Transfusion transmitted infection: viral and exotic diseases

Prevalence of Asymptomatic Malaria Parasitemia among Blood Donors in Cape Coast, Ghana: A Cross-Sectional Study

Background

Malaria is an important transfusion-associated infection in many parts of the world, particularly in sub-Saharan Africa, where it is endemic. We studied the prevalence of malaria parasites among blood donors in the Cape Coast Metropolitan Area.

Methods

A malaria parasite examination was added to the blood donor screening protocol for 240 voluntary and replacement blood donors (224 males and 16 females) between December 2020 and July 2021.

Results

Overall, 2.5% (6/240) had Plasmodium falciparum trophozoites detected in their blood sample. The remaining had no parasites detected. Four of the 148 who passed the blood donor screening tests were infected. The remaining two with malaria parasites failed one screening test. These included one donor with "hepatitis B + P. falciparum" and another with "syphilis + P. falciparum" parasite coinfection. All blood donors who had malaria parasites detected in their blood were males. Most donors, 45.8% (110/240), were in the 26-35 age group, with the highest prevalence of 1.3% (3/240). Blood group O was predominant (75.0%, 180/240), followed by B (12.9%, 31/240), A (11.3%, 27/240), and AB (0.8%, 2/240). All malaria parasites detected were among individuals with blood group O. Moreover, 96.3% (231/240) were rhesus-positive and had the highest prevalence of 2.1% (5/240).

Conclusions

Screening of blood donors in Ghana does not include malaria, although there is the potential for transmission through blood products. Malaria transmission via blood transfusion remains an issue of public health concern, as indicated in the results of this current study. We recommend studies on malaria prevention, pretransfusion and posttransfusion, and pathogen reduction technology.

Characterization of putative drug resistant biomarkers in Plasmodium falciparum isolated from Ghanaian blood donors

BACKGROUND

Plasmodium falciparum parasites, which could harbour anti-malaria drug resistance genes, are commonly detected in blood donors in malaria-endemic areas. Notwithstanding, anti-malaria drug resistant biomarkers have not been characterized in blood donors with asymptomatic P. falciparum infection.

METHODS

A total of 771 blood donors were selected from five districts in the Greater Accra Region, Ghana. Each donor sample was screened with malaria rapid diagnostic test (RDT) kit and parasitaemia quantified microscopically. Dried blood spots from malaria positive samples were genotyped for P. falciparum chloroquine resistance transporter (Pfcrt), P. falciparum multi-drug resistance (Pfmdr1), P. falciparum dihydropteroate-synthetase (Pfdhps), P. falciparum dihydrofolate-reductase (Pfdhfr) and Kelch 13 propeller domain on chromosome 13 (Kelch 13) genes.

RESULTS

Of the 771 blood donors, 91 (11.8%) were positive by RDT. Analysis of sequence reads indicated successful genotyping of Pfcrt, Pfmdr1, Pfdhfr, Pfdhps and Kelch 13 genes in 84.6, 81.3, 86.8, 86.9 and 92.3% of the isolates respectively. Overall, 21 different mutant haplotypes were identified in 69 isolates (75.8%). In Pfcrt, CVIET haplotype was observed in 11.6% samples while in Pfmdr1, triple mutation (resulting in YFN haplotype) was detected in 8.1% of isolates. In Pfdhfr gene, triple mutation resulting in IRNI haplotype and in Pfdhps gene, quintuple mutation resulting in AGESS haplotype was identified in 17.7% parasite isolates. Finally, five non-synonymous Kelch 13 alleles were detected; C580Y (3.6%), P615L (4.8%), A578S (4.8%), I543V (2.4%) and A676S (1.2%) were detected.

CONCLUSION

Results obtained in this study indicated various frequencies of mutant alleles in Pfcrt, Pfmdr1, Pfdhfr, Pfdhps and Kelch 13 genes from P. falciparum infected blood donors. These alleles could reduce the efficacy of standard malaria treatment in transfusion-transmitted malaria cases. Incorporating malaria screening into donor screening protocol to defer infected donors is therefore recommended.

