The IDC website currently focuses its resources on two health topics: HIV/AIDS and Maternal and Child Health. There are, however, many other significant health topics in global health that have implications for diagnostics in resource-limited settings. These include tuberculosis, malaria and neglected tropical diseases, among others. Resources on important issues in diagnostics for infectious diseases and health topics other than HIV/AIDS and Maternal and Child Health can be found under Other Health Topics on this site.
Development and Evaluation
In order to guide developers in product design and development of diagnostic tests, in particular those for use at or near the point of patient care, standards are needed. The standards are a set of desired operational and technical specifications for diagnostic platforms being developed for use at various levels of the laboratory system in resource-limited settings. These standards can be summarized in a Target Product Profile (TPP) that provides a clear set of minimal and optimal standards for each platform, including the device, if any, and the assay. A TPP sets forth specifications for each test platform and is generally divided into three main sections: (i) intended use; (ii) technical performance; and (iii) operational characteristics.
Once diagnostic products are developed, it is essential for developers to have an in-depth understanding of the evaluation process for in vitro diagnostics (IVDs) in-country in order to facilitate introduction and uptake of their products. There are currently no uniform diagnostic quality standards to guide product selection in resource-limited settings. As a result, in-country evaluations are an essential part of the development process for new IVDs. Such evaluations generally take place in two stages: (i) clinical evaluations in controlled settings in-country that test, among other things, internal consistency (precision) as well as accuracy against an appropriate reference technology, and (ii) field evaluations in-country that introduce additional variables, including the use of the product by minimally-trained lay operators.
Resources associated with these areas include:
- TPPs for a number of specific diagnostic assays – e.g. quantitative viral load assay for HIV/AIDs
- Links to UNITAID landscape reports, which contain descriptions of pipeline technologies.
- General principles on how to design and conduct diagnostic evaluations
- Standardized/generic protocols for clinical evaluations
- A network of accredited evaluation sites in-country for various IVDs
- Publications of test performance, including systematic reviews
Policy and Implementation
The ultimate decision to introduce new diagnostic technologies in-country rests with the ministry of health. In-country policies must accommodate the new technologies and ministries often require guidance with respect to appropriate technology placement, impact and cost-effectiveness.
In order to achieve successful implementation and uptake of a diagnostic in-country, it is essential that developers understand the landscape and the tools to effectively coordinate these activities. A number of systems support diagnostic testing in-country. These include:
- Supply chain
- Human resources and training
- Service delivery design
- Service and maintenance
- Quality assurance
Successful implementation of new diagnostic technologies requires that each of these systems functions well, but they are often weak or lacking in-country. For example, ineffective supply chain systems (forecasting, procurement and distribution) can lead to perennial consumable and reagent shortages.
Shortages not only lead to costly emergency fixes, but also are detrimental to the quality of patient care. Some common diagnostic tests require not only test reagents, but also numerous associated consumables, collection supplies, and quality controls to come together at the same time to ensure a quality result.
In resource-limited settings, supply chain challenges include:
- Remote locations – hours from major towns, poor road conditions, seasonally impassable
- Limited infrastructure – limited electricity and access to communication
- Paper-based recordkeeping
- Human resources capacity
These problems are more pronounced when implementing point-of-care diagnostics, which require more devices/tests in more remote locations than centralized testing; for which it is more costly and complex to distribute reagents and consumables; and which requires procurement, forecasting and managing inventories of testing supplies at a greater number of sites.
Technology implementation challenges include managing each of these areas of weakness, including training, service/maintenance and piloting quality assurance systems. It also includes understanding and navigating the various key partners in-country, in addition to ministries of health.
Resources associated with these areas include:
- Technology assessment and strategic placement tools
- Models for impact assessment and cost-effectiveness
- Sources of diagnostic and laboratory practice training
- Quality Assurance/Quality Control materials and information on quality management of diagnostic laboratories
- Toolkits (e.g. rapid syphilis test toolkit) and links to other toolkits
- Links to publications on operations research
The purpose of regulation is to protect public health by assuring the safety, effectiveness, and quality of diagnostic tests while enabling timely access to beneficial new products.
This website contains resources on a range of regulatory topics including:
Originally published on 21 April 2017
In December 2016, the International Diagnostics Centre (IDC), the London School of Hygiene and Tropical Medicine (LSHTM) and the African Society of Laboratory Medicine (ASLM) convened a workshop comprised of key stakeholders and opinion leaders to address and clarify critical issues relating to the use of CD4 testing in the management of HIV.
Originally published on 23 August 2016
The UNITAID Tuberculosis Diagnostics Technology and Market Landscape is published annually and is prepared as part of a broad and ongoing effort to understand the technology and market landscape for tu- berculosis (TB) diagnostics.
Originally published on 23 August 2016
The 2016 Malaria diagnostics technology and market landscape is part of a broad and ongoing effort to understand the technology and market landscapes for malaria diagnostics.
Originally published on 12 July 2016
We estimated seroprevalence and correlates of selected infections in pregnant women and blood donors in a resourcelimited setting. Methods. We performed a cross-sectional analysis of laboratory seroprevalence data from pregnant women and voluntary blood donors from facilities in Cameroon in 2014.
Posted on 30 August 2016
The transition to an integrated approach to HIV and Sexually Transmitted and Bloodborne Infection (STBBI) prevention will impact testing services in Nova Scotia. In order to respond to the consequences of this policy-level decision, this study explored stakeholders’ perceptions of integration and its consequences.
Originally published on 11 November 2015
Acceptability and feasibility of point-of-care CD4 testing on HIV continuum of care in low and middle income countries: a systematic review
CD4 testing is, and will remain an important part of HIV treatment and care in low and middle income countries (LMICs). We report the findings of a systematic review assessing acceptability and feasibility of POC CD4 testing in field settings.
Originally published on 9 July 2016
Point-of-care (POC) viral load tests are being developed to monitor patients on antiretroviral therapy (ART) in sub-Saharan Africa. Test design involves trade-offs between test attributes, including accuracy, complexity, robustness and cost.
Originally published on 18 July 2016
Zika virus is an emerging flavivirus widely spreading through Latin America. Molecular diagnosis of the infection can be performed using serum, urine and saliva samples, although a well-defined diagnostic algorithm is not yet established. We describe a series of 24 cases of imported zika virus infection into Catalonia (northeastern Spain).
Originally published on 17 May 2016
To help achieve tuberculosis (TB) elimination goals, the World Health Organization (WHO) now recommends systematic screening of high-risk groups such as people living with HIV (PLHIV) . However, current screening tools have a high false-positive rate (1) (symptom-based screening) or are difficult to implement in health centers (chest radiography) .
Originally published on 21 July 2016
Development, roll-out and impact of Xpert MTB/RIF for tuberculosis: what lessons have we learnt and how can we do better?
The global roll-out of Xpert MTB/RIF (Cepheid Inc., Sunnyvale, CA, USA) has changed the diagnostic landscape of tuberculosis (TB). More than 16 million tests have been performed in 122 countries since 2011, and detection of multidrug-resistant TB has increased three- to eight-fold compared to conventional testing.