Covid-19 and leptospirosis: Cytokine storm and the use of steroids

The majority of patients with Covid-19 have a good outcome. However, complications principally of acute respiratory distress syndrome (ARDS) and multiple-organ failure can occur rapidly. Leptospirosis, a zoonotic disease, is similar to Covid-19 in that most infections are mild or asymptomatic and only a small number develop ARDS. Cytokine storm is considered to be the main incriminating factor in both. High dose steroids have been used to ameliorate the effects in leptospirosis, and similarly, reports suggest a benefit in Covid-19. SARS CoV-2 and leptospira, one a virus and the other a bacterium, are two species separated by millions of years of evolution, but producing illnesses with similar spectra, with cytokine storm being the common precipitating factor. As data are accrued from around the world, more light may be shed on features analogous to both pathways.