Variability in the Use of Platelet Transfusion in Patients with Intracerebral Hemorrhage: Observations from the Ethnic/Racial Variations of Intracerebral Hemorrhage Study

BACKGROUND

We examined platelet transfusion (PTx) in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study, hypothesizing that rates of PTx would vary among hospitals and depend on whether patients were on an antiplatelet therapy or underwent intracerebral hemorrhage (ICH) surgical treatment.

METHODS

The ERICH study is a prospective observational study evaluating risk factors for ICH among whites, blacks, and Hispanics. We identified factors associated with PTx, examined practice patterns of PTx across the United States, and explored the association of PTx with mortality and poor outcome (modified Rankin Scale score 4-6).

RESULTS

Nineteen centers enrolled 2572 ICH cases; 11.7% received PTx. Factors significantly associated with PTx were antiplatelet use before onset (odds ratio [OR], 5.02; 95% confidence interval [CI], 3.81-6.61, P < .0001), thrombocytopenia (OR, 13.53; 95% CI, 8.43-21.72, P < .0001), and ventriculostomy placement (OR, 1.85; 95% CI, 1.36-2.52, P < .0001). Blacks were less likely (OR, .57; 95% CI, .41-0.80) to receive PTx. Among patients who received PTx, 42.4% were not on an antiplatelet therapy before onset. Twenty-three percent of patients on antiplatelet therapy received PTx, but percentages varied from 0% to 71% across centers. There was no difference in mortality or poor outcome at 3 months between patients receiving PTx and those who did not.

CONCLUSIONS

The frequency of PTx for ICH varies across academic centers. Thrombocytopenia, antiplatelet use, vascular risk factors, and ventriculostomy placement were associated with PTx. PTx was not associated with improved outcomes. We anticipate reduced PTx use over time given recent clinical trial data suggesting its use could be harmful; however, the issue of whether surgical management warrants PTx remains.

Comparative evaluation of a rapid diagnostic test, an antibody ELISA, and a pLDH ELISA in detecting asymptomatic malaria parasitaemia in blood donors in Buea, Cameroon

BACKGROUND

In malaria endemic areas, infected blood donors serve as a source of infection to blood recipients, which may adversely affect their prognosis. This necessitates the proper screening of blood to be used for transfusion in these areas. The purpose of this study was to determine the prevalence of malaria parasitaemia in blood donors in Buea, Cameroon, and to evaluate the performance of a rapid diagnostic test (RDT), a malaria antibody enzyme-linked immunosorbent assay (ELISA), and a Plasmodium lactate dehydrogenase (pLDH) ELISA in the detection of asymptomatic malaria parasitaemia in the target population.

METHODS

In a prospective study conducted between September 2015 and June 2016, 1 240 potential blood donors were enrolled. The donors were screened for malaria parasites using Giemsa microscopy (GM) and a RDT. A sub-sample of 184 samples, comprising 88 positive and 96 negative samples, were selected for the evaluation of the pLDH ELISA and the antibody ELISA. The chi-square test and correlation analysis were performed as part of the statistical analyses. The statistical significance cut-off was set at P < 0.05.

RESULTS

The prevalence of malaria parasitaemia in this study was found to be 8.1% (95% CI: 6.6 - 9.7). The prevalence was not observed to be dependent on the age or sex of the participants. The RDT had a sensitivity (88.0%), specificity (99.1%), and negative predictive value (99.0%) higher than the ELISAs. The performance of the pLDH ELISA, which demonstrated the highest positive predictive value (91.6%), was generally comparable to the RDT. The sensitivity was lowest with the antibody ELISA (69.9%), which also demonstrated the highest false positive and false negative rates. The detection threshold for the pLDH (three parasites/μl) was lower compared to the RDT (50 - 60 parasites/μl). Non-significant positive correlations were observed between the parasite density and the pLDH titers and malaria antibody titers.

CONCLUSIONS

Overall, the RDT and the pLDH ELISA demonstrated a perfectly correlated agreement with GM, meanwhile the antibody ELISA demonstrated a substantially correlated agreement with GM. The pLDH is therefore recommended for mass screening of blood (to detect malaria parasitaemia) for transfusions in the study area. However, where this is not feasible, an RDT will suffice.

