Importance of Malarial Exclusion in a Thrombocytopenic Febrile Patient in an Endemic Area

Abstract

AIM OF THE STUDY:To evaluate the role of platelet count for predicting malarial infection and to determine the frequency and severity of thrombocytopenia in malarial parasite positive patients. STUDY DESIGN: The study included 150 patients who presented with fever in Santosh Medical College and Hospital, Ghaziabad. 97 patients with malaria were identified, rest were taken as control. Infection with both plasmodium vivax and plasmodium falciparum species was included. Thrombocytopenia was defined as platelet count less than 150000/cmm. RESULTS: Among 97 patients positive for malarial parasite, 78[80%] were found to have thrombocytopenia Overall 86 patients had plasmodium vivax while 8 patients had plasmodium falciparum infection and 3 had mixed infection. The frequency of thrombocytopenia was 78% [n=67] in vivax and 88% [n=7] in falciparum infection. Our study found the sensitivity of platelet count for diagnosing malaria was 80% and the specificity was 85%. Positive predictive value was 91% and negative predictive value was 83%. CONCLUSION: Platelet count can serve as an important initial screening tool in our setting. A finding of thrombocytopenia should increase the suspicion of malaria and more specific tests should be performed. Thrombocytopenia was a common haematological finding in patients with plasmodium infection, however its presence is not a distinguishing feature between the two types of malaria. Severe thrombocytopenia can occur in plasmodium vivax malaria although it is more common in plasmodium falciparum malaria.