The failure to detect CSF SARS-CoV-2 RNA does not diminish the likelihood of direct CNS infection because it is only recovered from blood in 1% of the actively infected cases (18), and increased levels CSF IgM are also more commonly found as evidence for CNS infection than viral recovery in other encephalitides, including those for infection with Japanese encephalitis virus (19), dengue virus (20), human parvovirus 4 (21), and rabies virus (22). This evidence concerns the gene CD40LG and infection.