found that I could do certain aspects, but not theatre, which was the side of medicine I really liked.

I know people in nursing who haven't declared they're HIV-positive. Once I was watching an operation and got chatting to one of the nurses. She said they'd even lost one or two of the surgeons over the years, because they had contracted HIV and had to give up their jobs.

Anyway, I went back to college, did an access course, and then went to Coventry University, where I'm about to graduate in four weeks' time. I would definitely apply for theatre in the future. I find that very exciting, and it's an option now.