Acyclovir for 30 days

M. tuberculosis

Consider INH for + PPD with epidemiological exposures

Table 16.2. Routine infection evaluation of organ transplant candidates

All Candidates

• Serologic screening for syphilis (VDRL or RPR)

• Serologic testing for CMV

• Serologic testing for HSV

• Serologic testing for VZV

• Serologic testing for EBV

• Serologic testing for Toxoplasma

• Serologic testing for hepatitis A, B, and C

• Tuberculin skin testing (PPD)

• Chest radiograph

• Urinalysis and urine culture

Candidates with Specific Exposure History

• Serologic screening for Histoplasma capsulatum

• Serologic screening for Coccidioides immitis

• Serologic screening for Strongyloides stercoralis (or 3 fecal specimens)

ern United States, Northern Mexico), and Strongyloides stercoralis (Southeast Asia, Puerto Rico, certain areas of rural Kentucky, Tennessee and Louisiana).

Pre-transplantation infection testing (Table 16.2) includes a complete blood count (CBC) with differential, blood chemistries, urinalysis and urine culture, a tuberculin skin test (PPD), and a chest radiograph (CXR). Serologic evaluation for toxoplasmosis (particularly for heart transplant), syphilis (RPR or VDRL), cytomegalovirus (CMV), herpes simplex viruses (HSV), and varicella zoster virus (VZV) are routinely obtained. Additional screening for viruses includes serologic testing for human immunodeficiency virus (HIV), hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV). All candidates with the appropriate endemic exposures should have serologies for S. stercoralis and the endemic mycoses, H. capsulatum and C. immitis. In lung transplant candidates, especially those with cystic fibrosis, sputum cultures are important for the detection of colonization of the respiratory tract by pathogens such as Aspergillus species and Burkholderia cepacia. These organisms pose a risk for the development of significant infections after transplantation as the recipient becomes immunosuppressed. CT imaging of the paranasal sinuses should be considered for patients with cystic fibrosis and others with a history of recurrent or symptomatic sinus infections.

Timing of Post-Transplantation Infections

Susceptibility of a host to the development of an infection after transplantation varies according to specific environmental circumstances, surgical factors, and the level of immunosuppression at any given time. Transplant-related infections are categorized according to the relative risk periods that correspond to the evolution of immune deficiencies and technical factors that render the recipient vulnerable to infection. While it is important to entertain infectious etiologies within this context, the transplant physician should consider a broader differential diagnosis of infection in the transplant recipient, as atypical pathogens and presentations of disease can occur in these hosts throughout the post-transplant course.

First Month Post-Transplantation

At this time the degree of immunosuppression is not high enough to render patients susceptible to opportunistic pathogens; therefore, the most frequent infections are related to surgical and nosocomial complications such as bacterial and candidal wound infections, urinary tract infections, nosocomial pneumonias, and central venous catheter-associated bacteremias and fungemias. When dealing with infected recipients in this time period, consideration is given to the type of organ transplanted and the anatomical details of the surgical intervention, as infection is often related to such factors. Patients may have infection related to prolonged stays in the intensive care unit including Clostridium difficile-associated diarrhea or infections with antimicrobial-resistant bacteria such as vancomycin-resistant enterococci. HSV is the only common viral pathogen of this period, manifesting as stomatitis in HSV-seropositive patients.

The Early Post-Transplant Period

This period extends from the second to the sixth month after transplantation. During this time, the level of immunosuppression is most intense. Patients are at high risk of developing serious opportunistic infections including CMV infection and disease, Pneumocystis carinii pneumonitis (PCP), invasive aspergillosis, disseminated toxoplasmosis, dermatomal and disseminated VZV infection, and certain bacterial infections such as listeriosis. Pre-existing infectious agents that can also reactivate during this period include Mycobacterium tuberculosis and the endemic mycoses.

The Late Post-Transplant Period

Beyond six months after transplantation, recipients that have not had allograft rejection episodes requiring increase immunosuppression are at risk for the usual community-acquired infections; however, certain opportunistic infections can still manifest at this late time. Examples include tuberculosis, cryptococcosis, nocardiosis, and herpes zoster. Recurrence of HBV and HCV infections is also seen.

The time frame outlined above is "set back" whenever allograft rejection is treated and immunosuppression is augmented with anti-CD3 monoclonal antibodies (OKT3), anti-lymphocyte globulin (ALG), steroid boluses, or radiation. Recipients with chronic allograft rejection also remain at higher risk for the development of opportunistic infections.

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