Doctors who see patients for sexually transmitted diseases often encounter a problem: Some people don’t come back for their test results and therefore don’t get treated.
That lack of follow-up is one reason why the three most common sexually transmitted diseases — chlamydia, gonorrhea and syphilis — are on the rise for the first time in years. When people don’t get treated, they continue to pass on the disease.
Researchers across the country, including at the University and Maryland, Baltimore County and the John Hopkins University, hope to remedy the problem by developing faster STD tests that allow patients to get the results before they leave the doctor’s office. The scientists are working on tests that can produce answers in mere minutes rather than days.
Rapid tests already exist for syphilis or HIV that allow patients to learn if they have those infections in 10 minutes, but the fastest test for the more common chlamydia and gonorrhea takes 90 minutes. Doctors, researchers and health advocates said that’s still too long. While they are much better than older tests, some practitioners say they may lose patients whose appointments could be over before the results arrive.
“We need more of these and quickly,” said William Smith, executive director of the National Coalition of STD Directors. “A key to making progress is having tests that are quick and reliable for diagnosing STDs. The quicker the test result, the quicker the delivery of treatment, the less spread of diseases we have in our communities.”
Chris Geddes, a professor of chemistry and biochemistry at UMBC, is working on technology that would shorten the time it takes to determine a person’s chlamydia and gonorrhea status.
Older-model tests take swabs from the vagina and penis and grow that bacteria in a lab over a couple of days to detect the diseases. A test Geddes has developed can detect gonorrhea and chlamydia in about eight minutes by targeting DNA.
With Geddes’ test, a swab is used, but it is put into a solution that is then placed in a testing device he developed. The device uses microwave technology that quickly detects the DNA sequence specific to chlamydia or gonorrhea. A metal-enhanced fluorescence technology increases the test’s sensitivity by amplifying tiny light signatures on the DNA sequence..
“It is very accurate because we are targeting the DNA very specific to the bug,” said Geddes, also director of the Institute of Fluorescence at UMBC. “No other bug can have that DNA.”
Geddes also said his test costs less than $1, while typical tests cost about $50.
The technology was tested on a small scale in a nearly 300-person trial, and the results, published in 2013, found the tests to be more accurate, faster and cheaper than what is currently on the market. Geddes is now in the midst of an 1,800-person trial, funded by the National Institutes of Health, with researchers at the Cincinnati Children’s Hospital Medical Center and the University of Cincinnati College of Medicine.
While the first study looked just at chlamydia, the NIH research is testing the UMBC technology for diagnosis of chlamydia and gonorrhea simultaneously.
Still, commercial use could be several years away. The current study will take up to two years. Even if the test proves effective, a company would need to acquire the technology and apply to the U.S. Food and Drug Administration for approval, a process that can also take years.
Charlotte Gaydos, director of the Johns Hopkins Center for the Development of Point-of-Care Tests for Sexually Transmitted Disease, said that it is building up to be a groundbreaking time for rapid STD tests. She said she knows of 25 companies working on various tests.
“There are a lot of companies working on them,” said Gaydos, whose center funded Geddes’ original research. “I think there are several of them that will hit the market at the same time.”
Researchers at Johns Hopkins have developed a low-cost diagnostic tool, slightly larger than a coffee mug, that detects chlamydia within 30 minutes. The prototype, developed by researchers in the Hopkins Department of Biomedical Engineering, is made of a disposable cartridge for a genital swab sample and a heating unit that incubates the DNA to facilitate a reaction. The test results are delivered to and processed by a mobile app on a smartphone connected to the battery-powered device.
A November report by the CDC found that cases of chlamydia, gonorrhea, and syphilis had increased in 2014 for the first time since 2006. The data showed more than 1.4 million cases of chlamydia were reported in 2014, up 2.8 percent since 2013. Rates of primary and secondary syphilis — the most infectious stages — and gonorrhea increased by 15.1 percent and 5.1 percent, respectively. There were 350,062 reported cases of gonorrhea and 19,999 reported cases of syphilis.
The CDC and the United States Preventive Services Task Force recommend annual chlamydia and gonorrhea screening for sexually active women younger than 25, but many people don’t adhere and don’t know they are infected.
Chlamydia and gonorrhea often have no symptoms and, if untreated, can lead to infertility, pelvic inflammatory disease and other health problems. While rarer, syphilis, if untreated, can damage the brain, nerves, eyes and heart, often years after the initial infection.
Health advocates say if they can get more people tested immediately in the office they could treat them more quickly and protect many others. Various reasons exists for why patients may not come back for test results and treatment. They may not be able to get off of work or don’t have transportation. There is also the stigma associated with sexually transmitted eases.
“If somebody is coming to the doctor with symptoms or just wanting to know if they have been exposed to an STD, we want to be able to use that visit as a point of intervention,” said Baltimore Health Commissioner Dr. Leana Wen. “If we can get the results sooner, we can reduce the time the individual can have to spread the STD and protect others as well.”
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