A New Zealand child born with HIV in 2002 was only diagnosed with the disease last year.
The child, aged 10 - whose gender, name and home town have been kept a secret - was diagnosed with the disease after falling ill. Until then, the child had remained healthy.
The child's mother was subsequently tested for HIV and was also found to have the disease.
The 10-year-old was one of 170 people diagnosed with HIV last year - 143 for the first time in this country - according to the figures released by the Aids Epidemiology Group this week.
The family of the country's most famous Aids victim, Eve van Grafhorst, said the unidentified family would receive great support from the community, if their experience was anything to go by.
Eve died, aged 11, in 1993. Her sister Dana Lee, 40, who now works at a kindergarten in Auckland, said: "I can understand why a family would want to keep something like this quiet. However, the support our family got from the community in Hastings was outstanding, and we were given help with everything from moving home to having food on the table."
Medical experts were surprised that the child had reached the age of 10 before being diagnosed with the disease - most children born with HIV fall ill at age 2 or 3.
But Starship Children's health paediatric infectious disease specialist Dr Lesley Voss said it was a reminder to health staff.
"The age of diagnosis can certainly be very old, which is why I remind my colleagues when a child comes through with an unusual illness, or could be consistent with an immune abnormality, then they should always think of HIV testing," Voss said.
Such cases were rare these days, thanks to the roll-out of a national screening programme.
"We will know most of these women's status at time of pregnancy, and we would manage them. The mother would be on treatment and the baby would be able to be managed," she said.
The screening programme was rolled out from 2006 to 2008, and is now part of routine antenatal tests.
Since 1995, 115 babies have been born to women known to have HIV, but none of those babies was infected.
University of Otago Associate Professor Nigel Dickson, director of the Aids Epidemiology Group, which monitors HIV infections, said the 10-year-old's case indicated there might still be some children with undetected HIV.
He said those children did not pose a risk to the wider community.
"Children do not pose a risk. But when those undiagnosed children become sexually active, they pose a risk to other people."
Since 1985, about 25 babies have been born with HIV in New Zealand.
• 143 people diagnosed with HIV for the first time in NZ last year
• 80 (approx) men infected through sex with other men
• 40 (approx, at least 11 women) infected through hetero sex
• 1 child infected through mother at birth