Blood Safety

Export Indicator

Percentage of donated blood units screened for HIV in a quality-assured manner
What it measures

 To assess progress in screening of blood donations in a quality-assured manner.


Blood safety programmes aim to ensure that all blood units are screened for transfusion-transmissible
infections, including HIV, and that only those units that are non-reactive on screening tests are released
for clinical use. In many countries, blood units are not screened for all the major transfusion-transmissible infections. Often, even when screening does occur, the safety of blood is compromised by inaccurate test results due to the poor quality or incorrect storage of test kits. Furthermore, inadequate staff training or a lack of standard operating procedures may result in laboratory errors. This could lead to blood units being classified as safe even when they are infectious, posing a serious risk of transmission of HIV through unsafe blood.

Universal (100%) screening of donated blood for HIV and other transfusion-transmissible infections
cannot be achieved without mechanisms to ensure quality and continuity in screening. In some countries, interruptions to supplies of test kits and reagents, or emergency situations, can result in the use of blood for transfusion without screening for transfusion-transmissible infections. The development of systems for reliable and regular supplies of low-cost, high-quality test kits and reagents and effective stock management are therefore essential to ensure universal quality screening of blood units.

Thus, it is crucial that all donated blood units be screened for HIV in a quality-assured manner. The
following methodologies are two key components of quality assurance in screening.
1. The use of documented and standardized procedures (standard operating procedures) for the
screening of every blood unit.
2. Participation of the laboratories in an External Quality Assessment Scheme for HIV screening in
which external assessment of the laboratory’s performance is conducted using samples of known, but
undisclosed, content to assess its quality system and assist in improving standards of performance.


Number of donated blood units screened for HIV in a quality assured manner. For the purposes of data collection screening in a quality assured manner if defined as screening performed in blood centres/
blood screening laboratories that (i) follow documented standard operating procedures and (ii) participate in an external quality assurance (EQA) scheme


Total number of blood units donated.

In this context, donation refers to any blood collected for the purposes of medical use. This includes all possible types of providers of blood, regardless of whether they receive remuneration or not.


Numerator / Denominator

Method of measurement

The information relates to data from the previous 12 months (January– December). This information should be available from the National Blood Transfusion Service or the officers responsible for the National Blood Programme in the Ministry of Health.

The following information is required to measure this indicator.
1. The total number of blood units that were donated in the country
2. For each blood centre and blood screening laboratory that screens donated blood for HIV:
i. The number of units of blood donated in each blood centre/blood screening laboratory;
ii. The number of donated units screened in the blood centre/blood screening laboratory;
iii. If the blood centre/blood screening laboratory followed documented standard operating procedures for HIV screening;
iv. If the blood centre/blood screening laboratory participated in an External Quality Assessment Scheme for HIV screening.

From this information, the indicator can be calculated.

Examples of the data needed to calculate this indicator are shown in a Table on page 31 of UNGASS' Guidelines on Constrauction of Core Indicators, 2010 Reporting.

Measurement frequency



Condom type: N/A

Education: N/A

Gender: N/A

Geographic location: N/A

HIV status: N/A

Pregnancy status: N/A

Sector: N/A

Service Type: N/A

Target: N/A

Time period: N/A

Type of orphan: N/A

Vulnerability status: N/A

Explanation of the numerator
Explanation of the denominator
Strengths and weaknesses

If the blood screening laboratory follows documented and standardized procedures for the screening of
blood, this implies a certain level of uniformity, reliability and consistency of performance by staff trained
to use the standard operating procedures. If a blood screening laboratory participates in an External
Quality Assurance Scheme, this implies that the quality of HIV screening performed is being assessed at regular intervals. It is important to view the percentage of screened blood units in relation to these two
basic components of quality as both are required to ensure the quality of procedures.

Countries provide data to the WHO Global Database on Blood Safety on this indicator annually. Locally,
these data can be obtained by contacting the National Blood Transfusion Service, the National Blood
Programme and/or the National AIDS Programme.

Further information