Infections in Renal Transplant Recipients.

INTRODUCTION : Advances in a wide variety of disciplines over the past 3 decades has made renal transplantation the most effective means of rehabilitating patients with end stage renal disease1. The transplantation of solid organs, initially an experimental act, has evolved with successful procedures that provide the best chance for survival and rehabilitation for hopelessly ill patients2. The first recorded Human renal transplant was performed by Joboulay Carrels teacher in 19063 using xenografts. The first human kidney allotransplant was carried out by the Soviet Surgeon Yu Yu Vorovoy in 19354.With the shortage of live organ donors, use of organs from cadaver became a viable alternative5. The results of cadaver transplant are improving progressively with the advent of cyclosporine and would shortly be comparable with that of live related donor transplant. As the availability of suitable cadaver kidneys does not match the requirement of all end stage renal failure patients6, live donor transplantation continues with the advent of lesser waiting period and fewer episodes of rejection. In India, the first renal transplantation was done in the late 1960’s by Sen et al in Bombay. Successful live related renal transplant programme was begun in CMC, Vellore in 1971. First free renal transplantation in a government hospital in South India was conducted by Prof. M.A.Muthusethupathi in Government Royapettah Hospital, Madras in 1981. AIMS AND OBJECTIVES : • To study the infections in renal transplant recipients during the period Jan2004 to Dec 2005. • To analyse the infectious episodes in relation to systems and the microorganisms involved. • To study the infectious episodes relevant to post transplant follow up duration. • To determine the in vitro susceptibility and resistance pattern of the bacterial isolates to different antimicrobial agents. • To analyse the morbidity and mortality in renal transplant recipients due to infections. MATERIALS AND METHODS : The study group comprised 88 cases of renal transplant recipients, who underwent renal transplantation for end stage renal failure (ESRF) at Government General Hospital, Chennai. It included two groups: Group1 - 60 consecutive cases of renal transplantation performed on ESRF patients from Jan 2004 to Dec 2005 and including 59 live related donor kidney transplantation and 1 cadaver transplantation. Group 2 - 28 renal transplant recipients who were transplanted before Jan 2004 and admitted for treatment during Jan 2004 to Dec 2005. All renal transplant recipients were screened pre operatively for the presence of any overt or occult infection by a. Urine culture, b. Ear ,Nose, throat, axilla, umbilicus, groin and vascular access swab culture, c. Serological test for infection with Hepatitis B, Hepatitis C, Cytomegalovirus and Human immunodeficiency virus, d. X ray chest, ECG, Echocardiogram, e. HLA Typing of donor and recipient. RESULTS : Eighty eight renal transplant recipients were included in the present study.  The predominant age group undergoing renal transplantation was between 21 - 40 yrs.  There was a Male preponderance undergoing renal transplantation.  Total number of infectious episodes in this study were 246.  Urinary Tract infections (52.8%) were the commonest infection observed in this study. This was followed by Respiratory tract infection (10.3%), Drain infection (9.3%), Gastrointestinal tract infection (6.9%), Bacteremia (4.4%), Skin and soft tissue infection (4%), Hepatitis (3.6%), Cytomegalovirus infection (3.2%), Wound infection (2.4%), Malaria (1.6%), Central nervous system infection (0.4%).  The microorganisms involved in the infections were Bacteria (71.9%), Fungus (17.4%), Virus (6.9%) and Parasite (3.6%).  In Urinary tract infection, E.coli (39.4%) followed by Klebsiella pneumoniae (24.5%) were the predominant bacterial isolates. Candida albicans (81.2%) were the commonest fungus isolated.  In Respiratory tract infections, Klebsiella pneumoniae (45.4%) and Mycobacterium tuberculosis (27%) were the most frequently isolated organisms. Aspergillus flavus, Aspergillus fumigatus, Candida albicans and Mucor were the fungi isolated.  The majority of drain infections were caused by Pseudomonas aeruginosa followed by E.coli and Candida albicans. CONCLUSION : Klebsiella pneumoniae and Pseudomonas aeruginosa were the invasive bacteria causing Bacteremia in renal transplant recipients.  Bacterial causes of Skin and soft tissue infections were Staph aureus, E.coli, Pseudomonas aeruginosa and Mycobacterium tuberculosis. Trichophyton rubrum, Trichophyton mentagrophytes and Aspergillus flavus constituted the fungal causes of Skin and soft tissue infections.  Only 6 patients had wound infection. The organisms isolated were Klebsiella sp, Staph aureus, E.coli and Candida albicans.  Plasmodium falciparum and Plasmodium vivax were involved as etiological agents causing infection in 4 patients.  Cryptococcus neoformans was isolated in one case of meningitis.  Hepatitis B (23.5%) and Hepatitis C (29.4%) were the organisms causing Viral Hepatitis.  In the first one month post transplant period, the most common infection was Urinary tract infection (71.8%) followed by Drain infection (17.9%). Between 1 to 6 months post transplant duration, Urinary tract infections (40.9%) were predominant followed by Respiratory tract infections (21.3%).  Infection by Mycobacterium tuberculosis occurred predominantly within one year post transplant duration.  Viral infections (Hepatitis B, Hepatitis C, CMV) occurred predominantly after 6 months post transplant period. Gram positive bacteria showed 100% sensitivity to Vancomycin followed by Erythromycin.  Gram negative bacteria were 100% sensitive to Imipenem followed by Cefaperazone. ESBL production was positive in 11 gram negative isolates.  Plasmid was isolated in 8 Pseudomonas aeruginosa isolates.  The mortality rate in this study was 11.6% of which Bacteremia constituted 40%. It is clearly emphasized that early and correct recognition of infectious agents in renal transplant recipients during immediate and late post transplant period will improve the outcome of the patients.