Adverse Drug Reaction Monitoring in Ethiopia: Analysis of case reports, 2002-2007

Background: Ensuring the health and safety of the public from adverse reaction of drugs is paramount. Adverse Drug Reactions Monitoring (ADRM) is a system that is put in place to ensure the health and safety of the public from adverse reactions of drugs. It heavily relies on health professionals (HPs) reporting of adverse events of drugs to drug regulators, in Ethiopia to the Drug Administration and Control Authority (DACA). The processed information, based on reported cases, is used to improve evidence based practice and underpins decisions to mitigate drug safety issues by drug regulators. However, the effectiveness of the ongoing ADRM system in Ethiopia in terms of its detection has never been evaluated.Objective: To explore the magnitude of ADRM and suggest some practical improvement in Ethiopia.Methods: The study analyzed the number of adverse drug reaction case reports received by DACA in a period of six years (2002 – 2007GC). All cases reported over the study period were included for analysis. Descriptive analysis was carried out to estimate the prevalence of adverse drug reactions and to assess their trend over the study period. To assess the strengths and weakness of the ongoing national ADRM, cases were analyzed by their location, time of occurrence, type of the health professional who made the case reports, drugs implicated, clinical manifestations and age of subjects affected.Results: A total of 249 ADR cases were reported between 2002 and 2007. An average of 0.5 ADR cases per million populations were reported annually. The majority (36%) of all the cases were for 31 to 40 years of age. Cases were reported mainly (63%) from health facilities in the capital city. Physicians made 76% of all cases reported. Antiretroviral drugs were implicated in 70% of the cases reported. The most widely adverse events reported were dermatological disorders.Conclusions: The level of ADR case reporting is very low showing the need to address major constraints of ongoing ADR monitoring. Thus, comprehensive measures aimed at improving under-reporting and effectiveness of ADRM should be instituted. [Ethiop. J. Health Dev. 2011;25(2):168-173

Electroencephalographic patterns in Ethiopian patients with epilepsy: A retrospective review

Background: Epilepsy is a common problem throughout sub-Saharan Africa, including Ethiopia. Electroencephalography (EEG) is useful for the diagnosis and proper treatment of this condition. However, the literature is scanty of reports describing EEG patterns in Ethiopian patients with epilepsy. This study attempts to bridge that gap and provide a baseline for further research into the etiological basis of specific epileptiform abnormalities.Objective: To review EEG patterns in Ethiopian patients with epilepsy.Methods: We retrospectively reviewed EEG records of patients with epilepsy presenting to a specialized referral hospital (Addis Ababa University Tikur Anbessa Teaching Hospital) and a private clinic (Yehuleshet Higher Clinic) between September 2008 and August 2010.Results: Two hundred and fifty one patients with mean age of 26 years (SD 14.8) and 1.2:1 male: female ratio was included in the study. One hundred and forty nine patients (59.4%) harbored EEG abnormalities. The majority of these abnormalities 61.1% were epileptiform discharges; the remainder 38.9% being nonspecific patterns. The most common epileptiform discharges were focal, with or without secondary generalization in 63.7%. These focal discharges originated from the left cerebral hemisphere in 43.1% cases and the right in 39.7%; 17.2% were bilateral. Multifocal cerebral and temporal lobe discharges accounted for 43.1% and 39.7% of all focal discharges, respectively.Conclusion: The most common EEG abnormalities in Ethiopian patients with epilepsy are focal interictal epileptiform discharges, typically originating from multifocal cerebral loci and the temporal lobe, without hemispheric lateralization. It provides a foundation for prospective studies to address the etiological basis of focal abnormalities

A new method to measure Bowen ratios using high-resolution vertical dry and wet bulb temperature profiles

The Bowen ratio surface energy balance method is a relatively simple method to determine the latent heat flux and the actual land surface evaporation. The Bowen ratio method is based on the measurement of air temperature and vapour pressure gradients. If these measurements are performed at only two heights, correctness of data becomes critical. In this paper we present the concept of a new measurement method to estimate the Bowen ratio based on vertical dry and wet bulb temperature profiles with high spatial resolution. A short field experiment with distributed temperature sensing (DTS) in a fibre optic cable with 13 measurement points in the vertical was undertaken. A dry and a wetted section of a fibre optic cable were suspended on a 6 m high tower installed over a sugar beet trial plot near Pietermaritzburg (South Africa). Using the DTS cable as a psychrometer, a near continuous observation of vapour pressure and air temperature at 0.20 m intervals was established. These data allowed the computation of the Bowen ratio with a high spatial and temporal precision. The daytime latent and sensible heat fluxes were estimated by combining the Bowen ratio values from the DTS-based system with independent measurements of net radiation and soil heat flux. The sensible heat flux, which is the relevant term to evaluate, derived from the DTS-based Bowen ratio (BR-DTS) was compared with that derived from co-located eddy covariance (<i>R</i>² = 0.91), surface layer scintillometer (<i>R</i>² = 0.81) and surface renewal (<i>R</i>² = 0.86) systems. By using multiple measurement points instead of two, more confidence in the derived Bowen ratio values is obtained