Acute Normovolemic Hemodilution in Total Knee Arthroplasty: A Prospective Study

In this prospective, randomized, controlled trial we sought to evaluate the effectiveness of acute normovolemic hemodilution (ANH) in terms of decreasing the need for allogeneic transfusion after conventional unilateral total knee arthroplasty (TKA). TKA is often performed with an occlusive tourniquet, and thus, it could be considered ideally suited for ANH, because the chief benefit of ANH is red blood cell loss reduction and the shedding of whole blood perioperatively at lower hematocrit levels. Between January 2012 and May 2012, 40 consecutive patients scheduled to undergo elective, primary, cemented, unilateral TKA for knee osteoarthritis were enrolled. Patients were randomized to either a study (ANH) group (n = 20; Group A) or a control group (n = 20; Group B). Units of allogeneic blood transfused was considered the primary outcome. In the ANH group, less allogeneic blood transfusion (6 units in Group A versus 15 units in Group B) was required after operation. Six patients, who required a transfusion in Group A received 1 unit of allogeneic blood. In contrast, 6 of 9 patients, who required transfusion in Group B, received at least 2 units of allogeneic blood (P &lt; 0.05). There was no complication related to the methods of the protocol. ANH is likely to reduce postoperative allogeneic transfusion requirement in patients undergoing unilateral TKA. However, adjunctive strategies are required to further reduce allogeneic blood transfusion requirements.

Malaria and blood transfusion: major issues of blood safety in malaria-endemic countries and strategies for mitigating the risk of Plasmodium parasites

Malaria inflicts humankind over centuries, and it remains as a major threat to both clinical medicine and public health worldwide. Though hemotherapy is a life-sustaining modality, it continues to be a possible source of disease transmission. Hence, hemovigilance is a matter of grave concern in the malaria-prone third-world countries. In order to pursue an effective research on hemovigilance, a comprehensive search has been conducted by using the premier academic-scientific databases, WHO documents, and English-language search engines. One hundred two appropriate articles were chosen for data extraction, with a particular reference to emerging pathogens transmitted through blood transfusion, specifically malaria. Blood donation screening is done through microscopic examination and immunological assays to improve the safety of blood products by detection major blood-borne pathogens, viz., HIV, HBV, HCV, syphilis, and malarial parasites. Transfusion therapy significantly dwindles the preventable morbidity and mortality attributed to various illnesses and diseases, particularly AIDS, tuberculosis, and malaria. Examination of thick and thin blood smears are performed to detect positivity and to identify the Plasmodium species, respectively. However, all of these existing diagnostic tools have their own limitations in terms of sensitivity, specificity, cost-effectiveness, and lack of resources and skilled personnel. Globally, despite the mandate need of screening blood and its components according to the blood-establishment protocols, it is seldom practiced in the low-income/poverty-stricken settings. In addition, each and every single phase of transfusion chain carries sizable inherent risks from donors to recipients. Interestingly, opportunities also lie ahead to enhance the safety of blood-supply chain and patients. It can be achieved through sustainable blood-management strategies like (1) appropriate usage of precise diagnostic tools/techniques, (2) promoting hemovigilance system, and (3) adopting novel processes of inactivation technology. Furthermore, selection of the zero-risk donors could pave the way to build a transmissible malaria-free world in the near future.

Post-operative blood loss in total knee arthroplasty: knee flexion versus pharmacological techniques

PURPOSE

To compare the blood loss and the blood transfusion between a control group and a group of patients following either a local administration of tranexamic acid or a mechanical post-operative knee flexion, a controlled randomized study was performed.

METHODS

Sixty patients affected by primary knee osteoarthritis and candidates to receive a primary unilateral total knee arthroplasty were enrolled in a prospective, randomized, controlled study. Exclusion criteria were the following: tranexamic acid allergy, the use of pharmacological anticoagulant therapy, previous knee surgery and renal failure. For each patient, the following parameters were investigated: the blood loss volume, the haemoglobin and haematocrit concentrations and the blood transfusion needs.

