Buruli ulcer laboratory network and new external quality assessment programme for PCR-based diagnosis in the WHO African Region. Terms of reference
Overview
Since 2009, the Institute of Tropical Medicine (ITM) in Antwerp, Belgium has organized a biennial external quality assessment (EQA) programme to assess the proficiency of laboratories involved in the diagnosis of Buruli ulcer by molecular detection of Mycobacterium ulcerans in clinical samples. The fourth round, organized in 2018, was the latest EQA conducted by ITM. During the 12th meeting of the WHO Technical Advisory Group on Buruli ulcer (Geneva, 27 March 2019), ITM announced that it was discontinuing the EQA programme.
In response, the Group recommended that EQA be assumed by an African country in which Buruli ulcer is endemic, for sustainability purposes. In the meantime, data presented by national programme managers at a meeting on Buruli ulcer (Geneva, 25–27 March 2019) demonstrated a continuing poor rate of confirmation of cases by polymerase chain reaction (PCR). WHO therefore considers that there is an urgent need to analyse the impact of the four previous rounds of external evaluation in order to direct future action.
A total of 18 laboratories from 13 countries participated in the four rounds of EQA: 10 laboratories from eight African endemic countries, four of which participated in all four rounds and three in three rounds. The overall results showed that the median performance of these laboratories improved over the four rounds. However, the proportion of laboratories reporting false–positive cases remains high and indicates a problem of specificity probably due to contamination. The proportion of laboratories reporting both false–positive and false–negative results raises the issue of the quality of the data reported by WHO in Africa as well as the results of the studies carried out in these different laboratories in various countries.
As ITM has discontinued the evaluation process, a model should be proposed to improve the performance of laboratories involved in the molecular diagnosis of Buruli ulcer in endemic countries in Africa in order to ensure that patients receive correct diagnostic results and that data recorded by WHO are accurate, reliable and comparable with those of other continents such as Australia.
WHO intends to transfer the EQA programme to a volunteer laboratory in an endemic African country that demonstrated good performance during the four rounds of EQA. The Mycobacteriology service of the Pasteur Center of Cameroon was judged one of the best performing laboratories and has the capacity and the experience to implement and conduct a new EQA programme.
ASSOCIATED DOCUMENT
