Comparing two survey methods of measuring health-related indicators: Lot Quality Assurance Sampling and Demographic Health Surveys

Objectives Two common methods used to measure indicators for health programme monitoring and evaluation are the demographic and health surveys (DHS) and lot quality assurance sampling (LQAS); each one has different strengths. We report on both methods when utilised in comparable situations. Methods We compared 24 indicators in south-west Uganda, where data for prevalence estimations were collected independently for the two methods in 2011 (LQAS: n = 8876; DHS: n = 1200). Data were stratified (e.g. gender and age) resulting in 37 comparisons. We used a two-sample two-sided Z-test of proportions to compare both methods. Results The average difference between LQAS and DHS for 37 estimates was 0.062 (SD = 0.093; median = 0.039). The average difference among the 21 failures to reject equality of proportions was 0.010 (SD = 0.041; median = 0.009); among the 16 rejections, it was 0.130 (SD = 0.010, median = 0.118). Seven of the 16 rejections exhibited absolute differences of 0.10 and 0.20 (mean = 0.261, SD = 0.083). Conclusion There is 75.7% agreement across the two surveys. Both methods yield regional results, but only LQAS provides information at less granular levels (e.g. the district level) where managerial action is taken. The cost advantage and localisation make LQAS feasible to conduct more frequently, and provides the possibility for real-time health outcomes monitoring

Experimental and Computational Fluid Dynamics study of microcarrier suspension during the cultivation of Mesenchymal Stem Cells in an ambr250 bioreactor

The ambr250 unit is a fully automated disposable 100-250 ml bioreactor for R&D that has been developed by TAP Biosystems, now part of Sartorius-Stedim, widely used for scale down and scale up modelling studies. Recently, mesenchymal stem cells (MSCs) have become strong candidates for cell-based therapies based on in vitro growth on microcarriers in stirred bioreactors. However, to fully realize the MSCs potential, a number of key processing issues need to be addressed because of the huge number of cells that are required. Thus, the fluid dynamics characteristics of the stirred ambr250 bioreactor must be sufficiently well understood to enable scale-up to larger bioreactors to be efficiently accomplished particularly because of the special issues arising from the presence of the particulate solid phase. One of the most critical aspects for MSC cultivation on microcarriers is the minimum agitator speed required to achieve complete microcarriers suspension, NJS. Under these conditions, the surface area of all the attached cells is available for transfer of nutrients (including oxygen) to the cells and metabolites from them, whilst higher speeds hardly increase these transport processes and may lead to damaging fluid dynamic stresses being generated1. This suspension condition can be studied experimentally if equipment is specially modified to make easy visual observation of the two-phase flow in the bioreactor but during actual growth that is very difficult. Therefore, it is extremely beneficial to both measure NJS and compare the measured values with predictions based on computational fluid dynamics (CFD) for validation. Once validated, then CFD is a very useful tool for analyzing flow patterns, mixing time, mean and local specific energy dissipation rates and other parameters important for scale up. In this work we examined the fluid dynamics of the two-phase particle-liquid system with an experimental analysis and a CFD simulation using a lattice-Boltzmann base software and particle tracking of an ambr250 vessel at different stirring conditions. Cell culture was also performed in parallel to analyse the cell growth at and around NJS and the results were compared to the performance in a spinner flask bioreactor. The CFD and experimental results will be discussed in detail along with their scale-up implications. References 1) Nienow, A. W., Coopman, K., Heathman, T. R. J., Rafiq, Q. A. and C. J. Hewitt (2016). “Bioreactor Engineering Fundamentals for Stem Cell Manufacturing”. In: “Stem Cell Manufacturing”, (Eds. J.M.S. Cabral, C.L. de Silva, L. G. Chase and M. M. Diogo), Elsevier Science, Cambridge, USA; Chapter 3, pp 43 – 76

A novel use of high density SNP assays to optimize choice of different crossbred dairy cattle genotypes in smallholder systems in East Africa

We present use of SNP technologies to obtain for the first time, rapid, large-scale, in situ estimates of performance of crossbred cows in smallholder herds. Compared to historical approaches, our approach allowed optimum crossbreed choices to be determined more rapidly and without question about the relevance of the environment. High-density SNP assays were used to estimate breed composition for a monitored population comprising 1292 cows from 610 smallholder farms in Kenya. The achieved milk yields are much lower than generally assumed and lactation curves are very flat out to 400 days. In poor production environments, lower grade crosses (containing <60% exotic dairy alleles) had the same yield as high grade crosses. Allowing for the larger size and maintenance requirements of high grade exotics, lower grade exotics will be the most economically productive animals in these environments

Comparing two survey methods of measuring health-related indicators: Lot Quality Assurance Sampling and Demographic Health Surveys

ObjectivesTwo common methods used to measure indicators for health programme monitoring and evaluation are the demographic and health surveys (DHS) and lot quality assurance sampling (LQAS); each one has different strengths. We report on both methods when utilised in comparable situations.MethodsWe compared 24 indicators in south-west Uganda, where data for prevalence estimations were collected independently for the two methods in 2011 (LQAS: n = 8876; DHS: n = 1200). Data were stratified (e.g. gender and age) resulting in 37 comparisons. We used a two-sample two-sided Z-test of proportions to compare both methods.ResultsThe average difference between LQAS and DHS for 37 estimates was 0.062 (SD = 0.093; median = 0.039). The average difference among the 21 failures to reject equality of proportions was 0.010 (SD = 0.041; median = 0.009); among the 16 rejections, it was 0.130 (SD = 0.010, median = 0.118). Seven of the 16 rejections exhibited absolute differences of 0.10 and 0.20 (mean = 0.261, SD = 0.083).ConclusionThere is 75.7% agreement across the two surveys. Both methods yield regional results, but only LQAS provides information at less granular levels (e.g. the district level) where managerial action is taken. The cost advantage and localisation make LQAS feasible to conduct more frequently, and provides the possibility for real-time health outcomes monitoring

