Spatiotemporal analysis of droughts using self-calibrating Palmer’s Drought Severity Index in the central region of South Africa

Published ArticleThe loss of life and property from drought events has forced society to focus on the development of reliable early warning systems which may enable farmers and other stakeholders to correctly and timely adapt to the expected impacts of climatic hazard. However, a scientific approach to a reliable early warning system for a region requires, among others, characterisation of drought events in the region in terms of duration, magnitude, intensity and frequency using standard drought indices. Therefore, the objective of this study was to identify and characterise drought events in the Modder River basin, central region of South Africa, using a self-calibrated Palmer’s Drought Severity Index (sc-PDSI). Attempts were also made to establish a relationship between meteorological and hydrological drought events in the region. During the period of analysis, the total number of drought episodes identified in the study area ranged between eight and sixteen. It was found that the most severe drought episodes occurred during the period 1992–1995 followed by the period 1982–1987. Results of analysis of seasonal drought events in one of the quaternary catchments (C52A) revealed that peak drought events during the three summer months (November, December and January) occurred in the area in 1993. However, in terms of event magnitude and intensity, the worst drought events were recorded during the period December 1982–July 1987, followed by the event that ensued during December 1989–September 1995. Results of analysis of decadal variation of drought events showed that the number of extreme and moderate drought events recorded in the catchment showed statistically significant increasing trends during the five decades at 5 % significance level. Moreover, spectral analysis of sc-PDSI time series in the region identified periodicities in the time series ranging from 6 years (C52E) to 16 years (C52K). In terms of the spatial extent of extreme drought events, the maximum areal coverage (91 %) was recorded in November 1998, followed by December 1998 and December–January 1999 (43 %). Analysis of the relative frequency of droughts of varying categories revealed that extreme drought events were most prevalent in the C52E (2.72 %) quaternary catchment, followed by C52C (2.21 %). The study also found an average lag time of 10 months between the onsets of meteorological and hydrological drought events in the region

Health gains and fi nancial risk protection aff orded by public fi nancing of selected interventions in Ethiopia: an extended cost-eff ectiveness analysis

Background The way in which a government chooses to fi nance a health intervention can aff ect the uptake of health interventions and consequently the extent of health gains. In addition to health gains, some policies such as public fi nance can insure against catastrophic health expenditures. We aimed to evaluate the health and fi nancial risk protection benefi ts of selected interventions that could be publicly fi nanced by the government of Ethiopia. Methods We used extended cost-eff ectiveness analysis to assess the health gains (deaths averted) and fi nancial risk protection aff orded (cases of poverty averted) by a bundle of nine (among many other) interventions that the Government of Ethiopia aims to make universally available. These nine interventions were measles vaccination, rotavirus vaccination, pneumococcal conjugate vaccination, diarrhoea treatment, malaria treatment, pneumonia treatment, caesarean section surgery, hypertension treatment, and tuberculosis treatment. Findings Our analysis shows that, per dollar spent by the Ethiopian Government, the interventions that avert the most deaths are measles vaccination (367 deaths averted per $100 000 spent), pneumococcal conjugate vaccination (170 deaths averted per$100 000 spent), and caesarean section surgery (141 deaths averted per $100 000 spent). The interventions that avert the most cases of poverty are caesarean section surgery (98 cases averted per$100 000 spent), tuberculosis treatment (96 cases averted per $100 000 spent), and hypertension treatment (84 cases averted per$100 000 spent). Interpretation Our approach incorporates fi nancial risk protection into the economic evaluation of health interventions and therefore provides information about the effi ciency of attainment of both major objectives of a health system: improved health and fi nancial risk protection. One intervention might rank higher on one or both metrics than another, which shows how intervention choice—the selection of a pathway to universal health coverage—might involve weighing up of sometimes competing objectives. This understanding can help policy makers to select interventions to target specifi c policy goals (ie, improved health or fi nancial risk protection). It is especially relevant for the design and sequencing of universal health coverage to meet the needs of poor populations

