Hello everyone. This is Dr. Anne Rompalo, and I'm going to talk about Sexually Transmitted Infections, STIs. What are they and why do we care? At the end of this module, you will be able to describe the known amount of common STIs that occur globally and nationally, list common sequalae of STIs in women, and assess challenges in control of STIs from a global and national perspective. So globally, there's more than one million sexually transmitted infections that are acquired every day. The majority of these STIs have no symptoms or only mild symptoms and therefore they're not recognized. Women bear the disproportionate burden of STIs and their adverse outcomes such as infertility, mother-to-child transmission of STIs, for example, in women with human papillomavirus infection. More than 290 million women are indeed infected. There are over 500,000 women with HPV induced cervical cancer and 266,000 cervical cancer deaths. Turning to syphilis, the World Health Organization estimates over 900,000 pregnant women worldwide were infected with syphilis in 2013, 350,000 adverse birth outcomes including stillbirths were results of these infections. According to CDC estimates, 918 reported congenital syphilis cases occurred in 2017 in the United States, and this is an increase of about 154 percent since 2013. So this slide illustrates the WHO 2017 estimates of sexually transmitted infections. So what STIs does the WHO actually look for and record? That would be syphilis, gonorrhea, chlamydia, and trichomoniasis. The global burden is about 357 million new infections. The US burden according to the 2017 CDC data is 2.3 million new infections. Specifically chlamydia, 1,708,569 cases, which actually is like a 22 percent increase since 2013, gonorrhea over 500,000 cases, which represents 67 percent increase since 2013, and primary and secondary syphilis, which is considered incidents syphilis, over 30,000 cases, which is a 76 percent increase since 2013. So here are the key facts. STI pathogen resistance to antimicrobial agents especially for gonorrhea is a major threat to reducing STIs globally. The WHO estimates show that more than 500 million people are infected with genital herpes. STIs, such as herpes and syphilis can increase the risk of HIV acquisition threefold or more in some studies. The WHO estimates there were 36.7 million people living with HIV globally in 2016. One million HIV related deaths in 2016, and the heaviest burden is in the 15-49-year-old age group. Sub- Saharan Africa bears the greatest burden in this age group with an estimated 4.2 percent population prevalence. Turning to the United States, there was 1.1 million adults and adolescents living with HIV at the end of 2015. So let's focus nationally. The US is experiencing steep, sustained increases in sexually transmitted diseases. As we talked about, gonorrhea cases increased 67 percent, syphilis 76 percent, and we're almost at the two million mark for chlamydia, which is the most common condition reported to the CDC. Again, we also in review talked about undiagnosed STIs that can lead to severe health problems especially in women and that's ectopic pregnancy, increased HIV risk, and of course infertility. We have continued concerns about Antibiotic Resistant Gonorrhea. Gonorrhea is expected to eventually wear down our last highly effective antibiotics, lab tests show a small but growing fraction of gonorrhea samples have signs of emerging antibiotic resistance. The CDC currently is recommending two-drug combination to preserve our last highly effective antibiotics. If we focus on HIV incidence, the annual HIV infections have been declining since their height in the mid 1980s, but we're in a stall period now. Following the five-years of decline, the estimated number of new HIV infections began to level off in 2013, as you can see in this graph, at about 40,000 cases. So we need to get on top of this epidemic. HIV increases in some groups and it decreased in others, and you can see data here of new HIV infections by race and transmission groups. In gay and bisexual men, it's been stable at about 26,000 new infections per year. It appears to have decreased in heterosexuals by 17 percent and it decreased 30 percent in people who inject drugs. So to go back to the first slide and think about it, we talked a little bit about some STIs, we'll go into greater depth as we move on in this course. But why do we care? Well, because they're prevalent, the incidence is high, the consequences are steep, and a lot of them are asymptomatic. So we really need to get on top of this. We'll talk in the next few lectures about clinical presentations and as I alluded to, many are asymptomatic. So we have to screen, ask questions, figure out who's at risk, and do some testing, and then we have to report appropriately to find out where these STIs are happening, and hopefully get at prevention and control. I'll see you in the next lecture.
