Thursday, February 10, 2011

On HIV , Race and Gender. Questions.

I wanted to write something on this topic for the National Black HIV/AIDS Awareness Day but learned far too late that I don't know enough about the topic and that I couldn't study enough in the amount of time I had available. Besides, people with far more expertise were writing on the topic. So I set what I had collected aside.

But the topic keeps bothering me and wants to come out because of some questions it provoked, especially on the gender ratios of new infections among African-Americans, Hispanics and whites. Here is the relevant picture, on estimated rates of NEW HIV infections in 2006, per 100 000:

The picture is not that different when we look at the total number of people who have been diagnosed with HIV, not just new cases:
By race/ethnicity, African Americans face the most severe burden of HIV in the United States (US). At the end of 2007, blacks accounted for almost half (46%) of people living with a diagnosis of HIV infection in the 37 states and 5 US dependent areas with long-term, confidential, name-based HIV reporting. In 2006, blacks accounted for nearly half (45%) of new infections in the 50 states and the District of Columbia. Even though new HIV infections among blacks overall have been roughly stable since the early 1990s, compared with members of other races and ethnicities they continue to account for a higher proportion of cases at all stages of HIV—from new infections to deaths.

The data show both a gender difference and a difference between racial and ethnic groups in both new cases and overall cases. Men are more likely to have HIV than women and minorities are more likely to have HIV than whites (when analyzed within a gender).

The reasons for some of these differences are fairly well understood. The race/ethnicity differences have much to do with the income gradient. Individuals with low incomes are both more likely to get infected and less likely to be diagnosed and treated early, and minorities have a higher percentage of low-income people than whites do.

The gender differences are partly related to the ease with which HIV is transmitted in different types of sexual activities as these quotes about African-American men and women suggest:
New HIV Infections
In 2006, black men accounted for two-thirds of new infections (65%) among all blacks. The rate of new HIV infection for black men was 6 times as high as that of white men, nearly 3 times that of Hispanic/Latino men, and twice that of black women.
In 2006, black men who have sex with men (MSM)2 represented 63% of new infections among all black men, and 35% among all MSM. HIV infection rates are higher among black MSM compared to other MSM. More new HIV infections occurred among young black MSM (aged 13–29) than among any other age and racial group of MSM.
Today, women account for more than 1 in 4 new HIV/AIDS cases in the United States. Of these newly infected women, about 2 out of 3 are African-American. Most of these women got HIV from having unprotected sex with a man.
In 2006, the rate of new HIV infection for black women was nearly 15 times as high as that of white women and nearly four times that of Latinas. And, HIV/AIDS is a leading cause of death of African-American women in many age groups.

But none of this really explains why, say, the rate of newly diagnosed HIV infections differs between men and women of different ethnicity/race the way it does. Take the data on the table I posted above. If we calculate the female/male new infection ratios for each race/ethnicity, we get the following numbers: 0.19 for whites, 0.33 for Hispanics and 0.48 for African-Americans. What explains these differences?

I don't think it has to do with access to services because these comparisons control for the correlation between that and race/ethnicity. Neither do I think that it has to do with the basic risk differences women and men face in various types of sexual activities. Something more must be going on to make those ratios differ the way they do. I have no idea what it is but I bet there are more expert people who could educate me.

And my apologies for writing such a dry and emotionless article on a topic which is both painful and neglected, these days.