key: cord-0727503-1h16sal3 authors: Kies, Kami D; Thomas, Amber S; Binnicker, Matthew J; Bashynski, Kelli L; Patel, Robin title: Decrease in Enteroviral Meningitis - An Unexpected Benefit of COVID-19 Mitigation? date: 2020-12-23 journal: Clin Infect Dis DOI: 10.1093/cid/ciaa1881 sha: 9e3751eda42f41483741cf86a9dcc14586f11322 doc_id: 727503 cord_uid: 1h16sal3 Enteroviral meningitis is seasonal, typically exhibiting a rise in prevalence in late summer/early fall. Based on clinical microbiology laboratory testing data of cerebrospinal fluid, the expected August/September/October peak in enteroviral meningitis did not occur in 2020, possibly related to COVID-19 mitigation strategies. Strategies in place to prevent spread of COVID-19 present a unique opportunity to assess potential effects of these interventions on other infectious diseases. For example, studies from China, Taiwan, Japan, South Korea, Singapore, Brazil, Australia, Chile, South Africa and the United States describe decreased influenza activity during the COVID-19 pandemic (8) (9) (10) (11) (12) (13) (14) . We previously reported using high-volume clinical microbiology laboratory data to visualize seasonality of infectious agents, including Legionella species (1), Bordetella pertussis (2) , and coronaviruses 229E, HKU1, NL63 and OC43 (3). Enteroviral meningitis is seasonal, with polymerase chain reaction (PCR) testing of cerebrospinal fluid (CSF) for enterovirus typically revealing a rise in positivity in August, September and October, and a nadir in the early part of the year. In 2020, however, we noted based on laboratory test positivity rates, that the expected late summer/early fall peak of enterovirus did not occur. We reviewed nine years of testing data for enteroviral meningitis at Mayo Clinic and Mayo Clinic Laboratories (Rochester, MN), comparing 2020 to the eight prior years. Testing was performed on CSF using either a laboratory-developed real-time PCR assay for enterovirus or the BioFire FilmArray Meningitis/Encephalitis (ME) panel; test utilization strategies were in place to prevent simultaneous ordering of both tests. pandemic (5) . Taken together with our findings, this suggests that respiratory infectious A c c e p t e d M a n u s c r i p t diseases other than COVID-19 may be being affected by strategies to reduce the spread of COVID-19. Enteroviral meningitis is a central nervous system infection, with transmission of the associated virus typically occurring person-to-person; it seems to have been impacted by COVID-19 control strategies. This is also supported by there being no obvious change human herpes virus 6, varicella zoster virus or herpes simplex virus 2 positivity rates in CSF in 2020, viruses which typically reactivate to cause central nervous system infection. While our observation regarding enteroviral meningitis is not surprising, we are unaware that it has been previously observed. It is possible there may be a delay in peak of positivity of enteroviral meningitis, and that cases may rise in the months to come; given that we are now beyond the typical seasonal peak however, this seems unlikely. It is possible that the findings reported are unique to us; it would be interesting to examine PCR positivity rates for enterovirus in other regions. Enteroviral meningitis is not a universally reportable disease in the United States, and therefore, use of laboratory data to recognize changing epidemiology can be helpful. The epidemiologic changes observed in enteroviral meningitis may relate to physical distancing, masking, hand hygiene, school closures, teleworking, and/or reductions in travel associate with COVID-19. Our findings do not prove causality, and the changing epidemiology of enteroviral meningitis could relate to other factors than COVID-19 control strategies. Overall, however, it seems plausible that the two are connected, providing a unique opportunity to observe how the epidemiology of various infectious diseases can be impacted by precautionary efforts implemented on a global scale. A c c e p t e d M a n u s c r i p t Funding and conflict of interest: There was no specific funding for this study. Dr. Patel reports grants from Merck, ContraFect, TenNor Therapeutics Limited, Hylomorph and Shionogi. Dr. Patel is a consultant to Curetis, Specific Technologies, Next Gen Diagnostics, PathoQuest, Selux Diagnostics, 1928 Diagnostics, PhAST, and Qvella; monies are paid to Mayo Clinic. Dr. Patel is also a consultant to Netflix. In addition, Dr. Patel has a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent on an anti-biofilm substance issued. Dr. Patel receives an editor's stipend from IDSA, and honoraria from the NBME, Up-to-Date and the Infectious Diseases Board Review Course. Dr. Binnicker reports personal fees from DiaSorin Molecular outside the submitted work. 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