For couples to prevent unintended pregnancy after unprotected intercourse, emergency contraception offers a means. Yet unprotected intercourse also increases the risks of contracting a sexually transmitted disease (STD). Are there emergency measures that can be taken to reduce this risk after exposure?
Yes, experts say. However, these measures have limitations and are recommended only for certain groups of people, such as women who are victims of sexual assault. Emergency treatment of STDs is not recommended for routine use.
"The principal problem [with emergency treatment] is the multitude of STDs," says Dr. Robert Johnson, a medical epidemiologist with the Division of STD Prevention at the U.S. Centers for Disease Control and Prevention (CDC). "There isn't a single drug that can treat all STDs. The viral agents cannot be treated. Coming up with a regimen is problematic."
There are more than 20 types of sexually transmitted diseases. While latex condoms, used consistently and correctly, can reduce the risks of all of them, no single drug can successfully treat all of them.
Combinations of antibiotics may be used to reduce a woman's risks of infection from some bacterial STDs following sexual assault. Genital washing and medications have shown some effectiveness in preventing STDs among men serving in the military. Douches, used by many women to cleanse the vagina, may not help prevent STDs and may actually promote infection in cases where contamination is introduced.
Worldwide, an estimated 250 million new cases of STDs occur annually.1 Most scientists now agree that STD infection increases an individual's risk of contracting HIV, the virus that causes AIDS. There is evidence that STDs that cause genital sores, such as herpes, chancroid and syphilis, can enhance the risks of HIV transmission by creating a site of entry for the AIDS virus. Other STDs, which do not produce ulcers but do produce inflammation, may also increase susceptibility to HIV.2
Because latex condoms can prevent transmission of both bacterial and viral STDs, and because antibiotics can successfully treat bacterial STDs once a diagnosis has been made, research to find a method of emergency STD prevention -- one that could be used after unprotected sexual intercourse but before symptoms develop -- has been limited.
However, research is under way to develop microbicides, which would kill both bacterial and viral STD pathogens. Some researchers have speculated that these products, designed for use prior to sexual intercourse to prevent infection, might also be used for postcoital or emergency STD prevention.
"The need for such a product is evidenced by emerging data concerning the widespread prevalence of non-consensual and coercive sex in women's lives, even within married and consensual unions," write Christopher Elias of the Population Council and Lori Heise of the Health and Development Policy Project. "A postcoital method might also have some utility for women, especially adolescents, in communities where 'planning' to have sex is unacceptable."3
Postcoital STD treatment could also be helpful for couples who use condoms as a means of STD prevention but experience condom breakage or slippage, much as emergency contraception is used to prevent pregnancy when a couple experiences condom failure.
Sexual assault
For women who are the victims of sexual assault or non-consensual sex, the CDC has developed guidelines for emergency STD treatment. The guidelines recommend a combination of antibiotics, given within hours after sexual intercourse. This combination is designed to prevent the infections most commonly diagnosed after sexual assault -- trichomoniasis, chlamydia, gonorrhea and vaginal bacteriosis.
The CDC recommends: 125 milligrams of ceftriaxone injected intramuscularly in a single dose; two grams of metronidazole orally in a single dose; and 100 milligrams of doxycycline taken orally twice a day for seven days.4
The CDC also recommends that health-care providers counsel the client about symptoms of STDs and the need for her to return to the clinic if these occur. Providers should counsel the client to use condoms until the antibiotic treatment is complete, to prevent the possibility of any STD transmission to her partner.
If available, clients should be given a vaccine to protect against Hepatitis B. If laboratory tests are available for STDs, the client should return for follow-up examinations at two weeks and 12 weeks after the sexual assault.
The likelihood of contracting an STD after sexual intercourse is less than the risk of becoming pregnant. Fewer than one in five people are infected with an STD at any given time, while nine out of 10 women under age 35 are fertile and could become pregnant.5 The use of antibiotics as a preventive measure is often done for psychological reasons as well as biological ones. The client, who has already undergone the physical and emotional trauma of assault, may have one less consequence to worry about if she takes antibiotics.
There is some risk a woman will acquire HIV infection after sexual assault, but the CDC says the risks are very low. There are no emergency measures a health-care provider can take to reduce a woman's risk of HIV in this situation. Providers should offer HIV counseling and testing to clients, but some experts recommend that this be done during a return visit to the clinic, not during the initial visit when the client is frightened and upset.
Outside of use to prevent the development of STDs among sexual assault victims, the use of antibiotics for emergency STD prevention in the larger population is regarded by most experts as an unnecessary and an expensive use of scarce medical resources. "Emergency treatment will result in the overtreatment of people who are not infected," says Dr. Jonathan Zenilman, associate professor of medicine in the Infectious Disease Division of Johns Hopkins University in the United States. Given that some STDs have developed a resistance to certain antibiotics, treatment before diagnosis is not recommended.
