Diagnostic Swab Collection for HSV-1 Lesions
Swab Type and Collection Technique
- The American College of Physicians recommends using cotton-wool or Dacron swabs for HSV lesion sampling, as they are the standard collection tools, and avoiding calcium alginate swabs, which can interfere with viral recovery 1, 2
- The Infectious Diseases Society of America suggests opening vesicles with a sterile needle first, then collecting vesicular fluid content with the swab, and vigorously swabbing the base of the lesion to obtain epithelial cells, which are required for adequate examination 3, 1, 4, 5, 6
Diagnostic Testing Hierarchy
- The Centers for Disease Control and Prevention recommends that NAATs be the preferred diagnostic method, as they provide the highest sensitivity, especially for non-vesicular, ulcerative, or healing lesions, and allow HSV typing (HSV-1 vs HSV-2 differentiation) 3, 7
- The American Academy of Family Physicians notes that viral culture is less sensitive than NAAT, particularly for recurrent lesions, ulcerative (vs vesicular) lesions, and immunocompetent patients 3, 7
Critical Clinical Considerations
- The American College of Physicians advises collecting specimens as early as possible in the disease course, as vesicular lesions yield higher positivity rates than ulcerative lesions, and first episode lesions are more likely culture-positive than recurrent lesions 3, 7
- The Infectious Diseases Society of America recommends always requesting HSV typing (HSV-1 vs HSV-2) because 12-month recurrence rates differ dramatically: HSV-2 (90%) vs HSV-1 (55%) 3, 7
- The Centers for Disease Control and Prevention suggests not relying on serology for acute lesion diagnosis, as type-specific glycoprotein G-based serology cannot distinguish active from past infection, and not using point-of-care antibody tests in low-risk populations due to high false-positive rates 3, 7