RESULTS

Compared to the control group, the administration of systemic tranexamic acid significantly reduces (p < 0.05) both the blood loss (average reduction 39.8%) and the blood transfusion needs (64%). Furthermore, the tranexamic acid group shows a significant reduction (p < 0.05) compared to the knee flexion group of the blood loss (average reduction 31.8%) and the transfusion needs (65%). However, even if the knee flexion technique slightly reduces the blood loss (average reduction 11.6%) compared to the control group, this difference is not statistically significant (n.s.). Moreover, this treatment did not reduce the transfusion needs compared to the control group (n.s.). Incidence of complications was not influenced by any of the treatments.

CONCLUSIONS

The use of tranexamic acid compared to knee flexion and to control group significantly reduces blood loss and transfusion needs, without wound complications or symptomatic deep vein thrombosis.

LEVEL OF EVIDENCE

Prospective therapeutic study, Level I.

What is the best strategy for the prevention of transfusion-transmitted malaria in sub-Saharan African countries where malaria is endemic?

The transmission of malaria by blood transfusion was one of the first recorded incidents of transfusion-transmitted infections (TTIs). Although the World Health Organization (WHO) recommends that blood for transfusion should be screened for TTIs, malaria screening is not performed in most malaria-endemic countries in sub-Saharan Africa (SSA). The transfusion of infected red blood cells may lead to severe post-transfusion clinical manifestations of malaria, which could be rapidly fatal. Ensuring that blood supply in endemic countries is free from malaria is highly problematical, as most of the donors may potentially harbour low levels of malaria parasites. Pre-transfusion screening within endemic settings has been identified as a cost-effective option for prevention of transfusion-transmitted malaria (TTM). But currently, there is no screening method that is practical, affordable and suitably sensitive for use by blood banks in SSA. Even if this method was available, rejection of malaria-positive donors would considerably jeopardize the blood supply and increase morbidity and mortality, especially among pregnant women and children who top the scale of blood transfusion users in SSA. In this context, the systematic prophylaxis of recipients with anti-malarials could constitute a good alternative, as it prevents any deferral of donor units as well as the occurrence of TTM. With the on-going programme, namely the Affordable Medicine Facility - Malaria, there is an increase in the availability of low-priced artemisinin-based combination therapy that can be used for systematic prophylaxis. It appears nonetheless an urgent need to conduct cost-benefit studies in order to evaluate each of the TTM preventive methods. This approach could permit the design and implementation of an evidence-based measure of TTM prevention in SSA, advocating thereby its widespread use in the region.

Is a Plasmodium lactate dehydrogenase (pLDH) enzyme-linked immunosorbent (ELISA)-based assay a valid tool for detecting risky malaria blood donations in Africa?

Background

Malaria is a leading cause of mortality in southern Benin. The main causative agent, Plasmodium falciparum, poses a threat on critical transfusions in pregnant women and children. This study’s objective was to compare the performance of different malaria screening methods in blood donors in southern Benin, a malaria-endemic country.

Methods

Blood from 2,515 voluntary blood donors in Benin was collected over a period of 10 months in ethylenediaminetetraacetic acid (EDTA) tubes, which were then classified according to extraction time: long rainy season, short dry season, short rainy season, and long dry season. Microscopic examination was used to count parasites. Parasite density (PD) was expressed as the number of parasites per μL of blood. Pan Plasmodium pLDH detection was assessed by an ELISA-malaria antigen test. Using crude soluble P. falciparum antigens, an ELISA-malaria antibody test detected anti-Plasmodium antibodies.

Results

Among the 2,515 blood donors (2,025 males and 488 females) screened, the rate of asymptomatic Plasmodium carriage was 295/2,515 (11.72%, 95% CI: 10.5-13.1%). Males had a higher infection rate (12.4%) than did females (8.8%). Parasite density was very low: between seven and100 parasites per μL of blood was reported in 80% of donors with parasitaemia. Three Plasmodium species were diagnosed: P. falciparum in 280/295 patients (95.0%), Plasmodium malariae in 14/295 (5.0%), and Plasmodium ovale in 1/295 (0.34%). Malaria prevalence in donors was higher during the rainy seasons (13.7%) compared with the dry seasons (9.9%). The use of a highly sensitive assay enabled pan Plasmodium pLDH detection in 966/2,515 (38.4%, 95% CI: 36.5%-40.3%). Malaria antibody prevalence was 1,859/2,515 (73.9%, 95% CI: 72.16-75.6%). Donors’ antigenaemia and antibody levels varied significantly (P <0.05) over the course of the four seasons. The highest antigenaemia rate 323/630 (51.3%), was observed during the short rainy season, while the highest antibody prevalence, 751/886 (84.7%), was recorded during the long dry season.

