Descriptive Transcript
music // Title card reads Back to Basic Toronto, 2014. Dr. Charu Kaushic. Gender Differences in HIV. Charu Kaushic stands alone on the main stage at the Back to Basic conference. An on-screen graphic identifies her as the OHTN Applied HIV Research Chair and Professor, Pathology and Molecular Medicine, McMaster Immunology Research Centre, McMaster University.
Charu Kaushic: And then, when you start looking at some statistics and numbers, and look for what do we know about gender? Or, how can we look at gender differences in HIV? And these are the kind of graphs that you come up with.
Kaushic displays a bar graph of new HIV infections in men and women in the United States in 2010. White MSM have the highest number of new infections at 11,200. Black MSM follow at 10,400. Latino MSM: 6,700. Black heterosexual women: 5,300. Black heterosexual men: 2,700. White heterosexual women: 1,300. Latina heterosexual women: 1,200. Black men who use injection drugs: 1,100. Black women who use injection drugs: 850.
So, basically, there’s no differentiation between all the different grades of genders. What you find are differences between men and women. So, those are the kind of numbers that we typically throw out, that are used for developing next generation of treatments, cures, treatment cascades, those are all dependent on these numbers. So, here’s an example.
But, even with these numbers, which are very simple numbers, men and women — you can see that, in places like Africa — and this was taken from CDC in 2010 numbers — you can see that the top bars are white MSM — or, sorry, this is actually CDC in in the United States. I think I switched slides this morning. But you can see a little bit more gradation in terms of the numbers that are there. So these are new HIV infections in United States from 2010. And you can see white MSM, black MSM, you know, second category: hispanic, latino MSM. And then black heterosexual women.
So, you can see different categories of prevalence in new HIV infections, which is very prototypical of North America, where it’s still a majority is in MSM. And the new numbers show that it’s also increasing in immigrant populations, especially here in Ontario. So, that’s the kind of numbers that you — at least you have some idea of, you know, sexual identities of people and, sort of, broad biological differences according to sex.
Kaushic displays a bar graph showing the percentage of adults ages 15-49 living with HIV/AIDS in southern Africa. The exact values are not given on the slide, but, in each case, women account for a higher percentage of people living with HIV than men. The countries listed are Botswana, Lesotho, Namibia, South Africa, and Swaziland. Women account for 15-30% while men account for 10-20%.
But then you go to places like Africa — and these are numbers from 2011, in southern Africa — and these are adult-aged adults — reproductive-aged adults. And you see the differences. And you can basically see men, women, simple categories and you can see that, even with these simple categories, you can see the high numbers of prevalence in women — hovering around 30% in many of the southern African countries. And, compared to that, the numbers in men look less. But, if you consider what they are compared to North America, these are very high numbers. So, basically, 20-25% prevalence in men and about 30% in women. And these are the places where we have numbers.
Kaushic displays a slide containing a screenshot of a report by the CDC entitled “HIV Among Transgender People in the United States” which she references below. Bullet points on the slide read: transgender communities in US are among the highest risk groups for HIV; data for this population is not uniformly collected: there is no accurate information; from the data collected, newly identified HIV infections in transgender people is estimated at 2.1% compared to women 0.4% and men 1.2%; Review of available data from different countries shows prevalence for HIV positive women is 50 times as high as for other adults of reproductive age; in one study in US, HIV-positive test in Black transgender women 56.3% compared to white 16.7% or Latino 16.1%.
I had to search around to find any data for transgender. So, you can see how difficult an issue it is, you know, to find, and how to help, and how to develop treatment cascades for people who don’t identify with one or, you know, simple genders, or some simple male or female sex.
This is from CDC from 2013 — November, 2013, and what the CDC says is that transgender communities in US are among high groups for HIV. Even in US, the data is not uniformly collected. So, there’s no accurate information that’s available. From the data collected, they find that the transgender people have higher prevalence compared to any other category. What’s startling is that the people who are transgender have about — transgender women, in particular — have about 50-fold higher risk of contracting HIV.
