title: A Clinical Study of Acute Kidney Injury in Tropical Acute Febrile Illness.
abstract: BACKGROUND
  Tropical Acute Febrile Illness (TAFI) is one of the most common causes of morbidity within the community. Acute Kidney Injury (AKI) due to infective and non infective causes is a major complication. Presence of AKI is a major cause of mortality among patients with TAFI.
  
  
  OBJECTIVE
  To study the spectrum of tropical acute febrile illness; the proportion, spectrum and staging of acute kidney injury; Renal Replacement Therapy (RRT) initiation and in-hospital mortality.
  
  
  METHODS
  A total of 600 TAFI patients were prospectively studied at a tertiary care centre in coastal Karnataka between September 2012 and September 2014 for the aetiology of TAFI; the development and staging of AKI based on Kidney disease: Improving global outcomes (KDIGO) guidelines; the initiation of RRT and in-hospital mortality.
  
  
  METHODS
  Data analysis was done using SPSS version 17.0 with statistical significance calculated using chi-square and Fisher's exact t-test for which p-value <0.05 was considered significant.
  
  
  RESULTS
  The spectrum of TAFI, in decreasing order, was vivax malaria, leptospirosis, dengue fever, falciparum malaria, mixed malaria, enteric fever, scrub typhus and the most common aetiology was malaria. The proportion of AKI was 54%. The most common cause of AKI, its stages 2 and 3, RRT initiation and in-hospital mortality was leptospirosis; and AKI stage 1 was dengue fever. KDIGO AKI stage 1, 2 and 3 was seen in 46.9%, 31.2% and 21.9% of AKI patients, respectively. RRT initiation was required in 10.2% of AKI patients and in-hospital mortality was 3% among all patients. AKI, RRT initiationand in-hospital mortality were significantly associated with older age, fever duration and other presenting complaints, examination findings, renal function and other parameters, leptospirosis, dengue fever, falciparum malaria.
  
  
  CONCLUSIONS
  The aetiology in about half of TAFI patients in coastal Karnataka was malaria. More than 50% develop AKI with greater than one-fifth of them progressing to AKI stage 3 and one-tenth requiring RRT. The most common cause of AKI, AKI stage 2, 3, RRT initiation and in-hospital mortality was leptospirosis. AKI was present in almost all patients with leptospirosis. Therefore leptospirosis was the most nephrotoxic acute febrile illness in the present study population. Dengue fever was the most common cause of AKI stage 1. Vivax malaria was the third most common cause of AKI. The factors like age, presenting complaints, examination findings, renal function and other parameters, aetiology and RRT initiation may be used to predict AKI and in-hospital mortality.
authors.affiliation: Senior Resident, Department of Medicine, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Jayalal Jayapalan
authors.initials: JJ
authors.lastname: Nair
authors.affiliation: Assistant Professor, Department of Medicine, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Ajay
authors.initials: A
authors.lastname: Bhat
authors.affiliation: Dean and Professor of Medicine, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Mangalore Venkatraya
authors.initials: MV
authors.lastname: Prabhu
keywords: Coastal Karnataka; Improving global outcomes; In-hospital mortality; Kidney disease; Renal replacement therapy