Month: August 2023

While the FDA rules for blood donation were revised twice in the last decade, one group — men who have sex with men (MSM) — continued to be turned away from donating. Now new, evidence-based FDA rules embraced by the American Red Cross will focus on individual risk rather than groupwide restrictions.

Medical experts consider the new rules safe based on extensive evidence. Let’s review the changes here.

The new blood donation rules: One set of questions

The May 2023 FDA guidelines recommend asking every potential blood donor the same screening questions. These questions ask about behavior that raises risk for HIV, which can be spread through a transfusion.

Blood donation is then allowed, or not, based on personal risk factors for HIV and other blood-borne diseases.

Questions for potential blood donors

Screening questions focus on the risk of recent HIV infection, which is more likely to be missed by routine testing than a longstanding infection.

The screening questions ask everyone — regardless of gender, sex, or sexual orientation — whether in the past three months they have

• had a new sexual partner and engaged in anal sex
• had more than one sexual partner and engaged in anal sex
• taken medicines to prevent HIV infection (such as pre-exposure prophylaxis, or PrEP)
• exchanged sex for pay or drugs, or used nonprescription injection drugs
• had sex with someone who has previously tested positive for HIV infection
• had sex with someone who exchanged sex for pay or drugs
• had sex with someone who used nonprescription injection drugs.

When is a waiting period recommended before giving blood?

• Answering no to all of these screening questions suggests a person has a low risk of having a recently acquired HIV infection. No waiting period is necessary.
• Answering yes to any of these screening questions raises concern that a potential donor might have an HIV infection. A three-month delay before giving blood is advised.

Does a waiting period before giving blood apply in other situations?

Yes:

• A three-month delay before giving blood is recommended after a blood transfusion; treatment for gonorrhea or syphilis; or after most body piercings or tattoos not done with single-use equipment. These are not new rules.
• A waiting period before giving blood is recommended for people who take medicines to prevent HIV infection, called PrEP (pre-exposure prophylaxis). PrEP might cause a test for HIV to be negative even if infection is present. The new guidelines recommend delaying blood donation until three months after the last use of PrEP pills, or a two-year delay after a person receives long-acting, injected PrEP.

Who cannot donate blood?

Anyone who has had a confirmed positive test for HIV infection or has taken medicines to treat HIV infection is permanently banned from donating blood. This rule is not new.

Why were previous rules more restrictive?

In 1983, soon after the HIV epidemic began in the US, researchers recognized that blood transfusions could spread the infection from blood donor to recipient. US guidelines banned men who had sex with men from giving blood. A lifetime prohibition was intended to limit the spread of HIV.

At that time, HIV and AIDS were more common in certain groups, not only among MSM, but also among people from Haiti and sub-Saharan Africa, and people with hemophilia. This led to blood donation bans for some of these people, as well.

A lot has changed in the world of HIV in the last several decades, especially the development of highly accurate testing and highly effective prevention and treatment. Still, the rules regarding blood donation were slow to change.

The ban from the 1980s for MSM remained in place until 2015. At that time, rules were changed to allow MSM to donate only if they attested to having had no sex with a man for 12 months. In 2020, the period of sexual abstinence was reduced, this time to three months.

Why are the blood donation guideline changes important?

• Removing unnecessary restrictions that apply only to certain groups is a step forward in reducing discrimination and stigma for people who wish to donate blood but were turned away in the past.
• The critical shortage in our blood supply has worsened since the start of the COVID-19 pandemic. These revised rules are expected to significantly boost the number of blood donors.

The bottom line

Science and hard evidence should drive policy regarding blood donation as much as possible. Guidelines should not unnecessarily burden any particular group. These new guidelines represent progress in that regard.

Of course, these changes will be closely monitored to make sure the blood supply remains safe. My guess is that they’ll endure. And it wouldn’t surprise me if there is additional lifting of restrictions in the future.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

There are certain things our bodies do so often and so automatically that we barely notice them. Yawning, growling stomachs, and runny noses are good examples. Each is a universal part of our daily human experience.

But did you ever wonder why? Below are a few things we know and a few we suspect.

Why do you yawn?

Perhaps you associate yawning only with being tired or bored. While we don’t know exactly why people yawn, there’s no shortage of theories. Yawning may

• stretch out our lungs and nearby tissues, preventing tiny airways in the lungs from collapsing
• distribute a chemical called surfactant, a gooey liquid that coats the tiny air pockets in the lungs and helps keep them open
• help prepare our bodies for transitions between wakefulness and rest: For example, yawning often occurs after a period of relaxation and when awakening from sleep. And it may serve as an internal signal that it’s time to sleep, or time to take a break from activities (such as driving).
• play a role in maintaining proper brain temperature: Our brain functions best within a narrow range of temperatures. Some experts believe yawning can help cool the brain through complex effects on nearby circulation and the sinuses.

It’s also unclear why yawning is contagious. In the animal kingdom, it’s common to see contagious yawning among members of a group, perhaps as a signal for collective behavior (such as moving from activity to rest).

Why does your stomach growl?

That rumbling in your stomach is known medically as borborygmi — an excellent Scrabble word if you have the right letters. We usually assume it reflects hunger. And it’s true that the experience of hunger can make itself heard in anticipation of a meal.

But your stomach may also growl after a meal, when the stomach and intestines propel liquids and food through the digestive tract. Stress can also trigger stomach rumbling.

What’s causing all that noise — and is it ever a problem? It may be due to gas moving around in response to muscular contractions of the intestinal walls. Occasionally, noises from the abdomen may be a sign of an intestinal infection or other trouble. If you’re experiencing other symptoms, such as pain or fever, check in with your doctor. But the vast majority of noises are harmless and a sign that your gut is working normally.

Why does your nose run?

Sometimes it can seem like your nose is running for no reason. But there are some well-known triggers, such as:

• Infection. When you have a cold, mucous membranes produce more mucus as part of your defense system: more mucous flowing out means fewer germs getting in.
• Allergies. Pollen, ragweed, or other triggers stimulate immune cells that produce histamine. Histamine opens up blood vessels just beneath the mucous membranes, and that leads to increased production and release of fluid and mucus. As with infection, this response may be helpful to dilute the offending trigger and rid it from the area.
• Cold, dry air. The inside surface of the nose is covered with mucous membranes that warm and humidify air well before it reaches the lungs. When you inhale dry, cold air through your nose, these membranes humidify the air by secreting water and mucus.
• Spicy foods. Spices like capsaicin act as an irritant to the sinuses and mucous membranes, which release fluid in response.

The bottom line

Some of the most common everyday human experiences are also some of the least understood. There are many other examples, of course: Why are we ticklish? What purpose do hiccups serve? What’s the deal with brain freeze? Perhaps topics for another day.

It may seem like a leap of faith, but it’s likely there are very good reasons for the way our bodies work — even when we don’t know what those reasons are.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD