STDs: A MAJOR CONTEMPORARY PUBLIC HEALTH CONCERN Sexually Transmitted Diseases

Given the advances in medicine and public health over the past several decades, most people might assume that the incidence and prevalence of sexually-transmitted diseases (STDs) is declining; however, the scientific evidence suggests otherwise. Recent estimates from the Centers for Disease Control and Prevention (CDC) in the United States suggest that 20 million new STD infections occur every year and cost the U.S. health care system close to $16 billion dollars annually (CDC, 2013). This is up from 12 million STD infections and $10 billion dollars annually during the mid-1990s (Zenilman, 2004). In 2011, reports of chlamydia incidence set another annual record, double from what it was just 10 years ago (CDC, 2011). To better understand the health threats facing Americans when they engage in sexual activity this report will review what is known about the most common STDs infecting the population. The epidemiology, diagnosis, treatment, and management of the diseases will be the main focus of this article.

STD Epidemiology

The number of organisms that fall within the classification of an STD is over 25 (Zenilman, 2004); however, Satterwhite and colleagues (2013), in their study on the prevalence and incidence of STDs among U.S. men and women, limited their analysis to eight of the most common: Chlamydia, gonorrhea, syphilis, genital herpes, human papillomavirus (HPV), hepatitis B, human immunodeficiency virus (HIV), and trichomoniasis. While many of these diseases can be cured through modern treatments, long-term consequences are common (Zenilman, 2004).

The demographic most affected by STDs are adolescents and young adults (Zenilman, 2004). Salazar and colleagues (2009) cite studies that have found that gonorrhea, chlamydia, trichomoniasis, and HPV are common among sexually active teens. Some of the adverse outcomes include female infertility, male sterility, and mental health problems, which would partially explain the economic burden of STDs in the 15 to 24-year-old age category totaling $6.5 billion in the year 2000.

One contributing factor to increased STD prevalence and incidence among adolescents and young adults is the age of first marriage, which has increased by 4 to 5 years between 1960 and 2000 (Salazar, Santelli, Crosby, & DiClemente, 2009). The number of years that a person in this age group must remain vigilant against acquiring an STD has therefore increased considerably. In addition, the 15 to 24 age group represents only 25% of the sexually active population in the U.S., yet they incur half of all STDs infections. Given the CDC's 2013 estimate of 20 million new STD infections in the U.S. annually, this implies that close to half of these occur in persons between the ages of 15 and 24. This assumption was confirmed in a study by Satterwhite and colleagues (2013) who found that an estimated 19.7 million new STD infections occurred in 2008 and half were in individuals between the ages of 15- and 24-years. By comparison, the 15 to 24 age group only represents about 20% of the 110 million current STD infections in the U.S. The subgroup most affected is adolescent girls between the ages of 14- and 19-years, with an estimated 26% currently infected with HPV, chlamydia, herpes, and/or trichomoniasis (Salazar, Santelli, Crosby, & DiClemente, 2009).

When Lindau and colleagues (2007) interviewed approximately 3,000 U.S. adults between the ages of 57- and 85-years they were surprised to find that many were still sexually active. For example, in the 57 to 60 age group over 90% still experiencing excellent health were sexually active during the previous year. For the oldest age group, 81 to 85, close to 50% in excellent health were still sexually active. Successful aging comes with a price though. Close to 10% of new HIV infections in 2006 were in people over the age of 50 (Minichiello, Hawkes, & Pitts, 2011). Although most STD studies tend to exclude older adults, a study reviewed by Minichiello and colleagues (2011) revealed a 50% increase in new STD cases between 1996 and 2008 in older adults. Older adults who seek care often explain that concerns about pregnancy are minimal and assume that an older partner is disease free, so condoms are rarely used.

Etiology, Diagnosis, and Treatment/Management of Common STDs

Gonorrhea -- The bacterium Neisseria gonorrhoeae is almost exclusively transmitted from host to host during human sexual activity (Dyck, Meheus, & Piot, 1999). While many gonorrhea infections will produce a pussy discharge from the infected genitals, a diagnosis must be confirmed using laboratory culture or immunological tests. If left untreated for a prolonged period any number of negative outcomes can occur, including infertility, sterility, ectopic pregnancy, conjunctivitis, and a disseminated infection. Successfully resolving a gonorrhea infection has become...