Conclusion

Blood donations infected with Plasmodium can transmit malaria to donation recipients. Malaria diagnostic methods are currently available, but the feasibility criteria for mass screening in endemic areas become preponderant. Detection of the pLDH antigen seems to be an adequate screening tool in endemic areas, for this antigen indicates parasite presence. Routine screening of all donated blood would prevent infected blood donations and reduce P. falciparum transmission in critical patients, such as children and pregnant women. This tool would also decrease medical prophylaxis in donation recipients and contribute to lower Plasmodium resistance.

Limit allogeneic blood use with routine re-use of patient's own blood: a prospective, randomized, controlled trial in total hip surgery

BACKGROUND

There are risks related to blood incompatibility and blood-borne diseases when using allogeneic blood transfusion. Several alternatives exist today, one of which, used for autologous blood salvage perioperatively, is the Sangvia Blood Management System. This study was designed to investigate the efficacy of the system and to add data to previously reported safety results.

METHODOLOGY/PRINCIPAL FINDINGS

Two hundred sixteen patients undergoing primary or revision total hip arthroplasty (THA) were enrolled in this randomized, controlled, assessor-blinded multicenter study. Randomization was either autologous blood transfusion (Sangvia group) or no use of autologous blood (Control group), both in combination with a transfusion protocol for allogeneic transfusion. Patients were followed during hospital stay and at two months after discharge. The primary outcome was allogeneic blood transfusion frequency. Data on blood loss, postoperative hemoglobin/hematocrit, safety and quality of life were also collected. The effectiveness analysis including all patients showed an allogeneic blood transfusion rate of 14% in both groups. The efficacy analysis included 197 patients and showed a transfusion rate of 9% in the Sangvia group as compared to 13% in the Control group (95%CI -0.05-0.12, p = 0.5016). A mean of 522 mL autologous blood was returned in the Sangvia group and lower calculated blood loss was seen. 1095 mL vs 1285 mL in the Control group (95%CI 31-346, p = 0.0175). No differences in postoperative hemoglobin was detected but a lower hematocrit reduction after surgery was seen among patients receiving autologous blood. No relevant differences were found for safety parameters or quality of life.

CONCLUSIONS/SIGNIFICANCE

General low use of allogeneic blood in THA is seen in the current study of the Sangvia system used together with a transfusion protocol. The trial setting is under-powered due to premature termination and therefore not able to verify efficacy for the system itself but contributes with descriptive data on safety.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00822588.

Transfusion-transmitted malaria: case report of asymptomatic donor harboring Plasmodium malariae

Malaria in Brazil is endemic in the Amazon region, but autochthonous cases with low parasitaemia occur in the Atlantic Forest area of the country. According to Brazilian legislation no test is mandatory for blood donors from non-endemic areas. However if they have traveled to malaria transmission regions they are deferred for six months before they can donate. This report describes a transfusion-transmitted malaria case in Sao Paulo, Brazil, where one recipient received infected blood and developed the disease. He lived in Sao Paulo and had no previous transfusion or trips to endemic areas, including those of low endemicity, such as Atlantic Forest. Thick blood smears confirmed Plasmodiummalariae. All donors lived in Sao Paulo and one of them (Donor 045-0) showed positive hemoscopy and PCR. This asymptomatic donor had traveled to Juquia, in the Atlantic Forest area of S ao Paulo State, where sporadic cases of autochthonous malaria are described. DNA assay revealed P. malariae in the donor's (Donor 045-0) blood. Serum archives of the recipient and of all blood donors were analyzed by ELISA using both P. vivax and P. falciparum antigens, and IFAT with P. malariae. Donor 045-0's serum was P. malariae IFAT positive and the P. vivax ELISA was reactive. In addition, two out of 44 donors' archive sera were also P. vivax ELISA reactive. All sera were P. falciparum ELISA negative. This case suggests the need of reviewing donor selection criteria and deferral strategies to prevent possible cases of transfusion-transmitted malaria.