Military experience
The use of postcoital emergency treatment for STDs has had some success in the U.S. military. During World War I, military officials tried to reduce the incidence of STDs through educational campaigns that emphasized the need for servicemen to be "100 percent efficient to win the war." Military personnel were encouraged to practice abstinence to prevent sexually transmitted diseases.
Servicemen who did engage in sexual activity with prostitutes were told to return to their military base and report for emergency treatment within three hours after sexual intercourse. The procedure involved several steps. First, the soldier urinated, then washed his genitals with soap and water, followed by bichloride of mercury. A medical attendant inspected the soldier's genital area, then injected Protargol, which contains silver protein, into the penis. The soldier would urinate five minutes later. Finally, calomel ointment was rubbed onto the penis, and the penis was wrapped in wax paper. The soldier was not to urinate for at least four to five hours after treatment.
To further reduce the incidence of sexually transmitted disease during World War I, U.S. soldiers were given an emergency treatment packet they could administer themselves. This was done on an experimental basis for soldiers who did not have access to a health clinic. The packet contained calomel ointment, carbolic acid and camphor.
Military health officials estimated this treatment could be 99.6 percent effective in preventing syphilis, gonorrhea and chancroid. Statistics on the success of military efforts to reduce STDs were not published. However, military officials estimate that several million men received emergency STD treatment.
During World War II, the U.S. military sought to reduce the incidence of STDs by offering educational programs, emergency STD treatment and condoms for STD prevention. With the discovery that antibiotics could effectively treat bacterial STDs, and the knowledge that condoms could prevent STD transmission, the use of emergency STD clinics diminished.6
In the 1970s, a study among some 500 U.S. male sailors who had sexual intercourse with women while on shore leave in the western Pacific concluded that STD infection rates did not decrease significantly if a man urinated within 30 minutes after intercourse or if he washed his genitals within an hour.7 Another study among 1,000 male sailors found that 200 mg of minocycline, taken orally a few hours after intercourse, offered some protection against the subsequent development of gonorrhea. However, researchers did not recommend widespread use of the antibiotic because drug-resistant strains of gonorrhea could develop.8
Vaginal douching
Because many women practice routine vaginal douching for hygienic purposes, there has been speculation that postcoital douching might reduce the incidence of STDs. Studies have shown that douching may not offer any type of protection against STDs. In fact, it may promote some types of reproductive tract infections.
While vaginal douching may decrease the risks of gonorrhea, it may increase the risks of pelvic inflammatory disease and ectopic pregnancy.9 A study of more than 600 women in the United States found those who douched were more likely to have risk factors for STDs, including multiple sexual partners and first sexual intercourse at an early age. However, others say it is difficult to determine whether douching increases a woman's risk of infection or whether douching is simply a common practice among women at risk of STDs for other reasons.10
Normally, the pH in the vagina is low (acidic), but the pH levels change during intercourse with ejaculation, menses, estrogen deficiency, menopause and bacterial vaginosis. Researchers believe that pH levels in the vagina may play an important role in STD transmission.
Several small studies have examined the changes in normal vaginal microorganisms after douching. One study of 20 women in the United States found that small amounts of a douche preparation containing the antiseptic, chlorhexidine gluconate, did not significantly alter the vaginal flora after 30 days of use.11 A small study at the Universita di Sassari in Italy evaluated seven vaginal douche preparations to determine their in vitro effects on lactobacilli, a bacteria commonly found in the vagina. Lactobacilli produce hydrogen peroxide, which inhibits the growth of some pathogens, possibly STD pathogens.12 Researchers concluded that frequent use of these douches could change the composition of the normal vaginal flora.13 A study of 10 women in the United States, which compared two types of douche preparations, found that those containing acetic acid (the acid in vinegar) caused short-term minor changes in the vaginal flora, while solutions containing povidone-iodine (Betadine) caused significant changes in the vaginal flora, which could increase the risks of infections and possibly the risks of pelvic inflammatory disease.14
The use of soft drinks as a postcoital douche is frequently suggested as a folk remedy to prevent pregnancy after unprotected sex, but is not effective since sperm enter the cervix within seconds after ejaculation. A study of seven men in Nigeria examined the effects of four different types of soft drinks on in vitro motility of sperm. The study found that one brand of drink, Krest bitter lemon, immobilized all sperm within one minute. The study did not, however, explore microbicidal effects.15 A study conducted in the United States investigated the spermicidal effects of Coca-Cola and found that different formulations of the soft drink did reduce sperm motility.16 A separate study of cola drinks found little effect on sperm motility. Researchers suggested the introduction of these liquids into the vagina might cause infection.17
Some researchers suggest that a microbicidal postcoital douche might be more culturally acceptable than condoms, which require negotiation between partners. A postcoital douche of tea or beer, which has a low pH, or sour milk, which contains lactobacilli that result in low pH levels, might offer protection against STDs, including AIDS, researchers suggest.
