12 research outputs found
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Isolation of Angola-like Marburg virus from Egyptian rousette bats from West Africa.
Marburg virus (MARV) causes sporadic outbreaks of severe Marburg virus disease (MVD). Most MVD outbreaks originated in East Africa and field studies in East Africa, South Africa, Zambia, and Gabon identified the Egyptian rousette bat (ERB; Rousettus aegyptiacus) as a natural reservoir. However, the largest recorded MVD outbreak with the highest case-fatality ratio happened in 2005 in Angola, where direct spillover from bats was not shown. Here, collaborative studies by the Centers for Disease Control and Prevention, Njala University, University of California, Davis USAID-PREDICT, and the University of Makeni identify MARV circulating in ERBs in Sierra Leone. PCR, antibody and virus isolation data from 1755 bats of 42 species shows active MARV infection in approximately 2.5% of ERBs. Phylogenetic analysis identifies MARVs that are similar to the Angola strain. These results provide evidence of MARV circulation in West Africa and demonstrate the value of pathogen surveillance to identify previously undetected threats
South African Ebola diagnostic response in Sierra Leone : a modular high biosafety field laboratory
BACKGROUND : In August 2014, the National Institute for Communicable Diseases (NICD) in South Africa
established a modular high-biosafety field Ebola diagnostic laboratory (SA FEDL) near
Freetown, Sierra Leone in response to the rapidly increasing number of Ebola virus disease
(EVD) cases.
METHODS AND FINDINGS : The SA FEDL operated in the Western Area of Sierra Leone, which remained a ÂŞhotspotÂş of
the EVD epidemic for months. The FEDL was the only diagnostic capacity available to
respond to the overwhelming demand for rapid EVD laboratory diagnosis for several weeks
in the initial stages of the EVD crisis in the capital of Sierra Leone. Furthermore, the NICD
set out to establish local capacity amongst Sierra Leonean nationals in all aspects of the
FEDL functions from the outset. This led to the successful hand-over of the FEDL to the
Sierra Leone Ministry of Health and Sanitation in March 2015. Between 25 August 2014 and
22 June 2016, the laboratory tested 11,250 specimens mostly from the Western Urban and
Western Rural regions of Sierra Leone, of which 2,379 (21.14%) tested positive for Ebola
virus RNA.
CONCLUSIONS : he bio-safety standards and the portability of the SA FEDL, offered a cost-effective and practical alternative for the rapid deployment of a field-operated high biocontainment facility. The SA FEDL teams demonstrated that it is highly beneficial to train the national staff in the course of formidable disease outbreak and accomplished their full integration into all operational and diagnostic aspects of the laboratory. This initiative contributed to the international efforts in bringing the EVD outbreak under control in Sierra Leone, as well as capacitating local African scientists and technologists to respond to diagnostic needs that might be required in future outbreaks of highly contagious pathogens.S1 Video. ÂŞHotÂş processing of Ebola clinical specimens, PPE and decontamination procedures
in South African modular, field-operated biocontainment facility in Sierra Leone.Janusz T Paweska was supported by
funding from National Research Foundation and
the Global Disease Detection Programmehttp://www.plosntds.orgam2017Microbiology and Plant Patholog
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Improvement in the Surveillance System for Livestock Diseases and Antimicrobial Use Following Operational Research Studies in Sierra Leone January–March 2023
In Sierra Leone, two operational research (OR) studies in 2019 and 2021 showed deficiencies in the data being captured by the Integrated Animal Disease Surveillance and Reporting (IADSR) system. This third OR study was conducted in 2023 to assess whether the second OR study’s results and recommendations were disseminated with the key stakeholders, the uptake of the recommendations, improvements in data capture in the IADSR system, and to describe the data on livestock disease and antimicrobial use. In 2022, on seven occasions, the authors of the second OR study disseminated the study’s findings. Of the four recommendations, the one on improving laboratory infrastructure for confirmation of animal disease was not implemented. The district animal health weekly surveillance reports received through the IADSR system were sustained at 88% between the second (2021) and third (2023) studies. In both studies, the proportion of sick animals receiving antibiotics (25%) remained the same, but the use of “critically important antimicrobials for veterinary use” declined from 77% (in 2021) to 69% (in 2023). The IADSR system has improved considerably in providing information on animal health and antibiotic use, and sequential OR studies have played a key role in its improvement
Number of specimens from EVD suspected cases in Sierra Leone tested daily (total blood and buccal swabs) by SA FEDL during the first weeks of operation, 25 August—30 Sept 2014.
