BACKGROUND: After lung transplantation (LuTX) a high level of immunosuppression is
needed to prevent rejection of the graft. Together with earlier colonization by pathogens,
immunosuppression makes recipients more susceptible to infections, especially during
the first postoperative year. As seasonality of lower respiratory tract infections
(LRTI) is well-known in chronic lung diseases, we assessed seasonal changes of pathogen
spectrum and number of infections in the first postoperative year in LuTX recipients.
METHODS: LRTI were analyzed in 28 Hungarian adult LuTX patients. Incidence and spectrum
of microorganism causing LRTI were evaluated according to post-transplant time and
seasonal temperature and humidity changes. RESULTS: A total of 69 cases of LRTI were
registered (average: 1.9 cases/patient; range: 0-14). Gram-negative=59, gram-positive=26,
and fungal=31 pathogens were detected, with polymicrobial samples in 46% of all cases.
Increased number of LRTI was observed in the cold season (1.68+/-1.54 vs 0.79+/-0.92
case/month/patient, P<.01) and significant negative correlations were identified between
the incidence of polymicrobial and bacterial infections and temperature (r2 =0.1535,
P<.05, r2 =0.3144, P<.01, respectively). In addition, positive correlation was observed
between polymicrobial infections and humidity (r2 =0.1403, P<.05). Higher incidence
of LRTI was also noted in the cold season, when accounting for the differences in
immunosuppression. CONCLUSION: Seasons influenced the incidence of LRTI in the first
postoperative year in LuTX recipients. More intensive vigilance for possible gram-negative
and polymicrobial infections is needed in these patients in cold and wet seasons in
the continental climate zone, regardless of underlying disease.
