Assessing water availability under pastoral livestock systems in drought-prone Isiolo District, Kenya

Water availability / Water demand / Surface water / Groundwater / Wells / Salinity / Livestock / Grazing / Land use / Water supply / Drainage / GIS / Databases / Cost recovery

Implications of Charcoal Briquette Produced by Local Communities on Livelihoods and Environment in Nairobi Kenya

The residents of Nairobi, Kenya, use 700 tonnes of charcoal per day, producing about 88 tonnes of charcoal dust that is found in most of the charcoal retailing stalls that is disposed of in water drainage systems or in black garbage heaps. The high costs of cooking fuel results in poor households using unhealthy materials such as plastic waste. Further, poor households are opting to cook foods that take a short time to prepare irrespective of their nutritional value. This article presents experiences with community self-help groups producing charcoal fuel briquettes from charcoal dust in poorer nieghbourhoods of Nairobi for home use and sale. Households that produced charcoal fuel briquettes for own use and those that bought them saved 70% and 30% of money spent on cooking energy respectively. The charcoal fuel briquettes have been found to be environmentally beneficial since they produce less smoke and increase total cooking energy by more than 15%, thereby saving an equivalent volume of trees that would be cut down for charcoal. Charcoal briquette production is a viable opportunity for good quality and affordable cooking fuel. Bioenergy and waste management initiatives should promote recovery of organic by-products for charcoal briquette production

Evaluation of the Performance of Smallholder Pumped Irrigation Systems, in Arid and Semi-arid Areas of Kenya

A study was carried out to evaluate the performance of smallholder pumped irrigation systems with a view of comparing if the system operated within the designed optimal engineering standards. Different parameters studied were selection, design and operations of the irrigation systems with detailed analysis on energy uses for pumping (fuel use), efficiency of pumping devices as well as pump power required and energy losses (headlosses) during pumping. Semi structured questionnaires were administered to 80 smallholder farmers practicing pumped irrigated agriculture in Mitubiri location of Kakuzi division and Kithimani sub location of Yatta division, Kenya. An observational study was done to identify the irrigation methods used. Detailed study was done in 10 farms (5 in each study site) using pumped irrigated agriculture and water application through furrow irrigation system. 79 % of the farmers assessed used small motorized pumps run by petrol and diesel fuel and ranging from 4.0-6.5 horsepower. Water was pumped from nearby rivers and conveyed to their farms using closed conduits, open channels or a combination of both.  Furrow irrigation method was widely used by 94% of the farmers studied in the two study areas. 60% of the irrigation setups using PVC pipes in water conveyance had the allowable water discharge within the design optimal range. The frictional head loss in the PVC pipes used exceeded the design limit for 60% of the irrigation systems while 90% of the irrigation setups used fittings whose resultant frictional head losses were within the desired optimal range. Of the 10 pumps evaluated, 6 of them operated below the optimal design efficiency level while fuel consumption rate of each pump varied. The study of the amount of fuel used to run the different pumps used in the 10 farm setups varied from one farm to the other. In some farms, mean fuel amount used to irrigate 1 hectare of land was in excess of 60L/ha while in other farm setups, fuel used was as low as 5L/ha. The varied fuel amounts used could be attributed to varied factors in each farm such as topographic elevations, water conveyance distance and different make and model of pump. An assessment of fuel consumption rate for each of the 10 pumps at similar operational speed was also different. Pumps age did not affect its efficiency. A comparison of the calculated pump power required and the power rated on the pumps being used showed a big difference indicating that the farmers used pumps which had a higher power rating than required. The effect of using an oversized pump is high initial cost of purchasing the pump as well as high operation costs due to high fuel use.From the study, it was found that smallholder pumped irrigated agriculture despite showing tremendous increase in uptake faces numerous challenges ranging from components selection, design and use leading to poor performance

Farm water use efficiency assessment for smallholder pumped irrigation systems in the arid and semi-arid areas of Kenya

Water use efficiency for irrigated agriculture still remains low.  This presents a risky trend in the near future due to diminishing water resources as well as rising population demanding increased food supplies.  The objective of the study was to investigate pumped irrigation methods used by smallholder farmers in the arid and semi-arid land environments as well as assess the water use efficiency during crop production under usual farmer management.  The study was carried out in Mitubiri location of Kakuzi division and Kithimani sub location of Yatta division, Kenya.  Observational study during the field transect walks in the study sites identified methods of irrigation used by the smallholder farmers, water conveyance as well as application methods and the soil physical properties.  Questionnaires were developed and administered to 80 farmers in order to find out the socio-economic status of the people and the agricultural practices carried out.  A detailed study was carried out in 10 experimental plots set in the study areas.  Water losses during conveyance and application were assessed in the experimental plots.  Of the five farms where water conveyance was through secondary canals, the mean water conveyance efficiency was found to be 81.4%.  Water application efficiency in the ten blocks under different crops grown i.e. baby corns (Zea mays L.), French beans (Phaseolus vulgaris L), tomatoes (Lycopersicon esculentum L) and water melon (citrullus lanatus) in the months of April to July 2009 was assessed.  On average, water application efficiency ranged from 19.5% to 30 % for the crops assessed which was far below the recommended range of 65% for surface irrigation methods.  The study hence shows that there is a need to improve water use efficiency in smallholder irrigated agriculture in order to conserve water and ensure no shortages of water during the times of high water demand

Use of rapid diagnostic tests in malaria school surveys in Kenya: does their under-performance matter for planning malaria control?

