(Supplement)/Common Sense-HIV combined with other STDs can be a dangerous mix

Each year, there are about 333 million new cases of curable sexually transmitted diseases (STD) worldwide, according to the World Health Organization. In the United States, there are 12 million new STD cases each year.

The areas of the country with the highest rates of STDs like syphilis and gonorrhea (such as the South) also have the highest HIV prevalence among childbearing women.

People who are prone to STDs have a greater risk of becoming infected with HIV, which is also an STD (but not a curable one). This is because the same risky behaviors make people more susceptible to both kinds of diseases. However, researchers now believe that people who have untreated STDs actually have a greater chance of contracting HIV when they have sex with an HIV-infected person. Likewise, a person who has both HIV and another STD is more likely to spread HIV to uninfected people with whom he or she has sex.

If you are infected with HIV, you need to be aware that it poses an extra danger to your sexual partners if either you or they have an STD.

The Atlanta-based Centers for Disease Control and Pre ven tion (CDC) and the National Institute of Allergy and Infec tious Diseases in Bethesda, MD, have developed information about STDs and their role in spreading HIV. Some of that information is presented below:

How do we know that STDs increase the risk of spreading HIV?

Epidemiological studies have repeatedly demonstrated that people are two to five times more likely to become infected with HIV when other STDs are present. These other STDs include common ones like gonorrhea, chlamydia, syphilis, hepatitis B, herpes, and human papillomavirus (HPV).

Also, biological studies suggest that STDs both increase susceptibility to HIV infection and that they increase the likelihood of infecting other people when STDs are present.

Why do STDs increase HIV susceptibility and infectiousness?

STDs that cause genital lesions can create a portal of entry for HIV. STDs that do not cause lesions still can cause an increase the number of HIV target cells (CD4 cells) in women's cervical secretions, thereby likely increasing their HIV susceptibility.

Also, studies have demonstrated that co-infection with HIV and other STDs results in more shedding of HIV and in greater concentrations of HIV being shed. In African studies, co-infection with gonorrhea and HIV more than doubles the proportion of HIV-infected individuals with HIV RNA detectable in genital secretions. Furthermore, the median concentration of HIV RNA in semen is dramatically increased in co-infected men compared with men infected with HIV alone.

Can STD treatment help prevent HIV transmission?

Yes. New evidence indicates that STD detection and treatment can substantially reduce HIV transmission. If you and your partners are checked and treated for STDs, you will greatly reduce the chance that they will become infected with HIV.

For example, STD treatment reduces the prevalence and magnitude of HIV shedding. Treatment of gonorrhea in HIV-infected men has resulted in a reduction in the number of men who shed HIV, as well as a lower concentration of HIV shed. After STD treatment, the level of shedding among co-infected men returns to the level seen in men who are not co-infected.

Also, STD treatment reduces the spread of HIV infection in communities. A community-level, randomized trial in a rural African community in Tanzania demonstrated a 42% decrease in new, heterosexually transmitted HIV infections in communities with improved STD treatment. An ongoing study in Uganda is further exploring the impact of mass STD treatment in slowing the spread of HIV.

What is a brief description of each of the common STDs?

Gonorrhea: Also called "the clap," gonorrhea is caused by the bacterium Neisseria gonorrhoeae, and it can be transmitted by sexual penetration. Women, in whom it may first infect the cervix, typically experience a cloudy, yellow vaginal discharge, abdominal pain, and irregular menstrual bleeding. Men may have a cloudy discharge from the penis and experience painful urination. When it's contracted orally, you may experience a sore throat, and if the rectum is infected from anal intercourse, it may become inflamed.

• Syphilis: Syphilis bacteria spreads from the sores of an infected person to a sexual partner's mucous membranes of the genital area, mouth, or anus. Within 90 days after infection, a person may develop a painless, smooth, red sore at the infection site. After the initial infection, a person may develop discolored spots or patches on the hands and feet and patches in the mouth, throat, and cervix. Also, there may be a rash over the body and the person may have flu-like symptoms. If untreated, syphilis can cause severe heart disease, paralysis, and death.

• Hepatitis B: About 10% of people who contract this viral infection will develop chronic hepatitis B and be infected for life. It can lead to cirrhosis and liver cancer. Symptoms include a fever, fatigue, nausea, foul breath, appetite loss, hives, and pain below the ribs on the right side.

• Human Papillomavirus (HPV): A common STD, HPV has infected an estimated 40 million Americans. HPV causes genital warts, which can appear on the head of the penis or on the vagina, vulva, cervix, anus, urethra, mouth, and throat. They may not be visible, or they may cluster into a cauliflower-like growth. The warts typically are painless, but they also could itch and burn or become irritated if no treatment is received. HPV is transmitted by direct skin-to-skin contact during sex. Women could develop an abnormal Pap smear many years after being infected.

• Chlamydia: Caused by the microorganism Chlamydia trachomatis, it's the most common STD in the U.S. Symp toms include burning during urination, swelling in the testicles, irregular vaginal bleeding, itching in the genital area, abdominal pain, milky discharge from the penis, fever, and nausea. Early treatment is critical.

• Herpes: Herpes simplex virus (HSV) is a viral infection that causes cold sores or fever blisters in the mouth when it's herpes simplex type one, and genital sores when it's herpes simplex type two. While not as dangerous as other STDs, it has no cure. Symptoms typically develop within two to 10 days after contact with the virus. It causes small red bumps and may develop into painful sores and blisters. Also, people may have flu-like symptoms, muscle aches, and swollen glands. The virus can remain dormant in nerve cells near the spinal cord, and it may be reactivated, causing new sores.

Where can I find out more about STDs and HIV?

You may contact the CDC National Prevention Informa tion Network at P.O. Box 6003, Rockville, MD 20849-6003; telephone: (800) 458-5231; the CDC National AIDS Hotline at (800) 342-AIDS (2437), or in Spanish at (800) 344-SIDA (7432); the CDC National STD Hotline at (800) 227-8922; or go to the CDC's Web site at www.cdc.gov.

You may also contact the Office of Communications, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892. Telephone: (301) 496-5717.