I have been hearing many concerned questions about Monkeypox lately, and I wanted to add onto the great job already done by Dan Scungio in his previous post on how laboratorians should be safe around Monkey pox suspected samples. As a part of the queer community, I’ve heard from several people who are very concerned as this is predominately spread among men who have sex with men. I’ll be focusing on what is new about Monkeypox, how it is different, where it is spreading, and what can be done about it so far. I’ll address questions like should we be sequencing Monkeypox like COVID-19 and does your smallpox vaccination will protect you.
What is Monkey Pox?
This is an orthopox virus that is from the same family as smallpox, which was so effectively cleared from human circulation that vaccines were discontinued in the U.S. in the early 1980’s. It causes a systemic disease characterized by lesions that start as a red, flat rash (macula) then form vesicles that break open, crust and resolve in 2-4 weeks. If you ever had chicken pox, you may recall how painful it was, and this is the major symptom that requires medical management.
Is it really that big of a concern?
Initially case increases were attributed to undiagnosed disease just as happened with COVID-19 initially. However, now that commercial labs are testing for it and access to testing is not an issue, we still see case counts increasing. This indicates that the rapid spread is real and concerning. That rapid spread is one reason that it has now been declared a national public health emergency.
How is it tested for?
Initially testing was sent out to one of the CDC regional testing centers. However, there were only 60-70 of these sites and they had limited capacity for high throughput testing. Then Labcorp and Quest they can each perform PCR testing, which has expanded access greatly. However they have different specimen types they accept:
- Labcorp: Lesion swab in VTM sent frozen or refrigerated (room temp not acceptable)
- Quest: Lesion swab in VTM
What is new?
- It has been in Sub-Saharan Africa for a long time.
- Early summer it began to spread into other continents like Europe.
- U.S. now has the highest levels of Monkeypox cases.
This all reinforces the impact of communicable diseases in a global society.
How are symptoms different?
- The rash may begin without the typical prodrome symptoms of fever, malaise, etc.
- Spread occurs by skin to skin contact
Does my smallpox vaccine protect me?
- Smallpox vaccines are 85% effective for 3-5 years
- Unknown how well they work after many years
- They likely decrease severity of disease even if it was given many years ago.
What can be done to prevent it?
- Monkeypox vaccination: requires 2 shots. Space out 4 weeks apart.
- FDA recently approved 1) decreasing the dose and 2) performing subcutaneous injection.
- This would increase the effective doses by 5x and still produce a robust immune response.
Should we be sequencing it?
- There are 3 major clades of the virus with the Congo clade being more severe (10% death rate) than the one we are seeing (West African: 3%)
- These differences can be found by PCR based tests
- There is no treatment difference based on the clade.
- If this continues to spread and mutate, then there could be a reason to sequence the virus.
- Some evidence suggests the mutation rate is 2x higher than would be expected.
- However, the last known samples were sequenced >5 years ago and not many were sampled to get a very accurate measure of the mutation rate.
- So this news about mutation rate should be taken with a grain of salt.
- Thornhill JP, et al. Monkeypox Virus Infection in Humans across 16 Countries — April–June 2022. NEJM. July 2022. DOI: 10.1056/NEJMoa2207323
–Jeff SoRelle, MD is Assistant Instructor of Pathology at the University of Texas Southwestern Medical Center in Dallas, TX working in the Next Generation Sequencing lab. His clinical research interests include understanding how lab medicine impacts transgender healthcare and improving genetic variant interpretation. Follow him on Twitter @Jeff_SoRelle.