[Medical advice for foreign travelers. Travel diarrhea--how to prevent it, how to treat it?].

neurotropic alphaherpesvirus that invokes cellularmediated immunity in patients who develop the primary infection varicella (chickenpox). The virus remains dormant in the cranial nerve ganglia, dorsal root ganglia and autonomic ganglia along the neuraxis for years after the initial infection. Reactivation of latent VZV in such infected neural ganglia produces dematomal skin lesions called herpes zoster or shingles (Figure).1 Such reactivation occurs when cellular immunity declines – i.e. with increasing age, with some diseases (e.g. malignancy or HIV infection) or when patients are on certain treatments such as chemotherapy, immunosuppressants or corticosteroids.1 Complete resolution of symptoms occurs in two to four weeks in many patients.2 However, some patients may continue to suffer from prolonged sequelae of shingles