Role of the Bone Marrow Examination among Undifferentiated Fever in Tropics

Background: Bone marrow aspiration and biopsy is one of the most important diagnostic tools for evaluation of undifferentiated fever. The positivity yield of these samples is highly specific that provides additional evidence for clinical decision making among the undifferentiated febrile cases. With this background we evaluated the bone marrow results of undifferentiated febrile cases for the last five years at B.P. Koirala Institute of Health Sciences, Dharan, Nepal. The objective of the study was to measure the sensitivity of the bone marrow investigations among undifferentiated febrile cohort. Methods: A retrospective study was performed from January 2010 till December 2014 evaluating bone marrow reports. Completed request forms and the histopathological reports of the bone marrow specimens were reviewed. Statistical data was analyzed using SPSS 17 and p-value of <0.05 was considered significant. Results: Over the half decade 319 specimens were collected for bone marrow biopsy out of that 27% were requested for undifferentiated fever. The mean and median age of the biopsy performed patients was 35 and 31 years respectively. Among all biopsy samples 59% was adequate for evaluation however among the undifferentiated febrile cases biopsy samples only 45% was adequate for evaluation. The sensitivity of bone marrow biopsy was 34%. There were 714 bone marrow aspiration samples of that 84% was adequate for evaluation. The most common etiological diagnosis for the undifferentiated fever from the marrow evaluation was visceral leishmaniasis (53%). The sensitivity of the bone marrow aspiration and aspiration or biopsy for visceral leishmaniasis was 95% and 98% respectively. (p value 0.03) Conclusion: Bone marrow aspiration is highly sensitive and specific for the diagnosis of visceral leishmaniasis among the undifferentiated fever at tropics in Nepal.