Epidemiology of Infantile Visceral Leishmaniasis in Western Algerian And The Convenience of Serum For The Disease Diagnosis by PCR and Immunochromatography

Abstract

Epidemiological situation of infantile visceral leishmaniasis (IVL), which is a public health problem in Algeria, is almost unknown in the cities of Western part of the country. The aim of this study was to analyze the epidemiological, clinical, biological, therapeutic, and evolutionary aspects of IVL in Western Algeria, to evaluate the performance of the immunochromatography as a rapid diagnostic test of the disease, and to propose a diagnosis approach by real-time polymerase chain reaction (RT-PCR) assay from the serum. This prospective study was performed on 63 suspicious cases of visceral leishmaniasis collected from the infectious diseases department at the Pediatric Hospital of Oran from January 2012 to July 2017. For each patient, the epidemiological parameters, and the clinical and biological data were collected. Bone marrow and blood samples were drawn from all cases. Bone marrow was performed to research amastigote forms of Leishmania and to identify the species by PCR-sequencing. Blood samples were used to detect anti-Leishmania antibodies as well as parasite DNA. Patients from the Western regions were mostly from rural areas. Sensitivity of RT-PCR from the bone marrow and from serum was 95.45% and 94.44%, respectively. The immunochromatography allowed the disease's diagnosis for 11 cases whose myelogram did not confirm the presence of the amastigote forms of Leishmania. Immunochromatography was revealed to be a good technique for disease diagnosis regarding the strongly evocative clinical signs. The results also suggest the interest of the RT-PCR assay from patient serum as a non-invasive sample, in the detection of parasite DNA.

Keywords: Imunochromatography; Leishmania infantum; RT-PCR; bone marrow; sequencing; serum.

Fig. 1

Distribution of cases according to the state of provenance

Fig. 2

Distribution of cases according to clinical signs suggestive of the VL. HPMG : hepatomegaly; SPMG: splenomegaly

Fig. 3

Distribution of cases according to the biological signs. SR: Increased sedimentation rate

Fig. 4

Leishmania amastigote forms. A: intracellular and B: extracellular forms observed under optical microscope (x 1000)

Fig. 5

Phylogenetic tree of the Leishmania species. Phylogenetic tree was drawn based on sequences of the ITS1 (500 pb), ITS2 (400 bp), and Cytb (800 bp) amplified from bone marrow samples of prospective cases