The canonical view of herpes simplex virus 2, a common infectious virus that can cause painful genital lesions and also increases a person’s chance of acquiring HIV, is that of a sleeping giant, a virus that lies dormant for the majority of the time and occasionally flares up in one spot, leading to the external symptoms of visible and painful lesions. The virus lives in nerve cells adjacent to the spinal cord known as sacral root ganglia, and traffics from these nerve cells to genital skin cells during a reactivation episode. Recent work from VIDI scientists and other groups have shown that HSV-2 reactivation from the ganglia happens far more frequently than was previously appreciated. Now, new work led by VIDI research associate Dr. Christine Johnston shows that HSV-2 often reactivates in multiple sites at once, in contrast to the original view that the virus shows itself in one place only.
To examine the pattern of HSV-2 reactivation, Johnston and colleagues, including VIDI affiliate investigator Dr. Anna Wald, joint assistant member Dr. Amalia Magaret and VIDI co-director Dr. Larry Corey, examined four HSV-2 positive women over a period of 30 days. They took daily swabs from seven different locations from the genitals and anus, looked for the presence of HSV DNA using a sensitive PCR technique, and also looked for lesions in the area. Altogether, they analyzed nearly 100 samples in the four women. The researchers found that when HSV is present, 59 percent of the time it was present in multiple locations. Lesions cropped up in multiple sites nearly 30 percent of the time. In some cases, the researchers also found virus present on both sides of the body, meaning the virus must have come from different nerve branches.
Although the study size was small, these findings add to the growing field of evidence that HSV-2 reactivation occurs more frequently and in more places than originally thought, and effective treatments to prevent spread of the virus will have to take this into account.
Overlapping reactivations of herpes simplex virus type 2 in the genital and perianal mucosa. Tata S, Johnston C, Huang ML, Selke S, Magaret A, Corey L, Wald A. J Infect Dis. 2010 Feb 15;201(4):499-504.