Comparison of recombinant A2-ELISA with rKE16 dipstick and direct agglutination tests for diagnosis of visceral leishmaniasis in dogs in Northwestern Iran

Abstract

Introduction: Various methods are used for the diagnosis of visceral leishmaniasis (VL), such as microscopic examination, culture and inoculation of laboratory animals; however, serological assays are commonly used for the detection of antibodies in serum samples with a wide range of specifi city and sensitivity. Methods: The purpose of this study was to compare three serological methods, including rA2-ELISA, the recombinant KE16 (rKE16) dipstick test and the direct agglutination test (DAT), for the detection of antibodies against VL antigens. The assays utilized 350 statistically based random serum samples from domestic dogs with clinical symptoms as well as samples from asymptomatic and healthy dogs from rural and urban areas of the Meshkinshahr district, northwestern Iran. Results: Samples were assessed, and the following positive rates were obtained: 11.5% by rKE16, 26.9% by DAT and 49.8% by ELISA. The sensitivity among symptomatic dogs was 32.4% with rKE16, 100% with DAT and 52.9% with ELISA. Conversely, rA2-ELISA was less specifi c for asymptomatic dogs, at 46.5%, compared with DAT, at 88.9%. Conclusions: This study recommends rA2-ELISA as a parallel assay combined with DAT to detect VL infection among dogs. Further evaluations should be performed to develop an inexpensive and reliable serologic test for the detection of Leishmania infantum among infected dogs.

The Diagnostic Accuracy of Direct Agglutination Test for Serodiagnosis of Human Visceral Leishmaniasis: A Systematic Review with Meta-analysis

“…Until the 1990, VL diagnosis was needed to parasitological con rmation including microscopy or culture of the spleen,bone-marrow, lymph nodes and sometimes peripheral blood specemens. The invasiveness and sometimes fatal complications particularly associated with splenic aspiration caused to develop of simple and accurate serological tests such as DAT (41,42). Although the IFAT and ELISA are two important serological methods for diagnosis of human VL but they require speci c materials and equipments (1,43).The rK39-based tests are easy to perform, quick, cheap and give reproducible results and can therefore be used for early diagnosis of VL at both peripheral and central levels of public health centers.…”

“…On the other hand, rK39 strip tests have some limitations, as with other serologic tests, anti-Leishmania antibodies patients can be persisted for months after cure of VL, moreover, it has low speci city in sub-clinical and asymptomatic forms of L.donovani or L.inantum/chagasi infections, particularly among Sudanese population (22,42,44). A newly developed assay based on the detection of antibodies to the rk28 fusion protein reported a very promising sensitivity and speci city (96% and 98%, respectively) of ELISA to detect anti-Leishmania antibodies in sera among VL patients.…”

“…A newly developed assay based on the detection of antibodies to the rk28 fusion protein reported a very promising sensitivity and speci city (96% and 98%, respectively) of ELISA to detect anti-Leishmania antibodies in sera among VL patients. However, the rK26, A2-ELISA and rKE16 dipstick recombinant antigens from amastigote forms of L.infantum or L.donovani was prepared and laboratory assessments were performed with desirable results (40)(41)(42). Among the available serological tests for the diagnosis of VL, DAT is simple, highly speci c and sensitive, reliable and cost-effective test can be used in eld as well as laboratory studies (41,(45)(46)(47)(48)(49).…”

The Diagnostic Accuracy of Direct Agglutination Test for Serodiagnosis of Human Visceral Leishmaniasis: A Systematic Review with Meta-analysis

“…A newly developed assay based on the detection of antibodies to the rk28 fusion protein reported a very promising sensitivity and speci city (96% and 98%, respectively) of ELISA to detect anti-Leishmania antibodies in sera among VL patients. The rK26, A2-ELISA and rKE16 dipstick recombinant antigens from amastigote forms of L.infantum or L.donovani was prepared and laboratory assessments were performed with desirable results (40)(41)(42). Among the available serological tests for the diagnosis of VL, DAT is a simple, highly speci c and sensitive, reliable and cost-effective test that can be used in eld as well as laboratory studies (43)(44)(45)(46)(47).…”

Cloning, expression and purification of recombinant A2 protein from Leishmania infantum for diagnosis of visceral leishmaniasis in Iran

“…VL is characterized by the presence of; fever, hepatosplenomegaly, swollen lymph nodes and weight loss, depending on the Leishmania species and the host's immune response against the parasite [2]. Different methods are used for the diagnosis of VL based on aspirates or biopsy specimens of visceral tissues (spleen, liver, bone marrow), which are subjected to microscopic examination and culture, and serological methods such as the indirect fluorescent antibody (IFA), the indirect hemagglutination assay (IHA), the direct agglutination test (DAT) and enzyme-linked immunosorbent assay (ELISA) [3]. Several antigens (Ag) are used for serological detection of antibody but most common is crud soluble Ag (CSA).…”