To Your Good Health: Not uncommon for titer not to drop to undetectable

DEAR DR. ROACH: In October 2018 I was treated for syphilis, and had a VDRL titer of 1:128. A few months later, the titer was 1:8, but has stayed at 1:8 since then. Why hasn’t it gone down? — Y.Y.

ANSWER: VDRL and RPR are antibody tests for syphilis. They are nonspecific and can have false positive results, meaning a person can have a positive test but never have been exposed to syphilis. But decades of experience using these tests have made them an important part of monitoring therapy.

In your case, your titers dropped by a dramatic amount: sixteenfold. This is consistent with curing the syphilis you had back in 2018. However, the titer had not dropped down to nondetectable, as it usually does. This is called the “serofast state.” It is not uncommon, as 20% or more of people successfully treated for syphilis will continue to have detectable antibodies on their RPR or VDRL tests.

If you have not had a recent test for HIV, you should, because syphilis and HIV can be transmitted the same way — and sometimes at the same time — and because people who are HIV positive are more likely to have a prolonged serofast state.

DEAR DR. ROACH: The last time I went to the dentist was March 2020, at the beginning of the pandemic. The office had me sign a form saying that I was aware of the possibility of the virus being in water droplets because they use so much water in their treatments. I have not been back to the dentist since then. I received my vaccinations and was excited to go back to the dentist, but my daughter thought that it wasn’t a good idea because we live where there is still a high number of new cases. Do you think it is safe to get my teeth cleaned and get an implant? They use water to clean them. — J.C.

ANSWER: At the beginning of the pandemic, we did not have a good understanding of how the virus was spread, but now it is pretty clear that the vast majority of spread is from person-to-person transmission via respiratory secretions. Early on, we were not as consistent as we should have been about recommending mask wearing, but now it is clear that when both people (a person infected with COVID-19, even if they don’t know it, and a person susceptible to getting the infection) are wearing effective masks, the likelihood of transmission is low. A six-month study showed zero transmission of COVID-19 in dentists’ offices when they were compliant with best practices.

The water droplets a dentist or hygienist uses to clean teeth are not going to spread COVID-19. If your dental office is following recommendations, then it’s very safe to go to the dentist. Of course, you must be safe when traveling too.

DEAR DR. ROACH: I am a 58-year-old female with lupus and have been taking 10 mg prednisone for 40 weeks. I am in the process of tapering off this medication. My bone mass was OK before the medication. Am I at a high risk of bone loss after taking this medication for almost a year? — M.W.

ANSWER: Bone mass in women tends to decrease after menopause, and 58 is in that age range. Prednisone, even at a relatively low dose of 10 mg, absolutely increases the rate of bone loss. I would recommend periodic testing of your bone density. The best time to get the follow-up reading is not clear and depends on what the precise result was when you had it tested, but rechecking in two years is a general rule that may need to be adjusted for individuals.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to or send mail to 628 Virginia Dr., Orlando, FL 32803.

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