Extending periodic eddy covariance latent heat fluxes through tree sap-flow measurements to estimate long-term total evaporation in a peat swamp forest

A combination of measurement and modelling was used to find a pragmatic solution to estimate the annual total evaporation from the rare and indigenous Nkazana Peat Swamp Forest (PSF) on the east coast of Southern Africa to improve the water balance estimates within the area. Actual total evaporation (ETa) was measured during three window periods (between 7 and 9 days each) using an eddy covariance (EC) system on a telescopic mast above the forest canopy. Sap flows of an understory tree and an emergent tree were measured using a low-maintenance heat pulse velocity system for an entire hydrological year (October 2009 to September 2010). An empirical model was derived, describing the relationship between ETa from the Nkazana PSF and sap-flow measurements. These overlapped during two of the window periods (R2 = 0.92 and 0.90), providing hourly estimates of ETa from the Nkazana PSF for a year, totalling 1125 mm (while rainfall was 650 mm). In building the empirical model, it was found that to include the understory tree sap flow provided no benefit to the model performance. In addition, the relationship between the emergent tree sap flow with ETa between the two field campaigns was consistent and could be represented by a single empirical model (R2 = 0.90; RMSE = 0.08 mm h−1). During the window periods of EC measurement, no single meteorological variable was found to describe the Nkazana PSF ETa satisfactorily. However, in terms of evaporation models, the hourly FAO Penman–Monteith reference evaporation (ETo) best described ETa during the August 2009 (R2 = 0.75), November 2009 (R2 = 0.85) and March 2010 (R2 = 0.76) field campaigns, compared to the Priestley–Taylor potential evaporation (ETp) model (R2 = 0.54, 0.74 and 0.62 during the respective field campaigns). From the extended record of ETa (derived in this study from sap flow) and ETo, a monthly crop factor (Kc) was derived for the Nkazana PSF, providing a method of estimating long-term swamp forest water-use from meteorological data. The monthly Kc indicated two distinct periods. From February to May, it was between 1.2 and 1.4 compared with June to January, when the crop factor was 0.8 to 1.0. The derived monthly Kc values were verified as accurate (to one significant digit) using historical data measured at the same site, also using EC, from a previous study. The measurements provided insights into the microclimate within a subtropical peat swamp forest and the contrasting sap flow of emergent and understory trees. They showed that expensive, high-maintenance equipment can be used during manageable window periods in conjunction with low-maintenance systems, dedicated to individual trees, to derive a model to estimate long-term ETa over remote heterogeneous forests. In addition, the contrast in annual ETa and rainfall emphasised the reliance of the Nkazana PSF on groundwater

Hypertension treatment practices and its determinants among ambulatory patients:Retrospective cohort study in Ethiopia

Objectives We examined determinants of achieving blood pressure control in patients with hypertension and of treatment intensification in patients with uncontrolled blood pressure (BP).Design A retrospective cohort study in six public hospitals, Ethiopia.Participants Adult ambulatory patients with hypertension and with at least one previously prescribed antihypertensive medication in the study hospital.Outcome Controlled BP (&lt;140/90 mm Hg) and treatment intensification of patients with uncontrolled BP.Results The study population comprised 897 patients. Their mean age was 57 (SD 14) years, 63% were females, and 35% had one or more cardiometabolic comorbidities mainly diabetes mellitus. BP was controlled in 37% of patients. Treatment was intensified for 23% patients with uncontrolled BP. In multivariable (logistic regression) analysis, determinants positively associated with controlled BP were treatment at general hospitals (OR 1.89, 95% CI 1.26 to 2.83) compared with specialised hospitals and longer treatment duration (OR 1.04, 95% CI 1.01 to 1.06). Negatively associated determinants were previously uncontrolled BP (OR 0.30, 95% CI 0.21 to 0.43), treatment regimens with diuretics (OR 0.68, 95% CI 0.50 to 0.94) and age (OR 0.99, 95% CI 0.98 to 1.00). The only significant-positive-determinant for treatment intensification was duration of therapy (OR 1.05, 95% CI 1.02 to 1.09).Conclusions The level of controlled BP and treatment intensification practice in this study was low. The findings suggest the need for in-depth understanding and interventions of the identified determinants such as uncontrolled BP on consecutive visits, older age and type of hospital.</p

Use of portable FTIR spectrometers for detecting greenhouse gas emissions of the megacity Berlin - Part 1: Instrumental line shape characterisation and calibration of a quintuple of spectrometers

