BackgroundExternal quality assessments (EQA) are an alternative to cross-checking of blood slides in the quality control of malaria microscopy. This study reports the findings of an EQA of malaria microscopy in the Democratic Republic of the Congo (DRC).MethodsAfter validation, an EQA slide panel and a questionnaire were delivered to diagnostic laboratories in four provinces of DRC. The panel included three samples for diagnosis (sample 1: Plasmodium falciparum, 177,000/μl, sample 2: P. falciparum, 2,500/μl, sample 3: no parasites seen), one didactic sample (Howell-Jolly bodies) and one sample for assessing the quality of staining. Participating laboratories were addressed and selected through the network of the National Tuberculosis Control Programme. Participants were asked to return the responses together with a stained thin and thick blood film for evaluation of Giemsa stain quality.ResultsAmong 174 participants (response rate 95.1%), 26.2% scored samples 1, 2 and 3 correctly and 34.3%, 21.5% and 5.8% of participants reported major errors in one, two or three samples respectively. Major errors included reporting "no malaria" or "non-falciparum malaria" for Plasmodium falciparum-positive samples 1 and 2 (16.1% and 34.9% of participants respectively) and "P. falciparum" for Plasmodium negative sample 3 (24.0%). Howell-Jolly bodies (didactic sample) were not recognized by any of the participants but reported as "P. falciparum" by 16.7% of participants. With parasite density expressed according to the "plus system", 16.1% and 21.5% of participants scored one "+" different from the reference score for samples 1 and 2 respectively and 9.7% and 2.9% participants scored more than two "+" different. When expressed as counts of asexual parasites/μl, more than two-thirds of results were outside the mean ± 2SD reference values. The quality of the Giemsa stain was poor, with less than 20% slides complying with all criteria assessed. Only one quarter of participants purchase Giemsa stain from suppliers of documented reliability and half of participants use a buffered staining solution. One third of participants had participated in a formal training about malaria diagnosis, half of them earlier than 2007.ConclusionThe present EQA revealed a poor quality of malaria microscopy in DRC.

BackgroundAlthough malaria rapid diagnostic tests (RDT) are simple to perform, they remain subject to errors, mainly related to the post-analytical phase. We organized the first large scale SMS based external quality assessment (EQA) on correct reading and interpretation of photographs of a three-band malaria RDT among laboratory health workers in the Democratic Republic of the Congo (DR Congo).Methods and FindingsHigh resolution EQA photographs of 10 RDT results together with a questionnaire were distributed to health facilities in 9 out of 11 provinces in DR Congo. Each laboratory health worker answered the EQA by Short Message Service (SMS). Filled-in questionnaires from each health facility were sent back to Kinshasa. A total of 1849 laboratory health workers in 1014 health facilities participated. Most frequent errors in RDT reading were i) failure to recognize invalid (13.2–32.5% ) or negative test results (9.8–12.8%), (ii) overlooking faint test lines (4.1–31.2%) and (iii) incorrect identification of the malaria species (12.1–17.4%). No uniform strategy for diagnosis of malaria at the health facility was present. Stock outs of RDTs occurred frequently. Half of the health facilities had not received an RDT training. Only two thirds used the RDT recommended by the National Malaria Control Program. Performance of RDT reading was positively associated with training and the technical level of health facility. Facilities with RDT positivity rates >50% and located in Eastern DR Congo performed worse.ConclusionsOur study confirmed that errors in reading and interpretation of malaria RDTs are widespread and highlighted the problem of stock outs of RDTs. Adequate training of end-users in the application of malaria RDTs associated with regular EQAs is recommended.

BackgroundMalaria rapid diagnostic tests (RDTs) are increasingly used as a tool for the diagnosis of malaria, both in endemic and in non-endemic settings. The present study reports the results of an external quality assessment (EQA) session on RDTs in a non-endemic setting.MethodsAfter validation of antigen stability during shipment at room temperature, three clinical samples and a questionnaire were sent to clinical laboratories in Belgium and the Grand Duchy of Luxembourg using malaria RDTs. Participants were asked to report the results of the RDTs as observations (visibility of the RDT control and test lines) and interpretations (report as formulated to the clinician). In addition, participants were invited to fill in a questionnaire on the place of RDTs in the diagnostic strategy of malaria.ResultsA total of 128/133 (96.2%) of clinical laboratories using RDTs participated. Six three-band and one four-band RDT brands were used. Analytical errors were rare and included (i) not recognizing invalid RDT results (1.6%) and (ii) missing the diagnosis of Plasmodium falciparum (0.8%). Minor errors were related to RDT test result interpretation and included (i) reporting "RDT positive" without species identification in the case of P. falciparum and non-falciparum species (16.9% and 6.5% respectively) and (ii) adding incorrect comments to the report (3.2%). Some of these errors were related to incorrect RDT package insert instructions such as (i) not reporting the possibility of mixed species infection in the case of P. falciparum and Plasmodium vivax (35.5% and 18.5% respectively) and (ii) the interpretation of P. vivax instead of non-falciparum species at the presence of a pan-species antigen line (4.0%). According to the questionnaire, 48.8% of participants processed ≤20 requests for malaria diagnosis in 2009. During opening hours, 93.6% of 125 participants used RDTs as an adjunct to microscopy but outside opening hours, nearly one third of 113 participants relied on RDTs as the primary (4.4%) or the single tool (25.7%) for malaria diagnosis.ConclusionIn this non-endemic setting, errors in RDT performance were mainly related to RDT test line interpretations, partly due to incorrect package insert instructions. The reliance on RDTs as the primary or the single tool for the diagnosis of malaria outside opening hours is of concern and should be avoided.

The present External Quality Assessment (EQA) assessed microscopy of blood parasites among diagnostic laboratories in the Democratic Republic of the Congo. The EQA addressed 445 participants in 10/11 provinces (October 2013–April 2014). Participants were sent a panel of five slides and asked to return a routinely stained slide which was assessed for quality of preparation and staining. Response rate was 89.9% (400/445). For slide 1 (no parasites), 30.6% participants reported malaria, mostly Plasmodium falciparum. Only 11.0% participants reported slide 2 (Plasmodium malariae) correctly, 71.0% reported “malaria” or “Plasmodium falciparum” (considered acceptable). Slide 3 contained Plasmodium falciparum (109/μl) and Trypanosoma brucei brucei trypomastigotes: they were each reported by 32.5% and 16.5% participants respectively, 6.0% reported both. Slide 4 (Trypanosoma) was recognised by 44.9% participants. Slide 5 (Plasmodium ovale) was correctly reported by 6.2% participants, another 68.8% replied “malaria” or “Plasmodium falciparum” (considered acceptable). Only 13.6% of routine slides returned were correctly prepared and stained. The proportion of correct/acceptable scores for at least 4/5 slides was higher among EQA-experienced participants compared to first time participants (40.9% versus 22.4%, p = 0.001) and higher among those being trained < 2 years ago compared to those who were not (42.9% versus 26.3%, p = 0.01). Among diagnostic laboratories in Democratic Republic of the Congo, performance of blood parasite microscopy including non-falciparum species and Trypanosoma was poor. Recent training and previous EQA participation were associated with a better performance.