Acute respiratory distress syndrome in Plasmodium vivax malaria. A case-control study of comparison between ARDS and non-ARDS patients in P. Vivax malaria

Background: Plasmodium vivax was conventionally considered to be a benign parasite for centuries but in the recent years have proved to be a virulent parasite causing severe malaria. Acute respiratory distress syndrome (ARDS) is one of such severe complications with a significant morbidity and mortality. The objective of this study was to find the prevalence of ARDS and identify the associated factors that could potentially lead to ARDS in patients with vivax malaria. Methods: A retrospective case-control study was conducted at a tertiary hospital in New Delhi. 329 patients with an established diagnosis of Plasmodium vivax mono-infection were identified using hospital medical records, the associated factors were evaluated and compared to calculate the odds of developing ARDS. All patients were categorized into ARDS cases and non-ARDS controls. Results: The incidence of ARDS was 7% with a female sex predominance (60.86%). Mean urea (71.5 mg/dl), creatinine (2.7 mg/dl), and AST (97.8 units/l) elevation in addition to decreased hemoglobin (7.7 gm/dl) and platelets count (38,217 cells/µl) proved to be significantly associated with ARDS in our study. Conclusions: Plasmodium vivax is a virulent parasite and can cause severe malaria even in the setting of isolated infection. Cytokine mediated diffuse inflammatory response is a postulated pathophysiology causing ARDS.