Hemorrhagic fever with renal syndrome (HFRS, Korean hemorrhagic fever)

Abstract

Sirs, Recently we experienced a case of hemorrhagic fever with renal syndrome (HFRS) and normal findings of kidney magnetic resonance imaging (MRI). A Korean girl aged 14 years 9 months was referred to Gyeongsang National University Children’s Hospital with symptoms of fever and hypotension. Three days prior to referral she had developed fever. These symptoms continued for 2 days and were then followed by abdominal pain, nausea, vomiting, diarrhoea and back pain. At this time, an abrupt decrease of blood pressure (80/40 mmHg) occurred. On presentation, she looked acutely ill. Her blood pressure was 120/ 90 mmHg and temperature 39°C. Except for diffuse tenderness and suspicious rebound tenderness on the abdomen, other findings on physical examination were normal. Initial laboratory values were: haemoglobin level 12.9 g/dl, white blood cell count (WBC) 18.1×10/l, platelet count 250×10/l blood urea nitrogen 17 mg/dl and serum creatinine 1.5 mg/dl. The blood urea nitrogen/ creatinine (BUN/Cr) slowly rose to 47/5.1 for 5 days without decrease of urine output. Fever declined slowly to 36.5°C for 5 days. On the sixth hospital day, urinary output was over 5,000 ml/day and MRI was checked, which was normal. At discharge on the 12th hospital day, serum Cr was 0.8 mg/dl and urinary output was normalised. The indirect immunofluorescent test for Hantaan virus performed on the second and 12th hospital days was at 1:2,560 and 1:1280 dilutions, respectively. Discrimination between Hantaan and Seoul viruses was done by plaque reduction neutralisation tests. She was diagnosed with HFRS caused by Hantaan virus [1]. Hemorrhagic fever by Hantaan virus accounts for 75% of Korean hemorrhagic fever, and compared with that caused by the Seoul virus has more severe clinical symptoms. It can cause complications, including hypopituitarism, and has a recorded death rate of up to 2∼7%. Infection by Seoul virus accounts for 10∼25% of all hemorrhagic fever and is mild in severity, often completely cured without complications and less than a 1% death rate. With Seoul virus infection, there is a tendency for the bleeding trait or the main symptom, kidney disorder, is milder than with Hantaan virus infection while liver function disorder is more severe. Haemoglobin counts suddenly increase in the hypotension stage, more than a half of which are above 50% in hematocrit [2]. Characteristic mucocutaneous manifestations and usual findings of hemoconcentration, thrombocytopenia, elevated liver enzymes and lactic acid dehydrogenase (LDH) of Korean hemorrhagic fever were not found in this patient. Kim et al. reported a low signal intensity along the outer renal medulla on the T2-weighted MRI image in all patients in oliguric or diuretic phase [3]. What is truly related with this form of Korean hemorrhagic fever due to Hantaan virus? I am not sure, but the economic growth, good health hygiene and strong host defence could be the answer. Patients with acute renal failure of unknown aetiology with ill-defined febrile or gastrointestinal disease need specific serological tests for Korean hemorrhagic fever. Pediatr Nephrol (2007) 22:156–157 DOI 10.1007/s00467-006-0234-z