Testing, testing: the advancing diagnostics for sexually transmitted infections

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Sexually transmitted infections (STIs) have seen a rise in the years following the Covid-19 pandemic, with 2022 seeing more than 2.5 million cases of syphilis, gonorrhoea, and chlamydia in the US alone, according to the Centre for Disease Control. 

Highlighted within the CDC’s report are several concerns revolving around a sharp increase in the rates of syphilis, which rose from 113,739 in 2018, to 203,500 in 2022, representing a five-year rise of 78.9%. At the same time, the UK’s National Health Service (NHS) found that there were 392,453 diagnoses of new STIs in England, an increase of 23.8% compared to 2021. The same report found that rates of infectious syphilis (primary, secondary and early latent) are increasing among men. 

It is no wonder then that the overall market for devices designed to track and diagnose STIs has seen consistent growth. In one example, a GlobalData market model predicts that the overall market size for tests that examine for treponema pallidum, a component of syphilis, is predicted to rise from an estimated $540m in 2023, with that figure expected to rise to $743m by the end of 2033. 

To that end, Medical Device Network explores how the medical device market is responding to the rise in STIs. 

One of the major hurdles to the continued testing and screening of patients worldwide is getting patients into a facility to test themselves in the first place. Many governments have driven efforts to encourage more proactive screening habits, as well as accompanying devices. One area of development is devices that double up as sexual health tests to allow for more personal and convenient testing. 

Adapting commonly used health items into diagnostic tools has already seen some success. One such example is Q-pad by US-based company Qvin, a diagnostic menstrual pad with a removable strip designed to identify signs of diabetes but also designed to check for symptoms of high-risk human papillomavirus (HR-HPV). 

Another company that has been experimenting in this space is women’s health firm, Daye, which has launched its own hybrid diagnostic product, a tampon with the ability to screen for STIs. 

Daye founder and CEO Valentina Milanova detailed how the company launched a series of clinical trials for the diagnostic tampon, one of which enrolled 375 patients across the UK and Italy to test its efficacy, safety and acceptability. 

Milanova said: “After completing clinical trials with over 600 patients, we were able to demonstrate that the tampon increases the rate of sensitivity and specificity for diagnostic assays, including sexually transmitted infections, human papillomavirus and common vaginal infections like vaginosis and thrush. 

“We were pleasantly surprised by how quickly we were able to recruit patients to our clinical trial. We are currently running two clinical trials, one comparing our diagnostic tampon to a swab test, and another comparing our diagnostic tampon to cytology. The swab test was designed for use in the nose or throat and is not really suitable for gynecological health screening. Cytology is a procedure by which the cervix is agitated and tissue from the cervix is collected and compared to normal cervical cell growth. So, this is what we are comparing against.” 

Milanova continued: “What we are most excited about is the incredibly positive response we have had from some of the participants in the studies, it’s usually hard to recruit women for clinical trials. We still don’t have infrastructure [in the industry] in place to factor women into clinical trial recruitment at the same rate as we are inviting men. We anticipated that it would take longer to initiate our trial but within the first week we had already onboarded all the patients we needed.” 

Milanova explained how one of the barriers to getting ethics approval for clinical trials examining the device was having to explain the call for such tests to largely older male researchers who were less able to understand a diagnostic tampon. At the same time, the lack of funding directed towards female health concerns, especially regarding sexual health, has only worsened the stigma around getting tested. 

Milanova added: “They just could not understand what was wrong with existing solutions because they had never had to have a big metal tube inserted into their vagina. So, it was harder for us to get our point across to an ethics committee. 

“I think the biggest issue when it comes to the state of gynaecological health today is the lack of research, which is caused by the lack of research funding. Currently, less than 1% of the entirety of venture capital funding that goes to the entirety of the health tech space goes to Women’s Health. 

“The majority of the femtech companies that I know today were created in conditions of extreme scarcity, and at some point, this will inevitably affect the quality of the final products that are being developed, and it will also affect the quality of the patient outcomes and the patient journeys that are being created.” 