Mortality and Disability-adjusted Life-years (DALYs) for common neglected tropical Diseases in Ethiopia, 1990 to 2015: evidence from the Global Burden of Disease Study 2015

Introduction: Neglected tropical diseases (NTDs) are important public health problems in Ethiopia. In 2013, the Federal Ministry of Health (FMOH) has launched a national NTD master plan to eliminate major NTDs of public health importance by 2020. Benchmarking the current status of NTDs in the country is important to monitor and evaluate the progress in the implementation of interventions and their impacts. Therefore, this study aims to assess the trends of mortality and Disability-adjusted Life-Years (DALY) for the priority NTDs over the last 25 years. Methods: We used the Global Burden of Disease (GBD) 2015 estimates for this study. The GBD 2015 data source for cause of death and DALY estimation included verbal autopsy (VA), Demographic and Health Surveys (DHS), malaria indicator surveys (MICS) and other disease specific surveys, Ministry of Health reports submitted to United Nations (UN) agencies and published scientific articles. Cause of Death Ensemble modeling (CODEm) and/or natural history models were used to estimate malaria and NTDs mortality rates. DALY were estimated as the sum of Years of Life Lost (YLL) due to premature mortality and Years Lived with Disability (YLD). Results: All NTDs caused an estimated of 6,293 deaths (95% uncertainty interval (UI): 3699 – 10,080) in 1990 and 3,593 deaths (95% UI: 2051 – 6178) in 2015, a 70% reduction over the 25 years. Age-standardised mortality rates due to schistosomiasis, STH and leshmaniasis have declined by 91.3%, 73.5% and 21.6% respectively between 1990 to 2015. The number of DALYs due to all NTDs has declined from 814.4 thousand (95% UI: 548 thousand–1.2 million) in 1990 to 579.5 thousand (95%UI: 309.4 thousand – 1.3 million) in 2015. Age-standardised DALY rates due to all NTDs declined by 30.4%, from 17.6 per 1000(95%UI: 12.5-26.5) in 1990 to 12.2 per 1000(95%UI: 6.5 – 27.4) in 2015. Age-standardised DALY rate for trachoma declined from 92.7 per 100,000(95% UI: 63.2 – 128.4) in 1990 to 41.2 per 100,000(95%UI: 27.4 – 59.2) in 2015, a 55.6% reduction between 1990 and 2015. Age-standardised DALY rates for onchocerciasis, schistosomiasis and lymphiatic filariasis decreased by 66.2%, 29.4% and 12.5% respectively between 1990 and 2015. DALY rate for ascariasis fell by 56.8% over the past 25 years. Conclusions: Ethiopia has made a remarkable progress in reducing the DALY rates for most of the NTDs over the last 25 years. The rapid scale of interventions and broader system strengthening may have a lasting impact on achieving the 2020 goal of elimination of most of NTDs. Ethiopia should strengthen the coverage of integrated interventions of NTD through proper coordination with other health programs and sectors and community participation to eliminate NTDs by 2020

EURL ECVAM Workshop on New Generation of Physiologically-Based Kinetic Models in Risk Assessment

