Growth Response of Dekoko (Pisum sativum var. abyssinicum) to Nitrogen and Phosphorus Fertilizers at Enderta Woreda, Northern Ethiopia

A field experiment was conducted to investigate the influence of different nitrogen and phosphorus fertilizer on dekoko (Pisum sativum var.abyssinicum) growth parameters. The Experiment was conducted in 2013/14 at the experimental field of Mekelle University Endayesus Campus, Northern Ethiopia. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications. It comprises four treatments viz. Control (with no fertilizer), 30 kg N ha-1+30 kg P2O5 ha-1, 60 kg N ha-1+60 kg P2O5 ha-1 and 90 kg N ha-1+90 kg P2O5 ha-1. Data on growth parameters like: leaf area, number of branches per plant and plant height were measured and collected. Results show that, the effect of N + P2O5 on in all the growth parameters of dekoko was significant at 5% Probability level. The highest leaf area index (2.82m2m-2) among N+P2O5 levels, was recorded from 90 Kg/ha N +90 Kg/ha P2O5. Similarly highest Plant height (50.83Cm) was found from the treatment combination of 90 Kg/ha N +90 Kg/ha P2O5. Maximum number of basal branches (2.73) was obtained from the highest treatment combination. Keywords: Growth attributes, nitrogen, phosphorus, Pisum sativum var. abyssinicu

A Review on: Performance Evaluation of Crop Simulation Model (APSIM) in Prediction Crop Growth, Development and Yield in Semi Arid Tropics

Crop Simulation Models (CSM) are computerized representations of crop growth, development and yield, simulated through mathematical equations as functions of soil conditions, weather and management practices. The Crop simulation models like agricultural production system simulator can save time and resources better prediction accuracy is the most important point that should be considered in decision making process. Most models are not tested or poorly tested, and hence their usefulness in decision making process is unproven. Therefore, this paper Reviews the performance of the APSIM CSM simulation accuracy with respect to the simulation of the growth, development and yield of the selected crops. APSIM model is reliable crop simulation model in predicting development, Growth and yield of different crops in the semi arid tropics. Keywords: APSIM, CSM, Yield, Semi arid tropic

Response of Chickpea (Cicier Arietinium L.) to Rhizobium Inoculation and Blended fertilizer Rates in Laelay Maichew, Central Zone of Tigray, Northern Ethiopia

Low soil fertility is one of the limiting factor for low productivity of chickpea in Central zone of Tigray, Northern Ethiopia. Field experiment was therefore, conducted for two consecutive years (2016-2017) in Laelay Maichew (Hatsebo) to evaluate the effects of NPSB fertilizer and rhizobium inoculation on yield and yield components of chickpea. The experiment was laid out in a split plot design with three replications. Rhizobium inoculation was assigned to the main plots with two levels (with and without rhizobium inoculation) and NPSB fertilizer rates in sub plot with seven levels (0, 25, 50, 75, 100, 125 and 150 kg ha-1 NPSB). Data collected were subjected to the analysis of variance (ANOVA) using SAS software. A combined analysis of variance showed a significant interaction effects of NPSB and rhizobium inoculation on chickpea yield and yield components (P<0.05) across the two years. The highest number of pods per plant (76.8) was recorded from 125 kg ha‑1 NPSB along with rhizobium inoculation and the highest grain yields were obtained from 150 kg ha‑1 (3609 kg ha‑1) and 125 kg ha‑1 NPSB (3514 kg ha‑1) along with rhizobium inoculation. Maximum marginal rate of return (4106.68%) was gained when chickpea was inoculated with rhizobium and 125 kg ha-1 NPSB application. From the present results it could be concluded that 125 kg ha-1 NPSB along with rhizobium inoculation seeds would be the optimum treatment combination for enhancing chickpea yield and better profitability in soils with low level of available plant nutrients (NPSB)

Effects of Nitrogen and Phosphorus Fertilizers on Dekoko (Pisum sativum var.abyssinicum A. Braun) Yield and Yield related traits

A field experiment was conducted to investigate the influence of different nitrogen and phosphorus fertilizer levels on dekoko (Pisum sativum var.abyssinicum A.Braun) yield and yield components as well as to establish the net benefit at each fertilizer levels. The Experiment was conducted at Mekelle university Endayesus campus in Tigray, Northern Ethiopia in 2013/14. It was laid out in a randomized complete block design with four blocks. It comprises four nitrogen (N) and phosphorus (P) fertilizer treatments combinations. Viz., Control (N0P0), 30 kg N ha-1 and 30 kg P2O5 ha-1 (N1P1), 60 kg N ha-1 and 60 kg P2O5 ha-1(N2P2) and 90 kg N ha-1 and 90 kg P2O5 ha-1 (N3P3).The highest yield (2114.55 kg ha-1), biomass (5312.5 kg ha-1), nitrogen and phosphorus use efficiency (4.58 kg kg-¹) and maximum marginal rate of return (499%) were obtained when treated with N2P2. From the present results it could be concluded that 60 kg N ha-1 and 60 kg P2O5 ha-1 fertilizer rate would be optimum treatment combination for enhancing dekoko yield and yield components, NP use efficiency, and economic profitability. Therefore, application of 60 kg N ha-1 and 60 kg P2O5 ha-1 is recommended for better productivity and profitability of dekoko at low soil fertility levels

