Evaluation of rK-39 strip test using urine for diagnosis of visceral leishmaniasis in an endemic area in Bangladesh

Abstract

Diagnosis of visceral leishmaniasis (VL) by demonstration of parasites in tissue smears obtained from bone marrow, spleen or lymph nodes is risky, painful, and difficult. The rK-39 strip test is widely used for the diagnosis of VL using blood/serum samples in endemic countries. The aim of the study was to evaluate the rK-39 strip test using urine sample as a non-invasive means for the diagnosis of VL. The rk-39 strip test was performed using urine from 100 suspected VL cases along with 25 disease control (malarial febrile cases) and 50 healthy control (from endemic and non-endemic areas). All the VL suspected cases were positive with the rK-39 strip test using serum. The sensitivity and specificity of the rK-39 strip test using urine samples was 95% and 93.3%, respectively, compared to serum based rK-39 test. The findings suggest that the urine based rK-39 test could be a practical and efficient tool for the diagnosis of VL patients in rural areas, particularly where resources are limited.

Evaluation of rK-39 Strip Test Using Urine for Diagnosis of Visceral Leishmaniasis in an Endemic Region of India

“…29 However, the same study showed 5 positive samples among 25 samples of malaria patients, whereas in the present study, none of the malaria samples were found to be positive, because the sample size in this category was relatively small. Furthermore, this work needs to be corroborated with a large sample size in malaria and typhoid patients, where the symptoms are very similar to the symptoms of KA and can lead to diagnostic difficulty in clinical practice.…”

“…Both of these studies were performed in the same geographical region on parasitologically (LD bodies) and serologically (rK-39 test) positive VL cases, respectively. 29,32 In our study, the serum rK-39 ICT showed 100% sensitivity, whereas specificity was variable in control subjects. It showed that none of the healthy nonendemic controls were positive, whereas 6.2% and 3.85% of healthy endemic and other infectious disease controls gave positive reactions, respectively, which indicates false-positive reactions.…”

“…13,29,32,38 The works by Brandtzaeg and others 39 and Roitt and Lehner 40 reported that the mean IgG concentration was 14,730 mg/L in serum and 12,500 mg/L in urine. Although several different serological test formats exist for diagnosis of VL, many of them have not been validated in prospective field studies.…”

“…26,27 A few non-invasive sampling methods have been developed in VL diagnosis using human sputum, oral fluid, saliva, urine, and buccal swab samples with good sensitivity and specificity. [28][29][30][31] Advantages of the urine rK-39 ICT are that it is simple, rapid, non-invasive, and userfriendly, it has a reliable indicator, it is easy to collect, and it does not require equipment. Additionally, the results are unambiguous with high sensitivity and specificity.…”

“…Additionally, the results are unambiguous with high sensitivity and specificity. 29,32 Because young children are often vulnerable to VL infection, the use of urine will facilitate its use in field conditions. from confirmed VL patients and controls compared with serum samples.…”