90 research outputs found
Domestic water scarcity and rain water harvesting in non-perennial river basins Sri Lanka, Case-study Maspotha and Ganewaththa villages in Daduru Oya basin
Rainwater Harvester (RWH) has a long history in Sri Lanka. Spatial water scarcity within theintermediate zone has masked by the aggregative statistics. Sufficient number of natural and manmade water sources available within the zone. But most of them get dried in advance of dry season.Urbanization and population increase have been amplified the ground water extraction. Maspotha andGanewaththa areas have been identified as most dried areas in Daduru Oya basin. Objective of thisstudy is to identify the natural and physical resource availability to introduce RWH systems. Randomlyselected households samples were interviewed. Secondary data were collected from InternationalWater Management Institute and from other relevant government offices. Multiple regression analysiswas done to identify significant factors. Descriptive analysis was done from other collected data.Land fragmentation and the urbanization are sign ificantly affected for the present increment of spatialdrought frequency. 55 percent of households use their own well for drinking water and 30 percent ofhouseholds use community wells for drinking water. Ownership, water availability and the proximityto water source determine the amount of water usage. The pattern of the domestic water usage hasbeen changed over the time and 15 percent of households have water sealed bathrooms. The averageroof area and the average rainfall have shown positive sign for application ofRWH systems. Introducingthe RWH is difficult because of lack of technical knowledge and modest experiences about RWHwithin community. Satisfactory domestic water supply in close proximity would make more direct andindirect benefits
Spatial variation and clustering of anaemia prevalence in school-aged children in Western Kenya
Control of Busseola fusca and Chilo partellus stem borers by Bacillus thuringiensis (Bt)-δ-endotoxins from Cry1Ab gene Event MON810 in greenhouse containment trials
Previous testing of several public Bacillus thuringiensis (Bt)-maize events did not show control of the African stem borer (Busseola fusca Fuller), an important stem borer species, without which stewardship would be compromised by the possibility of rapid development of resistance to Bt deltaendotoxins. This study was carried out to test Bt-maize Event MON810 as an option to control all major stem borer species in Kenya. Two Bt-maize hybrids, DKC8073YG and DKC8053YG, both containing Bt Event MON810 of Cry1Ab gene were imported to carry out greenhouse containment trials. The hybrids together with the controls were grown in 10 replications upto the V6 and V8 stages. Infestations on whole plants were carried out at two stages of growth using 5 neonates of the spotted stem borer (Chilo partellus Swinhoe) and B. fusca. Bt-maize Event MON810 hybrids showed resistance to both stem borer species with low leaf damage scores and few surviving larvae recovered from the whole plant. The public Bt-maize Event 223 did not control B. fusca. Deploying Bt-maize Event MON810 may, therefore, be used to control the two species of stem borers. However, the efficacy of Bt-maize Event MON810 will, need to be evaluated under field environments.Key words: Bacillus thuringiensis (Bt) maize, cry1A (b) proteins, stem borers, transgenic
A fouryear followup of school children after masstreatment for Schistosomiasis and Soil Transmitted Helminths in Mwea, Central Kenya
Poly-parasitism infections are common in school children in tropical regions, especially in Africa. In a school based schistosomiasis and soil-transmitted helminths de-worming model project in Mwea, Kenya, approximately 40,000 school age children from 86 schools were treated annually with a standard dose of praziquantel (40mg/kg body weight) and albendazole (400mg). A cohort of approximately 2,300 children from 5 sentinel schools were followed up at multiple time points each year for four years and examined for intestinal helminths (Schistosoma mansoni, Trichuris trichiura, Hookworm (Necator americanus) and Ascaris lumbricoides). The overall prevalence of infection in the five schools before treatment was 47.4% for S. mansoni, 16.7% for N. americanus, 0.8% for T. trichiura and 1.7% for A. lumbricoides. The mean intensity of infection, as measured by eggs per gram of faeces (epg) was 146.2 for S. mansoni, 36.3 for N. americanus 1.0 for T. trichiura and 35.8 for A. lumbricoides. After 4 rounds of treatment, prevalence of S. mansoni reduced significantly by 88.7% to 5.4% (95%CI=3.6% -7.1%), a 97.1% reduction. The prevalence and intensity of S. mansoni infection varied by school according to its proximity to irrigated area, with those schools closest to the irrigated areas presenting higher infection prevalence and intensity. Re-infection with schistosomiasis following treatment was observed and is likely to reflect continued environmental transmission due to non-treatment of the adult population. Soil-transmitted helminths are less prevalent in the cohort, with corresponding lower intensity. This may allow albendazole treatment to be reduced to every 2 or 3 years. This study has shown that periodic administration of anthelminthic drugs reduces the prevalence and intensity (which is likely to be a close proxy of morbidity) of intestinal parasitic infections in school-age children. Adults in the community could also be targeted where resources allow in order to further increasing the effectiveness of de-worming programmes.
