analysis of hematological parameters as a diagnostic test for malaria in patients with acute febrile illness: an institutional experience

Hematological changes are among the most common complications encountered in malaria. This study analyzes and statistically evaluates the hematological changes as a diagnostic test for malaria in patients with acute febrile illness and whether these could guide the physician to institute specific antimalarial treatment. The present study was an observational study, conducted from January to December 2012. A total of 723 patients presenting with acute febrile illness at our hospital were evaluated. A complete blood count and malarial parasite microscopy were performed for each patient. The findings showed that 172 out of 723 patients [24%] were diagnosed to have malaria by positive smear report. There were 121 males and 51 females with a male to female ratio of 2.3:1. Maximum number of cases were seen in the 20-30 years age group. There was a statistically significant reduction in hemoglobin [p<0.005], platelet count [p<0.001] and total leukocyte count [p< 0.001] levels in patients with malaria compared to those without the disease. Likelihood ratios for a positive result of platelets [6.2] and total leukocyte count [3.4] was relevant as compared to hemoglobin [1.61] and Red cell distribution width [1.79]. The negative predictive values for hemoglobin [79%], total leukocyte count [86%], platelets [94%] and Red cell distribution width [93%] were significant. Red cell distribution width values were found to be higher in patients with malaria than in patients without malaria [p< 0.001]. This study revealed that routinely used laboratory findings such as hemoglobin, leukocytes, platelet counts and even red cell distribution width values can provide a diagnostic clue in a patient with acute febrile illness in endemic areas, thus increasing the probability of malaria and enhancing prompt initiation of treatment