A new analysis from the Centers for Disease Control and Prevention shows that young black gay men, black women and white gay men in their 30s and 40s are much more likely to be newly infected with HIV than other groups in the United States. The study, which appears in this week's Morbidity and Mortality Weekly Report, shows 53 percent of the estimated 56,000 cases of new HIV infection in 2006 were among gay and bisexual men, and 46 percent of the infections occurred among black Americans.

The cause is not yet fully understood, but it appears that underestimation of personal risk plays a big role. For these high risk categories, it also seems to be a problem to maintain safe sexual behavior for a long period of time. Also, black women were almost 15 times more likely to get HIV than white women and almost four times more likely than Hispanic women.

While some allege that homophobia, poverty and discrimination are also notable factors, one cannot disregard that, probably, negligence and irresponsibility are, logically, the most important factors which create these disparities.

The Centers for Disease Control and Prevention have announced early August that the number of Americans who are infected with HIV has been undercounted for almost a decade. It appears that in 2006 there were at least 56,300 new HIV infections, significantly more than the 40,000 estimated in previous years. As expected, gay men are the most affected by new HIV infections.

Also, late July, a report by the Black AIDS Institute has found that the United States spearheads the global response to HIV/AIDS abroad, but neglects problems with the disease at home, especially among black people. The so-called "Black America," which is made up of some 39 million African Americans, would rank 16th in the world in the number of people living with HIV. Blacks present a gene variant, which, while ensuring a higher level of protection against some types of malaria, increases the vulnerability to HIV infection.

A study presented on August 5 at the XVII International AIDS Conference in Mexico City has concluded that heterosexual activity may be associated with higher risks of contracting HIV than previously thought. The standard estimates of 1/1000 chance of getting HIV in a heterosexual encounter is much higher in reality because it doesn't make use of risk factors.

As expected, the highest risk among heterosexual contacts is anal sex, which carries a risk of 1 in 3.1 contacts of getting HIV. At the other end of the spectrum, there were even zero transmission cases after 100 normal penile-vaginal intercourse acts. Circumcision lowers the risk of contracting the disease, whereas lesions such as genital ulcers significantly increase the risks.