Liberian Institute for Biomedical Research

Charlesville, Liberia

Liberian Institute for Biomedical Research

Charlesville, Liberia
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Obenauer P.J.,U.S. Navy | Abdel-Dayem M.S.,King Saud University | Stoops C.A.,U.S. Department of Agriculture | Villinski J.T.,Us Naval Medical Research Unit No 3 | And 4 more authors.
Journal of Medical Entomology | Year: 2013

Malaria infection is a serious public health problem throughout Liberia, but vector surveillance is limited or nonexistent in remote regions of the country. To better understand the spatial and temporal distribution of malaria vectors in Liberia and to support vector and malaria activities of the Liberian Ministry of Health, a study was conducted to determine the efficacy of light traps baited with a synthetic lure and CO2 for capturing Anopheles gambiae sensu lato (Giles). Traps with a ultraviolet, light-emitting diode, and incandescent lights baited with a synthetic skin lure and CO2 combinations were evaluated at four field sites in three counties of Liberia for five consecutive nights every 8 wk during 2011. In total, 4,788 mosquitoes representing 56 species from nine genera were collected throughout the 30-wk study; An. gambiae s. l. comprised 32% and of the148 An. gambiae s. s. collected, 85% were of the S form. A greater percentage of An. gambiae s. l. were collected in ultraviolet traps baited with a synthetic lure and CO2 compared with any other trap configuration. The influence of trap configuration on conclusions from surveillance efforts, specifically with regards to An. gambiae is discussed. © 2013 Entomological Society of America.

Alout H.,Colorado State University | Krajacich B.J.,Colorado State University | Meyers J.I.,Colorado State University | Grubaugh N.D.,Colorado State University | And 9 more authors.
Malaria Journal | Year: 2014

Background: Mass drug administration (MDA) of ivermectin to humans for control and elimination of filarial parasites can kill biting malaria vectors and lead to Plasmodium transmission reduction. This study examines the degree and duration of mosquitocidal effects resulting from single MDAs conducted in three different West African countries, and the subsequent reductions in parity and Plasmodium sporozoite rates. Methods: Indoor-resting, blood-fed and outdoor host-seeking Anopheles spp. were captured on days surrounding MDAs from 2008-2013 in Senegalese, Liberian and Burkinabé villages. Mortality was assessed on a portion of the indoor collection, and parity status was determined on host-seeking mosquitoes. The effect of MDA was then analysed against the time relative to the MDA, the distributed drugs and environmental variables. Results: Anopheles gambiae survivorship was reduced by 33.9% for one week following MDA and parity rates were significantly reduced for more than two weeks after the MDAs. Sporozoite rates were significantly reduced by >77% for two weeks following the MDAs in treatment villages despite occurring in the middle of intense transmission seasons. These observed effects were consistent across three different West African transmission dynamics. Conclusions: These data provide a comprehensive and crucial evidence base for the significant reduction in malaria transmission following single ivermectin MDAs across diverse field sites. Despite the limited duration of transmission reduction, these results support the hypothesis that repeated MDAs with optimal timing could help sustainably control malaria as well as filarial transmission.

PubMed | Liberian Institute for Biomedical Research, Centers for Disease Control and Prevention, Adjacent to Abbassa Fever Hospital, Us Naval Medical Research Unit No 3 and Naval Medical Research Unit No 6
Type: Journal Article | Journal: Journal of medical entomology | Year: 2016

Phlebotomine sand flies from three counties in Liberia were collected from January 2011 to July 2013. In total, 3,118 sand flies were collected: 18 species were identified, 13 of which represented new records for Liberia. An updated taxonomic checklist is provided with a brief note on sand fly biology, and the disease vector potential for species is discussed.

Kugelman J.R.,U.S. Army | Wiley M.R.,U.S. Army | Mate S.,U.S. Army | Ladner J.T.,U.S. Army | And 19 more authors.
Emerging Infectious Diseases | Year: 2015

To support Liberia’s response to the ongoing Ebola virus (EBOV) disease epidemic in Western Africa, we established in-country advanced genomic capabilities to monitor EBOV evolution. Twenty-five EBOV genomes were sequenced at the Liberian Institute for Biomedical Research, which provided an in-depth view of EBOV diversity in Liberia during September 2014–February 2015. These sequences were consistent with a single virus introduction to Liberia; however, shared ancestry with isolates from Mali indicated at least 1 additional instance of movement into or out of Liberia. The pace of change is generally consistent with previous estimates of mutation rate. We observed 23 nonsynonymous mutations and 1 nonsense mutation. Six of these changes are within known binding sites for sequence-based EBOV medical countermeasures; however, the diagnostic and therapeutic impact of EBOV evolution within Liberia appears to be low. © 2015, Centers for Disease Control and Prevention (CDC). All rights reserved.

