Usefulness of the rK39-Immunochromatographic Test, Direct Agglutination Test, and Leishmanin Skin Test for Detecting Asymptomatic Leishmania Infection in Children in a New Visceral Leishmaniasis Focus in Amhara State, Ethiopia

Abstract

Abstract. In areas where visceral leishmaniasis is anthroponotic, asymptomatically infected patients may play a role in transmission. Additionally, the number of asymptomatic patients in a disease-endemic area will also provide information on transmission dynamics. Libo Kemkem and Fogera districts (Amhara State, Ethiopia) are now considered newly established areas to which visceral leishmaniasis is endemic. In selected villages in these districts, we conducted a study to assess the usefulness of different approaches to estimate the asymptomatic infection rate. Of 605 participants, the rK39 immunochromatographic test was able to detect asymptomatic infection in 1.5% (9 of 605), direct agglutination test in 5.3% (32 of 605), and leishmanin skin test in 5.6% (33 of 589); the combined use of serologic methods and leishmanin skin test enabled detecting asymptomatic infection in 10.1% (61 of 605). We conclude that the best option to detect asymptomatic infection in this new visceral leishmaniasis-endemic focus is the combined use of the direct agglutination test and the leishmanin skin test.

Latent Infection with Leishmania donovani in Highly Endemic Villages in Bihar, India

“…There was limited overlap between both markers (kappa = 0.30), which is similar to what was observed in Ethiopia by Gadisa et al [26] and by Custodio et al [27].…”

Serological and Molecular Analysis of Leishmania Infection in Healthy Individuals from Two Districts of West Bengal, India, Endemic for Visceral Leishmaniasis

“…Therefore, procedures based on minimal invasive sampling, such as serologic analysis or qPCR assay, are more suitable for this purpose. Besides, some investigators used leishmanin skin test (LST), an another useful method for screening subclinical infection in the healthy population, 32 that measures a delayed-type hypersensitivity reaction to Leishmania antigens. Further, LST becomes positive later after infection and persist much longer than antileishmanial antibodies.…”

Diagnosis of Leishmania infantum using Direct Agglutination Test and rKE16 Dipstick Rapid Test in Domestic Dogs from Ardabil Province, Iran

“…Moreover in India, a study revealed that Ld-rKDD8 antigen was less sensitive and less specific as compared to rKE16 antigen for the diagnosis of VL (Sivakumar et al, 2008). Although, in an opposite data of a study in Amhara State, Ethiopia, the usefulness of the rK39-Immunochromatographic test, DAT and Leishmanin skin test for detecting asymptomatic Leishmania infection in children in a new VL focus were indicated (Gadisa et al, 2012), however in a supporting study, an evaluation of two rK39 Dipstick tests, DAT and IFA test for diagnosis of VL in a new epidemic site in highland of Ethiopia was made and both rK39 tests performed as well as DAT and they were indicated as suitable assays for VL diagnosis in first-level health centers in this area of Ethiopia (Canavate et al, 2011). In Sudan, a method was introduced as rKLO8, a novel L. donovani-derived recombinant immunodominant protein for sensitive detection of VL and it reported the increased reactivity of Sudanese VL sera with the rKLO and this antigen was confirmed as a potential candidate for diagnosis of VL in Sudan (Abass et al, 2013).…”

“…Different methods are used for the laboratory diagnosis of VL including the observation of the parasite in stained specimens and determination of specific antibodies against Leishmania spp. There are some publications from Iran, Brazil, India, Ethiopia and Sudan applied different assays for detection of VL in dogs and humans including DAT assay used for screening and serodiagnosis of human L. infantum infection in Iran (Akhoundi et al, 2010, DAT, rK39-based rapid test and ELISA-rK39 for diagnosis of VL in Brazil (De Assis et al, 2011;Pedras et al, 2008), Ld-rKDD8 and rKE16 antigens for the diagnosis of VL in India (Sivakumar et al, 2008), rK39 Dipstick tests, DAT, IFA test and Leishmanin skin test for diagnosis of VL in Ethiopia (Gadisa et al, 2012;Canavate et al, 2011), rKLO8 and rKLO as a candidate for diagnosis of VL in Sudan (Abass et al, 2013). There are also comparisons of some assays for VL detection including rK39 and rKE16 in the Indian subcontinent, Brazil and East Africa , immunochromatographic tests and DAT in Latin-America, East-Africa and Asia (Adams et al, 2012) and rKE16 and rK39 in diagnosis of VL in India (Vaish et al, 2012).…”