Figure 1.

Algorithm for testing for chromosomally integrated HHV-6. Testing for chromosomally integrated HHV-6 (ciHHV6) should be considered in cases with atypical manifestations and/or high viral load > 10^5–6 in cellular samples (assuming that white blood count is normal) and/or detection of species HHV-6A (based on data that HHV-6A reactivation and disease are rarely seen in this patient population and appear to be primary detected in ciHHV6). Testing should also be considered in the absence of a virological response despite antiviral treatment (e.g., persistent detection without a ≥log₁₀ decline in viral load after ≥2 weeks). Testing of whole blood for ciHHV6 is available at University of Washington Virology Laboratory, Seattle, USA. (https://depts.washington.edu/uwviro/order/ accessed on 18 February 2024; https://testguide.labmed.uw.edu/view/HH6ABC?tabs=no accessed on 18 February 2024).