Without her, we would not be here today, says Mthuthuzeli Skosana, a patient of the clinic at Helen Joseph Hospital in Johannesburg.
Roberts' praises were being sung at the clinic's first-anniversary celebration on Monday.
Since the clinic's inception, more than 7 000 HIV-positive patients have passed through its doors, with 3 579 of them put on antiretroviral (ARV) treatment - the most at any health treatment site in South Africa.
'We need more people like her'
On Monday 2 000 of them celebrated more than one year on treatment.
In recent weeks the clinic has been able to provide ARV therapy to an extra 100 patients a week.
Words cannot describe how grateful we are. The incredible staff, headed by Sue Roberts, has been supportive and caring at all times. We need more people like her, said a patient, who wanted to be known only as Nomsa.
Nomsa said Themba Lethu, which means Our Hope in isiZulu, had brought the patients hope and much more.
Coming for treatment at the clinic is like attending a social club. If only there were more social clubs around where people could get help, she said.
'It's about treating people as you would like to be treated'
Roberts sees her work as not just about getting people on to ARVs: It's about treating people as you would like to be treated.
She added that the clinic was staffed by incredible individuals committed to helping others.
US Assistant Secretary of State Jendayi Frazer, whose government has provided funds for the establishment of the clinic, commended the work carried out by Roberts's team.
This would be a remarkable achievement in any setting, but in a resource-limited public health clinic, it is nothing short of miraculous, she said.
Frazer assured the clinic that the US government would continue to help as long as our help is needed.
But, while there was much to celebrate, patients raised some concerns about people who criticised ARVs and raised false hopes of miracle products that cure Aids.
Skosana said that the anti-ARV lobby contributed to the confusion of HIV-positive people in the community.
I challenge anyone who doubts whether ARVs work not to speak on our behalf. They should rather come and ask us. We live today because of them.
Phindile Madonsela, who has been living with HIV for the past eight years, said: We are not guinea pigs. Vitamins cannot replace ARVs.
We know nutrition is good but there comes a point where good nutrition and ARVs have to work hand in hand.
An emotional Wakhe Phangalele cried: My people are dying out there, but there are people who are saying HIV does not exist.
We are seeing it every day.(Source: IOL, 18 October,2005).