Discussion
Similarities in clinical presentation of pulmonary leptospirosis and covid-19 such as flu-like symptoms, acute respiratory distress, and CT-identified peripheral ground-glass opacities may cause misdiagnosis while the ongoing covid-19 pandemic going on all around the world (5). In order to confirm leptospirosis two tests’ results are needed; IgM- positive ELISA serology and a positive PCR (7). About 17.5% of the participants in a report who were positive in MAT were negative in IgM-ELISA and calculated the specificity and sensitivity of IgM-ELISA as 78.8% (8). That can be the reason why the IgM and IgM ELISA were negative in this patient.
There are criteria for establishing the severity of leptospirosis including: severe respiratory failure, initial renal injury with hypokalemia and elevation of transaminases (5). In this case potassium was always in a normal range but during the hospitalization it raised from 3.5 to 4.3; but in a Urine Analysis that was done fourth day of hospitalization showed proteinuria and 7-8 Red Blood Cells; the transaminases AST and ALT were always high during this time. So, because of these evidences severe leptospirosis infection can be considered for this patient. COVID-19 can rise the amount of D-dimer, LDH, AST and ALT (9), just like what was seen in this case.
A rise in the amount Procalcitonin (PCT) levels can happen in COVID-19. In a study PCT level was over eight times higher in patients who had more crucial appearance than in moderate patients (10) just like that, in this case PCT level was almost eighty times higher than the upper limit of the normal range.
Both COVID-19 and leptospirosis can cause Cytokine storms during the infection (11).
Leptospira is reported to be highly susceptible to a lot of antibiotics. Although Penicillin is the first choice for this infection, there are other antibiotics such as doxycycline, cefotaxime and ceftriaxone that are useful in treatment (12, 13). However, the treatments may be affective in early onset of the infection. Leptospirosis have some immune-mediated complications which can be controlled by adjuvant steroids (13).