Validation of two rapid diagnostic tests for visceral leishmaniasis in Kenya

Autor: Manica Balasegaram, Joke van Peteghem, Roberto de la Tour, Mark Riongoita, Rashid Juma, G. Kirigi, Simon Njenga, Adrian Laussermayer, François Chappuis, Raymond Omollo, Jane Mbui, Monique Wasunna
Rok vydání: 2012
Předmět:
Zdroj: PLoS Neglected Tropical Diseases
PLOS Neglected Tropical Diseases, Vol. 7, No 9 (2013) P. e2441
PLoS Neglected Tropical Diseases, Vol 7, Iss 9, p e2441 (2013)
ISSN: 1935-2735
1935-2727
Popis: Background Visceral leishmaniasis (VL) is a systemic parasitic disease that is fatal unless treated. In Kenya, national VL guidelines rely on microscopic examination of spleen aspirate to confirm diagnosis. As this procedure is invasive, it cannot be safely implemented in peripheral health structures, where non-invasive, accurate, easy to use diagnostic tests are needed. Methodology We evaluated the sensitivity, specificity and predictive values of two rapid diagnostic tests (RDT), DiaMed IT LEISH and Signal-KA, among consecutive patients with clinical suspicion of VL in two treatment centres located in Baringo and North Pokot District, Rift Valley province, Kenya. Microscopic examination of spleen aspirate was the reference diagnostic standard. Patients were prospectively recruited between May 2010 and July 2011. Principal Findings Of 251 eligible patients, 219 patients were analyzed, including 131 VL and 88 non-VL patients. The median age of VL patients was 16 years with predominance of males (66%). None of the tested VL patients were co-infected with HIV. Sensitivity and specificity of the DiaMed IT LEISH were 89.3% (95%CI: 82.7–94%) and 89.8% (95%CI: 81.5–95.2%), respectively. The Signal KA showed trends towards lower sensitivity (77.1%; 95%CI: 68.9–84%) and higher specificity (95.5%; 95%CI: 88.7–98.7%). Combining the tests did not improve the overall diagnostic performance, as all patients with a positive Signal KA were also positive with the DiaMed IT LEISH. Conclusion/Significance The DiaMed IT LEISH can be used to diagnose VL in Kenyan peripheral health facilities where microscopic examination of spleen aspirate or sophisticated serological techniques are not feasible. There is a crucial need for an improved RDT for VL diagnosis in East Africa.
Author Summary Visceral Leishmaniasis (VL) is potentially fatal if not treated promptly. Its diagnosis is based on the presence of parasites in spleen or bone marrow aspirates. These are invasive and risky procedures. Simple, rapid and non-invasive diagnostic tests are needed, notably in rural settings. We evaluated 2 rapid diagnostic tests, DiaMed IT LEISH and Signal KA for VL diagnosis, using splenic aspiration as the gold standard. The study was carried out in 2 hospitals located in Rift Valley province in Kenya, where VL is endemic. A total of 219 patients underwent splenic aspiration; 131 were positive and 88 were negative. DiaMed IT LEISH was able to correctly identify 117 of the positive cases, yielding a sensitivity of 89.3%, while Signal KA correctly identified 101, corresponding to a sensitivity of 77.1%. DiaMed IT LEISH was able to correctly label 79 of the 88 negative patients, yielding a specificity of 89.2%, while the Signal KA correctly labelled 84 of them, giving it a specificity of 95.5%. In conclusion, our study showed that rapid diagnostic tests can be used to diagnose VL in Kenyan rural health facilities, where splenic aspiration cannot be carried out safely.
Databáze: OpenAIRE
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