Chlamydia, an extremely common sexually transmitted infection affecting an estimated 131 million people worldwide, is currently easily treated by antibiotics in most cases.
But according to the World Health Organization, growing antibiotic resistance is making the treatment of a number of bacterial sexually transmitted diseases (STDs) more challenging.
The problem is most pronounced for gonorrhea, strains of which do not respond to any available antibiotics. But antibiotic resistance also exists for chlamydia and syphilis, making prevention and prompt treatment of these diseases critical.
But what if there were a therapy for STDs that didn’t involve antibiotics?
Researchers at the University of Waterloo in Ontario are working on developing just that.
As described in the February 4 issue of the journal Scientific Reports, the research team has developed a gene therapy for preventing and treating chlamydia. The hope is that once this therapy is perfected, it can be adapted for use in treating other sexually transmitted bacterial infections such as gonorrhea and syphilis.
New Approach Is Both Prevention and Treatment
“Our treatment is the first combination therapy, a two-pronged approach,” says the lead researcher, Emmanuel Ho, PhD, an associate professor in the school of pharmacy at the University of Waterloo.
The treatment makes use of nanoparticles to deliver treatment to infected cells. The dual approach prevents the majority of chlamydia bacteria from entering cells in the genital tract and then destroys any bacteria that is able to penetrate a cell wall.
In the laboratory, the gene therapy has successfully killed skin cells infected with chlamydia while at the same time protecting healthy cells. Currently, the only ways to prevent transmission of chlamydia are abstinence and the use of latex condoms. There is no vaccine available.
The first part of the therapy is preventive: It delivers a gene that reduces expression of the chlamydia protein on cells. “This means that we will be able to prevent or reduce the chlamydia actually binding to cells that it affects,” says Dr. Ho.
The second part is treatment that kicks in if the chlamydia is still able to infect the cells after the gene introduction. “We’re able to elicit a cellular response where cells form a bubble around the chlamydia and then kill it,” says Ho.
Research Is Preliminary — but Exciting
This novel therapy is still in the preclinical stage. The research team is a couple of years away from testing it in humans. (The team has been using a cell line.) But so far, the therapy has shown a 65 percent success rate.
Ho says, “That doesn’t sound too exciting to others, but it’s exciting to us in terms of science. This was based on a single treatment. When you take antibiotics, you have to take them for one or two weeks. If we treated it for an entire week, we expect that the percentage will be a lot higher. We need additional study.”
He adds, “The hope is that it will be developed into a cream or gel that women can apply to the vagina and men can apply to the penis at the time of intercourse, which is usually when transmission occurs.”
Chlamydia Symptoms May Not Be Apparent
Chlamydia is often asymptomatic until it has progressed to later stages, or symptoms are so mild that the infected person doesn’t pay much attention to them and therefore doesn’t seek treatment.
When they occur, symptoms of chlamydia may include:
- Pain or burning while urinating
- Pain during sexual activity
- Discharge from the vagina or penis
- Abdominal pain
- Swollen, tender testicles
- Pain, discharge, or bleeding from the anus
Why Chlamydia Needs to Be Treated Sooner Rather Than Later
If left untreated, chlamydia can lead to severe health problems in men, women, and newborns:
- Pregnant women can pass the disease onto their newborn during delivery, causing eye infections and pneumonia. It may also cause premature birth.
- In women, untreated chlamydia can cause pelvic inflammatory disease, which can lead to ectopic pregnancies and infertility.
- In men, untreated chlamydia can cause infection in the tube that carries sperm from the testicles.
Chlamydia Is the Most Common Condition Reported to the CDC
More than 1.7 million cases of chlamydia were diagnosed in 2017 in the United States, according to the Centers for Disease Control and Prevention (CDC). Of those, 45 percent occurred in 15- to 24-year-old women.
Because young women are at such high risk for chlamydia, the CDC recommends that sexually active women age 25 and younger get tested annually for chlamydia. Annual screening is also recommended for men who have sex with men and sexually active people living with HIV. All pregnant women should be screened for chlamydia at their first prenatal visit.