The European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM) Strategy Document on Toxicokinetics (TK) outlines strategies to enable prediction of systemic toxicity by applying new approach methodologies (NAM). The central feature of the strategy focuses on using physiologically-based kinetic (PBK) modelling to integrate data generated by in vitro and in silico methods for absorption, distribution, metabolism, and excretion (ADME) in humans for predicting whole-body TK behaviour, for environmental chemicals, drugs, nano-materials, and mixtures. In order to facilitate acceptance and use of this new generation of PBK models, which do not rely on animal/human in vivo data in the regulatory domain, experts were invited by EURL ECVAM to (i) identify current challenges in the application of PBK modelling to support regulatory decision making; (ii) discuss challenges in constructing models with no in vivo kinetic data and opportunities for estimating parameter values using in vitro and in silico methods; (iii) present the challenges in assessing model credibility relying on non-animal data and address strengths, uncertainties and limitations in such an approach; (iv) establish a good kinetic modelling practice workflow to serve as the foundation for guidance on the generation and use of in vitro and in silico data to construct PBK models designed to support regulatory decision making. To gauge the current state of PBK applications, experts were asked upfront of the workshop to fill a short survey. In the workshop, using presentations and discussions, the experts elaborated on the importance of being transparent about the model construct, assumptions, and applications to support assessment of model credibility. The experts offered several recommendations to address commonly perceived limitations of parameterization and evaluation of PBK models developed using non-animal data and its use in risk assessment, these include: (i) develop a decision tree for model construction; (ii) set up a task force for independent model peer review; (iii) establish a scoring system for model evaluation; (iv) attract additional funding to develop accessible modelling software.; (v) improve and facilitate communication between scientists (model developers, data provider) and risk assessors/regulators; and (vi) organise specific training for end users. The experts also acknowledged the critical need for developing a guidance document on building, characterising, reporting and documenting PBK models using non-animal data. This document would also need to include guidance on interpreting the model analysis for various risk assessment purposes, such as incorporating PBK models in integrated strategy approaches and integrating them with in vitro toxicity testing and adverse outcome pathways. This proposed guidance document will promote the development of PBK models using in vitro and silico data and facilitate the regulatory acceptance of PBK models for assessing safety of chemicals

Informing a target product profile for rapid tests to identify HBV-infected pregnant women with high viral loads: a discrete choice experiment with African healthcare workers

BACKGROUND: Elimination of mother-to-child transmission of hepatitis B virus (HBV) requires infant immunoprophylaxis and antiviral prophylaxis for pregnant women with high viral loads. Since real-time polymerase chain reaction (RT-PCR), a gold standard for assessing antiviral eligibility, is neither accessible nor affordable for women living in low-income and middle-income countries (LMICs), rapid diagnostic tests (RDTs) detecting alternative HBV markers may be needed. To inform future development of the target product profile (TPP) for RDTs to identify highly viremic women, we used a discrete choice experiment (DCE) and elicited preference and trade-off of healthcare workers (HCW) in Africa between the following four attributes of fictional RDTs: price, time-to-result, diagnostic sensitivity, and specificity. METHODS: Through an online questionnaire survey, we asked participants to indicate their preferred test from a set of two RDTs in seven choice tasks with varying levels of the four attributes. We used mixed multinomial logit models to quantify the utility gain or loss generated by each attribute. We attempted to define minimal and optimal criteria for test attributes that can satisfy ≥ 70% and ≥ 90% of HCWs, respectively, as an alternative to RT-PCR. RESULTS: A total of 555 HCWs from 41 African countries participated. Increases in sensitivity and specificity generated significant utility and increases in cost and time-to-result generated significant disutility. The size of the coefficients for the highest attribute levels relative to the reference levels were in the following order: sensitivity (β = 3.749), cost (β = -2.550), specificity (β = 1.134), and time-to-result (β = -0.284). Doctors cared most about test sensitivity, while public health practitioners cared about cost and midwives about time-to-result. For an RDT with 95% specificity, costing 1 US$, and yielding results in 20 min, the minimally acceptable test sensitivity would be 82.5% and the optimally acceptable sensitivity would be 87.5%. CONCLUSIONS: African HCWs would prefer an RDT with the following order of priority: higher sensitivity, lower cost, higher specificity, and shorter time-to-result. The development and optimization of RDTs that can meet the criteria are urgently needed to scale up the prevention of HBV mother-to-child transmission in LMICs

Age at menarche and the menstrual pattern of secondary school adolescents in northwest Ethiopia

