Blood transfusion in care of patients with Visceral Leishmaniasis: a review of practices in therapeutic efficacy studies

Anaemia is a common presentation feature in patients with visceral leishmaniasis (VL). Blood transfusion remains an important aspect of patient management in VL. However, triggers considered for making decisions on transfusion are poorly understood. This review is based on the Infectious Diseases Data Observatory (IDDO) VL clinical trials library, a database of all published efficacy studies since 1980 and has indexed 160 published trials (1980-2021). Description of blood transfusion was reported in 16 (10.1%) trials (n=3,459 patients). Transfusion was initiated solely based on haemoglobin (Hb) measurement in 9 studies, using a combination of Hb and other health conditions (epistaxis, poor health, or clinical instability) in 3 studies, and the criteria was unclear in 4 studies; Hb threshold ranged from 3-8 g/dL. Overall, the number of patients receiving transfusion was explicitly reported in 10 trials (n=2,421 patients enrolled). Of these, 217 patients underwent transfusion; 58 before treatment initiation and 46 during treatment or the follow-up phase, and the time of transfusion was unclear in 113. The median proportion of patients who received a transfusion in a study was 8.0% [Interquartile range (IQR): 4.7% to 47.2%; range: 0-100%; n=10 studies]. This review describes the variation in current clinical practice and is an important initial step in policy/guideline development, where both the patients haemoglobin concentration and clinical status must be considered.