Diane Ducret

Researchers tested 30 Long COVID patients with brain and mood symptoms and found reactivation of a commonly overlooked virus in 80% of them vs. 30% in older lab records, making the pattern strong enough to justify how viral reactivation and specifically HH7 relates to Long Covid's neurological and psychiatric symptoms. Diane Ducret and Tatjana Mijatovic, publishing in Viruses, reviewed diagnostic blood tests for human herpesvirus 7 (HHV-7), a very common virus that infects most people early in life and then lies dormant and occasionally reactivates when the immune system is stressed. All 30 patients had been tested within two years of a coronavirus disease 2019 (COVID) infection and reported lasting brain fog, memory trouble, anxiety, panic, or sleep disruption, and 76.7 percent of them showed active HHV-7 in their blood. Only 29.1 percent of 320 people tested before the pandemic showed the same thing in archived records, a gap the authors call statistically clear. The historical group was not matched to the long COVID patients by age or health status, and the long COVID patients sought testing themselves after hearing about herpesvirus reactivation in patient communities, so selection bias is possible. All six patients tested within a year of infection were positive, and virus levels among positives ran well above the lab's detection cutoff, arguing against a fluke reading. Among HHV-7-positive patients, 91.3 percent reported anxiety or panic symptoms, while HHV-7-negative patients in the same group did not show this pattern consistently; the symptoms were self-reported rather than clinically diagnosed. One patient tracked for over two years showed viral levels rising as her symptoms worsened to the point that hospitalization was considered, then falling toward zero alongside symptom improvement after antiviral treatment, though the drugs caused side effects and were later stopped. The authors call this a temporal association and stop short of claiming the virus caused her illness. Most prior work on herpesvirus reactivation after COVID focused on severely ill hospitalized patients during the acute infection. Ducret and Mijatovic's study instead targets lingering symptoms afterward and marks HHV-7 specifically as a candidate worth investigating in long COVID's neurological and psychiatric symptoms. The authors call their findings hypothesis-generating and say larger, matched, prospective studies are needed before HHV-7 could be considered a biomarker or treatment target. mdpi.com/1999-4915/18/9/1043