Regarding the timing of infection after solid organ transplantation:
a. Outline the relative risk and reasons for infection in the early (<30days), intermediate (1-6 months) and late (>6 months) periods. (30% marks)
b. List potential pathogens and sites of infection in each period. (40% marks)
c. Comment on prophylaxis for the prevention of infection post solid organ transplant. (30% marks)
Aim: To display a general awareness of post-transplant ID issues and principles of immunosuppression.
Key sources include: T Oh., All chapters on solid organ transplants. CanMEDS Medical Expert.
Discussion: A lack of depth and understanding of the different stages of immunosuppression was demonstrated by most candidates. The better answers highlighted the differences in infections at different stages of immunosuppression (early, intermediate, and late as stipulated in the stem.) and provided a rationale.
The expert answer detailed the risk of infections as being highest in the early post operative and intermediate stage and then falls as the immunosuppression requirements reduce and provided reasons why. The detailed answer outlined the common post operative infections including transplant-related and early hospital related infections and gave examples of likely pathogens at this time.
Opportunistic infectious aetiologies common to immunosuppressed patients were outlined in the successful answer.
The Oh's Manual chapters on solid organ transplantation referenced by the examiners consist of Chapter 101 (Liver transplantation) and Chapter 102 (Heart and lung transplantation) in the 8th edition. Unfortunately, they do not seem to contain enough information to answer this question. There is only this table in the liver chapter, as well as some scattered ideas, which would be difficult to knit together into a coherent answer. Fortunately, there is an excellent UpToDate entry on this subject, which spares the reader an hour of digging through Oh's. It is tempting to tabulate this answer, and perhaps the better candidates did so, but the 800 pixel width of Deranged Physiology does not lend itself very well to tables with multiple columns, and so the reader is treated to an unordered bullet list instead.
Relative risk of infection in the transplant recipient, and reasons:
Potential pathogens and sites of infection:
van Delden, Christian, et al. "Burden and timeline of infectious diseases in the first year after solid organ transplantation in the Swiss Transplant Cohort Study." Clinical infectious diseases 71.7 (2020): e159-e169.
Fishman, Jay A. "Infection in solid-organ transplant recipients." New England Journal of Medicine 357.25 (2007): 2601-2614.
Fishman, J. A. "Infection in organ transplantation." American Journal of Transplantation 17.4 (2017): 856-879.
Patel, Robin, and Carlos V. Paya. "Infections in solid-organ transplant recipients." Clinical microbiology reviews 10.1 (1997): 86-124.