HIV and ID Observations

It’s late November — the days are shorter and colder, and the trees have abandoned their bold plan to keep their leaves this winter.

We can forgive them their optimism — it was a historically warm October.

This time of year also brings us Thanksgiving, easily my pick for the best national holiday. Family, friends, food, a short work week, and no presents to buy — provided you’re not a turkey, what’s not to like?

Time for a list of ID/HIV things to be grateful for, an annual tradition:

• A better vaccine for herpes zoster has been FDA approved, and will be available soon. I’ve already covered the new “adjuvanted subunit” shingles vaccine in some detail here, but some of the advantages deserve repeating: it’s much more effective, it’s not a live virus vaccine so can be given to immunocompromised hosts, and it will be much easier to store and dispense. On the minus side is that two shots will be required; in addition, it will have more side effects than the current zoster vaccine (we won’t have a full understanding its safety profile until it’s in clinical practice). Nonetheless, one could envision a dramatic drop in this sometimes debilitating condition if the vaccine is widely adopted. Has a clever name, too.
• “Undetectable=Untransmittable” is now unequivocally endorsed by the National Institutes of Health and Centers for Disease Control. Support on this issue from these important research and public health agencies is critical to getting the word out — people with HIV on suppressive antiretroviral therapy cannot sexually transmit the virus to others. Here’s a terrific FAQ, and a concise editorial, both summarizing the data behind “U=U”. (H/T to Carlos Del Rio for this one.)
• Most people with an “allergy” to penicillin aren’t really allergic, and proving that they can take penicillin safely is easy and improves their care. Our hospital’s magazine did a special issue on immunology research, and asked me “What common lack of knowledge about the immune system would you like to correct?” Rather than mention some arcane fact about innate vs. adaptive immunity (about which I would just have been faking it), see my response below:
  Once “penicillin allergy” is off the problem list, all kinds of clinical benefits occur, including receipt of fewer unnecessary broad spectrum antibiotics and lower costs. Send your patients with “penicillin allergy” for skin testing now!
• The Immunization Action Coalition’s excellent web site, in particular their “Ask The Experts” section, continues to be an invaluable resource. We ID doctors get a lot of questions about vaccines from other clinicians, and this remains my go-to site for answers —  it’s clear, concise, authoritative, and well-referenced. Plus, it’s a point of pride in our house to stay current on vaccine recommendations, where my wife the pediatrician is no slouch on this topic. Got to keep up!
• Resistance to integrase inhibitors remains extremely rare. Despite this widespread use of this drug class, resistance is remarkably, wonderfully uncommon. The likely explanation is that the “INSTIs” are so potent and well-tolerated that patients on integrase-based regimens are either virologically suppressed (and hence don’t get resistance), or have very poor adherence (and hence don’t get resistance). Given the high resistance barrier of dolutegravir (and soon bictegravir), this fortunate situation should continue. Regardless, it will be critical to monitor the prevalence of integrase resistance globally as dolutegravir-based regimens increasingly become the default treatments in settings that don’t routinely use viral load monitoring.
• Staph aureus is becoming more sensitive to antibiotics. MRSA rates are down, penicillin-sensitive strains are up, and the bug rarely figures out how to develop resistance to either TMP-SMX or doxycycline. The big worries over vancomycin, daptomycin and linezolid resistance also never really materialized, and ceftaroline susceptibility also remains stable. For the record, I mentioned Staph last year, but I’m repeating now for two reasons: First, there isn’t a more important pathogen for inpatient Infectious Diseases than Staph aureus (first-year ID fellows undoubtedly would agree); and second, it’s a surprising counter to the grim news about untreatable gonorrhea, the spread of highly resistant acinetobacter, and the ever increasing rate of carbapenem-resistant enterobacteriaceae. No one knows why this is happening with staph, but hooray anyway! Let’s hope this trend continues.

That should do it for this year. What are you grateful for this Thanksgiving week?

And in the “harvest” theme …