Iodine status and sources of dietary iodine intake in Kenyan women and children

In 2009, the Government of Kenya adopted a mandatory iodine standard for all ediblesalt of 30-50 mg/kg with potassium iodate as a required fortificant. To assess the new standard, iodine nutrition measurements were included in the Kenya National Micronutrient Survey (KNMS) in 2011. Spot urine samples were obtained from 951 school-age children (SAC, 5 - 14y of age) and 623 non-pregnant women (NPW, 15 – 49y), together with 625 salt samples from their households. Because salt is the major dietary source of iodine as well as sodium in Kenya, sodium concentrations were measured in the same urine samples. Using the iodine and sodium data, the report introduces a novel regression technique to apportion the urinary iodine concentrations (UIC) in both survey groups to the key sources of iodine intake, namely, naturally present (native) iodine content, iodized salt in processed foods and iodized household salt. The salt iodine (SI) content in Kenya’s households (mean 40.3 mg/kg, SD 19.4 mg/kg) showed high-quality iodized salt supply. The SI content in 94.9% of households was ≥15 mg/kg. Median UIC findings in SAC (208 μg/L) and NPW (167 μg/L) indicated adequate iodine nutrition. Although variations in UIC values existed by age, gender (only in SAC), residence type, household wealth index, and region, median UIC findings were within the accepted optimum range in virtually all sub-categories. The findings do not suggest the need for change in Kenya’s universal salt iodization (USI) strategy or adjustment of the current salt iodine standard. Partitioning of UIC values by dietary sources of iodine intake in each survey group attributed ± 35% to native dietary iodine content, ± 45% to processed food and ± 20% to household salt. The UIC levels from native iodine intake alone (60.8 μg/L and 65.3 μg/L in SAC and NPW, respectively) fell below the threshold for iodine deficiency, which supports the inference that the current USI strategy in Kenya is effective in preventing iodine deficiency. The results from regression analysis indicate that the iodine intakes of SAC and NPW can be explained mainly, and in the same way, by their urinary sodium concentrations (UNaC) and the SI contents in salt from their households. The spot UNaC data do not accurately represent salt intake estimates but the mean UNaC findings may be useful for analyzing future changes in salt supply and use from efforts to reduce the salt intake of Kenya’s population.Keywords: Universal Salt Iodization, Dietary Iodine Sources, Population Iodine Status, Keny

Enhancing individual animal resilience to environmental disturbances to address low productivity in dairy cattle performing in sub-Saharan Africa

The current review examines potential solutions to enhance the sustainability and productivity of the dairy sector in sub-Saharan Africa (SSA) with an emphasis on breeding for resilience. Additionally, the paper explores various indicators for measuring resilience and provides insights into the data that can be utilized to quantify resilience in SSA’s dairy production systems. Dairy production contributes significantly to food and nutritional security and employment in SSA. However, besides the general lack of enabling policy and institutional environments, production is negatively affected by environmental challenges such as high temperatures and heat stress, diseases and parasites, unreliable rainfall patterns, shortages of feeds and forages and undue preference for taurine cattle breeds regardless of their poor adaptability to prevailing local conditions. Fostering the resilience capacity of dairy animals is imperative to combat climate-related adversities and maintain productivity. This can only be achieved if reliable and practical methods for quantifying and analyzing resilience in SSA are described and undertaken. This study has reviewed variance of deviations, root mean square of deviations, autocorrelation of deviations, skewness of deviations, slope of the reaction norm and its absolute value as possible indicators of resilience in SSA. While previous research has reported genetic variation and favorable correlations of these indicators with health, fitness, and fertility traits, their potential in SSA environments requires further investigation. Besides, labor- and cost-effective phenotypic data collection is essential for characterization of resilience using these indicators. Through this study, we propose frequently collected data on milk production traits, body fat-related traits, and activity patterns as suitable in the sub-Saharan Africa context. The African Asian Dairy Genetic Gains Project by the International Livestock Research Institute (ILRI) offers a valuable opportunity to collate data from diverse dairy systems in SSA for testing the potential of these indicators. Insights from this study are helpful in improving resilience of dairy animals in SSA, which would contribute to poverty alleviation, animal welfare improvement, and better preparedness in lieu of climate change in SSA.</p

Use of high density SNP genotypes to determine the breed composition of cross bred dairy cattle in smallholder farms: Assessment of reproductive and health performance

Reproductive performance and disease data were recorded for 2 years on 1,824 dairy cows in smallholder farms using participatory approaches and onfarm recording. Most animals experienced one service to conception. Calving intervals were long, ranging between 261 and 761 days, with an average of 451±101days. Herd level of production (HeL) had significant effect on calving interval. However, there was no difference between crossbreds with different levels of exotic breed percentage or in different HeL classes in disease incidence. Most animals had less than 2 treatment events, despite the high disease burden in the study areas. Mortality rates were low, ranging from 2.13% to 2.65%. Even though the crossbred animals had higher performance compared to indigenous animals, the gains obtained were below what would be possible with better management. These results suggest that crosses with low exotic proportions would be the most optimal for the production systems studied