Diagnoses and ordering practices driving blood demand for treatment of anemia in Tanzania.

BACKGROUND: Resource-limited countries in Africa experience blood shortages. Understanding clinical drivers of blood demand can inform strategies to increase blood availability. STUDY DESIGN AND METHODS: From a national representative sample of 42 hospitals in Tanzania, patient records and requests for whole blood (WB) and red blood cells (RBCs) to treat anemia were analyzed using data collected prospectively from June through September 2013. Abstracted data included cause of anemia, number of requested units, clinical signs, and pretransfusion hemoglobin (Hb) levels. Weighted projections of nationwide drivers of blood demand for the year, 2013, were calculated. Mean posttransfusion Hb levels were estimated, and blood requests were assessed for clinical appropriateness. RESULTS: Malaria was the leading driver of blood demand for anemia among children, accounting for 67% (55,949 units; standard deviation [SD], 1911 units) of projected units requested for children in 2013. Maternal hemorrhage was the leading driver of blood demand for anemia among adults, accounting for 21% (31,321 units; SD, 963 units) of projected units requested. Seventeen percent (26,133 units; SD, 1013 units) of projected requested units were deemed inappropriate. Adults with severe anemia had a mean Hb level of 3.7 g/dL and a mean of 1.6 WB or RBC units per request, resulting in an estimated mean posttransfusion Hb level of 5.3 g/dL. CONCLUSIONS: Strategies to prevent and treat underlying causes of anemia and decrease inappropriate blood requests will likely increase blood availability. Restrictive blood ordering practices seen in adults with severe anemia suggests undertreatment of anemia and may result in an underestimation of the national blood demand.

Estimating Tanzania's National Met and Unmet Blood Demand From a Survey of a Representative Sample of Hospitals.

Estimating blood demand to determine collection goals challenges many low-income countries. We sampled Tanzanian hospitals to estimate national blood demand. A representative sample based on probability proportional to size sampling of 42 of 273 (15%) Tanzanian transfusing hospitals was selected. Blood bank registers, patient medical records, and blood component disposition records were reviewed prospectively from June to September 2013 to determine the number of components requested and the number and proportion issued, not issued due to nonavailability, and not issued for other reasons. Data were estimated for an annual national estimate. Of an estimated 278 371 components requested in 2013, 6648 (2.4%) were not issued due to nonavailability, 34 591 (12.4%) were not issued for other reasons, and 244 535 (87.8%) were issued. Of these 278 371 components, 86 753 (31.2%) were requested by adult medical, 74 499 (26.8%) by pediatric medical, and 57 312 (20.6%) by obstetric units. In these 3 units, the proportion of units not issued due to nonavailability was 1.8%. Private (4.1%) and large (6%) hospitals had the largest proportion of units not issued because of nonavailability. Of 244 535 issued components, 91 690 (37.5%) were collected, tested, and issued from blood banks that are not part of the Tanzania National Blood Transfusion Services (TNBTS). Nearly 98% of blood component demand was met. However, a large portion of the blood supply for the hospitals came from non-TNBTS blood banks. TNBTS could increase availability of safe blood through assuring the quality of donor selection and donation testing at non-TNBTS blood banks.

Molecular epidemiology of hepatitis B virus infection in Tanzania.

Despite the significant public health problems associated with hepatitis B virus (HBV) in sub-Saharan Africa, many countries in this region do not have systematic HBV surveillance or genetic information on HBV circulating locally. Here, we report on the genetic characterization of 772 HBV strains from Tanzania. Phylogenetic analysis of the S-gene sequences showed prevalence of HBV genotype A (HBV/A, n=671, 86.9 %), followed by genotypes D (HBV/D, n=95, 12.3 %) and E (HBV/E, n=6, 0.8 %). All HBV/A sequences were further classified into subtype A1, while the HBV/D sequences were assigned to a new cluster. Among the Tanzanian sequences, 84 % of HBV/A1 and 94 % of HBV/D were unique. The Tanzanian and global HBV/A1 sequences were compared and were completely intermixed in the phylogenetic tree, with the Tanzanian sequences frequently generating long terminal branches, indicating a long history of HBV/A1 infections in the country. The time to the most recent common ancestor was estimated to be 188 years ago [95 % highest posterior density (HPD): 132 to 265 years] for HBV/A1 and 127 years ago (95 % HPD: 79 to 192 years) for HBV/D. The Bayesian skyline plot showed that the number of transmissions 'exploded' exponentially between 1960-1970 for HBV/A1 and 1970-1990 for HBV/D, with the effective population of HBV/A1 having expanded twice as much as that of HBV/D. The data suggest that Tanzania is at least a part of the geographic origin of the HBV/A1 subtype. A recent increase in the transmission rate and significant HBV genetic diversity should be taken into consideration when devising public health interventions to control HBV infections in Tanzania.