Malaria rapid diagnostic tests (RDTs) are known to yield false-positive results, and their use in epidemiologic surveys will overestimate infection prevalence and potentially hinder efficient targeting of interventions. To examine the consequences of using RDTs in school surveys, we compared three RDT brands used during a nationwide school survey in Kenya with expert microscopy and investigated the cost implications of using alternative diagnostic approaches in identifying localities with differing levels of infection. Overall, RDT sensitivity was 96.1% and specificity was 70.8%. In terms of classifying districts and schools according to prevalence categories, RDTs were most reliable for the 40% categories and least reliable in the 1-4.9% category. In low-prevalence settings, microscopy was the most expensive approach, and RDT results corrected by either microscopy or polymerase chain reaction were the cheapest. Use of polymerase chain reaction-corrected RDT results is recommended in school malaria surveys, especially in settings with low-to-moderate malaria transmission

Factors associated with the performance and cost-effectiveness of using lymphatic filariasis transmission assessment surveys for monitoring soil-transmitted helminths: a case study in Kenya.

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8-10 years of age to assess STH but suggest that key consideration is given to evaluation unit size

Prevalence and Types of Coinfections in Sleeping Sickness Patients in Kenya (2000/2009)

The occurrence of coinfections in human African trypanosomiasis (HAT) patients was investigated using a retrospective data of hospital records at the National Sleeping Sickness Referral Hospital in Alupe, Kenya. A total of 31 patients, 19 males and 12 females, were diagnosed with HAT between the years 2000 and 2009. The observed co-infections included malaria (100%), helminthosis (64.5%), typhoid (22.5%), urinary tract infections (16.1%), HIV (12.9%), and tuberculosis (3.2%). The species of helminthes observed included Ancylostoma duodenale (38.7%), Ascaris lumbricoides (45.7%), Strongyloides stercoralis (9.7%), and Taenia spp. (3.2%). The patients were also infected with Entamoeba spp. (32.3%) and Trichomonas hominis (22.6%) protozoan parasites. The main clinical signs observed at the point of admission included headache (74.2%), fever (48.4%), sleep disorders (45.2%), and general body pain (41.9%). The HAT patients were treated with suramin (early stage, 9/31) and melarsoprol (late stage, 22/31). In conclusion, the study has shown that HAT patients have multiple co-infections which may influence the disease pathogenesis and complicate management of HAT

Bancroftian filariasis in Kwale District, Kenya

Objective: To determine the prevalence of Wuchereria bancrofti infection in an area designated for filariasis control trial.Design: A cross-sectional survey.Setting: Three villages in Kinango location, Kwale district, Coast Province, Kenya.Subjects/participants: Oral informed consent to participate was obtained from adults and parents or guardians of children below fifteen years of age.Main outcome measures: Microfilaraemia prevalences, microfilarial densities and clinical manifestations.Results: The overall prevalence of microfilaraemia in the population was 16.4%. The prevalence of microfilaraemia was age-dependent and the overall microfilarial density (MFD) was 69.4 mf/ml (geometric mean) and significantly higher in males (95.8 mf/ml) than in females (48.6 mf/ml) (p < 0.05). The prevalence of clinical signs of infection was also agedependent with elephantiasis being significantly higher in females (2.3%) than in males (0.9%) (p < 0.05). Among the males, the major clinical manifestation was hydrocele (10.4%).Conclusion: These findings show high prevalence of bancroftian filariasis in Kwale district and warrant similar studies followed by implementation of intervention measures to reduce transmission in all areas of endemicity in the Coast Province

Modelling strategies to break transmission of lymphatic filariasis : aggregation, adherence and vector competence greatly alter elimination

Background: With ambitious targets to eliminate lymphatic filariasis over the coming years, there is a need to identify optimal strategies to achieve them in areas with different baseline prevalence and stages of control. Modelling can assist in identifying what data should be collected and what strategies are best for which scenarios. Methods: We develop a new individual-based, stochastic mathematical model of the transmission of lymphatic filariasis. We validate the model by fitting to a first time point and predicting future timepoints from surveillance data in Kenya and Sri Lanka, which have different vectors and different stages of the control programme. We then simulate different treatment scenarios in low, medium and high transmission settings, comparing once yearly mass drug administration (MDA) with more frequent MDA and higher coverage. We investigate the potential impact that vector control, systematic non-compliance and different levels of aggregation have on the dynamics of transmission and control. Results: In all settings, increasing coverage from 65 to 80 % has a similar impact on control to treating twice a year at 65 % coverage, for fewer drug treatments being distributed. Vector control has a large impact, even at moderate levels. The extent of aggregation of parasite loads amongst a small portion of the population, which has been estimated to be highly variable in different settings, can undermine the success of a programme, particularly if high risk sub-communities are not accessing interventions. Conclusion: Even moderate levels of vector control have a large impact both on the reduction in prevalence and the maintenance of gains made during MDA, even when parasite loads are highly aggregated, and use of vector control is at moderate levels. For the same prevalence, differences in aggregation and adherence can result in very different dynamics. The novel analysis of a small amount of surveillance data and resulting simulations highlight the need for more individual level data to be analysed to effectively tailor programmes in the drive for elimination