Study of clinical profile of acute respiratory distress syndrome and acute lung injury in Plasmodium vivax malaria.

dia. Plasmodium vivax accounts for more than half of all malaria cases in Asia1. Severe malaria is typically caused by Plasmodium falciparum and it is manifested by various organ involvements; for example, kidney, lung or CNS. Plasmodium vivax malaria usually presents as a benign acute febrile disease. Severe P. vivax malaria was first reported by Kocher et al1, from Bikaner in northwest India. In this study P. vivax monoinfection, i.e. absence of P. falciparium coinfection, causing severe disease was proven by PCR test1–2. In a study done at our institute in 2009, various complications like thrombocytopenia, acute kidney injury, hepatic involvement, anaemia, ARDS/ALI, cerebral involvement and shock were observed with P. vivax malaria. Analysis of deaths in these patients has shown that the lung complications in form of ARDS/ALI were present in almost all the patients who succumbed to death3. Hence, we did this study to throw more light on the clinical profile of ARDS/ALI in P. vivax malaria. Sporadic cases of P. vivax causing severe malaria and ARDS have been reported in the last 30 years. Acute respiratory distress syndrome (ARDS) as a complication of P. vivax infection was reported in a traveller, with low immunity against malaria, returning from Venezuela4 and from Gujarat, India5. In all of these cases the symptoms developed after commencement of antimalarial therapy indicating inflammatory response to parasite killing. The present study was undertaken to study the clinical profile of ARDS/ALI in P. vivax malaria including the demographic profile, other system complications due to malaria, mortality, risk factors for mortality; to compare mortality in vivax malaria and ARDS with falciparum malaria and ARDS and to confirm the temporal association of antimalarial therapy with onset of ARDS/ALI. It was a retrospective observational study done in a medical ICU of a tertiary care public hospital in Mumbai. Duration of study was from January 2011 to June 2013 (two and a half years). The study commenced after obtaining approval from Institutional Ethics Committee. All adult patients admitted in medical wards and MICU who were positive for P. vivax malaria either on peripheral smear or malaria antigen test or both and also having ARDS or ALI were included in the study. ARDS was defined as PaO2/FiO2<200, diffuse pulmonary infiltrates on chest radiograph and normal left atrial pressure. Acute lung injury (ALI) was defined as PaO2/FiO2 200– 300, diffuse pulmonary infiltrates on chest radiograph and normal left atrial pressure. All patients who had P. falciparum or mixed malaria or dengue or leptospirosis or any other alternative diagnosis were excluded from the study. The data were obtained from medical records of the hospital. Following data were noted in each case: the demographic profile of these patients; reports of peripheral smear, malarial antigen test, ABG analysis, chest radiograph findings; whether antimalarial therapy was started before the onset of breathlessness; therapeutic intervention in the form of high flow oxygen or invasive or non-invasive ventilation, antimalarials used; other complications associated with malaria like anaemia, thrombocytopenia, acute kidney injury, hepatic involvement, shock and cerebral involvement; comorbid conditions like diabetes mellitus, hypertension, asthma, chronic obstructive pulmonary disease (COPD), ischemic heart disease, HIV infection; ventilator associated complications and death or survival. Data were analysed using Student’s t-test and Fischer’s exact test as the sample size was small (30). Thirty patients satisfied both inclusion and exclusion criteria and were included in the study. Twenty-eight had peripheral smear positive for vivax malaria; 13 had malaria antigen test positive and 11 had both the tests positive. Twenty two (73.3%) were males and 8 (26.67%) were females. The age of patients ranged between 13 and 82 yr with mean age of 35.18 yr. Comorbid conditions were present in four patients; two had diabetes mellitus J Vector Borne Dis 51, December 2014, pp. 339–342