New study points to high STI rates among teens, major disparities among population groups.One in four U.S. women aged 14-19 has a sexually transmitted infection (STI STI systolic time intervals. ), according to a study released in March 2008 by researchers from the Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. (CDC See Control Data, century date change and Back Orifice.
CDC - Control Data Corporation ). Prevalence was 40% among those who said they were sexually experienced. The data are drawn from the 2003-2004 National Health and Nutrition Examination Surveys (NHANES NHANES National Health and Nutrition Examination Survey (US CDC) ), a nationally representative survey that is notable for relying on actual medical testing, rather than self-reported infection--important because many STIs are asymptomatic.
The new figures were trumpeted in newspapers around the country and are in many ways distressing. The STI cases in the study include chlamydia chlamydia (kləmĭd`ēə), genus of microorganisms that cause a variety of diseases in humans and other animals. Psittacosis, or parrot fever, caused by the species Chlamydia psittaci, (3.9% of the teens), trichomoniasis trichomoniasis (trĭk'əmənī`əsĭs), sexually transmitted disease caused by the parasitic protozoan Trichomonas vaginalis. (2.5%) and genital herpes Genital Herpes Definition
Genital herpes is a sexually transmitted disease caused by a herpes virus. The disease is characterized by the formation of fluid-filled, painful blisters in the genital area. (1.9%), all of which can increase one's vulnerability to HIV HIV (Human Immunodeficiency Virus), either of two closely related retroviruses that invade T-helper lymphocytes and are responsible for AIDS. There are two types of HIV: HIV-1 and HIV-2. HIV-1 is responsible for the vast majority of AIDS in the United States. infection and impact fertility, maternal and child health, or both. Chlamydia and trichomoniasis are curable cur·a·ble
Capable of being cured or healed. ; herpes is not, although treatment can suppress outbreaks and reduce the chances of passing it on to a partner. Several even less common STIs were missing from the study, including gonorrhea gonorrhea (gŏnərē`ə), common infectious disease caused by a bacterium (Neisseria gonorrhoeae), involving chiefly the mucous membranes of the genitourinary tract. , syphilis and HIV.
In one key respect, however, the overall STI rates may not be as alarming they first appear. Roughly two-thirds of the infections were of human papillomavirus human papillomavirus (HPV), any of a family of more than 60 viruses that cause various growths, including plantar warts and genital warts, a sexually transmitted disease. Detectable warts can be or removed, usually by chemicals, freezing, or laser, but often recur. (HPV HPV human papillomavirus.
human papilloma virus
Human papilloma virus (HPV) ), found among 18.3% of the teens. Yet, although ail 25 of the strains studied are deemed "high risk" by medical researchers, the most serious HPV strains are considerably less common. Four strains of HPV account for 70% of cervical cancer cases and 90% of genital warts. Another CDC analysis, from 2007, found that infection with one or more of these four strains is about one-fifth as common as infection with a "high risk" strain overall.
Perhaps more important is the fact that most HPV infections--including the highest-risk strains--are cleared naturally and safely by a woman's body. A study released in April by researchers from the National Cancer Institute found that more than half of infections clear within six months; other studies have found that nine in 10 infections are fought off within two years. Moreover, the simple and relatively inexpensive Pap test has been proven extremely successful in detecting cervical abnormalities long before they may develop into cancer and while they are easily treated. So, although HPV is so common that it can be seen as virtually a marker for sexual activity, cervical cancer is quite rare in this country: roughly 10,000 cases per year, resulting in 3,700 deaths.
The study's most important finding, rather, may be its confirmation of severe disparities in STI rates by race and ethnicity. Nearly half of black teens in the study were found to have one or more of the four STIs, compared with only one in five white or Mexican American teens (see chart). This disparity is independent of factors such as income and number of sexual partners.
The new study adds weight to calls for expanded STI screening, treatment and prevention--in which there are also serious racial and economic disparities. More than half of cervical cancer cases, for example, occur among women who have not had a Pap test in the past three years, women who are disproportionately low-income and of color. The combination of increased access to Pap tests and even more sophisticated diagnostic technologies and the rollout of the HPV vaccine--which targets some of the highest-risk strains--hold the potential to virtually eliminate cervical cancer in this country. Similarly, the U.S. government recommends routine screening for chlamydia among sexually active women 25 and younger. If fully funded and paired with treatment for the woman and her partner, this initiative could make substantial headway in reducing disparities in the incidence and impact of that STI as well
DISTURBING DISPARITIES Half of black teenage women in the United States have at least one of the four most common STIs, a rate that is two-and-a-half times as high as that for their white and Mexican American peers. % with STI, U.S females 14-19 Non-Hispanic with 20.3 Mexican American 19.7 Non-Hispanic black 47.7 Note: Includes infeclion with chlamydia, trichomoniasis, genital herpes or one of 25 strains of human papillomavirus linked to cervical cancer or genitol warts. Sourco:Conters for Disease Control and Prevention. 2008. Note: Table made from bar graph