Mate S.E.,U.S. Army | Kugelman J.R.,U.S. Army | Nyenswah T.G.,Ministry of Health and Social Welfare | Ladner J.T.,U.S. Army | And 37 more authors.
New England Journal of Medicine | Year: 2015

A suspected case of sexual transmission from a male survivor of Ebola virus disease (EVD) to his female partner (the patient in this report) occurred in Liberia in March 2015. Ebola virus (EBOV) genomes assembled from blood samples from the patient and a semen sample from the survivor were consistent with direct transmission. The genomes shared three substitutions that were absent from all other Western African EBOV sequences and that were distinct from the last documented transmission chain in Liberia before this case. Combined with epidemiologic data, the genomic analysis provides evidence of sexual transmission of EBOV and evidence of the persistence of infective EBOV in semen for 179 days or more after the onset of EVD. Copyright © 2015 Massachusetts Medical Society. All rights reserved.

PubMed | Liberian Institute for Biomedical Research, Centers for Disease Control and Prevention, World Health Organization, University of Edinburgh and 5 more.
Type: Journal Article | Journal: Science advances | Year: 2016

On 29 June 2015, Liberias respite from Ebola virus disease (EVD) was interrupted for the second time by a renewed outbreak (flare-up) of seven confirmed cases. We demonstrate that, similar to the March 2015 flare-up associated with sexual transmission, this new flare-up was a reemergence of a Liberian transmission chain originating from a persistently infected source rather than a reintroduction from a reservoir or a neighboring country with active transmission. Although distinct, Ebola virus (EBOV) genomes from both flare-ups exhibit significantly low genetic divergence, indicating a reduced rate of EBOV evolution during persistent infection. Using this rate of change as a signature, we identified two additional EVD clusters that possibly arose from persistently infected sources. These findings highlight the risk of EVD flare-ups even after an outbreak is declared over.

Grubaugh N.D.,Colorado State University | Sharma S.,Boston University | Krajacich B.J.,Colorado State University | Fakoli III L.S.,Liberian Institute for Biomedical Research | And 6 more authors.
PLoS Neglected Tropical Diseases | Year: 2015

Globally, regions at the highest risk for emerging infectious diseases are often the ones with the fewest resources. As a result, implementing sustainable infectious disease surveillance systems in these regions is challenging. The cost of these programs and difficulties associated with collecting, storing and transporting relevant samples have hindered them in the regions where they are most needed. Therefore, we tested the sensitivity and feasibility of a novel surveillance technique called xenosurveillance. This approach utilizes the host feeding preferences and behaviors of Anopheles gambiae, which are highly anthropophilic and rest indoors after feeding, to sample viruses in human beings. We hypothesized that mosquito bloodmeals could be used to detect vertebrate viral pathogens within realistic field collection timeframes and clinically relevant concentrations. To validate this approach, we examined variables influencing virus detection such as the duration between mosquito blood feeding and mosquito processing, the pathogen nucleic acid stability in the mosquito gut and the pathogen load present in the host’s blood at the time of bloodmeal ingestion using our laboratory model. Our findings revealed that viral nucleic acids, at clinically relevant concentrations, could be detected from engorged mosquitoes for up to 24 hours post feeding by qRT-PCR. Subsequently, we tested this approach in the field by examining blood from engorged mosquitoes from two field sites in Liberia. Using next-generation sequencing and PCR we were able to detect the genetic signatures of multiple viral pathogens including Epstein-Barr virus and canine distemper virus.Together, these data demonstrate the feasibility of xenosurveillance and in doing so validated a simple and non-invasive surveillance tool that could be used to complement current biosurveillance efforts.

PubMed | Liberian Institute for Biomedical Research, Institute Of Recherche En Science Of La Sante, United States Naval Medical Research Unit No 3 and Colorado State University
Type: | Journal: Virology | Year: 2016

Anopheles gambiae are a major vector of malaria in sub-Saharan Africa. Viruses that naturally infect these mosquitoes may impact their physiology and ability to transmit pathogens. We therefore used metagenomics sequencing to search for viruses in adult Anopheles mosquitoes collected from Liberia, Senegal, and Burkina Faso. We identified a number of virus and virus-like sequences from mosquito midgut contents, including 14 coding-complete genome segments and 26 partial sequences. The coding-complete sequences define new viruses in the order Mononegavirales, and the families Flaviviridae, and Totiviridae. The identification of a flavivirus infecting Anopheles mosquitoes broadens our understanding of the evolution and host range of this virus family. This study increases our understanding of virus diversity in general, begins to define the virome of a medically important vector in its natural setting, and lays groundwork for future studies examining the potential impact of these viruses on anopheles biology and disease transmission.

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