Prognostic Value of C-Reactive Protein in SARS-CoV-2 Infection: A Simplified Biomarker of COVID-19 Severity in Northern Ethiopia

Purpose To evaluate the role of C-reactive protein (CRP) in predicting severe COVID-19 patients. Methods A prospective observational cohort study was conducted from July 15 to October 28, 2020, at Kuyha COVID-19 isolation and treatment center hospital, Mekelle City, Northern Ethiopia. A total of 670 blood samples were collected serially. SARS-CoV-2 infection was confirmed by RT-PCR from nasopharyngeal swabs and CRP concentration was determined using Cobas Integra 400 Plus (Roche). Data were analyzed using STATA version 14. P-value < 0.05 was considered statistically significant. Results Overall, COVID-19 patients had significantly elevated CRP at baseline when compared to PCR-negative controls [median 11.1 (IQR: 2.0– 127.8) mg/L vs 0.9 (IQR: 0.5– 1.9) mg/L; p=0.0004)]. Those with severe COVID-19 clinical presentation had significantly higher median CRP levels compared to those with non-severe cases [166.1 (IQR: 48.6– 332.5) mg/L vs 2.4 (IQR: 1.2– 7.6) mg/L; p< 0.00001)]. Moreover, COVID-19 patients exhibited higher median CRP levels at baseline [58 (IQR: 2.0– 127.8) mg/L] that decreased significantly to 2.4 (IQR: 1.4– 3.9) mg/L after 40 days after symptom onset (p< 0.0001). Performance of CRP levels determined using ROC analysis distinguished severe from non-severe COVID-19 patients, with an AUC value of 0.83 (95% CI: 0.73– 0.91; p=0.001; 77.4% sensitivity and 89.4% specificity). In multivariable analysis, CRP levels above 30 mg/L were significantly associated with an increased risk of developing severe COVID-19 for those who have higher ages and comorbidities (ARR 3.99, 95% CI: 1.35– 11.82; p=0.013). Conclusion CRP was found to be an independent determinant factor for severe COVID-19 patients. Therefore, CRP levels in COVID-19 patients in African settings may provide a simple, prompt, and inexpensive assessment of the severity status at baseline and monitoring of treatment outcomes

Longitudinal profile of antibody response to SARS-CoV-2 in patients with COVID-19 in a setting from Sub-Saharan Africa: A prospective longitudinal study.

BACKGROUND Serological testing for SARS-CoV-2 plays an important role for epidemiological studies, in aiding the diagnosis of COVID-19, and assess vaccine responses. Little is known on dynamics of SARS-CoV-2 serology in African settings. Here, we aimed to characterize the longitudinal antibody response profile to SARS-CoV-2 in Ethiopia. METHODS In this prospective study, a total of 102 PCR-confirmed COVID-19 patients were enrolled. We obtained 802 plasma samples collected serially. SARS-CoV-2 antibodies were determined using four lateral flow immune-assays (LFIAs), and an electrochemiluminescent immunoassay. We determined longitudinal antibody response to SARS-CoV-2 as well as seroconversion dynamics. RESULTS Serological positivity rate ranged between 12%-91%, depending on timing after symptom onset. There was no difference in positivity rate between severe and non-severe COVID-19 cases. The specificity ranged between 90%-97%. Agreement between different assays ranged between 84%-92%. The estimated positive predictive value (PPV) for IgM or IgG in a scenario with seroprevalence at 5% varies from 33% to 58%. Nonetheless, when the population seroprevalence increases to 25% and 50%, there is a corresponding increases in the estimated PPVs. The estimated negative-predictive value (NPV) in a low seroprevalence scenario (5%) is high (>99%). However, the estimated NPV in a high seroprevalence scenario (50%) for IgM or IgG is reduced significantly to 80% to 85%. Overall, 28/102 (27.5%) seroconverted by one or more assays tested, within a median time of 11 (IQR: 9-15) days post symptom onset. The median seroconversion time among symptomatic cases tended to be shorter when compared to asymptomatic patients [9 (IQR: 6-11) vs. 15 (IQR: 13-21) days; p = 0.002]. Overall, seroconversion reached 100% 5.5 weeks after the onset of symptoms. Notably, of the remaining 74 COVID-19 patients included in the cohort, 64 (62.8%) were positive for antibody at the time of enrollment, and 10 (9.8%) patients failed to mount a detectable antibody response by any of the assays tested during follow-up. CONCLUSIONS Longitudinal assessment of antibody response in African COVID-19 patients revealed heterogeneous responses. This underscores the need for a comprehensive evaluation of seroassays before implementation. Factors associated with failure to seroconvert needs further research

