STD Awareness: HIV and AIDS

Our immune systems are beautiful things, refined through millions of years of evolution. The immune system’s complexity is testament to the “arms race” that has been taking place between our species and the harmful pathogens that surround us. Last century, a virus called human immunodeficiency virus (HIV) emerged, and it found a weak spot in our immune system’s armor. HIV has been exploiting this weakness ever since, and an HIV infection can eventually progress to a disease called AIDS, or acquired immune deficiency syndrome. AIDS is a condition that disables our immune system’s ability to function properly, rendering us vulnerable to a host of opportunistic infections and cancers.


Even if you don’t think you’ve been exposed, HIV testing can be a good idea.


HIV is transmitted via bodily fluids: blood, semen, pre-seminal fluid (which can be present without ejaculation), breast milk, vaginal fluids, and rectal mucus. (It can also be present in bodily fluids like amniotic fluid, cerebrospinal fluid, and synovial fluid, to which health-care workers might be exposed.) The virus is not transmitted by fluids like snot, saliva, sweat, tears, and urine — unless blood is present.

Activities that can bring you into contact with HIV-infected bodily fluids include injection drug use and sexual activities like anal, vaginal, or oral sex. It can also be transmitted to a fetus or baby during pregnancy, childbirth, or breastfeeding. In the early days of HIV, many infections occurred as a result of blood transfusions or organ transplants — though nowadays this is a rarity thanks to tissue screening. Lastly, health-care workers might be exposed to HIV through accidents involving needlesticks or cuts. Continue reading

STD Awareness: Viral Hepatitis

Hepatitis A virus particles are pictured in this electron micrograph. Image: Betty Partin, CDC

Hepatitis isn’t commonly thought of as a sexually transmitted disease (STD) — for most people, hepatitis conjures images of contaminated food or unsanitary restaurants. But hepatitis should be on the radar of anyone who is sexually active. There are several different viruses that cause hepatitis, and some can be sexually transmitted, including hepatitis A (HAV), hepatitis B (HBV), and, to a lesser extent, hepatitis C (HCV).

While HBV is most efficiently transmitted through blood, it can also easily hitch rides from person to person via sexual fluids. However, we covered HBV in depth last year in observance of World Hepatitis Day. As May is Hepatitis Awareness Month, we’ll turn the spotlight on HAV and HCV for this month’s installment of our STD Awareness series.

Hepatitis A (HAV)

HAV spreads through fecal-oral contact and is more widespread in parts of the world with poor sanitation. It is relatively rare in the United States, although in 2003 there was a hepatitis A outbreak outside of Pittsburgh — the largest in the United States — that was traced to improperly washed raw scallions. All told, there were 650 confirmed illnesses and four deaths. HAV is very resilient and can survive outside a host for long periods of time — other foodstuffs it can contaminate include filter-feeding shellfish, which can concentrate HAV from contaminated seawater in their tissues. When these shellfish are undercooked, they can pack quite a punch as billions of virus particles are released into the unsuspecting diner’s body.


Vaccination against hepatitis A confers lifelong immunity while sparing you from illness caused by a natural infection.


Unfortunately, no matter how well you clean your fresh produce or how long you cook shellfish, certain sexual activities can increase your risk of acquiring HAV. As with intestinal parasites, which can be present in minuscule amounts of fecal matter, so too can virus particles be present in microscopic bits of feces. Oral contact with the anus (“rimming” or anilingus) is the riskiest activity in terms of HAV transmission — oral-genital contact can also do the trick, as can manual contact between the anus and the mouth. While hepatitis A outbreaks have been reported among MSM — men who have sex with men — populations, oral-anal contact is associated with increased risk for HAV infection regardless of sexual orientation. To reduce your risk of sexual HAV transmission, use latex condoms or dental dams during oral activities. HAV can also be transmitted via blood, and hepatitis A outbreaks have been reported among IV drug users. Continue reading