Abstract
Objective: Typhoid fever, also known as enteric fever, is a potentially fatal multisystemic illness caused primarily by Salmonella typhi. Haematological parameters are significantly affected by typhoid fever,which can be used to diagnose and assess the prognosis of this condition.
Methods: The study was conducted at King Edward Medical University,Lahore from March 2010 to March 2011.A total of 150 patients who were confirmed to have Typhoid fever on the basis of Widal test or Typhidot test were enrolled in the study.CBCs, Peripheral smear and Reticulocyte counts ,PT and APTT.FDPs,D-Dimers tests were performed on all the patients.Bone marrow biopsy was performed on 48 patients as requested by physicians as a part of work up for pancytopenia and to get a bone marrow culture.Data was analyzed by SPSS to determine the frequencies and percentages.
Results:Cytopenias were found in 98% of the patients.Bone marrow showed prominent hemophagocytic activity in 100% of the patients.PT and APTT was also deranged in 48% of the patients.
Conclusion:Typhoid fever affects haematological parameters significantly ,these hematological parameters help not only in making the diagnosis but also to predict morbidity and help to guide management plan.

Key words: KEYWORDS:Typhoid Fever,Salmonella typhi,Haematological changes.