Effect of co-infection with intestinal parasites on COVID-19 severity: A prospective observational cohort study

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in a spectrum of clinical presentations. Evidence from Africa indicates that significantly less COVID-19 patients suffer from serious symptoms than in the industrialized world. We and others previously postulated a partial explanation for this phenomenon, being a different, more activated immune system due to parasite infections. Here, we aimed to test this hypothesis by investigating a potential correlation of co-infection with parasites with COVID-19 severity in an endemic area in Africa. Methods: Ethiopian COVID-19 patients were enrolled and screened for intestinal parasites, between July 2020 and March 2021. The primary outcome was the proportion of patients with severe COVID-19. Ordinal logistic regression models were used to estimate the association between parasite infection, and COVID-19 severity. Models were adjusted for sex, age, residence, education level, occupation, body mass index, and comorbidities. Findings: 751 SARS-CoV-2 infected patients were enrolled, of whom 284 (37.8%) had intestinal parasitic infection. Only 27/255 (10.6%) severe COVID-19 patients were co-infected with intestinal parasites, while 257/496 (51.8%) non-severe COVID-19 patients were parasite positive (p<0.0001). Patients co-infected with parasites had lower odds of developing severe COVID-19, with an adjusted odds ratio (aOR) of 0.23 (95% CI 0.17–0.30; p<0.0001) for all parasites, aOR 0.37 ([95% CI 0.26–0.51]; p<0.0001) for protozoa, and aOR 0.26 ([95% CI 0.19–0.35]; p<0.0001) for helminths. When stratified by species, co-infection with Entamoeba spp., Hymenolepis nana, Schistosoma mansoni, and Trichuris trichiura implied lower probability of developing severe COVID-19. There were 11 deaths (1.5%), and all were among patients without parasites (p = 0.009). Interpretation: Parasite co-infection is associated with a reduced risk of severe COVID-19 in African patients. Parasite-driven immunomodulatory responses may mute hyper-inflammation associated with severe COVID-19. Funding: European and Developing Countries Clinical Trials Partnership (EDCTP) – European Union, and Joep Lange Institute (JLI), The Netherlands

Performance of rapid rk39 tests for the diagnosis of visceral leishmaniasis in Ethiopia: a systematic review and meta-analysis

Background: Visceral Leishmaniasis (VL) is a severely neglected disease affecting millions of people with high mortality if left untreated. In Ethiopia, the primary laboratory diagnosis of VL is by using an antigen from a 39-amino acid sequence repeat of a kinesin-related (rK39) of leishmania donovani complex (L. donovani), rapid diagnostic tests (RDT). Different rk39 RDT brands are available with very variable performance and studies from Ethiopia showed a very wide range of sensitivity and specificity. Therefore, a systematic review and meta-analysis were conducted to determine the pooled sensitivity and specificity of rk39 RDT in Ethiopia. Method: PUBMED, EMBASE, and other sources were searched using predefined search terms to retrieve all relevant articles from 2007 to 2020. Heterogeneity was assessed by visually inspecting summary receiver operating curves (SROC), Spearman correlation coefficient (rs), Cochran Q test statistics, inconsistency square (I2) and subgroup analysis. The presence and statistical significance of publication bias were assessed by Egger's test at p < 0.05, and all the measurements showed the presence of considerable heterogeneity. Quality assessment of diagnostic accuracy studies (QUADAS-2) checklists was used to check the qualities of the study. Results: A total of 664 articles were retrieved, and of this 12 articles were included in the meta-analysis. Overall pooled sensitivity and specificity of the rk39 RDT to diagnose VL in Ethiopia were 88.0% (95% CI 86.0% to 89.0%) and 84.0% (95% CI 82.0% to 86.0%), respectively. The sensitivity and specificity of the rk39 RDT commercial test kits were DiaMed: 86.9% (95% CI 84.3% to 89.1%) and 82.2% (95% CI 79.3% to 85.0%), and InBios: 80.0% (95% CI 77.0% to 82.8%) and 97.4% (95% CI 95.0% to 98.8%), respectively. Conclusion: Referring to our result, rk39 RDT considered an essential rapid diagnostic test for VL diagnosis. Besides to the diagnostic accuracy, the features such as easy to perform, quick (10–20 min), cheap, equipment-free, electric and cold chain free, and result reproducibility, rk39 RDT is advisable to remains in practice as a diagnostic test at least in the remote VL endemic localities till a better test will come

