There are approximately 19 million new STD infections each year in the United States, reports the Centers for Disease Control (CDC). Nearly 50 percent of sexually transmitted diseases occur among people between ages 15 and 24; however, women and minorities are also severely affected.
The two most commonly reported infectious diseases in this country are chlamydia and gonorrhea, both of which can cause infertility if left untreated. Women are still slightly more likely to be infected with gonorrhea than men, and African-Americans are 19 times more likely to contract the disease than whites. The rate of gonorrhea infection in Hispanics is twice as high compared to whites, and the rate for American Indians/Alaskan Natives is three times as high.
Although safe sex awareness campaigns are ubiquitous, and new vaccines such as the human papillomavirus vaccine (HPV) provide more protection, much more needs to be done to control the STD epidemic. Throughout the 1990s cases of syphilis steadily declined and reached an all-time low in 2000; since then syphilis infections have been increasing, particularly among gay men. However, cases of syphilis in women have also increased each year in the current decade, mostly among African-American women. Also, infant infections increase with infections to women.
Aside from the health risks they pose - including pelvic inflammatory disease, cervical cancer, inflammation of the prostate and urethra, infertility, and death - STDs cost the health care system about $15.3 million annually. However, some recent advances show promise in improving the rate of infections and treatment of sexually transmitted diseases.
Patient-delivered Partner Treatment More Effective at Protecting Partners from STDs
A study published in Clinical Infectious Diseases indicated that giving men infected with STDs antibiotics to give to their partners was more effective than traditional methods of contacting and treating partners. With this approach, called patient-delivered partner treatment, 70 percent of men gave their partners the antibiotics, compared to 58 percent of men in the booklet-enhanced (giving tear-out referral cards) group, and 48 percent of men in the partner-referral group (telling partners to get treated).
The men in the patient-delivered partner treatment group were also less likely to engage in sex with their partners before they were treated for STDs. Another significant finding was that men in the patient-delivered partner treatment and booklet-enhanced groups were much less likely to test positive again for chlamydia and gonorrhea at the follow-up than men in the standard partner referral arm.
Nanotechnology May Provide a Better Way to Deliver STD Drugs
Researchers at Yale University have made a breakthrough in how potential antiviral drugs can be administered safely and effectively. The drugs are small interfering RNA (siRNA) molecules -and their names give a clue as to how they work. These molecules interfere with and knock out the function of genes in higher organisms, and in microbes that may cause STDs.
In the study the researchers designed siRNAs to target a gene in the female mouse reproductive tract. Using densely-loaded nanoparticles made of a biodegradable polymer called PLGA, they created a stable time-release vehicle to deliver the siRNAs to sensitive tissues in the female mouse reproductive system.
They found that the particles loaded with the drug agent moved effectively in two important ways - penetrating to reach cells below the surface of the mucosa, and distributing throughout the vaginal, cervical, and uterine regions. Also, the siRNAs stayed in the tissues for at least a week and knockdown of gene activity lasted up to 14 days.
According to the researchers, gene interference therapy is moving rapidly from basic research to application. The PLGA packaging used in this study is already approved as safe and non-toxic by the FDA, speeding the path to clinical trials for infectious agents such as HPV and HIV.
"This approach holds promise for global health and the ability of people to self-apply antimicrobial treatments," said lead author Kim Woodrow, postdoctoral fellow in Yale's School of Engineering and Applied Science. "It is safe and effective and much easier than getting an injection of vaccine."
Senior author W. Mark Saltzman of the Goizueta Foundation Professor of Biomedical Engineering and Chemical Engineering added that before human clinical testing can begin, the next step would be to test this approach directly in disease models, for example in the HIV model mice that have an immune system genetically identical to humans.
Study References
Journal: Clinical Infectious Diseases, Vol. 41(5) pp 623-9
Study Date: September 2005
Study Name: Patient‐Delivered Partner Treatment for Male Urethritis: A Randomized, Controlled Trial
Website: http://www.journals.uchicago.edu/doi/abs/10.1086/432476
Authors: Patricia Kissinger, Hamish Mohammed, Gwangi Richardson‐Alston, Jami S. Leichliter,
Stephanie N. Taylor, David H. Martin, and Thomas A. Farley
Journal: Nature Materials Vol. 8, 526-533
Study Date: May 2009
Study Name: Intravaginal gene silencing using biodegradable polymer nanoparticles densely loaded with small-interfering RNA.
Website: http://www.nature.com/nmat/journal/v8/n6/abs/nmat2444.html; http://opa.yale.edu/news/article.aspx?id=6665
Authors: Kim A. Woodrow, Yen Cu, Carmen J. Booth, Jennifer K. Saucier-Sawyer, Monica J. Wood, W. Mark Saltzman