<p>Abstract</p> <p>Background</p> <p>Population studies on normal and dysfunctional characteristics of menstrual cycles are scarce in Ethiopia. In addition variability in menarcheal age and menstrual characteristics are common. Knowledge on this variability is necessary for patient education and to guide clinical evaluation.</p> <p>Methods</p> <p>A cross sectional study was conducted in two small towns called Dabat and Kola Diba, northwest Ethiopia between April and May 2007. Systematic sampling method was used to select 622 school girls from two secondary schools. A pretested questionnaire prepared in Amharic was used to gather data. Selected girls cooperated in answering the questionnaire in their classrooms under the supervision of the research team. Only 612 of the adolescent females were included in the final analysis, of which 305 were from Koladiba High School and 307 from Dabat.</p> <p>Results</p> <p>The age of the study subjects ranges between 14 and 19 with a mean (standard deviation) of 16.9 ± 1 years. About 92.2% had attained menarche by the time the survey was conducted. The probit analysis of the <it>status quo </it>data yielded a median (CI) age at menarche of 14.8 (13.9-15.3) years. The average age at menarche by recall method was 15.8 ± 1 years. The mean age at menarche was 0.3 years younger for urban females compared with rural ones (p < 0.001). A cycle length between 21 and 35 days was observed in 70.3% of the girls. The mean duration of flow was 4 ± 1.3 days with a range of 2-7 days. The menstrual cycles were irregular in 42.8% of the subjects. The overall prevalence of dysmenorrhoea was 72% among these subjects. Premenstrual symptoms were present in 435 of the females (75.4%). The leading sources of menarcheal information to the adolescents were mothers (39.7%), followed by their friends (26.6%) and teachers (21.8%).</p> <p>Conclusion</p> <p>In this study age of menarche was found to be delayed which is even higher than the findings indicated similar studies conducted in Ethiopia and other African countries. A significant number of students complain of abnormal menstrual cycle, dysmenorrhoea and premenstrual symptoms which call for appropriate counselling and management.</p

Iron deficiency anemia is not a rare problem among women of reproductive ages in Ethiopia: a community based cross sectional study

<p>Abstract</p> <p>Background</p> <p>In Ethiopia, the existence of iron deficiency anemia is controversial despite the fact that Ethiopia is one of the least developed in Africa with a high burden of nutrient deficiencies.</p> <p>Methods</p> <p>The first large nutrition study of a representative sample of women in Ethiopia was conducted from June to July 2005 and a systematically selected sub-sample of 970 of these subjects, 15 to 49 years old, were used in this analysis of nutritional anemia. Hemoglobin was measured from capillary blood using a portable HemoCue photometer. For serum ferritin, venous blood from antecubital veins was measured by an automated Elecsys 1020 using commercial kits. Diets were assessed via simplified food frequency questionnaire. The association of anemia to demographic and health variables was tested by chi-square and a stepwise backward logistic regression model was applied to test the significant associations observed in chi square tests.</p> <p>Results</p> <p>Mean hemoglobin ± SD was 11.5 ± 2.1 g/dL with a 29.4% prevalence of anemia. Mean serum ferritin was 58 ± 41.1 ug/L with a 32.1% prevalence of iron deficiency. The overall prevalence rate of iron deficiency anemia was 18.0%. Prevalence of anemia, iron deficiency, and iron deficiency anemia was highest among those 31-49 years old (p < 0.05). Intake of vegetables less than once a day and meat less than once a week was common and was associated with increased anemia (p = 0.001). Although the prevalence of anemia was slightly higher among women with parasitic infestation the difference was not significant (p = 0.9). Nonetheless, anemia was significantly higher in women with history of illness and the association was retained even when the variable was adjusted for its confounding effect in the logistic regression models (AOR = 0.3; 95%CI = 0.17 to 0.5) signifying that the most probable causes of anemia is nutrition related and to some extent chronic illnesses.</p> <p>Conclusion</p> <p>Moderate nutritional anemia in the form of iron deficiency anemia is a problem in Ethiopia and therefore, the need for improved supplementation to vulnerable groups is warranted to achieve the United Nation's Millennium Development Goals. Chronic illnesses are another important cause of anemia.</p