[Infection risk and efficacy of clinical selection techniques for volunteer blood donors]

Evaluation of blood donors questionnaire in a developing country: The case of Gabon

BACKGROUND

Blood transfusion is a life-saving therapeutic act without alternative. Each blood transfusion carries the risk of blood-borne pathogens transmission. The present study, is the first establishing the usefulness of blood donors screening questionnaire in the setting of the Gabonese National Blood Transfusion Center.

STUDY DESIGN

Nine hundred and thirty-four blood donors aged between 18 and 48 years old were initially enrolled and submitted to physical examination (body-mass index and blood pressure). After physical examination 854 donors were judged fit for blood donation and were randomly distributed in two groups. The first group of donors did not take the screening questionnaire; whereas the second group went through the screening questionnaire. Both groups were then tested for human immunodeficiency virus, hepatitis B, hepatitis C and syphilis.

RESULTS

Data revealed a seroprevalence among the donors of 2.5%, 2.5%, 1.1%, and 3.3% for the human immunodeficiency virus, hepatitis B, hepatitis C and syphilis markers respectively. In the Gabonese setting, blood donors' screening questionnaire reduced respectively by 0.6%, 0.35% and 1.3% the proportion of hepatitis B, hepatitis C and treponema pallidum seroreactive donors being selected for donation. The questionnaire had no positive effect on discriminating human immunodeficiency virus positive donors.

CONCLUSION

Blood donors' seroprevalence of blood-borne pathogens is relatively important in our setting. Blood donors' screening questionnaire reduced the proportion of hepatitis B, hepatitis C and syphilis seropositive blood donors. The questionnaire did not effectively discriminate human immunodeficiency virus-infected donor candidates.

Effectiveness of blood donor questionnaire directed at risk factor for transfusion transmitted infections in Pakistani population

Background:

Deferring blood donors who admit to high-risk behavior on questioning are likely to eliminate those in window period for transfusion transmitted infections (TTI). However, many questions have been implemented in some countries as part of donor history questionnaire, based on precautionary principle and not on evidence, and can result in increased donor losses. This study aims to identify effective risk-directed questions having high predictive value, in local context which can form part of blood donor deferral policies. For this, a case control study in a hospital blood bank having donation services was carried out prospectively over a period of three years.

Materials and Methods:

Two hundred and twenty donors, who were repeatedly reactive for HBsAg, anti-HCV, anti-HIV with EIA, and syphilis with TPHA, were the cases. Eight hundred and eighty four controls were the donors who tested negative for all TTI test. All donors answered seven hepatitis risk directed questions and their responses and reactivity status for TTI were used for statistical analysis with SPSS ver. 15.

Results:

Positive predictive value for history of jaundice at any age for HBsAg was 20%, while PPV for history of surgery in previous six months for both HBsAg and anti-HCVHCV was also around 20%, based on pretest probability of 7%. The post-test probability for these questions was around 30%. Odds ratios with 95% CI did not reveal any significant association of hepatitis with any of seven questions. Donor losses after deferring on basis of two questions were 5.3% per year, while deferral rate after all seven questions was 20%.

Conclusions:

Donors should be permanently deferred if there is history of jaundice at any age, while deferral period after surgery should be one year. Other risk-directed questions should not be used to defer donors. Donor deferral policies should be evidence based and questions with proven efficacy should be made part of donor history questionnaire to minimize donor losses.

Transfusion safety in francophone African countries: an analysis of strategies for the medical selection of blood donors

BACKGROUND

The goal of selecting a healthy blood donor is to safeguard donors and reduce the risks of infections and immunologic complications for recipients.

STUDY DESIGN AND METHODS

To evaluate the blood donor selection process, a survey was conducted in 28 blood transfusion centers located in 15 francophone African countries. Data collected included availability of blood products, risk factors for infection identified among blood donor candidates, the processing of the information collected before blood collection, the review process for the medical history of blood donor candidates, and deferral criteria for donor candidates.

RESULTS

During the year 2009, participating transfusion centers identified 366,924 blood donor candidates. A mean of 13% (range, 0%-36%) of the donor candidates were excluded based solely on their medical status. The main risk factors for blood-borne infections were having multiple sex partners, sexual intercourse with occasional partners, and religious scarification. Most transfusion centers collected this information verbally instead of having a written questionnaire. The topics least addressed were the possible complications relating to the donation, religious scarifications, and history of sickle cell anemia and hemorrhage. Only three centers recorded the temperature of the blood donors. The deferral criteria least reported were sickle cell anemia, piercing, scarification, and tattoo.

