KAtex antigen-detection test as a diagnostic tool for latent visceral leishmaniasis cases

Kala-azar is an infectious disease that mostly affects children under 5 years old, and, in untreated cases, is fatal. There are several routine serological tests employed to diagnose the disease, but thesetests have disadvantages. Parasitological diagnosis tools are accurate but invasive, while molecular tools are expensive and not commonly used. We report that the newly developed kAtex test is a rapid,non invasive and simple tool for the detection of visceral leishmaniasis (VL), capable of detecting and distinguishing between recovered, subclinical and latent cases. The study was carried out in endemicareas of Kalibar and Ahar districts, East Azerbaijan province, Northwest Iran. Urine and Sera samples were collected from 313 children under age 5 years old from the endemic area. Additionally, sera andurine of 18 confirmed VL patients were studied. Urine samples were tested by kAtex kit to detect VL antigen. All sera samples were also tested by other serological tests such as DAT, IFA, and ELISA (IgGand IgM). kAtex tests were positive for 10 out of 313 examined urine samples of children and 2 positive samples for ELISA-IgM, but were negative all for other serological tests. During clinical follow up of thekAtex positive individuals, three of them developed VL disease, with DAT titers for these individuals reaching 1/3200. The results show that kAtex is an effective screening test for latent infection of VL. Thetest discriminates between active disease, sub clinical and latent infections. Its results can complement DAT for the diagnosis of unconfirmed visceral leishmaniasis cases

Sand fly synthetic sex-aggregation pheromone co-located with insecticide reduces the incidence of infection in the canine reservoir of visceral leishmaniasis: a stratified cluster randomised trial

The predominant sand fly vector of the intracellular parasite Leishmania infantum, that causes human and canine visceral leishmaniasis in the Americas, is Lutzomyia longipalpis. Dogs are the proven reservoir. Vector control tools to reduce transmission suited to this predominantly exophilic vector are lacking. Insecticide-impregnated dog collars protect dogs against infectious bites from sand fly vectors, and result in reductions of new infections in both dogs and humans. However, collars are costly for endemic communities, and alternative approaches are needed. Recently the bulk synthesised sex-aggregation pheromone of male Lu. longipalpis was shown to attract large numbers of conspecific females to lethal pyrethroid insecticides, indicating the potential for use in a vector control application. This study, conducted in Brazil, evaluated the efficacy of this novel lure-and-kill approach to reduce seroconversion and infection incidence with L. infantum in the canine reservoir, in addition to measuring its impact on household abundance of Lu. longipalpis. Deployed in 14 stratified clusters, the outcomes were compared to those attributed to insecticide impregnated collars fitted to dogs in another 14 clusters; each intervention was compared to 14 clusters that received placebo treatments. The beneficial effects of the lure-and-kill method were most noticeable on confirmed infection incidence and clinical parasite loads, and in reducing sand fly abundance. The overall effect of the two interventions were not statistically dissimilar, though the confidence intervals were broad. We conclude that the novel low-cost lure-and-kill approach should be added to the vector control toolbox against visceral leishmaniasis in the Americas

The ability of T2/B4 primers to detect Leishmania infantum among peripheral blood of visceral leishmaniasis patients in Iran

Leishmaniasis, caused by protozoa of the genus leishmania, is a zoonotic and anthroponotic disease that is endemic through the tropical and subtropical regions. Twelve million people are affectedworldwide and 350 million are at risk. Visceral leishmaniasis in Iran is sporadic in almost all part of Iran and the endemic regions have increased in many districts throughout Iran, the Kalybar, Ahar andMeshkin-shahr districts in East Azarbaijan and Ardabil province in the Northwest of the country. Bone marrow aspiration or biopsy followed by demonstration of leishmania parasites by microscopic and/orcultural examination is the most common diagnosis procedure. These methods are invasive and high risk. The polymerase chain reaction (PCR) has been applied as an analytical method to reveal thepresence of small numbers of parasites directly in clinical samples. A PCR-based protocol for the detection of Leishmania infantum parasites in blood was developed and tested with human samplestaken from twenty three new visceral leishmaniasis cases referred from endemic area hospitals of Northwest Iran to Pediatric educational hospital of Tabriz University of Medical Sciences. Four differentprimer pairs were used which targeted genomic and kinetoplast DNAs. The results showed that the PCR assay's sensitivity was significantly dependent on the PCR primers used

Domestic dogs in a fragmented landscape in the Brazilian Atlantic Forest: abundance, habitat use and caring by owners

This study aimed at estimating the population size and attitudes of residents towards caring for domestic dogs, through questionnaire surveys, as well as the frequency of these animals in different habitats (anthropic and forest patch), using scent stations. The study was conducted in a severely fragmented area of the Brazilian Atlantic Forest. A large number of unrestricted dogs was recorded, averaging 6.2 ind/km². These dogs have owners and are regularly fed. Dog records decreased from the anthropogenic matrix to the forest patch edge, which suggests that dogs act as an edge effect on forest patches. Encounters between domestic dog and wild animals can still be frequent in severely fragmented landscapes, mainly at the forest edges. However the fact that most dogs have an owner and are more frequent in the anthropic habitat suggests that their putative effects are less severe than expected for a carnivore of such abundance, but the reinforcement of responsible ownership is needed to further ameliorate such effects