Strains resistant to penicillin and tetracycline developed in the 1970s, while strains resistant to fluoroquinolones began to appear in 2011. Current recommendations are to treat with 250 mg ceftriaxone by injection.
Chlamydia -- The bacterium Chlamydia trachomatis is the most common sexually transmitted microbe globally and can cause a number of medical complications, including conjunctivitis, pneumonia, and lymphogranulomas (Dyck, Meheus, & Piot, 1999). Samples are taken from various locations on the body and either cultured or tested immunologically for the presence of C. trachomatis. The wide prevalence of chlamydia infections can be explained in part by the lack of symptoms. For example, 50 and 70% of men and women, respectively, are asymptomatic; therefore, the CDC recommends that all women under 26-years of age and all women with multiple partners should be screened annually (Katz, Lee, & Wasserman, 2012). Treatment involves oral azithromycin or doxycycline.

Syphilis -- The bacterium Treponema palladium is one of four microbes within the genus Treponema that cause human disease, but T. palladium is the only one that causes syphilis (Dyck, Meheus, & Piot, 1999). Transmission occurs through direct contact between infected lesions of the mucosa and damaged skin. The infected area will develop an ulcer (chancre) within three weeks that is typically painless. If left untreated, the open sore will regress and the patient will remain asymptomatic for about six months. During this period the infection will disseminate throughout the body. Secondary lesions will form, but in the absence of a curative treatment a second asymptomatic period will occur that can last for years or decades. Serum antibodies to T. palladium will develop within one to four weeks, which is the basis for a positive diagnosis. The primary recommended treatment regimen, regardless of the stage of disease, is penicillin G. parenterally (Katz, Lee, & Wasserman, 2012).

Genital Herpes -- The genitals are the primary location of infection for the herpes simplex virus-2 (HSV-2), but HSV-1 has also been detected in this anatomic location despite showing a preference for the oral cavity (Dyck, Meheus, & Piot, 1999). Primary infections are often asymptomatic, but patients who are symptomatic will have puss-filled lesions on their genitals. A positive diagnosis can be confirmed either by culture or immunological tests. There is no known cure for genital herpes, but patients experiencing recurrent outbreaks may benefit from antiviral therapy using aciclovir, valaciclovir, or famciclovir (Peate, 2005, p. 61).

HIV -- The retrovirus that causes acquire immunodeficiency syndrome or AIDS is transmitted primarily through sexual contact (Dyck, Meheus, & Piot, 1999). Antibodies to the virus usually develop within one to four weeks after infection and a positive diagnosis is obtained by testing the serum for these antibodies. Many patients will remain asymptomatic for over a year following infection, but eventually begin to experience recurrent infections and cancerous growths atypical for healthy people (Peate, 2005, p. 68-69). Improvements in the management of the disease have progressed to the point that an AIDS diagnosis is no longer a certain death sentence.

HPV -- The virus that causes genital warts is transmitted primarily through sexual activity (Dyck, Meheus, & Piot, 1999). Typically a wart will develop due to entry of the virus into the basal germinal layer of the mucosa, but in some patients the HPV infection will generate an invasive tumor that results in cervical cancer. Unfortunately, a definitive diagnosis can only be obtained by detecting HPV nucleic acid sequence in a biological specimen, a test not commonly available in most laboratories. Current CDC recommendations are for all females and males between 11- and 26-years of age to be vaccinated (Katz, Lee, & Wasserman, 2012). A number of topical treatments are also available for treating genital warts.

STD Risk Factors

In young people, many of the same risk factors for teen pregnancy are relevant for STD exposure (Salazar, Santelli, Crosby, & DiClemente, 2009). These include socioeconomic status, ethnicity, a lack of parental involvement, risk-taking influences from peers, partner coercion, and multiple sexual partners. The CDC lists as risk factors a past history of STD infection, engaging in unprotected sex, multiple partners, multiple partners once removed, and STD seeking behavior (Katz, Lee, & Wasserman, 2012). Accordingly, public health initiatives designed to reduce the incidence of STD infections attempt to address these risk factors.

Conclusions

STDs, instead of fading away to the dustbin of medical history, seems to be taking advantage societal problems that lead…