Studies on West Nile virus infection in Egypt

We conducted a prospective cohort study to determine prevalence and incidence of West Nile virus [WNV] in Egypt. Cohorts were established in Upper [UE], Middle [ME], and Lower [LE] Egypt. Additionally, a cross-sectional serosurvey was performed in the North [NS] and South [SS] Sinai. Cohorts were bled initially and 1 year later. Sera were tested for WNV-IgG by ELISA and positive sera were confirmed by plaque reduction neutralization test [PRNT]. Sentinel chicken flocks placed in the above sites were bled monthly for virus isolation and serology. Mosquitoes were collected monthly from the above sites and tested for WNV. Human seroprevalence rates were 35%, 27%, 14%, 1% and 7% in UE, ME, LE, NS and SS, respectively. Seroconversion rates were 18%, 17% and 7% in UE, ME and LE, respectively; 49% of the seroconverters reported undiagnosed febrile illness. Sentinel chickens showed seroconversion in all study sites. WNV was isolated from both sentinel chickens and mosquitoes in cohort sites. This study demonstrates that WNV was actively circulating during the study period in different areas in Egypt and causing febrile illness in a considerable proportion of individuals in the study sites

Evaluation of preservation methods and simulated multiple infection on the fidelity of real-time PCR detection of Leishmania DNA

To detail the evaluation of a real-time polymerase chain reaction [PCR]-based approach to Leishmania detection. Also to test the fidelity of PCR diagnostics in a series of experiments mimicking infection by two species of Leishmania. Leishmania major [a causal agent of cutaneous leishmaniasis] infected Phlebotomus papatasi sandflies were generated to test the effect of four preservation methods on the fidelity of real-time PCR detection of Leishmania DNA. There was no effect of preservation methods on the sensitivity or specificity of two different assays. The ability of these assays to correctly diagnose cases of multiple infection was tested with artificial double infections created by combining DNA from pairs of Leishmania species [L, major, L. tropica and L, panamensis]. One assay failed to properly diagnose certain double infections but overall the PCR methodologies were robust. These findings provide important reassurances for subsequent real world investigations of Leishmania in vector, reservoir and human populations