Infectious Diseases

Is there any new information on the link between Zika virus and birth defects?

DEAR DOCTOR K: In a recent column, you said that doctors were still conducting research to see if the Zika virus does, as feared, cause birth defects -- particularly, babies born with small heads and brains. Has there been any new information on that?

DEAR READER: There has, and it's important. The new information was summarized in articles in the New England Journal of Medicine in April.

Do products that claim to boost immunity actually work?

DEAR DOCTOR K: I guess everyone wants a strong immune system. But is there anything to the claims of products that advertise that they boost immunity?

DEAR READER: In a word, no. Our immune system does a remarkable job of protecting us from bacteria, viruses and other microbes. That's good, because they can cause disease, suffering, even death. It seems logical to want to give your immune system a boost.

Does the immune system really change with the seasons

DEAR DOCTOR K: A friend heard about a study that said a person's immune system changes with the seasons. That seems incredible to me. But if it's true, it's fascinating. Do you know what she is talking about?

DEAR READER: I think I know the study she is referring to. Before describing what it found, it's worth talking a bit about the immune system and also about genes.

What is sepsis?

DEAR DOCTOR K: My father had routine surgery. Soon after, he developed something called sepsis that almost killed him. He's OK now, but I'd like to understand what happened to him.

DEAR READER: He and you are lucky. Not everyone makes it. Sepsis is a condition in which the immune system goes awry. Think of the immune system as our personal army, with an arsenal of weapons. It is meant to protect us from foreign invaders (like germs). Unfortunately, in attacking foreign germs, it sometimes can go overboard -- and its weapons can injure us.

Will a pertussis booster shot for me help protect my grandkids from whooping cough?

DEAR DOCTOR K: My son says that if I get a booster shot for pertussis, it will help protect his kids from getting whooping cough. That seems far-fetched to me.

DEAR READER: It's not far-fetched. Even if you were immunized against pertussis (the bacteria that cause whooping cough) as a child, you may need a booster shot. Why? Because pertussis is highly contagious, and without a booster shot you are at some risk for getting it. And if you get it, you could pass it on to your grandkids.

Should I get a flu vaccine this year even if last year’s vaccine didn’t prevent me from getting the flu?

DEAR DOCTOR K: I got the flu vaccine last year and still got the flu. Should I even bother with the flu vaccine this late?

DEAR READER: Yes, you should, but don't expect perfect protection this year, any more than you should have last year. Vaccines contain fragments of three or four strains that are predicted to dominate during the coming flu season. Different strains of the virus circulate each flu season (October-May).

How can I prevent recurrent UTIs?

DEAR DOCTOR K: I'm in my 30s and fairly healthy. However, I keep getting urinary tract infections. My husband and I want to know what I can do to prevent them.

DEAR READER: Many women know well the symptoms of a urinary tract infection (UTI). You might feel a frequent urge to urinate, yet pass little urine when you go. It may hurt when you urinate. Your urine might be cloudy, blood-tinged and strong-smelling. Furthermore, many women have a tendency to get repeated UTIs. UTIs are usually caused by bacteria that live in the gut and are present on the skin around the rectum.