Thursday was a very active day for the 25,000 participants of the 17th International AIDS Conference in Mexico City if we were to look on their agenda.

For example, one of the hot topics was the revealing of two studies, which gave hope that someday HIV/AIDS will be preventable. More exactly, Stephanie Planque, who presented the studies, said that people living with HIV for a long time produce rare and extremely potent antibodies that stop the disease from progressing, a process that one day might protect uninfected people from the virus as well. She explained that these antibodies, which fight against a HIV protein called gp120, might prove useful as a microbicide for blocking infection during sexual intercourse. If researchers trick the immune system to produce more antibodies of this kind, then they would have a vaccine, but “the road is long before we reach that point,” Planque cautioned.

HIV prevention was a key topic during the six-day conference and discussions held yesterday made no exception. One thing was pretty clear: more effort is needed to prevent new cases of HIV infection, meaning there should be more campaigns teaching people about HIV/AIDS and ways to prevent the disease. And it seems like authorities fail to provide what it takes to stop the infection from spreading.

For example, a report of the Centers for Disease Control and Prevention released yesterday at the conference said that just 40 percent of adults in the US were tested for HIV in 2006 (an estimated 71.5 million persons).

The report follows another one released ahead of the conference, which said that far more Americans are being newly infected with AIDS virus every year than previously estimated, meaning 56,000 a year instead of 40,000. The finding was due to some new methods the CDC used to come up with the higher number.

Both reports lead us to believe either that health authorities fail to provide the assistance and the necessary tests to detect HIV infections (preventing this way HIV spreading) or people fear to ask to be tested for HIV because it takes too much courage to admit that you might be infected with this terrible disease.

The CDC urged for “new strategies such as expanded screening in health-care settings” to have early diagnosis of HIV because having an early diagnosis “can improve the quality and length of their lives and adopt behaviors to prevent further HIV transmission.” They also recommended that the HIV test should become a standard test during any ordinary doctor’s visit thus removing the stigma of having asked for it.

Of course providing enough HIV tests is not sufficient to prevent the infection. Scientists cautioned that people are unaware of the risks they expose when having unprotected sex. And several studies presented at the conference showed that the risk was much higher among homosexual and bisexual men. While in the United States, 53 percent of new HIV infections in 2006 were in gay and bisexual men, in Mexico men who have sex with men are 109 times as likely as others to develop HIV. Use of condoms appropriately would diminish considerably the risk of infection but US studies involving gay and bisexual men infected with HIV showed that more than one third of them have recently had unprotected intercourse.