Keywords: Soil transmitted helminths, Schistosomiasis, school age, prevalence, Intensity, mass de-worming, school childre
A Fatal Outbreak of Campylobacter jejuni Enteritis in a Colony of Vervet Monkeys in Kenya
In a group of 50 wild-caught vervet monkeys trapped for experimental studies, 23 developed severe diarrhoea during the quarantine period. While 10 of these responded well to routine treatment with metronidazole, kaomycin and oral electrolytes, 13 initially showed slight improvement but later relapsed. Five of these failed to respond altogether and were euthanised. Fresh faecal samples were collected from the surviving eight monkeys and analysed for microbiology and drug sensitivity. Campylobacter jejuni, sensitive to erythromycin, was isolated from all the faecal samples. Following treatment with erythromycin, seven monkeys recovered fully within ten days but one died before the end of therapy. This study indicates that wild non-human primates may play a significant role as a reservoir of C. jejuni, whereby they may act as natural carriers of this human pathogen. Screening for Campylobacter sp in newly acquired monkeys is advisable as part of the quarantine procedures.
Whole genome analysis of local Kenyan and global sequences unravels the epidemiological and molecular evolutionary dynamics of RSV genotype ON1 strains
The respiratory syncytial virus (RSV) group A variant with the 72-nucleotide duplication in the G gene, genotype ON1, was first detected in Kilifi in 2012 and has almost completely replaced previously circulating genotype GA2 strains. This replacement suggests some fitness advantage of ON1 over the GA2 viruses, and might be accompanied by important genomic substitutions in ON1 viruses. Close observation of such a new virus introduction over time provides an opportunity to better understand the transmission and evolutionary dynamics of the pathogen. We have generated and analyzed 184 RSV-A whole genome sequences (WGS) from Kilifi (Kenya) collected between 2011 and 2016, the first ON1 genomes from Africa and the largest collection globally from a single location. Phylogenetic analysis indicates that RSV-A transmission into this coastal Kenya location is characterized by multiple introductions of viral lineages from diverse origins but with varied success in local transmission. We identify signature amino acid substitutions between ON1 and GA2 viruses within genes encoding the surface proteins (G, F), polymerase (L) and matrix M2-1 proteins, some of which were identified as positively selected, and thereby provide an enhanced picture of RSV-A diversity. Furthermore, five of the eleven RSV open reading frames (ORF) (i.e. G, F, L, N and P), analyzed separately, formed distinct phylogenetic clusters for the two genotypes. This might suggest that coding regions outside of the most frequently studied G ORF play a role in the adaptation of RSV to host populations with the alternative possibility that some of the substitutions are nothing more than genetic hitchhikers. Our analysis provides insight into the epidemiological processes that define RSV spread, highlights the genetic substitutions that characterize emerging strains, and demonstrates the utility of large-scale WGS in molecular epidemiological studies
Effect of a mobile phone intervention for female sex workers on unintended pregnancy in Kenya (WHISPER or SHOUT): a cluster-randomised controlled trial
Background: Female sex workers in low-income and middle-income countries face high risks of unintended pregnancy. We developed a 12-month, multifaceted short messaging service intervention (WHISPER) for female sex workers in Kenya who had the potential to become pregnant, to improve their contraceptive knowledge and behaviours. The aim of this study was to assess the effectiveness of the intervention to reduce the incidence of unintended pregnancy among sex workers in Kenya compared with an equal-attention control group receiving nutrition-focused messages (SHOUT).