A lethal case of Plasmodium falciparum infection in a young patient with end-stage renal failure who underwent regular hemodialysis

Acute renal failure associated with Plasmodium falciparum infection is already well recognized. Nevertheless, end-stage chronic renal failure and falciparum malaria comorbidity is a rare condition. We report a case of Plasmodium falciparum infection in a young male Javanese patient with end-stage chronic renal failure who underwent regular hemodialysis. This rare comorbidity led to rapid deterioration of consciousness and metabolic disturbances which had already existed in end-stage renal failure. Because of the immunosuppressive condition due to organ failure, the patient did not survive despite anti-malarial chemotherapy.

Molecular screening of Plasmodium sp. asymptomatic carriers among transfusion centers from Brazilian Amazon region

The transmission of malaria in Brazil is heterogeneous throughout endemic areas and the presence of asymptomatic Plasmodium sp. carriers (APCs) in the Brazilian Amazon has already been demonstrated. Malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. We evaluated the frequency of APCs in four blood services in distinct areas of the Brazilian Amazon region. DNA was obtained from 400 human blood samples for testing using the phenol-chloroform method followed by a nested-PCR protocol with species-specific primers. The positivity rate varied from 1 to 3% of blood donors from the four areas with an average of 2.3%. All positive individuals had mixed infections for Plasmodium vivax and Plasmodium falciparum. No significant differences in the results were detected among these areas; the majority of cases originated from the transfusion centres of Porto Velho, Rondônia State and Macapá, Amapá State. Although it is still unclear whether APC individuals may act as reservoirs of the parasite, efficient screening of APCs and malaria patients in Brazilian blood services from endemic areas needs to be improved.

Peri-operative blood management in elective orthopaedic surgery. A critical review of the literature

Blood loss during orthopaedic procedures can be extensive and the need for allogeneic blood is a common requirement. However, blood transfusion conceals a number of well-recognised risks and complications and blood products have become more expensive because of their specific preparation procedure. Surgical technique, awareness of the problem and restriction of transfusion triggers are important factors affecting the management of blood loss. Several studies have additionally shown the efficacy of epoetin injections in increasing the pre-operative haemoglobin level. On the other hand, the true benefit of pre-operative autologous donation, acute normovolemic haemodilution and COX-2 selective NSAIDs remains under dispute. Regarding the role of platelet rich plasmapheresis, fibrin sealing and anti-fibinolytic drugs more data are needed. Hypotensive epidural anaesthesia seems to be an advantageous method in minimising peri-operative blood loss. However, this is not a widely performed technique in orthopaedic surgery. In addition, post-operative blood cell saving systems after total knee or hip arthroplasty have been reported to significantly minimise allogeneic blood transfusions when compared to control groups. It can be concluded that many interventions diminish more or less allogeneic blood transfusion in elective orthopaedic surgery. Nevertheless more prospective studies are needed and appropriate algorithms should be applied in peri-operative blood loss management. This review presents an overview of the available interventions which aim to diminish the use of allogeneic blood in elective orthopaedic surgery.

