Immunological and hematological reference values for apparently healthy HIV-negative adults in Bahir Dar Town, Ethiopia

Background: Immunological and hematological reference values differ among different human beings with respect to sex, ethnicity, nutrition, altitude and health conditions. These could not be exceptional in the Ethiopian heterogeneous population. However, there are no nationally established reference values.Objective: The aim of the study was to determine reference values of immunological and hematological parameters for apparently healthy HIV-negative adults in Bahir Dar Town.Methods: A cross-sectional study was conducted from May to June, 2010 in Bahir Dar Town. Adults of both sexes above 18 years of age were recruited from the voluntary HIV counselling and testing centre in Felege Hiwot referral hospital. CD4+ and CD8+ T cells were enumerated using FACS count (Becton Dickinson) and hematological analyses were performed using Cell-DYN 1800 (Abbott Lab. USA).Results: A total of 405 adults consisting of 238 (58.7%) males and 167 (41.3%) females with the median age of 24(range 18 to 60) years were recruited. The median, mean (± SD) and 95% percentile ranges of immunological and hematological values were determined. The mean (±SD) values were: CD4+ T cells, 799 ± 218 (females) and 676 ± 235.6 (males); CD8+ T cells, 582 ±247 (females) and 659.5 ± 343 (males); CD4/CD8, 1.53±0.59 (females) and 1.19 ± 0.49 ( males); erythrocyte counts (1012/liter), 4.9±0.4 (female) and (5.4±0.5 male); hemoglobin (g/dl), 14.7±2 (females) and 16.5±1.8 (males); haematocrit (%), 44±4 (females) and 49±4.5 (males); platelets (109/litre), 277 ± 20 (both sex); absolute leukocyte (WBC) counts 6.6±3.6 x109/liter (both sexes); lymphocyte, 2.15±.59 x109/liter (both sexes); granulocytes (neutrophils), 3.7±1.6 x109/liter (both sexes).Conclusions: Absolute CD4+ T cell counts were lower than the reference value, which Ethiopia has adopted for HIV/AIDS therapy. Females had higher CD4+ T cell counts than males. Thus, considering these differences may be important in the process of using the national ART laboratory guideline for HIV/AIDS therapy. Establishing local reference values could have paramount importance for quality of health care in the clinical management of patients

Tapping height and season affect frankincense yield and wound recovery of Boswellia papyrifera trees

Boswellia papyrifera (Del.) Hochst is a threatened tropical dryland tree species. It is the source of frankincense, valued for its industrial, religious and traditional uses. This tree species is reported as under threat due to mortality from wound and inappropriate frankincense harvesting techniques. Two experiments were conducted simultaneously in the lowlands of North Western Gonder Zone, Ethiopia. The first experiment aimed to understand the effect of tapping height and tree size on wound recovery and frankincense yield and the second experiment dealt with understanding the effect of tapping schedule on survival and frankincense yield of different tree diameter sizes. Larger trees tapped at 1 m above the ground had the fastest wound recovery and highest frankincense yield. Higher tree survival was observed when tapping and resting schedule was alternated over years. However, mortality was higher when trees were tapped in consecutive years, without a resting year. The mean frankincense yield was 78 and 535 g/tree/year for small and large trees, respectively. Our result suggested that tree size, tapping height and resting time all have a significant effect on frankincense yield and wound recovery. Alternate year tapping of larger trees, with resting every three years, and avoiding tapping small trees are recommended for best wound recovery, survival, and to ensure sustainable production of frankincense

A comparative longitudinal study of bovine trypanosomiasis in tsetse-free and tsetse-infested zones of the Amhara region, northwest Ethiopia

A study was conducted to determine the incidence of trypanosome infections in cattle in tsetse-free and tsetse-infested zones of the Amhara Region of northwest Ethiopia. A total of six sentinel herds were established and the cattle observed during a period of 8 consecutive months. The prevalence of seropositive cattle was high in both the tsetse-free and tsetse-infested zones. The average monthly incidence of trypanosome infection, determined using molecular diagnostic tools, was 20.9% and 25.7% in the tsetse-free and the tsetse-infested zones, respectively. In the tsetse-free, Trypanosoma vivax was responsible for 90.9% of the cattle trypanosome infections. In the tsetse-infested zone, Trypanosoma congolense and T. vivax contributed almost equally to the trypanosome infections in cattle. Trypanosome infection, regardless of species, resulted in anaemia as evidenced by a significant decrease in the packed cell volume of the infected animal. The outcome of this longitudinal study suggests that control of trypanosomiasis in the Amhara Region cannot be achieved by tsetse control alone. Supplemental measures to include drug therapy and biting fly control are discussed

Seasonal prevalence of bovine trypanosomosis in a tsetse-infested zone and a tsetse-free zone of the Amhara Region, north-west Ethiopia

During a period of four consecutive years, trypanosomosis surveys were conducted in a tsetse-infested and tsetse-free area of the Amhara Region of north-west Ethiopia. In each study area randomly selected communal cattle were sampled and their blood was investigated using parasitological diagnostic methods. At the same time the population of biting flies was sampled. The monthly average prevalence of trypanosome infections in cattle did not differ significantly between study areas. In both study areas, the prevalence of trypanosome infections was highest during the long rainy season. Trypanosome infections were mainly due to Trypanosoma vivax and they significantly reduced the average packed cell volume and the body condition of the animals. The monthly prevalence of infection was correlated with the density of biting flies, such as Tabanidae and Stomoxys spp., in the preceding month suggesting an important role of mechanical transmission in the epidemiology of trypanosomosis in both areas