Diagnostic companies are looking to create STI tests that can diagnose multiple infections at once.

Market analysis carried out by GlobalData found that the number of tests produced that sought for only one kind of infection or indication is steadily on the decline, with tests only examining one indication seeing sales of 1,509,347 units in 2014, dropping as low as 496,918 in 2023. Conversely, the number of tests examining two indications rose from sales of 1,790,477 in 2014, to 4,900,293 by the end of 2023. 

The main reason for this is that a test that can cover multiple indications at once is both more cost-effective and at the same time much more likely to have an effective market presence by way of being used much more frequently. 

Breaking down the research, GlobalData healthcare analyst Selena Yu detailed how the shift in the overall healthcare market brought on by the Covid-19 pandemic impacted the STI testing landscape in a way that healthcare systems worldwide are only now starting to come to grips with. 

The post-pandemic years have similarly seen an uptick in the number of HIV tests being sold throughout the UK and US. It comes as the UK’s NHS reported a sharp rise in the number of HIV-positive tests registered in England, seeing a rise of 6% from 2,313 in 2021 to 2,444 in 2022. 

“During Covid-19, the rate of testing for HIV decreased because a lot of that money and funding was being put into Covid testing. A lot of specialists thought that because everyone is isolating, no one is having sex. That wasn’t quite true," Yu said. 

“So, HIV is an STI that does not self-resolve. The other STIs such as chlamydia or gonorrhoea are awful and can lead to other worse diseases or infertility, but HIV is very awful in terms of how it can progress when compared to other infections because it can lead to AIDS. 

“I think HIV testing is incredibly important, and I think a lot of it has to do with the stigma. In the past 30 or so years, people with HIV were more or less ostracised from society and it was associated with the gay community, so there was a lot of stigma there. But what we do know is that a lot of government campaigns have been working to get people from at-risk communities to get more frequently tested. We are talking about males who have sex with other males, people in sex work or people with multiple partners and I think that is where we are seeing a shift in the public health system.” 

The spike in infections such as gonorrhoea presents more than just a personal health problem but also a public health concern. The World Health Organization describes gonorrhoea as the second most reported bacterial STI in the world, with as many as 82 million people globally thought to be infected with the condition in 2020. If left untreated, gonorrhoea can spread to the bloodstream, which can be life-threatening. 

In turn, this has driven growing concern over the rise in anti-microbial resistant (AMR) strains of the infection, which itself has prompted the US’ own Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator (CARB-X), to begin investing funds into testing equipment for sexually transmitted infections that can identify antimicrobial resistant strains of infections such as gonorrhoea. 

Visby Medical has launched a portable rapid polymerase chain reaction (PCR) diagnostic test to detect the presence of the pathogen that causes gonorrhoea, Neisseria gonorrhoeae, as well as its susceptibility to ciprofloxacin, an antibiotic that some forms of gonorrhoea have developed a resistance to. 

Speaking with Medical Device Network, Visby Medical's chief medical officer Gary Schoolnik said: “Historically, gonococcus has been the poster child of antibiotic resistance amongst pathogens. By having the capacity to check what kind of infection it is on the Visby device, it means that if a person’s [infection] tests sensitive for ciprofloxacin, they can be cured with a single oral dose of ciprofloxacin. This avoids the necessity of an intramuscular injection with ceftriaxone. 

“We know that, at least in the United States, 70% of people infected with gonococcus are infected with ceftriaxone to sensitive strains. That means that 70% of people can be treated with a single dose of Ciprofloxacin, with a 99% cure rate." 

Schoolnik added: “We know that if we choose the inappropriate antibiotic, that this is what really drives antibiotic resistance in the world. If we look at the epidemic of antibiotic resistance, the single most important thing we can do is choose the right antibiotic right at the start of the infection and then continue to give that antibiotic until the infection is eradicated. 

“But unfortunately, up until now it's taken a number of days to determine whether an organism is sensitive or resistant to an antibiotic.”