Her Majesty The Queen has made her first ever visit to a specialist Aids centre, touring a clinic and officially opening a newly-expanded children's hospital set up by UK-based Christian charity Mildmay, in Kampala, Uganda.

In a public show of support, the Queen warmly greeted a HIV positive couple, Stephen and Grace Wakodo, who were present with two of their eight children. The Queen stretched out her arm to shake hands with the father, whose condition has been managed at The Mildmay Centre since 2002.

The Queen learnt that only one of their offspring is HIV positive, thanks to successful work around preventing mother-to-child HIV transmission.

She expressed her appreciation for how Mildmay's interventions are helping to reduce the numbers of infected children and described Mildmay's work as "impressive".

The centre's expertise in rehabilitating people with complex, distressing and ongoing problems related to HIV has meant that many adults have been able to go back to work and children go back to school.

After touring The Mildmay Centre clinic buildings - opened by the Princess Royal in 1998 - the Queen then proceeded to the Mildmay Paediatric Care Centre where she unveiled a plaque for the hospital's new Elizabeth Ward, named in her honour.

'Kiddukiro Hospital' now contains 53 beds for very sick children needing intensive rehabilitation or terminal care, and includes a critical care unit.

The Queen and the Duke of Edinburgh were then entertained by some colourful displays of African music and dance, including an amazing spectacle of 200 children, living with or affected by HIV and Aids, singing and drumming in celebration.

Another highlight involved meeting and chatting to a support group of 70 'Jajjas' - or grandmothers who are now looking after their own children's orphaned offspring - who put on a special dance for her.

A particularly moving point in the day was a fashion show featuring 12 babies and toddlers cared for by the Mildmay Paediatric Care Centre. They modelled traditional African costumes, one of which was made from bark cloth, and another featuring the Union flag. All the outfits had been specially tailored for the occasion by a member of staff.

The fashion show was a dream come true for one four-year-old girl with severe lung disease. Despite needing to be on oxygen to aid her breathing, she was adamant she would take part, being safely returned to her hospital bed just a few minutes later.

"We tried to do something different and make it a special day for the Queen to remember," said Ruth Sims, the founder of the Mildmay Paediatric Care Centre, who accompanied the Queen throughout her tour. "Generation after generation of children will hear about the day the Queen came to Mildmay.

"I also wanted to portray HIV positive children as 'normal'. Yes, they have to cope with terrible illness, their growth can be stunted and they can be very underweight. But if we provide treatment and care for them, the majority will get better. All is not lost. It's really important to get this message of hope across."

The Queen later praised the organisation's work in an address to the Ugandan Parliament, in which she declared:

"It is difficult sometimes, when the sorrow associated with this disease is so profound, to avoid a sense of despair. And yet there are growing numbers of people and organisations whose work gives cause for real hope. Today I visited The Mildmay Centre, which sets a remarkable example in the provision of care and relief for those who are ill as well as in educating people about how to protect themselves and their families.

"The role of centres such as this, which the Government of Uganda has done so much to encourage, will be central to achieving our common aim of controlling this cruel disease."

Dr Veronica Moss, the charity's UK-based chief executive, welcomed the Queen on arrival at the centres and said: "It was a privilege to show the Queen something of our transforming AIDS care and reveal that many would not be alive today without Mildmay's help.

"Meeting the Queen was a wonderful, encouraging and motivating occasion for our patients and staff. Everyone was thrilled to see her.'

The eagerness to see the Queen was reflected in the mass sleepover at the Mildmay Paediatric Care Centre on the eve of the visit - with some 320 children, including 200 from some of its rural day care programmes, and 24 community volunteers alongside 70 Jajjas (grandmothers of orphaned children).

The Queen's landmark visit to The Mildmay Centre and Mildmay Paediatric Care Centre formed part of the royal itinerary linked to the state visit to Uganda and Commonwealth Heads of Government Meeting.

The unprecedented level of interest generated by this visit brought back many memories of the support of the late Diana, Princess of Wales, of Mildmay's work, notably at the charity's UK hospital, and of the Aids cause in general, Mildmay said.