Malaria and blood transfusion

The transmission of malaria by blood transfusion was one of the first recorded incidents of transfusion-transmitted infection. Although a number of different infections have been reported to be transmitted by transfusion since then, on a global scale malaria remains one of the most common transfusion-transmitted infections. Transfusion-transmitted malaria can have serious consequences, as infection with Plasmodium falciparum may prove rapidly fatal. Ensuring that, in non-endemic countries, the blood supply is free from malaria is problematical, especially as travel to malarious areas is increasing and there is some spread of the disease into new areas, as well as a resurgence of malaria in areas where previously it had been eradicated. In non-endemic countries, donor deferral can be effective, but clear guidelines are needed. In endemic countries the problem is far greater as the majority of donors may be potentially infected with malaria parasites. In both situations, the simple deferral of donors may be wasteful and can eventually erode the donor base. Thus, other strategies are needed to ensure safety with sufficiency. However, the screening of donations for evidence of malaria is not without its problems. Although the examination of blood films is still the basis for diagnosing acute malaria, in most situations it is not sufficiently sensitive for blood bank screening. In non-endemic countries, donor deferral in combination with screening for specific antimalarial immunoglobulin provides an effective means of minimizing the risk of transmission. In endemic countries, more specific donor questioning, consideration of seasonal variation and geographical distribution may help to identify the population of donors who are most likely to be infected. In addition, the administration of antimalarials to transfusion recipients may help to prevent transmission. Nonetheless, no matter what strategy is adopted, it is likely that cases of transfusion-transmitted malaria may still occur, so malaria must always be considered in any patient with a febrile illness post-transfusion.

Blood saving protocol in elective total knee arthroplasty

BACKGROUND

To eliminate the need for allogeneic blood transfusion in patients undergoing elective total knee arthroplasty, we established and tried a protocol of combined methods, which is characterized by effectiveness, ease in application, and safety. It is based on perioperative administration of human recombinant erythropoietin plus iron and folic acid, mild acute normovolemic hemodilution, meticulous surgical technique, postoperative blood salvage through a closed-wound drainage system, and lower transfusion triggers.

DATA SOURCES

Sixty-one patients entered the protocol, and the results were retrospectively compared with the ones obtained from 58 consecutive patients who were operated on in the past before the use of any blood saving technique.

CONCLUSIONS

Only 5 patients of those who entered the protocol finally needed allogeneic blood transfusion, receiving a total number of 7 units, which is remarkable when compared with the 50 patients before the application of the protocol who required 111 units. Consequently, the utilization of allogeneic blood was reduced by 94%, a statistically quite significant result (P <0,001). We believe the protocol should be included in orthopedic surgeons' alternatives for blood saving in elective total knee arthroplasty.

Are there simple measures to reduce the risk of HIV infection through blood transfusion in a Zambian district hospital?

OBJECTIVE

To quantify the potential impact of simple measures to reduce the risk of iatrogenic HIV infection through blood transfusion in a Zambian district hospital.

METHODS

Three studies were conducted at St. Francis' Hospital, Katete, Zambia: (1) From 1991 to 1995 HIV seroprevalence among all listed blood donors and the impact of proper subgroup selection were studied retrospectively; (2) the sensitivity of locally used rapid antibody assays (HIV-spot/Wellcozyme HIV 1 & 2) for the detection of HIV in donor blood and the influence of the expiration date of the tests on this sensitivity were determined prospectively from June 1993 until March 1994 by screening all consecutive surgical patients and blood donors; (3) the number of unnecessary blood transfusions was determined retrospectively from January 1995 through January 1996 and prospectively from February 1996 through March 1996, and possibilities to reduce the total number of blood transfusions were considered.

RESULTS

(1) Excluding prisoners, who have an HIV seroprevalence of 19-25%, from the donor population significantly reduces the overall HIV seroprevalence from 13-16% to 8-9% (P < 0. 01). (2) Under local circumstances the sensitivity of the used rapid antibody assays was 6.8-17.9% lower than claimed by the manufacturer. Usage of non-expired tests increased the sensitivity significantly from 88.2% to 91.7% (P < 0.05). (3) None of the 294 studied blood transfusions can be classified as inappropriate according to international standards.

CONCLUSIONS

Simple measures such as proper subgroup selection among blood donors and correct use of non-expired tests may decrease the risk of iatrogenic HIV transmission. Stricter indications for blood transfusions will not substantially reduce the number of transfusions.

Incidence and clinical presentation of posttransfusion TT virus infection in prospectively followed transfusion recipients: emphasis on its relevance to hepatitis

BACKGROUND

A novel transfusion-transmissible human DNA virus, TT virus (TTV), has been discovered recently. An attempt was made to determine the incidence and clinical outcome of TTV infection in recipients of blood transfusion.

