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[e-drug] Quality of Malaria Tests in WHO Sources & Prices (4)

E-DRUG: Quality of Malaria Tests in WHO Sources & Prices (4)

We note the letter from Christa Hook and Daniel Berman of MSF (20 January 2005) 
regarding the Joint WHO-RBM-UNICEF-PSI-MSH publication of sources and prices of 
selected products for Prevention, Diagnosis and Control of Malaria. They raise 
some important issues regarding the purchase and use of malaria rapid 
diagnostic tests. 

As stated by MSF, the booklet gives names, format, and contact details of all 
diagnostic manufacturers. All known manufacturers were contacted, and those who 
responded were listed in the publication. The booklet provides advice on 
purchasing and use of malaria RDTs, with links to further information. As MSF 
would be aware, there is much published data on trials and use of malaria RDTs, 
including evidence of both successful and unsuccessful use of the same 
products. However, the quality of these studies is variable.  Furthermore, 
variation in performance may result from many factors, including variation in 
quality at manufacture, environmental damage to RDTs after purchase, variation 
in target antigen, and quality of published studies. Thus, publishing reliable 
information on the quality of tests, that can be extrapolated to most 
situations of potential use, is not straight-forward. WHO is developing a 
product testing programme for malaria RDTs ate present that will provide data 
to enable such information to be published, is building capacity for testing of 
quality after purchase, and is actively seeking funds to further this work.

As noted by MSF, the publication of data on a particular product by WHO is 
often taken as a sign of endorsement of that product.  However, the Sources and 
Prices booklet includes a clear disclaimer stating that the publication does 
not constitute an endorsement or warranty of the fitness of any product. 

Publication of data on heat stability and other aspects of RDT quality provided 
by manufacturers has been considered. However, WHO is aware that in some cases 
this is unreliable, and it has therefore been decided not to include it.

Evidence of good manufacturing practice, though not a marker of product 
effectiveness, is a useful guide to quality. As manufacturers work in a variety 
of jurisdictions, a variety of standards are in use (e.g. CE Mark, 
ISO13485:2003, FDA and other certifications) and their relevance to product 
effectiveness varies. WHO is in the process of finalizing an appropriate list 
of standards. WHO will then give manufacturers a period of notification to 
provide evidence of relevant certification prior to using these standards when 
publishing lists of manufacturers. It is important for availability of 
affordable, good quality products in endemic countries that manufacturers are 
not wrongly excluded.

In the meantime, WHO strongly recommends that purchasers request evidence of 
temperature stability testing and successful use from manufacturers during the 
procurement process, and do not purchase from manufacturers who can not provide 
such data. While it is impossible for WHO to verify the quality of such data at 
present, WHO is continuing to develop a transparent evidence-based product 
testing/prequalification system. This will include a representative panel of 
well-characterized parasites that will allow prediction of sensitivity and 
specificity in various geographical settings, and accellerated stability 

After purchase, monitoring of quality of RDT products and their use should 
continue. WHO provides further recommendations on this in the Sources and 
Prices booklet and in publications listed in the booklet and on 
www.wpro.who.int/rdt .

David Bell
Malaria diagnostics
Western Pacific Regional Office
World Health Organization
P.O. Box 2932
Manila, Philippines
Ph:  +63 2 5289756
Fax: +63 2 5211036

Roll Back Malaria Department
World Health Organization, 
20 avenue Appia, 
1211 Geneva 27, 
Fax: +41 (22) 791 4824

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