<p>Column = Number of specimens tested daily; Dotted line = Trend line of a number of specimens tested; Solid line = Maximum testing capacity of 58 specimens per day.</p
Layout of the SA FEDL in Freetown-Lakka, Sierra Leone with emergency generator and wiring to allow for rapid switch to generator mode in case of power failure.
<p>(<b>A</b>) Biocontainment negative pressure chamber (IsoArk), (<b>B</b>) Room housing biocontainment negative pressure chamber, (<b>C</b>) Donning room, (<b>D</b>) Doffing room, (<b>E</b>) Laboratory airlock area, (<b>F</b>) PCR amplification room, (<b>G</b>) PCR master mix room, (<b>H</b>) Specimens and reagents storage area, (<b>I</b>) RNA extraction room, (<b>J</b>) Facility entrance, (<b>K</b>) Toilet, (<b>L</b>) Office 1, (<b>M</b>) Office 2, (<b>N</b>) Office 3. Petrol generator (5.5 kVa) placement indicated by the red rectangle, distribution of extension cords are indicated with red lines, and emergency connection points by red stars.</p
Recommended from our members
Isolation of Angola-like Marburg virus from Egyptian rousette bats from West Africa.
Marburg virus (MARV) causes sporadic outbreaks of severe Marburg virus disease (MVD). Most MVD outbreaks originated in East Africa and field studies in East Africa, South Africa, Zambia, and Gabon identified the Egyptian rousette bat (ERB; Rousettus aegyptiacus) as a natural reservoir. However, the largest recorded MVD outbreak with the highest case-fatality ratio happened in 2005 in Angola, where direct spillover from bats was not shown. Here, collaborative studies by the Centers for Disease Control and Prevention, Njala University, University of California, Davis USAID-PREDICT, and the University of Makeni identify MARV circulating in ERBs in Sierra Leone. PCR, antibody and virus isolation data from 1755 bats of 42 species shows active MARV infection in approximately 2.5% of ERBs. Phylogenetic analysis identifies MARVs that are similar to the Angola strain. These results provide evidence of MARV circulation in West Africa and demonstrate the value of pathogen surveillance to identify previously undetected threats
Ebola virus polymerase gene TaqMan real-time RT-PCR results in blood specimens.
<p>Ebola virus polymerase gene TaqMan real-time RT-PCR results in blood specimens.</p
Operators dressed in BSL3 PPE (scrubs, Tyvek suits, surgical gown, double pair surgical gloves, gumboots, overshoes and PAPR with full face hood) entering the IsoArk main chamber through the airlock.
<p>Operators dressed in BSL3 PPE (scrubs, Tyvek suits, surgical gown, double pair surgical gloves, gumboots, overshoes and PAPR with full face hood) entering the IsoArk main chamber through the airlock.</p
South African Ebola diagnostic response in Sierra Leone: A modular high biosafety field laboratory - Fig 3
<p>(<b>A</b>) Operators dressed in BSL3 PPE processing clinical specimens from EVD suspected cases in a glovebox located within the IsoArk biocontainment negative pressure chamber, (<b>B</b>) Blood tubes in centrifuge adapters with safety caps passed into the main chamber of the glovebox for “hot” inactivation and aliquoting for long-term storage.</p