Rapid Treatment Crucial in Herpes Encephalitis

The largest case series to date of outcomes in patients with meningoencephalitis caused by the herpes simplex virus (HSV) shows early diagnosis and rapid treatment dramatically reduce risk.

Writing in Antimicrobiology Agents and Chemotherapy Hakan Erdem, MD, a professor of infectious diseases and clinical microbiology at Gulhane Medical Academy in Ankara, Turkey looked at data from 10 countries in the Middle East and Europe involving 438 patients.

All were patients whose cerebrospinal fluid tested positive for either HSV-1 or HSV-2.

The mean age of patients was 51 and about half were men.

HSV infection accounts for between 10% and 20% of all viral encephalitis wordwide, Erdem and colleagues wrote in the article.

In the study, only 44.5% of the patients received antiviral medications--usually intravenous acyclovir--with two days of their symptoms appearing.

Of those 53% had unfavorable outcomes, with 44 deaths and 188 adverse outcomes included disorders of memory, speech, behavior, and motor ability.

These symptoms and their severity were most pronounced in patients who did not get antiviral treatment within seven days.

The most common reason for the delays, Erdem said, "was seemingly that the symptoms related to encephalitis were not overt in many cases, but were relatively silent."

Physicians in such cases wrongly concluded that the patients may have had bacterial or viral meningitis.

Delays in treatment are less likely to happen in the US, he noted.

If a Gram stain for bacteria comes back negative--such test results are usually available within a few hours of lumbar puncture--US emergency physicians generally start acyclovir. Sometimes they start acyclovir before those results are in..

Erdem urged his colleagues to adopt a similarly aggressive treatment approach.

The countries in the study were Croatia, the Czech Republic, Denmark, Egypt, France, Iraq, Italy, Lebanon, Slovenia, and Turkey.