Utility of the loop-mediated isothermal amplification assay for the diagnosis of visceral leishmaniasis from blood samples in Ethiopia

Rapid and accurate diagnosis of visceral leishmaniasis (VL) is needed to initiate prompt treatment to reduce morbidity and mortality. Here, we evaluated the performance of loop-mediated isothermal amplification (LAMP) assay for the diagnosis of VL from blood in an endemic area in Ethiopia. LAMP was positive in 117/122 confirmed VL cases and negative in 149/152 controls, resulting in a sensitivity of 95.9% (95% CI: 90.69-98.66) and a specificity of 98.0% (95% CI: 94.34-99.59), respectively. The sensitivity of the LAMP assay was 95.0% (95% CI: 88.61-98.34) in HIV-negatives and 100% (95% CI: 85.18-100.0) in HIV-positives. Compared with microscopy, LAMP detected 82/87 (94.3%, 95% CI: 87.10-98.11) of the microscopy1 cases and was negative in 11/27 (40.7%, 95% CI: 22.39-61.20) of the microscopy2 cases. Compared with the rK39 serology, LAMP detected 113/120 (94.2%, 95% CI: 88.35-97.62) of the rK391 cases and was negative in 149/154 (96.8%, 95% CI: 92.59-98.94) of the rK392 cases. However, when compared with microscopy only, rK39 detected 83/87 (95.4%, 95% CI: 88.64-98.73) of the microscopy1 cases and negative in only 12/27 (44.4%, 95% CI: 25.48-64.67) of the microscopy- cases. There was an excellent agreement between rK39 and LAMP (Kappa 5 0.91, 95% CI: 0.86-0.96). Furthermore, an algorithm using rK39 followed by LAMP would yield a sensitivity of 99.2% (95%CI: 95.52-99.89) and a specificity of 98.0% (95% CI: 94.34-99.59). The findings demonstrate that LAMP assay is an accurate and rapid molecular assay for VL diagnosis, including in HIV-1 coinfected patients, in an endemic setting

Longitudinal profile of antibody response to SARS-CoV-2 in patients with COVID-19 in a setting from Sub-Saharan Africa: A prospective longitudinal study

BACKGROUND: Serological testing for SARS-CoV-2 plays an important role for epidemiological studies, in aiding the diagnosis of COVID-19, and assess vaccine responses. Little is known on dynamics of SARS-CoV-2 serology in African settings. Here, we aimed to characterize the longitudinal antibody response profile to SARS-CoV-2 in Ethiopia. METHODS: In this prospective study, a total of 102 PCR-confirmed COVID-19 patients were enrolled. We obtained 802 plasma samples collected serially. SARS-CoV-2 antibodies were determined using four lateral flow immune-assays (LFIAs), and an electrochemiluminescent immunoassay. We determined longitudinal antibody response to SARS-CoV-2 as well as seroconversion dynamics. RESULTS: Serological positivity rate ranged between 12%-91%, depending on timing after symptom onset. There was no difference in positivity rate between severe and non-severe COVID-19 cases. The specificity ranged between 90%-97%. Agreement between different assays ranged between 84%-92%. The estimated positive predictive value (PPV) for IgM or IgG in a scenario with seroprevalence at 5% varies from 33% to 58%. Nonetheless, when the population seroprevalence increases to 25% and 50%, there is a corresponding increases in the estimated PPVs. The estimated negative-predictive value (NPV) in a low seroprevalence scenario (5%) is high (>99%). However, the estimated NPV in a high seroprevalence scenario (50%) for IgM or IgG is reduced significantly to 80% to 85%. Overall, 28/102 (27.5%) seroconverted by one or more assays tested, within a median time of 11 (IQR: 9-15) days post symptom onset. The median seroconversion time among symptomatic cases tended to be shorter when compared to asymptomatic patients [9 (IQR: 6-11) vs. 15 (IQR: 13-21) days; p = 0.002]. Overall, seroconversion reached 100% 5.5 weeks after the onset of symptoms. Notably, of the remaining 74 COVID-19 patients included in the cohort, 64 (62.8%) were positive for antibody at the time of enrollment, and 10 (9.8%) patients failed to mount a detectable antibody response by any of the assays tested during follow-up. CONCLUSIONS: Longitudinal assessment of antibody response in African COVID-19 patients revealed heterogeneous responses. This underscores the need for a comprehensive evaluation of seroassays before implementation. Factors associated with failure to seroconvert needs further research