Few had heard of Lyme disease – a relatively rare tick-borne illness – until it burrowed its way on to the A-list. In 2015 it was revealed that the fashion model Bella Hadid had the disease; that same year Avril Lavigne’s Lyme diagnosis appeared on the cover of People magazine under the headline “I thought I was dying”. In 2016 Kris Kristofferson discovered that the memory loss he had been suffering in recent years was not due to Alzheimer’s but to Lyme disease. And this week news that the former England rugby player Matt Dawson also suffers from the condition dominated headlines. (In a recent memoir, Kelly Osbourne said that she had kept quiet about her Lyme disease because she feared it had become “the trendy disease to have right now”.)

Where once Lyme produced little interest and less cash, it is now the focus of high-profile fundraising galas and celebrity news. The Global Lyme Alliance, an American non-profit organisation, has said A-list interest is “essential” for raising money. Increased public awareness of the condition has helped too: rapid treatment with antibiotics is vital, and the early signs of Lyme disease – a tick bite and a circular rash – are easily missed.

When a public figure gets an illness, other sufferers benefit. Publicity can encourage those at risk to seek out testing. In the 1990s, after the basketball player Earvin “Magic” Johnson announced that he was HIV positive, the US’s National Aids Hotline reported a spike of 28,000 calls from people looking for more information on the disease. A similar phenomenon followed Angelina Jolie’s announcement of her double mastectomy: there was a rise in the number of screenings for harmful mutations in the BRCA1 and BRCA2 genes that increase the risk of breast and ovarian cancers. Around a third of people report that hearing about a celebrity’s cancer made them more likely to take a test for it.

Celebrity endorsement also speeds up charity donations, studies show. In 2006 the Top Gear presenter Richard Hammond was severely injured in a car crash, resulting in brain and spinal injuries. In 2011 he presented an appeal for the Spinal Research charity on BBC1’s monthly Lifeline show, which was more successful than any other on either that programme or the weekly Radio 4 Appeal show since 2007. In the UK, celebrities willing to talk about their mental illnesses, such as Stephen Fry and Ruby Wax, have helped mental health charities and encouraged politicians to send more public funding their way. Public pressure, including from the A-list, resulted in parliamentary debates and a promise that psychiatric conditions would be given “parity of esteem” in the NHS.

But those suffering from the kinds of diseases that celebrities do not get are not so lucky. There are many such people in Britain. There were 5,758 tuberculosis (TB) cases in England in 2015; rates in some parts of London were higher than those in Rwanda and Eritrea. Raising awareness would help: TB is an infectious and treatable disease. But it tends to affect rough sleepers and impoverished immigrants, not celebrities, and gets little attention. Doctors dealing with the illness in the UK have called it “a forgotten plague”.

That celebrities have so much power to sway health priorities should give us pause. Their causes may be worthy, but diseases that fall beneath their radar deserve attention too.