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SUMMARY: Yellow fever (YF), which is caused by a mosquito-borne virus, is an important viral hemorrhagic fever endemic in equatorial Africa and South America. Yellow fever virus (YFV) is the prototype of the family Flaviviridae and genus Flavivirus. The aim of this study was to determine the seroprevalence of YFV in selected health facilities in Western Kenya during the period 2010-2012. A total of 469 serum samples from febrile patients were tested for YFV antibodies using in-house IgM-capture ELISA, in-house indirect IgG ELISA, and 50z focus reduction neutralization test (FRNT 50 ). The present study did not identify any IgM ELISA-positive cases, indicating absence of recent YFV infection in the area. Twenty-eight samples (6z) tested positive for YFV IgG, because of either YFV vaccination or past exposure to various flaviviruses including YFV. Five cases were confirmed by FRNT 50 ; of these, 4 were either vaccination or natural infection during the YF outbreak in 1992-1993 or another period and 1 case was confirmed as a West Nile virus infection. Domestication and routine performance of arboviral differential diagnosis will help to address the phenomenon of pyrexia of unknown origin, contribute to arboviral research in developing countries, and enhance regular surveillance.Yellow fever (YF), a disease caused by mosquitoborne virus, is an important viral hemorrhagic fever endemic in equatorial Africa and South America (1,2). Yellow fever virus (YFV) is the prototype of the family Flaviviridae and genus Flavivirus (3). The genus Flavivirus contains approximately 70 viruses including YFV, dengue viruses (DENVs), Japanese encephalitis virus (JEV), and West Nile virus (WNV) that are of major human public health concern (4). An estimated annual incidence of 200,000 cases of YF causing 30,000 deaths is reported each affected individuals without treatment (4,5). In the eastern African region, YF outbreaks have been reported in Kenya (1992-1993) (6,7), South Sudan (2003, Uganda (2010-2011) (10), Sudan (2012) (11), and Ethiopia (2013) (12).YF cases are difficult to diagnose from the clinical symptoms in the early stages of the illness because of`n on-specific influenza-like symptoms'' that are similar to those of other febrile illnesses. Differential diagnoses may include malaria, viral hepatitis, dengue, leptospirosis, or other hemorrhagic fevers (13). WHO recommends case definition for suspected YF as``any case presenting with acute onset of fever, with jaundice appearing within 14 days after the onset of the first symptoms'' (14). The aim of this study was to determine the seroprevalence of YFV in selected health facilities in Western Kenya during the period 2010-2012.A total of 469 human whole blood samples were collected from the following healthcare facilities in Kenya: Andersen Medical Centre (AMC), Endebess Sub District Hospital (END), and Kitale District Hospital (KDH) in Trans Nzoia County; Centre for Infectious and Parasitic Diseases Control Research, Kenya Medical Research Institute (KEMRI) clinic (CIP) lo...

Aflatoxigenic fungi are most common filamentous fungi that synthesis aflatoxins and represent the major fungal pathogens to agricultural products. Aflatoxins remain a major threat to global food security, these molecules could be resisted into food during processing and in additional may remain within the food chain. Aflatoxins are carcinogenic, hepatotoxic, mutagenic, teratogenic, can inhibit numerous metabolic systems and immunosuppressive properties.Studies of aflatoxigenic strains can help to enhance strategies control and prevent aflatoxigenic fungi contamination and aflatoxins production in foodstuffs. In this study, isolation of Aspergillus species was based on morphological characteristics including the mycelium growth pattern, color, and properties of fruiting bodies of the fungi. The innovated technique loop-mediated isothermal amplification assay was applied to amplify Norsolorinic Acid gene.The loop-mediated isothermal amplification have been optimized by combination of the rapidity, simplicity and specificity to detect the target genomic DNA in the reactions. The amplification curves monitored by Loopamp realtime Turbidi meter were analyzed in order to distinguish aflatoxigenic and non-aflatoxigenic strains.Overall, the results showed that the loop-mediated isothermal amplification method was effective in detecting aflatoxigenic strains with high specificity of 71.5 % and sensitivity under lower concentrations of DNA. In additional, it was faster than the conventional polymerase chain reaction. The loop-mediated isothermal amplification assay described in this study might be a promising tool for prediction potential threats by aflatoxigenic fungi and aflatoxins risk in food and commodities.

BackgroundRift Valley Fever (RVF) is a mosquito-borne viral zoonosis. To detect RVF virus (RVFV) infection, indirect immunoglobulin G (IgG) and immunoglobulin M (IgM) enzyme linked immunosorbent assays (ELISAs) which utilize recombinant RVFV nucleocapsid (RVFV-N) protein as assay antigen, have reportedly been used, however, there is still a need to develop more sensitive and specific methods of detection.MethodsRVFV-N protein was expressed in Escherichia coli (E. coli) and purified by histidine-tag based affinity chromatography. This recombinant RVFV-N (rRVFV-N) protein was then used as antigen to develop an IgG sandwich ELISA and IgM capture ELISAs for human sera. Ninety six serum samples collected from healthy volunteers during the RVF surveillance programme in Kenya in 2013, and 93 serum samples collected from RVF-suspected patients during the 2006–2007 RVF outbreak in Kenya were used respectively, to evaluate the newly established rRVFV-N protein-based IgG sandwich ELISA and IgM capture ELISA systems in comparison with the inactivated virus-based ELISA systems.ResultsrRVFV-N protein-based-IgG sandwich ELISA and IgM capture ELISA for human sera were established. Both the new ELISA systems were in 100% concordance with the inactivated virus-based ELISA systems, with a sensitivity and specificity of 100%.ConclusionsRecombinant RVFV-N is a safe and affordable antigen for RVF diagnosis. Our rRVFV-N-based ELISA systems are safe and reliable tools for diagnosis of RVFV infection in humans and especially useful in large-scale epidemiological investigation and for application in developing countries.