infectious diseases
Leptospirosis
Symptoms and Signs of Leptospirosis
The incubation period ranges from 2 to 20 (usually 7 to 13) days. Leptospirosis is characteristically biphasic, although a few patients have only a fulminant monophasic illness. Thesepticemic phasestarts abruptly, with headache, severe muscular aches, chills, fever, cough, pharyngitis, chest pain, and, in some patients, hemoptysis. Conjunctival suffusion usually appears on the third or fourth day. Splenomegaly and hepatomegaly are uncommon. This phase lasts 4 to 9 days, with recurrent chills and fever that often spikes to > 39°C. Defervescence follows. Thesecond, or immune, phaseoccurs between the 6th day and 12th day of illness, correlating with appearance of antibodies in serum. Fever and earlier symptoms recur, and meningitis may develop. Iridocyclitis, optic neuritis, and peripheral neuropathy occur infrequently. Lung involvement may be severe with pulmonary hemorrhage. This phase typically lasts from 4 to 30 days. If acquired during pregnancy, leptospirosis, even during the convalescent period, may cause abortion. Weil syndrome(icteric leptospirosis) is a severe form with jaundice and usually azotemia, anemia, diminished consciousness, and continued fever. Onset is similar to that of less severe forms. However, hemorrhagic manifestations, which are due to capillary injury and include epistaxis, hemoptysis, petechiae, purpura, and ecchymoses, then develop and rarely progress to subarachnoid, adrenal, or gastrointestinal hemorrhage. Thrombocytopenia may occur. Signs of hepatocellular and renal dysfunction appear from the third to sixth day. Renal abnormalities include proteinuria, pyuria, hematuria, and azotemia. Hepatocellular damage is minimal, and healing is complete. Mortality is nil in anicteric patients. With jaundice, the case fatality rate is 5 to 10% (up to 40% in severe cases); it is higher in patients>age 60. 