So, you know, this is a CDC information sheet. If you have time, I suggest you take a look at it. But the numbers are pretty startling. And it’s mind-boggling that we shouldn’t be looking more into it. And I think there are attempts going on. But, clearly, this is one of the most at-risk populations, even in North America.
Kaushic displays a slide listing the biological differences between men and women in terms of HIV/AIDS. She reviews the items in the list below.
So, you know, when I was thinking about this, coming from a basic science perspective, I was thinking mostly of biological sex. So, here’s, sort of, my simplest — I’m sure this is in no way a complete, comprehensive list — but I was thinking of, what do I know about HIV immunology, virology, and how does being a man or woman make a difference between how your risks are, what your susceptibility is, what your treatment is? And it’s — you know, it’s completely different. So, it’s not a little bit different. It’s completely different.
So, here’s, you know, just sort of a very basic list. I highlighted in green some of the topics that are going to be covered during the day today, at various talks. You know, so, increased biological susceptibility among women. That’s — all numbers show that. Sexual violence, not to say that men are not victims of sexual violence, but in so many conflict zones around the world, women and children are primarily the target for sexual violence. Pregnancy increases susceptibility. Mother to child transmission issues are very specific to women. We know, now, that there are what we had worried about — that there may be menstrual cycle differences as well, in susceptibility. There’s a lot more studies that are going on, now, and we think that this may be a really good way of dealing with some of the issues around HIV susceptibilities, to understand the vaginal microbiome, and our own bacteria that can fight off these exogenous pathogens, or pathogens like HIV, that come from outside. And my own lab works on the hormonal contraceptive issues around, that may enhance risk — and you’ll hear some of those talks today. And ART use in pregnancy, which, Lena’s sitting here, and I think her lab does a lot of work in that. I’m going to give you an example of something very simple: how even viral loads differ between men and women. And chronic immune activation, which affects your lifestyle, and how long you live, and how quickly you develop AIDS, differs between men and women.
And on the bottom part is the list that I could think of in terms of differences — biological differences making a difference to men. You know, there’s a higher risk in MSM compared to most other categories of sexual transmission. Circumcision decreases susceptibility — so a bit of good news, there. Semen micro-environment, compartmentalization — I’m sure Rupert will talk about that later today. There’s a specific talk on male and gender factors. Viral reservoirs in testes. I think Reina Bendayan is here, and her lab does work on this aspect. Effect of HIV and ART on testosterone. You know, so, there’s definite issues with ART on testosterone levels in men.
And, finally, I’ll end with a slide to talk about those basic differences.
Kaushic displays a slide labelled “Differential response to HIV leads to lower viral loads, but higher chronic immune activation in women.” The image on the slide, which Kaushic describes below, depicts differences in the way men and women’s cells react to HIV. Women’s bodies, represented on the left side of the slide, produce much more interferon (indicated by a cluster of green dots) than men’s bodies.
So, here’s a very complicated-looking immunological slide, but what it basically shows on the left side is how women respond to HIV, and on the right side is how men respond to HIV. And this is cumulative research that has, you know, come by pointing out some very basic differences. And what’s shown on the top is HIV, and how cells — the same cell in a woman versus a man responds differently. And on the left, you’ll see lots of green dots. That’s interferon. So, that’s the first antiviral protein that the body — the cells — make when they see HIV. And, as you can see, in women, that’s a very big, profound response. The result of that is that, in acute HIV infection, women actually have lower viral loads. They have higher CD4 counts, unfortunately. That’s also a bad part. Because of these inflammatory proteins that are made at higher — in higher amounts, women fare worse in the chronic HIV infection part. Where they actually have higher immune activation.
So, clearly there are gender differences, starting from very basic first step of the body recognizing HIV. And you’ll hear those talks through the whole day today.
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