STUDY DESIGN AND METHODS

Serial serum samples collected as part of a prospective study of posttransfusion hepatitis were examined for TTV DNA by a nested PCR assay.

RESULTS

Among 150 adults undergoing cardiac surgery, posttransfusion specimens from 59 individuals were positive for TTV DNA. Pretransfusion sera were found to be positive in 13 of these individuals. Therefore, 46 (33.6%) of the 137 previously uninfected patients developed new TTV viremia after transfusion. Among the 46 patients, 3 were coinfected with HCV, 5 were coinfected with HGV, and 38 were infected with TTV alone. No apparent symptoms or signs were noted in the 38 patients infected by TTV alone or the 5 infected with HGV plus TTV. The average peak serum ALT activity was 31 IU per L, with persistently normal levels in 34 of the 38 patients with TTV infection alone. In 8 other patients who subsequently developed well-documented non-A-G hepatitis, 3 were positive for TTV (3/8 vs. 46/137, p = 0.8). In 12 patients followed for more than 1 year, TTV viremia persisted in every case.

CONCLUSION

In this population, TTV is transmitted by transfusion to approximately 30 percent of patients who undergo cardiac surgery. Most of the infections appear to become persistent. Despite the high prevalence rate, TTV does not appear to cause hepatitis on its own.

Risks, costs, and alternatives to platelet transfusions

The use of platelet transfusions has increased greatly in the past decade and is likely to continue to escalate because of the risks of thrombocytopenia in patients receiving dose-intensive cancer chemotherapy, the increased use of hematopoietic progenitor cell transplantation, and the prevalence of human immunodeficiency virus infection. Despite marked advances in procedures for ensuring the safety of platelets, including intensive donor screening, infectious disease marker testing, and increased use of leukodepletion techniques, platelet transfusions carry a significant risk for immunologic disorders and transmission of bacterial, viral, and perhaps other diseases and can entail a very high cost. In addition, thrombocytopenia has the potential to interfere with delivery of chemotherapy on schedule and at the planned doses, thus potentially compromising treatment outcome. The limitations of platelet transfusions have prompted the development of agents with the potential to stimulate platelet production and thus reduce or eliminate the need for transfusions. Two such agents, interleukin-11 (IL-11) and thrombopoietin (TPO), have demonstrated promise in clinical trials. In November, 1997, IL-11 received FDA approval for the prevention of severe thrombocytopenia in high risk patients receiving myelosuppressive chemotherapy. Thrombopoietic growth factors have the potential to greatly simplify and increase the safety of transfusion medicine.

Quality of reinfused drainage blood after total knee arthroplasty

Reinfusion of postoperative wound drainage blood has become an attractive alternative in primary total knee and hip arthroplasty. Quality of the drainage blood was studied with respect to content of extracellular bioactive substances and coagulation split products. Using the HandyVac ATS autotransfusion system, drainage blood was collected and reinfused within 6 hours postoperatively from 10 patients undergoing primary total knee arthroplasty. Blood samples were collected from the patients immediately after and 1 hour after opening of the tourniquet and after reinfusion of drainage blood. Samples were also collected from the drainage blood immediately before and at the end of reinfusion. The leukocyte-derived and platelet-derived bioactive substances histamine, eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO), plasminogen activator inhibitor type 1 (PAI-1), and activated complement factor C3(C3a) and various coagulation factors and split products were analyzed in patient and drainage blood samples. None of the patients received additional predonated autologous blood or allogeneic blood components during the study period. Within 6 hours postoperatively, 250 to 1,000 mL drainage blood was collected and reinfused. Histamine, ECP, EPX, MPO, PAI-1, and C3a content was significantly increased in drainage blood immediately before and at the end of reinfusion. Reinfusion did not change the concentration of these substances in samples from the patients. Coagulation factors and various split products showed that drainage blood was defibrinated. Reinfusion of drainage blood did not change the coagulative capacity of the patients. Drainage blood appears to be defibrinated and contains various extracellular leukocyte-derived and platelet-derived bioactive substances. Reinfusion does not change the coagulative capacity or the concentration of bioactive substances of patients.