Soap and water
Genital washing has been suggested as a means to prevent STD transmission to men. Studies of military personnel in World War I and World War II found that washing with soap and water soon after exposure to STDs helped prevent chancroid.
In sub-Saharan Africa, genital washing has been theoretically proposed as a way to reduce STD and HIV incidence. Lack of circumcision in men may be a risk factor for development of chancroid, a common cause of genital ulcer disease in Africa. Genital ulcer disease appears to be a risk factor for contracting HIV. Health advocates suggest that education about postcoital and precoital washing with instructions on how to clean the area beneath the foreskin of the penis might be one way to reduce the incidence of STDs in east, central and southern Africa, where male circumcision is less common and genital ulcer disease more common than in west Africa.18
But a study in Singapore, which questioned 100 prostitutes about methods they used to prevent sexually transmitted diseases, found that postcoital washing with antiseptic solutions had no STD prevention effect for this group of women.19
-- Barbara Barnett
Footnotes
Crosignani PG, Diczfalusy E, Newton J, et al. Sexually transmitted diseases. Hum Reprod 1992; 9:1330-34.
Mauck CR, Cordero M, Gabelnick H, et al., eds. Barrier Contraceptives: Current Status and Future Prospects. Proceedings of the Fourth Contraceptive Research and Development Program International Workshop, March 22-25, 1993, Santo Domingo, Dominican Republic. New York: John Wiley and Sons Inc., 1994.
Elias CJ, Heise LL. Challenges for the development of female-controlled vaginal microbicides. AIDS 1994; 8:1-9.
U.S. Centers for Disease Control and Prevention. 1993 Sexually Transmitted Diseases Treatment Guidelines. Atlanta: CDC, 1993.
Cates W Jr., Stone KM. Family planning, sexually transmitted diseases and contraceptive choice; a literature update -- part I. Fam Plann Perspect 1992; 24(12):75-84.
Brandt AM. No Magic Bullet: A Social History of Venereal Disease in the United States Since 1880. New York: Oxford University Press, 1985.
Hooper RR, Reynolds GH, Jones OG, et al. Cohort study of venereal disease. I: the risk of gonorrhea transmission from infected women to men. Am J Epidemiol 1978; 108(2):136-44.
Harrison WO, Hooper RR, Wiesner PJ, et al. A trial of minocycline given after exposure to prevent gonorrhea. N Engl J Med 1979; 300(19): 1074-78.
Chow WH, Daling JR, Weiss NS, et al. Vaginal douching as a potential risk for tubal ectopic pregnancy. Am Obstet Gynecol 1985; 153(7):72. Wolner-Hanssen P, Eschenbach D, Paavonen J, et al. Association between vaginal douching and acute pelvic inflammatory disease. JAMA 1990; 263:1936-41.
Rosenberg MJ, Phillips RS, Holmes MD. Vaginal douching: who and why? J Reproduct Med 1991; 36(10):753-58. Rosenberg MJ, Phillips RS. Does douching promote ascending infection? J Reproduct Med 1992; 37(11):930-38.
Shubair M, Stanek R, White S, et al. Effects of chlorhexidine gluconate on normal vaginal flora. Gyn Obstet Investigation 1992; 34(4):229-33.
Klebanoff SJ, Hillier SJ, Eschenbach DA, et al. Control of the microbial flora of the vagina by H2O2-generating lactobacilli. J Infect Dis 1991; 164(1):94-100.
Julian C, Piu L, Gavini E, et al. In vitro antibacterial activity of antiseptics against vaginal lactobacilli. European J Clinical Microbiology Infect Dis 1992; 11(12):1166-69.
Onderdonk AB, Delaney ML, Hinkson PL, et al. Quantitative and qualitative effects of douche preparations on vaginal microflora. Obstet Gynecol 1992; 80:333-38.
Nwoha PU. The immobilization of all spermatozoa in vitro by bitter lemon drink and the effect of alkaline pH. Contraception 1992; 46(6):537-42.
Umpierre SA, Hill JA, Anderson DJ. Effect of 'Coke' on sperm motility. N Engl J Med 1985; 313(21):2.
Hong CY, Shieh CC, Wu P, et al. The spermicidal potency of Coca-Cola and Pepsi-Cola. Hum Toxicol 1987; 6(5):395-96.
O'Farrell N. Soap and water prophylaxis for limiting genital ulcer disease and HIV-1 infection in men in sub-Saharan Africa. Genitourin Med 1993; 69:297-300.
Bradbeer CS, Thin RN, Tan T, et al. Prophylaxis against infection in Singaporean prostitutes. Genitourin Med 1988; 64(1):52-53.
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