D. Le Ray

Evaluation of a urinary antigen‐based latex agglutination test in the diagnosis of kala‐azar in eastern Nepal

Background  We evaluated the diagnostic accuracy as well as the reproducibility of the urine latex agglutination test ‘KAtex’ in the diagnosis of kala‐azar in patients recruited at a tertiary care centre in Dharan, Nepal, between November 2000 and January 2002.

Prospective evaluation and comparison of the direct agglutination test and an rK39‐antigen‐based dipstick test for the diagnosis of suspected kala‐azar in Nepal

The diagnosis of visceral leishmaniasis (kala‐azar) remains difficult in rural endemic areas and practical and reliable tests are badly needed. Two serological tests, the Direct Agglutination Test (DAT) and an rK39‐antigen‐based dipstick test, were compared to parasitological diagnosis in a group of 184 patients presenting at a tertiary care centre in south‐eastern Nepal with a history of fever ≥14 days and splenomegaly; 139 patients had a parasitologically proven kala‐azar and 45 patients had a negative parasitological work‐up. The rK39 dipstick showed a sensitivity of 97% and a specificity of 71%. The DAT was up to 99% sensitive with a low cut‐off titre (1:400) but its specificity did not exceed 82% even with a high cut‐off titre (1:51 200). Both tests could be used for screening suspect patients in endemic areas. However, their use as confirmatory tests should be restricted to situations where the proportion of kala‐azar among clinical suspect patients is high. The rK39 dipstick is cheaper and easier to use than the DAT and could be used widely provided that both its performance and production remain stable.

Multi-centre evaluation of repeatability and reproducibility of the direct agglutination test for visceral leishmaniasis

Summary objective  To evaluate the repeatability and reproducibility of the serological direct agglutination test (DAT) for visceral leishmaniasis (VL) with aqueous antigen in a multi‐centre study in VL‐endemic areas in Sudan, Kenya and Nepal.

How better drugs could change kala-azar control. Lessons from a cost-effectiveness analysis.

Conditional on correct diagnosis and treatment, current drug regimens for visceral leishmaniasis (VL) will only prevent about 90% of deaths. Furthermore, the cost of pentavalent antimonials, the long duration of the regimen and its parenteral administration are major obstacles for patients. Poor patient compliance and the use of counterfeit drugs contribute to therapeutic failure, amplification of the reservoir and the appearance of drug resistance. We assessed the impact of potential improvements in chemotherapy on the cost‐effectiveness of VL test‐treatment strategies. Competing test‐treatment strategies were compared in a formal decision analysis – from the viewpoint of the clinician facing a VL suspect –, with avoided VL‐mortality and cost as outcomes of interest. Sensitivity analysis was done involving the following parameters: efficacy, toxicity and cost of treatment including patient care. When safer and more efficacious drugs are considered, they only result in a more cost‐effective strategy if the total cost of treatment falls below US

Visceral leishmaniasis control: a public health perspective

390 per patient. A serological test‐treatment strategy remains the optimal choice, also when better drugs become available.