Infections in transplant patients

Abstract

Infections are a serious complication that may follow any organ transplant. The degree of immunosuppression and the period of time after transplantation determine the infection likely to be present. Bacterial infections occur early and may follow any organ transplant. After bone marrow transplantation bacteraemia is confirmed in up to 50% of patients during the early neutropenic phase. Response rates are satisfactory if therapy is initiated early. The Hickman’s catheter is a common source of bacteraemia with S.aureus and S.enidermidis the most frequently isolated pathogens. Infections occurring in the months following organ transplantation include salmonella septicaemia, pneumococcal pneumonia, staphylococcal sepsis, haemophilus pulmonary disease, listeriosis, legionella pneumonia and occasionally mycobacterial disease. Pulmonary nocardiosis has been a problem particularly in cardiac transplant recipients. Herpes viruses may cause significant morbidity and mortality in transplant recipients. Herpes simplex reactivates early and is effectively controlled by oral acyclovir. Cytomegalovirus (CMV) infections occur 1-3 months post transplant and CMV pneumonitis is often fatal. Preliminary results suggest prophylactic ganciclovir is effective in controlling CMV disease. Varicella zoster may occur later and is treated with acyclovir. Candida albicans oropharyngitis and oesophagitis are common in the early phase whilst systemic infections caused by Asnerpillus spp . Fusarium spp and members of the order Mucorales occur at a later stage and usually require invasive procedures for definitive diagnosis. Parasitic infections include Pneumocystis carinii pneumonia (PCP), Toxoplasma gondii myocarditis and pneumonitis and occasionally giardiasis, amoebiasis and strongyloidiasis. Prevention of PCP with cotrimoxazole or dapsone has been very successful. Prophylaxis for other parasitic infections is not warranted in view of their infrequent occurrence.