tailieunhanh - Chapter 126. Infections in Transplant Recipients (Part 4)

Herpes Simplex Virus Within the first 2 weeks after transplantation, most patients who are seropositive for HSV-1 excrete the virus from the oropharynx. The ability to isolate HSV declines with time. Administration of prophylactic acyclovir (or valacyclovir) to seropositive HSCT recipients has been shown to reduce mucositis and prevent HSV pneumonia (a rare condition reported almost exclusively in allogeneic HSCT recipients). Both esophagitis (usually due to HSV-1) and anogenital disease (commonly induced by HSV-2) may be prevented with acyclovir prophylaxis. For further discussion, see Chap. 172. Varicella-Zoster Virus Reactivation of herpes zoster may occur within the first month but more commonly. | Chapter 126. Infections in Transplant Recipients Part 4 Herpes Simplex Virus Within the first 2 weeks after transplantation most patients who are seropositive for HSV-1 excrete the virus from the oropharynx. The ability to isolate HSV declines with time. Administration of prophylactic acyclovir or valacyclovir to seropositive HSCT recipients has been shown to reduce mucositis and prevent HSV pneumonia a rare condition reported almost exclusively in allogeneic HSCT recipients . Both esophagitis usually due to HSV-1 and anogenital disease commonly induced by HSV-2 may be prevented with acyclovir prophylaxis. For further discussion see Chap. 172. Varicella-Zoster Virus Reactivation of herpes zoster may occur within the first month but more commonly occurs several months after transplantation. Reactivation rates are 40 for allogeneic recipients and 25 for autologous recipients. Localized zoster can spread rapidly in an immunosuppressed patient. Fortunately disseminated disease can usually be controlled with high doses of acyclovir. Because of frequent dissemination among patients with skin lesions acyclovir is given prophylactically in some centers to prevent severe disease. Low doses of acyclovir 400 mg orally three times daily appear to be effective in preventing reactivation of VZV. However acyclovir can also suppress the development of VZV-specific immunity. Thus its administration for only 6 months after transplantation does not prevent zoster from occurring when treatment is stopped. Some data suggest that administration of low doses of acyclovir for an entire year after transplantation is effective and may eliminate most cases of posttransplantation zoster. For further discussion see Chap. 173. Cytomegalovirus The onset of CMV disease interstitial pneumonia bone marrow suppression graft failure hepatitis colitis usually begins 30-90 days after transplantation when the granulocyte count is adequate but immunologic reconstitution has not occurred. CMV disease .