It can bind to thrombin that decreases the fibrin formation. Reduced fibrin formation increases the risk of bleeding. Leptospira also secretes sphingomyelinase and haemolysin that target red blood cells.Leptospira spreads rapidly to all organs through the bloodstream. They mainly affect the liver. They invade spaces between hepatocytes, causing apoptosis. The damaged hepatocytes and hepatocyte intercellular junctions cause leakage of bile into the bloodstream, causing elevated levels of bilirubin, resulting in jaundice. Congested liver sinusoids and perisinusoidal spaces have been reported. Meanwhile, in the lungs, petechiae or frank bleeding can be found at the alveolar septum and spaces between alveoli. Leptospira secretes toxins that cause mild to severe kidney failure or interstitial nephritis. The kidney failure can recover completely or lead to atrophy and fibrosis. Rarely, inflammation of the heart muscles, coronary arteries, and aorta are found. Diagnosis
Laboratory tests
For those who are infected, a complete blood count may show a high white cell count and a low platelet count. When a low haemoglobin count is present together with a low white cell count and thrombocytopenia, bone marrow suppression should be considered. Erythrocyte sedimentation rate and C-reactive protein may also be elevated.The kidneys are commonly involved in leptospirosis. Blood urea and creatinine levels will be elevated. Leptospirosis increases potassium excretion in urine, which leads to a low potassium level and a low sodium level in the blood. Urinalysis may reveal the presence of protein, white blood cells, and microscopic haematuria.
In one study, it reduced the number of leptospirosis cases in military personnel undergoing exercises in the jungles. In another study, it reduced the number of symptomatic cases after exposure to leptospirosis under heavy rainfall in endemic areas. Treatment
Most leptospiral cases resolve spontaneously. Early initiation of antibiotics may prevent the progression to severe disease. Therefore, in resource-limited settings, antibiotics can be started once leptospirosis is suspected after history taking and examination.For mild leptospirosis, antibiotic recommendations such as doxycycline, azithromycin, ampicillin and amoxicillin were based solely on in vitro testing. In 2001, the WHO recommended oral doxycycline (2 mg/kg up to 100 mg every 12 hours) for five to seven days for those with mild leptospirosis. Tetracycline, ampicillin, and amoxicillin can also be used in such cases. However, in areas where rickettsia and leptospirosis are both endemic, azithromycin and doxycycline are the drugs of choice.Based on a 1988 study, intravenous (IV) benzylpenicillin (also known as penicillin G) is recommended for the treatment of severe leptospirosis. Intravenous benzylpenicillin (30 mg/kg up to 1.2 g every six hours) is used for five to seven days. Amoxicillin, ampicillin, and erythromycin may also be used for severe cases. Ceftriaxone (1 g IV every 24 hours for seven days) is also effective for severe leptospirosis. Cefotaxime (1 g IV every six hours for seven days) and doxycycline (200 mg initially followed by 100 mg IV every 12 hours for seven days) are equally effective as benzylpenicillin (1.5 million units IV every six hours for seven days).