Leptospirosis in Northeastern Thailand

During an outbreak of leptospirosis in northeastern Thailand, 148 patients with serologically diagnosed leptospirosis were seen in Loei Hospital. The clinical features were consistent with those described for the classic manifestation of the disease. However, hypotension was a common finding: noted in 94 patients (64%) upon admission or early in the course of the disease. Of these hypotensive patients, 64 (68%) had impaired renal function: 30 patients (32%) had prerenal azotemia and 34 (36%) were in renal failure. Pulmonary complications, including pulmonary edema, hemorrhage, ARDS, and interstitial pneumonitis, occurred in 22% of patients and were often associated with renal failure. A clear association existed between hypotension and renal failure and pulmonary complications. The overall mortality rate was 3.4%. The causes of death were pulmonary complications, renal failure, and sepsis. The death rate among patients with complications was 11.6%. Blood exchange, in addition to conventional treatment, was beneficial in severe leptospirosis with complications and hyperbilirubinemia. Correspondence: Prof Visith Sitprija, Queen Saovabha Memorial Institute, 1871, Rama 4 Road, Bangkok 10330, Thailand. Fax: ++66 (0) 2254 0212 E-mail: [email protected] INTRODUCTION Leptospirosis is a common zoonotic disease in the tropics. The disease is seen sporadically among farmers, fishermen, and sewage workers. Although the clinical features of the disease may follow the classic description (Sitprija, 1996), there are often differences in the prevalence of symptoms, the severity of the disease and its complications (Zaki and Shieh, 1996; Daher et al, 1999; Marotto et al, 1999) which might reflect variations in bacterial virulence, bacterial load, and clinical management. In recent years there has been an outbreak of the disease in northeastern Thailand. We report on our clinical experience of leptospirosis in Loei Hospital, a general hospital in northeastern Thailand; we have given special attention to the hypotension that may develop early in the course of the disease and to the other severe complications of leptospirosis. MATERIALS AND METHODS From January 1999 to August 31, 2000, 475 patients admitted to Loei Hospital fulfilled WHO criteria for the clinical diagnosis of leptospirosis (Faine, 1982). One hundred and fortyeight of these patients had their diagnosis of leptospirosis confirmed by positive serology (microagglutination). The common serotypes were L. pyrogenes and L. sejroe; other serotypes included L. bratislava, L. pomona, L. copenhageni, L. javanica, L. ballico, L. bangkok, L. wollfi and L. akiyami. One hundred and seven were male and 41 were female; in ages ranged from 8 to 76 years with an average of 36 years; the patients were farmers and fishermen. They were admitted to the hospital between 1 and 14 days after the onset of fever (average 4 days). Penicillin was given intravenously (2 megaunits) every 6 hours for 7 days; ceftriaxone (2 g/day) was given if there was evidence of associated sepsis. Vital signs were recorded every 30 minutes on the first day of admission and every 4 hours thereafter. For those with hypotension (mean arterial pressure < 70 mmHg) 200 ml of normal saline were given intraveSOUTHEAST ASIAN J TROP MED PUBLIC HEALTH Vol 33 No. 1 March 2002 156 nously within 15 minutes; the rate was then adjusted to 300 ml/h with close observation of blood pressure, lung signs, central venous pressure, and urine output. If there was no rise in blood pressure and no increase in urine output within 2 hours, dopamine (2 μg/kg/min) was given. If the urine flow remained low despite the correction of hypotension, intravenous furosemide (40-120 mg) was given. When the urinary output had responded adequately, intravenous fluid administration was maintained to match the urine flow rate for 48 hours; in the absence of a response in the urinary output, or in the presence of pulmonary crepitations, intravenous fluid was restricted. Early intubation and ventilatory support, using 100% oxygen and positive end-expiratory pressure (10 cm water), were instituted for patients with pulmonary complications [acute respiratory distress syndrome (ARDS), pulmonary edema or hemorrhage]. Platelet transfusions were given to those with pulmonary hemorrhage and severe thrombocytopenia (platelets < 50,000/mm). In ARDS and pulmonary edema, fluid intake was restricted. Either hemodialysis or peritoneal dialysis was performed for the patients with blood urea nitrogen (BUN) over 70 mg% and hypercatabolism (BUN increment >20 mg/dl/day). In addition to dialysis, blood exchange (1.5 blood volume) was instituted for the patients with pulmonary complications or hyperbilirubinemia (total bilirubin >25 mg/dl). In early cases, when hemodialysis was not available, only blood exchange was performed. Tumor necrosis factor alpha (TNFα) in the serum was determined on the second or third day of admission by enzyme-linked immunosorbent assay (Cytoscreen; Biosource International, Camarillo, CA) in 28 patients.