The mother of supermodels Gigi and Bella Hadid has raised eyebrows after comparing Lyme disease to HIV. The former Real Housewives Of Beverly Hills Yolanda Hadid made the link between the chronic conditions during a recent promotional appearance in Sydney.

Addressing a star-studded crowd at an event promoting Australian Channel Nine's new digital portal for women – Honey – she said: "We all pull together so beautifully for HIV.

"Lyme is three times more prevalent right now, it's a world-wide epidemic, the first case was diagnosed in 1972... yet we haven't done anything about it."

The Dutch former model has made no secret of her personal struggle with Lyme disease, which she suffered from for five years.

Although Yolanda is desperate to find a cure, Sydney-based doctor Brad McKay said it was not helpful that she compared the two diseases as Lymes Disease is rarely fatal.

Following her remarks he told News AU: "If HIV isn't treated, people die. If Lyme disease isn't treated, then people can feel unwell for a very long time. If it's not diagnosed, then it can cause damage to many different parts of the human body."

Nic Holas, the founder of The Institute of Many, a grassroots movement for people living with HIV added that we should be should be wary of "falling into the numbers game".

He added: "Any chronic condition needs people to step forward and put themselves forward."

Back in October, Yolanda revealed that Bella has been "struggling" with the infectious condition, which ended the 20-year-old's hopes of being an Olympic-level equestrian rider.

"She's always tired," Yolanda said on the Good Day New York show, "She could sleep for 10 hours and wake up [and say], 'I'm still tired.' In the younger generation, it comes up like anxiety, severe exhaustion, joint pain, flu-like symptoms and they just keep struggling over it."

Lyme disease is a bacterial infection spread to humans by infected ticks. Symptoms of the condition include pain and swelling in the joints, heart problems, inflammation of the membranes surrounding the brain and spinal cord and increased sensitivity to light. Unlike Human immunodeficiency virus (HIV) which can cause the immune system to fail and leads to life-threatening infections and cancers to thrive, it can be successfully treated with a course of antibiotic tablets.