Several low resolution spectrometers were used to investigate the CO2 and CH4 emissions of the megacity Berlin. Before and after the campaign the instruments were tested side-by-side. An excellent level of agreement and stability was found between the different spectrometers: the drifts in XCO2 and XCH4 are within 0.005 and 0.035%, respectively. The instrumental line shape characteristics of all spectrometers were found to be close to nominal. Cross-calibration factors for XCH4 and XCO2 were established for each spectrometer. An empirical airmass correction factor has been applied. As a last calibration step, using a co-located TCCON spectrometer as a reference, a common factor has been derived for the low-resolution campaign spectrometers, which ensures that the records are compatible to the WMO in-situ scale. Finally as a first result of the Berlin campaign we show the excellent agreement of ground pressure values obtained from total column measurements and in situ records

Calibration and instrumental line shape characterization of a set of portable FTIR spectrometers for detecting greenhouse gas emissions

A comprehensive calibration procedure for mobile, low-resolution, solar-absorption FTIR spectrometers, used for greenhouse gases observations, is developed. These instruments commend themselves for campaign use and deployment at remote sites. The instrumental line shape (ILS) of each spectrometer has been thoroughly characterized by analyzing the shape of H2O signatures in open path spectra. A setup for the external source is suggested and the invariance of derived ILS parameters with regard to chosen path length is demonstrated. The instrumental line shape characteristics of all spectrometers were found to be close to nominal. Side-by-side solar observations before and after a campaign, which involved shipping of all spectrometers to a selected target site and back, are applied for verifying the temporal invariability of instrumental characteristics and for deriving intercalibration factors for XCO2 and XCH4, which take into account residual differences of instrumental characteristics. An excellent level of agreement and stability was found between the different spectrometers: the uncorrected biases in XCO2 and XCH4 are smaller than 0.01 and 0.15 %, respectively, and the drifts are smaller than 0.005 and 0.035 %. As an additional sensitive demonstration of the instrumental performance we show the excellent agreement of ground pressure values obtained from the total column measurements of O2 and barometric records. We find a calibration factor of 0.9700 for the spectroscopic measurements in comparison to the barometric records and a very small scatter between the individual spectrometers (0.02 %). As a final calibration step, using a co-located TCCON (Total Carbon Column Observation Network) spectrometer as a reference, a common scaling factor has been derived for the XCO2 and XCH4 products, which ensures that the records are traceable to the WMO in situ scale. © Author(s) 2015

Use of portable FTIR spectrometers for detecting greenhouse gas emissions of the megacity Berlin - Part 2: Observed time series of XCO₂ and XCH₄

Five portable Bruker EM27/SUN FTIR spectrometers have been used for the accurate and precise observation of column averaged abundances of CO2 and CH4 around the megacity Berlin. In the first part of this work (Frey et al., 2015) we have presented the various measures that were undertaken to ensure that the observations are consistent between sites, accurate and precise. Here, we present the recorded time series of XCH4 and XCO2 and demonstrate that the CO2 emissions of Berlin can be clearly identified in the observations. A simple dispersion model is applied which indicates a total strength of the Berlin source of about 0.8 t CO2 s-1. In the Supplement of this work, we provide the measured dataset and auxiliary data. We hope that the model community will exploit this unique dataset for state-of-the art inversion studies of CO2 and CH4 sources in the Berlin area

Seasonal variations of transpiration efficiency coefficient of irrigated wheat

Global diminishing water resources, especially due to climate change have serious impacts on evaporation (E) from the soil surface, transpiration (T) from plants (crops) and grain yield, which relates to water use efficiency of different crops. A study was conducted at Kenilworth over two wheat cropping seasons (2007 and 2008) with the objectives of: (i) evaluating the effect of soils and seasons on T, E and yield, and (ii) relating these parameters to transpiration efficiency coefficient. The treatments included two soil types and two soil surface treatments (bare and mulched), which were all replicated four times. Weekly irrigation was done using a surface drip system while maintaining the water table at a constant depth. Soil water content was monitored using a neutron probe. Neither soils nor seasons were found to significantly influence the partitioning of evapotranspiration (ET), and T varied from 74 to 76% of ET while E varied between 24 and 26%. Surface treatments caused significant differences in grain yield in both seasons. Reducing evaporative loss improves the water productivity of wheat, which has an important implication in dryland farming

Application of portable FTIR spectrometers for detecting greenhouse gas emissions of the major city Berlin

Five portable Bruker EM27/SUN FTIR (Fourier transform infrared) spectrometers have been used for the accurate and precise observation of column-averaged abundances of CO2 and CH4 around the major city Berlin. In the work by Frey et al. (2015), a calibration procedure is developed and applied to the set of spectrometers used for the Berlin campaign. Here, we describe the observational setup of the campaign and aspects of the data analysis, and we present the recorded time series of XCH4 and XCO2. We demonstrate that the CO2 emissions of Berlin can be clearly identified in the observations. A simple dispersion model is applied which indicates a total strength of the Berlin source of about 0.8 t CO2 s-1. In the Supplement of this work, we provide the measured data set and auxiliary data. We hope that the model community will exploit this unique data set for state-of-the art inversion studies of CO2 and CH4 sources in the Berlin area. © Author(s) 2015