Mapping leaf chlorophyll content from Sentinel-2 and RapidEye data in spruce stands using the invertible forest reflectance model

Leaf chlorophyll plays an essential role in controlling photosynthesis, physiological activities and forest health. In this study, the performance of Sentinel-2 and RapidEye satellite data and the Invertible Forest Reflectance Model (INFORM) radiative transfer model (RTM) for retrieving and mapping of leaf chlorophyll content in the Norway spruce (Picea abies) stands of a temperate forest was evaluated. Biochemical properties of leaf samples as well as stand structural characteristics were collected in two subsequent field campaigns during July 2015 and 2016 in the Bavarian Forest National Park (BFNP), Germany, parallel with the timing of the RapidEye and Sentinel-2 images. Leaf chlorophyll was measured both destructively and nondestructively using wet chemical spectrophotometry analysis and a hand-held chlorophyll content meter. The INFORM was utilised in the forward mode to generate two lookup tables (LUTs) in the spectral band settings of RapidEye and Sentinel-2 data using information obtained from the field campaigns. Before generating the LUTs, the sensitivity of the model input parameters to the spectral data from RapidEye and Sentinel-2 were examined. The canopy reflectance of the studied plots were obtained from the satellite images and used as input for the inversion of LUTs. The coefficient of determination (R2), root mean square errors (RMSE), and the normalised root mean square errors (NRMSE), between the retrieved and measured leaf chlorophyll, were then used to examine the attained results from RapidEye and Sentinel-2 data, respectively. The use of multiple solutions and spectral subsets for the inversion process were further investigated to enhance the retrieval accuracy of foliar chlorophyll. The result of the sensitivity analysis demonstrated that the simulated canopy reflectance of Sentinel-2 is sensitive to the alternation of all INFORM input parameters, while the simulated canopy reflectance from RapidEye did not show sensitivity to leaf water content variations. In general, there was agreement between the simulated and measured reflectance spectra from RapidEye and Sentinel-2, particularly in the visible and red-edge regions. However, examining the average absolute error from the simulated and measured reflectance revealed a large discrepancy in spectral bands around the near-infrared shoulder. The relationship between retrieved and measured leaf chlorophyll content from the Sentinel-2 data had a higher coefficient of determination with a higher NRMSE (NRMSE = 0.36 μg/cm2, R2 = 0.45) compared to those obtained using the RapidEye data (NRMSE = 0.31 μg/cm2 and R2 = 0.39). Using the mean of the ten best solutions (retrieved chlorophyll) the retrieval error for both Sentinel-2 and RapidEye data decreased (NRMSE = 0.34, NRMSE = 0.26, respectively), as compared to only selecting the single best solution. When the Sentinel-2 red edge bands were used as the spectral subset, the retrieval error of leaf chlorophyll decreased indicating the importance of red edge, as well as properly located spectral bands, for leaf chlorophyll estimation. The chlorophyll maps produced by the inversion of the two LUTs effectively represented the variation of foliar chlorophyll in BFNP and confirmed our earlier findings on the observed stress pattern caused by insect infestation. Our findings emphasise the importance of multispectral satellites which benefits from red edge spectral bands such as Sentinel-2 as well as RapidEye for regional mapping of vegetation foliar properties, particularly, chlorophyll using RTMs such as INFORM

Aberrant use and poor quality of trypanocides: a risk for drug resistance in south western Ethiopia

Abstract Background Trypanocidal drugs have been used to control African animal trypanosomosis for several decades. In Ethiopia, these drugs are available from both authorized (legal) and unauthorized (illegal) sources but documentation on utilization practices and quality of circulating products is scanty. This study looked at the practices of trypanocidal drug utilization by farmers and the integrity of active ingredient in trypanocides sold in Gurage zone, south western Ethiopia. The surveys were based on a structured questionnaire and drug quality determination of commonly used brands originating from European and Asian companies and sold at both authorized and unauthorized markets. One hundred farmers were interviewed and 50 drug samples were collected in 2013 (Diminazene aceturate = 33 and Isometamidium chloride = 17; 25 from authorized and 25 from unauthorized sources). Samples were tested at the OIE-certified Veterinary Drug Control Laboratory (LACOMEV) in Dakar, Senegal, by using galenic standards and high performance liquid chromatography. Results Trypanosomosis was found to be a major threat according to all interviewed livestock keepers in the study area. Diminazene aceturate and isometamidium chloride were preferred by 79% and 21% of the respondents respectively, and 85% of them indicated that an animal receives more than six treatments per year. About 60% of these treatments were reported to be administered by untrained farmers. Trypanocidal drug sources included both unauthorized outlets (56%) and authorized government and private sources (44%). A wide availability and usage of substandard quality drugs was revealed. Twenty eight percent of trypanocidal drugs tested failed to comply with quality requirements. There was no significant difference in the frequency of non-compliance between diminazene-based and isometamidium chloride products (P = 0.87) irrespective of the marketing channel (official and unofficial). However, higher rates of non-compliant trypanocides were detected for drugs originating from Asia than from Europe (P = 0.029). Conclusion The findings revealed the presence of risk factors for the development of drug resistance, i.e. wide distribution of poor quality drugs as well as substandard administration practices. Therefore, it is strongly recommended to enforce regulatory measures for quality control of veterinary drugs, to expand and strengthen veterinary services and to undertake trypanocidal drug efficacy studies of wider coverage