Biology subjects

Oumar Faye

Publications and source records attributed to Oumar Faye.

2 recordsLinked to original sources

bioRxiv2016

Rapid molecular detection of Zika virus in urine using the recombinase polymerase amplification assay

BackgroundCurrently the detection of Zika virus (ZIKV) in patient samples is done by real-time RT-PCR. Samples collected from rural area are sent to highly equipped laboratories for screening. A rapid point-of-care test is needed to detect the virus, especially at low resource settings.\n\nMethodology/Principal FindingsIn this report, we describe the development of a reverse transcription isothermal recombinase polymerase amplification (RT-RPA) assay for the identification of ZIKV. RT-RPA assay was portable, sensitive (21 RNA molecules), and rapid (3-15 minutes). No cross-reactivity was detected to other flaviviruses, alphaviruses and arboviruses. Compared to real-time RT-PCR, the diagnostic sensitivity was 92%, while the specificity was 100%.\n\nConclusions/SignificanceThe developed assay is a promising platform for rapid point of need detection of ZIKV in low resource settings and elsewhere (e.g. during mass gathering).\n\nAuthor SummaryCurrently, Dengue (DENV), Zika (ZIKV) and Chikungunya (CHIKV) viruses represent a global threat. The clinical picture of the acute febrile diseases caused by DENV, ZIKV and CHIKV is very similar, in addition, the same mosquito vector is involved in the transmission cycle. The differentiation between them is of great importance as supportive treatment differs and the identification of any of the three viruses prompts implementation of control measures to avoid spreading of an outbreak. We have developed an assay for the detection of ZIKV genome. The assay based on isothermal \"recombinase polymerase amplification\" assay, which was performed at one temperature (42{degrees}C). The result was obtained in maximum of 15 minutes. Moreover, the assay is easy to be implemented at low resource settings.

Microbiology↗

bioRxiv2016

Monkey in the middle: monkeys serve as amplification hosts but not reservoir hosts of sylvatic chikungunya virus

Athropod-borne viruses (arboviruses) pose the greatest risk of spillover into humans of any class of pathogens. Such spillover may occur as a one-step jump from a reservoir host species into humans or as a two-step jump from the reservoir to a different amplification host species and thence to humans. Despite the widespread havoc wreaked by emerging arboviruses, little is known about their transmission dynamics in reservoir and amplification hosts. Here we used serosurveillance and mathematical modeling to elucidate the role of monkeys in the sylvatic, enzootic cycle of chikungunya virus (CHIKV). Over three years, 219 African green monkeys, 78 patas monkeys, and 440 Guinea baboons were captured in the region surrounding Kedougou, Senegal. The age of each animal was determined by anthropometry and dentition, and exposure to CHIKV was determined by detection of neutralizing antibodies. We estimate age-specific CHIKV seroprevalence, force of infection (FoI), and basic reproductive number (R0) in each species. Among the different species, CHIKV Fol ranged from 0.13 to 1.12 (95% CI, 0.81-2.28) and R0 ranged from 1.5 (95% CI, 1.3-1.9) to 6.6 (95% CI, 5.1-10.4). CHIKV infection of infant monkeys was detected even when the virus was not detected in a concurrent survey of primatophilic mosquitoes and when population seropositivity, and therefore immunity, was too high for monkeys themselves to support continuous CHIKV transmission. We therefore conclude that monkeys in this region serve primarily as amplification rather than reservoir hosts of CHIKV. Additional efforts are needed to identify other vertebrate hosts capable of supporting continuous circulation.

Ecology↗