Development and assessment of loop-mediated isothermal amplification [LAMP] assay for the diagnosis of human visceral leishmaniasis in Iran

Parasitological methods for the diagnosis of Visceral leishmaniasis [VL] require invasive procedures, so serological and molecular approaches have been developed but are not generally applicable in the field. We evaluated a loop mediated isothermal amplification [LAMP] assay using blood from VL patients and compared it to nested PCR. Forty-seven subjects with clinical features [fever, hepatosplenomegaly and anemia] were confirmed positive for VL by the direct agglutination test [DAT] at titers >3200. Forty DAT negative individuals from non-endemic areas with no clinical signs or symptoms of VL served as controls. A LAMP assay was performed using a set of six primers targeting leishmania infantum kinetoplast DNA [kDNA] minicircle gene under isothermal [64 degree C] conditions. For nested PCR we used primers targeting the kDNA minicircle gene. The LAMP assay provided a detection limit of 1 parasite in 1 ml of j peripheral blood and detected L. infantum DNA in 44 of 47 DAT-confirmed VL cases, with diagnostic sensitivity of 93.6% [95% CI]. No L. infantum DNA was amplified in controls, indicating a specificity of 100%. The nested PCR yielded sensitivity of 96% [95% CI] and a specificity of 100% [95% CI]. The LAMP assay gave results similar to those of nested PCR but in a shorter time. The LAMP method is simple; requires no sophisticated equipment; has a short reaction time; and results, indicated by turbidity of the reaction mixture, are observable with the naked eye

Frequency of Toxoplasma gondii in HIV positive patients from West of Iran by ELISA and PCR

Toxoplasma gondii, the obligate intracellular parasite is life threatening in AIDS patients. Diagnosis of toxoplasmosis is based on serological methods especially increasing of IgM and IgG titers, but finding of parasite or its components [antigenemia] may be beneficial method in order to detection of acute toxoplasmosis in immunocompromised patients. Ninety-four serum samples from HIV positive patients were collected from Sanandaj, Kordistan west of Iran. These patients were lived in Sanandaj of whom 26 were prisoners infected with HIV virus in prison. Toxoplasma gondii antibodies were determined by IgG ELISA. T. gondii antigen was identified by capture- ELISA. PCR was performed on samples with T. gondii antigenemia. CD4+ T cells counts had been determined by flowcytometry and were obtained from records of each patient. Among the examined HIV seropositive individuals, 19.1% [18/94] and 5.3% [5/94] were positive for Toxoplasma-IgG and antigenemia, respectively. Besides, one of the samples was positively detected by PCR method. Mean age of participants was 37.9 +/- 9.5 year. Prevalence of IgG antibody and antgenemia was higher in age group of 40-50 years old. The Mean of CD4+ T cells counts of participants [total of HIV+ patients, IgG positive patients and patients with antigenemia] was 699.2 +/- 345.2, 655.1 +/- 237.9 and 620.2 +/- 215.1 respectively. Capture-ELISA and PCR could confirm the T. gondii acute infection in HIV positive patients. For precise diagnosis of acute toxoplasmosis in HIV positive patient, performance of more studies based on more sensitive types of PCR is suggested

[Study on the association of Toxocariasis with allergic rhinitis in individuals referred to Rasoul Akram Hospital, Tehran]

Toxocariasis is a common worldwide zoonotic parasite infection caused by the larvae of Toxocara catti and Toxocara canis. Allergic rhinitis is the most common chronic diseases in the upper respiratory tract. The main symptoms are sneezing, watery rhinorrhea, itching in the nose, eyes and palate. The purpose of this study was to investigate the association between toxocara seropositivity and allergic rhinitis compared with the control population. This cross-sectional study was carried out from September 2009 to February 2011 on 93 patients with allergic rhinitis and 87 control subjects. Confirmation of the diagnosis of allergic rhinitis was defined by history and positive epicutaneous prick test. Control subjects were healthy based on history and no signs of allergic rhinitis and other allergic diseases were seen. Blood and fecal samples were taken from both groups. Sera were separated, labeled and stored at -20°C until used. Stool samples were examined by a wet mount and formalin-ethyl acetate concentration technique. The diagnosis of toxocariasis was established by IgG anti Toxocara and IgE total by ELISA method. In case group [allergic rhinitis] from 93 patients, 50 patients [53.8%] were males and 43 [46.2%] were female. In the control group of 87 individuals studied, 56 [64.4%] were males and 31 [35.6%] were female. In cases and controls, 5 [5.4%] and 3 [3.4%] of sera were positive for IgG Toxocara, respectively. There was no statistical difference in Toxocara seropositivity in both groups [p =0.39]. It seems to be in contrast to worms and allergies several factors, including phase worm infections [acute and chronic], parasite load, parasite species and resistance genes are involved and this require further studies in different ages and populations

A Case of Fatal Strongyloidiasis in a Patient with Chronic Lymphocytic Leukemia and Molecular Characterization of the Isolate

Strongyloides stercoralis is a human intestinal parasite which may lead to complicated strongyloidiasis in immunocompromised. Here, a case of complicated strongyloidiasis in a patient with chronic lymphocytic leukemia is reported. Presence of numerous S. stercoralis larvae in feces and sputum confirmed the diagnosis of hyperinfection syndrome in this patient. Following recovery of filariform larvae from agar plate culture of the stool, the isolate was characterized for the ITS1 region of ribosomal DNA gene by nested-PCR and sequencing. Albendazole therapy did not have cure effects; and just at the beginning of taking ivermectin, the patient died. The most important clue to prevent such fatal consequences is early diagnosis and proper treatment.