52 Years of Lassa Fever Outbreaks in Nigeria, 1969–2020: An Epidemiologic Analysis of the Temporal and Spatial Trends

ABSTRACT. The year 2020 made 52 years since the first report of Lassa fever (LF) outbreaks from Nigeria, but what progress has been made in its control? We sought to answer this through an epidemiologic analysis of the temporal and spatial trends of the outbreaks from 1969 to 2020. The analysis showed an overall strengthening of the outbreaks, hallmarked by the change from irregular to regular annual and from limited local to nationwide outbreaks, while there was a sharp contrast between the upward trend in case numbers and downward trend in case fatality. Pending the availability of effective vaccines, greater effort is required to reverse the upward trend in case numbers and sustain the downward trend in case fatality. We discuss the factors associated with the observed trends as well as the prerequisites for further improvements.

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Temporal and spatial trends of chloride and sodium in groundwater in New Hampshire, 1960–2011

Open-File Report ◽

10.3133/ofr20121236 ◽

2012 ◽

Cited By ~ 1

Author(s):

Laura Medalie

Keyword(s):

New Hampshire ◽

Spatial Trends ◽

Temporal And Spatial ◽

Temporal And Spatial Trends

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Temporal trends of halogenated flame retardants in the atmosphere of the Canadian Great Lakes Basin (2005–2014)

Environmental Science Processes & Impacts ◽

10.1039/c7em00549k ◽

2018 ◽

Vol 20 (3) ◽

pp. 469-479 ◽

Cited By ~ 11

Author(s):

Chubashini Shunthirasingham ◽

Nick Alexandrou ◽

Kenneth A. Brice ◽

Helena Dryfhout-Clark ◽

Ky Su ◽

...

Keyword(s):

Great Lakes ◽

Flame Retardants ◽

Temporal Trends ◽

Great Lakes Basin ◽

Spatial Trends ◽

Temporal And Spatial ◽

Temporal And Spatial Trends ◽

Halogenated Flame Retardants ◽

Air Concentrations

Temporal and spatial trends of total air concentrations (gas + particle) of halogenated flame retardants at the Canadian Great Lakes Basin were assessed (2005–2014).

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Temporal and spatial trends in riverine suspended sediment and associated polycyclic aromatic compounds (PAC) within the Athabasca oil sands region

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.01.105 ◽

2018 ◽

Vol 626 ◽

pp. 1382-1393 ◽

Cited By ~ 9

Author(s):

Ian G. Droppo ◽

Peter di Cenzo ◽

Jessica Power ◽

Christina Jaskot ◽

Patricia A. Chambers ◽

...

Keyword(s):

Suspended Sediment ◽

Aromatic Compounds ◽

Oil Sands ◽

Polycyclic Aromatic Compounds ◽

Athabasca Oil Sands ◽

Athabasca Oil Sands Region ◽

Spatial Trends ◽

Polycyclic Aromatic ◽

Temporal And Spatial ◽

Temporal And Spatial Trends

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Temporal and spatial trends in insecticide resistance in Anopheles arabiensis in Sudan: outcomes from an evaluation of implications of insecticide resistance for malaria vector control

Parasites & Vectors ◽

10.1186/s13071-018-2732-9 ◽

2018 ◽

Vol 11 (1) ◽

Cited By ~ 6

Author(s):

Bashir Adam Ismail ◽

Hmooda Toto Kafy ◽

Jihad Eltaher Sulieman ◽

Krishanthi Subramaniam ◽

Brent Thomas ◽

...

Keyword(s):

Insecticide Resistance ◽

Vector Control ◽

Malaria Vector ◽

Anopheles Arabiensis ◽

Malaria Vector Control ◽

Spatial Trends ◽

Temporal And Spatial ◽

Temporal And Spatial Trends

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Distribution of mercury and methylmercury in the sediments of a lowland river system

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2004.1408 ◽

2005 ◽

Vol 461 (2057) ◽

pp. 1335-1355 ◽

Cited By ~ 6

Author(s):

Jason W Birkett ◽

John N Lester

Keyword(s):

Point Source ◽

Total Mercury ◽

Sewage Treatment ◽

River System ◽

Initial Increase ◽

Surficial Sediments ◽

Spatial Trends ◽

The Mean ◽

Temporal And Spatial ◽

Temporal And Spatial Trends

Concentrations of total mercury (T-Hg) and methylmercury (MeHg) were determined in surficial sediments from the River Yare, Norfolk, UK over the period 1986–1998, to assess the temporal and spatial trends of contamination arising from a historical point source discharge. The results demonstrate that the spatial distribution pattern follows that of a distinct pollution plume in the sediments with an initial increase 2–3 km downstream from the point source discharge at Whitlingham sewage treatment works (STW) outfall. Temporally, this pollution plume remains evident, although there has been an overall decline in the mean T-Hg concentrations from 5.4 in 1986 to 1.8 mg kg −1 in 1998. The major factor for this improvement has been the reduction in discharge of metals from the STW, together with burial by a fresh overlay of uncontaminated sediments. MeHg concentrations also exhibited a dispersed pollution plume. Mean concentrations of MeHg fluctuated during the study period between 3.3 and 8.5 μg kg −1 . There has been no concomitant decline in MeHg concentrations over this period. MeHg was found to constitute less than 1% of T-Hg concentrations in the sediments. The weak correlations observed between T-Hg and MeHg concentrations indicate external environmental factors have a significant influence on determining MeHg concentrations in the sedimentary compartment.

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