CONCLUSIONS

The medical selection process was not performed systemically and thoroughly enough, given the regional epidemiologic risks. It is essential to identify the risk factors specific to francophone African countries and modify the current medical history questionnaires to develop a more effective and relevant selection process.

[Is it possible to organize into a hierarchy blood donation contraindications?]

Because it symbolizes henceforth the sanitary risk and fears which are linked to it, the blood transfusion must master the potential or real risks associated to its practice. The analysis of these risks leads to confirm the initial selection phase of candidates for blood donation as an always original stage of the blood transfusion safety towards the identified infectious risks, but also mainly towards the emergent or modelled risks. The evaluation of the current system of prevention leads to consider two potential dangers: the ineffectiveness of the selection because of the lack of meaning given to this stage, and the donors' disaffection caused by badly accepted or badly justified deferrals. The deficit of meaning can be due to an insufficient information of the population as for the policy of collective prevention of transfusion-transmitted infectious diseases. It can be worsened by the construction of the pre-donation interview which can appear as a succession of questions without visible links. This paper suggests risk analysis to blood transfusion, and a reflection to improve this important stage of blood product safety approach represent by the selection of candidates to a blood donation.

[The physician's role in blood donation]

In France, proper transfusion practices impose that the medical pre-donation interview be done by a physician. In Anglo-Saxon countries, it is more often performed by a nurse. The physician's job is not limited to the clinical selection of blood donation volunteers. In the production process, the physician is implicated in the safety and supply of labile blood products. The practice of the profession requires educational and communication skills. As the manager of a medical team working in mobile sites, the physician must ensure the respect of ethics and professional regulations by the staff he or she trains and supervises.

[Risk behavior among blood donors: efficacy of a new questionnaire]

The clinical selection of volunteers for blood donation is essential to reduce the risk of viral transmission by blood transfusion. The aim of this study was to evaluate a new questionnaire for a pre-donation medical interview. This questionnaire was developed by transfusion practitioners, epidemiologists and professional investigators, and focused on risk behaviors of blood donors and their partners. Five blood banks in the French Ile-de-France region (around Paris), participated in the study from May 1995 to January 1996. All participating doctors were specifically trained by professional investigators. The sex and the age of donors, the type of collection, the duration of interviews and the reasons for exclusion from donation were recorded. The results were compared to those of a prior study dealing with a sample of 15,000 donors presenting the same characteristics, whose blood was taken of at the same collection sites in 1993. Of the 1,527 volunteers donating blood, 14% were interviewed in fixed centers and 86% by moving teams (38% in firms, 22% in towns, 13% in civil service facilities, 13% in school or academic centers). For 15.9% of the volunteers, this was the first donation (range: 7.3% in fixed centers to 41.5% in school and academic centers). The mean duration of the interview was 11 min (10 min for volunteers included, 14 min for donors excluded from donation). It decreased from 14 min at the beginning of the study to 10 min by the end of the study. The percentage of donors excluded for risk behavior (3.7% in 1995-96 vs 1.5% in 1993, P < 0.001), or medical reasons (12.2% in 1995-96 vs 8.4%, in 1993, P < 0.001) was significantly greater in 1995-96 than in 1993 (15.9% vs 9.9%, P < 0.001). In 1995-96, 35.0% of exclusions for risk behavior were related to male homosexuality, multiple partners or the risk behavior of the partner vs 12% in 1993 (P < 0.001). The risk of exclusion was 5.5 times higher for donors not living in a couple. The results obtained demonstrated the value of this new approach to the medical interview.

Implicit valuation of a blood-exclusion decision

This paper presents an implicit valuation of Israel's decision to exclude blood donations from Ethiopian immigrants. The approach adopts assumptions that deliberately overstate the public health effectiveness of this policy, for if such an analysis fails to justify exclusion on public health grounds, nothing will. Building on a recent (over)estimate of the number of infectious donations prevented by the ban, the analysis considers the cost of HIV-infectious donations entering the blood supply, the benefits of healthy donations, and the cost of needlessly screening blood that will be discarded without regard to the test result. The analysis also highlights the social costs of excluding donors on the basis of ethnicity. The possibility of downstream HIV transmission from transfusion recipients infected from contaminated blood is also considered. All such calculations are made in a manner that deliberately favors the exclusion decision. In spite of such a one-sided analysis, the author concludes that the exclusion policy is not justifiable on cost-benefit grounds if the social costs of exclusion exceed $218,000 per year, or $3.63 per Ethiopian immigrant annually.