Issue: December 2019
November 05, 2019
3 min read

Crowd-sourced STD diagnoses on Reddit likely to be ‘wildly inaccurate’

Issue: December 2019
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Reddit users frequently crowd-source STD diagnoses, including many who use the website for a second opinion after receiving an initial diagnosis from a health care professional, according to findings from a case study published in JAMA.

They are likely getting bad advice, researchers believe, indicating an area where clinicians could have a positive impact on the sexual health of patients.

STDs are on the rise in the United States, with reported cases of chlamydia, gonorrhea and syphilis hitting around 2.4 million in 2018 — the fifth record-setting year in a row.

“There is a changing sexual health landscape in the U.S.,” Matthew Prior, director of communications at the National Coalition of STD Directors, told Infectious Disease News. “Clinicians and public health practitioners need to meet people where they are. We need to be on these [sites] where people are getting their information so we can provide them with medically accurate, culturally competent health information.”

Reddit users frequently crowd-source STD diagnosis.
Source: Adobe Stock.

Researchers investigated how frequently social media is used to diagnose STDs, focusing on Reddit, a site with 330 million monthly active users that hosts more than 232 health forums, including a large “subreddit” named r/STD, which allows the public sharing of any information related to STDs, they explained.

In the study, John W. Ayers, PhD, MA, vice chief of innovation in the division of infectious disease and global public health at the University of California, San Diego, and colleagues collected all posts published to the r/STD subreddit from November 2010 through February 2019, totaling 16,979 posts over the 9-year period.

According to the study, 58% of posts requested a crowd diagnosis (95% CI, 54%-63%), with 31% including a photo of the symptoms (95% CI, 26%-36%). Among posts requesting a crowd-diagnosis, 20% were looking for a second opinion to an original diagnosis given by a health care professional (95% CI, 15%-24%).

For all posts requesting a crowd-diagnosis, 87% received a reply (95% CI, 83%-91%), with the first response occurring in a median of just over 3 hours. According to the study, 79% of posts were answered within 1 day (95% CI, 74%-84%).

Ayers said it is unclear what proportion of the diagnoses were correct, but it is likely that “crowd-diagnoses are wildly inaccurate.”

“There is no way to know, given even infectious disease physicians on our research team said they could not make a diagnosis from a social media post,” he told Infectious Disease News.


According to Ayers and colleagues, crowd-sourcing on social media has some advantages, providing users with anonymity, a rapid response to their questions and multiple opinions. But there are dangers.

“Misdiagnosis could allow ongoing disease transmission, and others viewing a post may wrongly self-diagnose their own conditions,” they wrote.

The researchers recommended that health care professionals partner with social media platforms to “promote the potential benefits of crowd-diagnosis while suppressing potential harms.”

“Social media platforms could be improved to facilitate more reliable and actionable crowd-diagnoses,” Ayers said in a news release. “For instance, experts could moderate requests for crowd-diagnoses, resulting in social media being a vehicle to connect the public to professional health care.”

According to Julie Dombrowski, MD, MPH, associate professor of medicine at the University of Washington and deputy director for public health at the Seattle & King County HIV/STD program, patients using Reddit to crowd-source STD information may not be aware of STD services in their area.

“Public health and medical professionals could partner with social media platforms or join as users to spread accurate information about sexual health, promote effective interventions like the HPV vaccine and STD screening, and link users to health services for individual assessment,” she told Infectious Disease News. “I don’t think we can stem the flow of misinformation about STDs, but perhaps we could counteract misinformation by spreading accurate information in a way that catches users’ attention.” – by Marley Ghizzone


Nobles AL, et al. JAMA. 2019;doi:10.1001/jama.2019.14390.

Disclosures: Ayers reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures. Dombrowski reports receiving research support from Hologic Inc. through grants to the University of Washington. Prior reports no relevant financial disclosures.