Leptospirosis 2001

Abstract

A 20-year-old man was admitted to Siriraj Hospital because of high fever and jaundice. He also had acute renal failure. According to the other clinical manifestations and laboratory investigations, the differential diagnosis included severe systemic infections, especially leptospirosis and scrub typhus. A definitive diagnosis was obtained by a positive microscopic agglutination test for Leptospira interrogans, serovar bratislava. Serological tests for scrub typhus and dengue infection were negative. The number of patients with leptospirosis has been increasing in many hospitals and outbreaks of the disease have been reported in northeastern Thailand since 1997. In October 1999, Leptospira interrogans, serovar pyrogenes was isolated from the blood of a febrile patient with clinical leptospirosis in Burium province. This pathogen was used to study the progressive microanatomical changes within organs including the kidney, lungs, liver, gastrocnemius and hamstring muscles of infected hamsters. The kidney showed degenerative changes of the renal tubular cells and many pathological appearances of the glomerular tuft. Interstitial nephritis and pyelonephritis were also found. In the lungs, the alveolar and interalveolar capillaries were engorged with red blood cells. Both bronchopneumonitis and interstitial pneumonitis were observed. The liver showed cloudy swelling of hepatocytes which lead to dissociation of the hepatic cords. Vascular and sinusoidal congestion, prominent Kupffer cells and inflammatory cell infiltration in the parenchyma, and sinusoids as well as the portal area were demonstrated. Hepatocellular necrosis was found scattered throughout the hepatic lobules. Some hamsters showed blood vessel congestion in the gastrocnemius and hamstring muscles. Inflammatory cell infiltration was shown in the perimysium of the gastrocnemius muscle of one hamster. Another showed necrosis of some muscle fibers together with inflammatory cell infiltration which are sings of muscular inflammation. The prevention and control of Leptospirosis is discussed.