Methods: Our two-arm, cluster-randomised controlled trial was done in sex-work venues in two subcounties of Mombasa, Kenya (Kisauni and Changamwe). Participants, aged 16–34 years, not pregnant or planning pregnancy, able to read text messages in English, residing in the study area, and who had a personal mobile phone with one of two phone networks, were recruited from 93 randomly selected sex-work venues (clusters). Random cluster allocation (1:1) to the intervention or control group was concealed from participants and researchers until the intervention started. Both groups received text messages in English delivered two to three times per week for 12 months (137 messages in total), as well as additional on-demand messages. Message content in the intervention group focused on promotion of contraception, particularly long-acting reversible contraception and dual method contraceptive use; message content in the control group focused on promotion of nutritional knowledge and practices, including food safety, preparation, and purchasing. The primary endpoint, analysed in all participants who were randomly assigned and attended at least one follow-up visit, compared unintended pregnancy incidence between groups using discrete-time survival analysis at 6 and 12 months. This trial is registered with Australian New Zealand Clinical Trials Registry, ACTRN12616000852459, and is closed to new participants.
Findings: Between Sept 14, 2016, and May 16, 2017, 1728 individuals were approached to take part in the study. Of these, 1155 were eligible for full screening, 1035 were screened, and 882 were eligible, enrolled, and randomly assigned (451 participants from 47 venues in the intervention group; 431 participants from 46 venues in the control group). 401 participants from the intervention group and 385 participants from the control group were included in the primary analysis. Incidence of unintended pregnancy was 15·5 per 100 person-years in the intervention group and 14·7 per 100 person-years in the control group (hazard ratio 0·98, 95% CI 0·69–1·39). Interpretation The intervention had no measurable effect on unintended pregnancy incidence. Mobile health interventions, even when acceptable and rigorously designed, are unlikely to have a sufficient effect on behaviour among female sex workers to change pregnancy incidence when used in isolation.
Funding: National Health and Medical Research Council of Australia
<i>Trypanosoma brucei rhodesiense</i> transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis
Sleeping sickness is caused by a species of trypanosome blood parasite that is transmitted by tsetse flies. To understand better how infection with this parasite leads to disease, we provide here the most detailed description yet of the course of infection and disease onset in vervet monkeys. One infected tsetse fly was allowed to feed on each host individual, and in all cases infections were successful. The characteristics of infection and disease were similar in all hosts, but the rate of progression varied considerably. Parasites were first detected in the blood 4-10 days after infection, showing that migration of parasites from the site of fly bite was very rapid. Anaemia was a key feature of disease, with a reduction in the numbers and average size of red blood cells and associated decline in numbers of platelets and white blood cells. One to six weeks after infection, parasites were observed in the cerebrospinal fluid (CSF), indicating that they had moved from the blood into the brain; this was associated with a white cell infiltration. This study shows that fly-transmitted infection in vervets accurately mimics human disease and provides a robust model to understand better how sleeping sickness develops
Methods for the sampling and analysis of marine aerosols: results from the 2008 GEOTRACES aerosol intercalibration experiment
Atmospheric deposition of trace elements and isotopes (TEI) is an important source of trace metals to the open ocean, impacting TEI budgets and distributions, stimulating oceanic primary productivity, and influencing biological community structure and function. Thus, accurate sampling of aerosol TEIs is a vital component of ongoing GEOTRACES cruises, and standardized aerosol TEI sampling and analysis procedures allow the comparison of data from different sites and investigators. Here, we report the results of an aerosol analysis intercalibration study by seventeen laboratories for select GEOTRACES-relevant aerosol species (Al, Fe, Ti, V, Zn, Pb, Hg, NO3-, and SO42-) for samples collected in September 2008. The collection equipment and filter substrates are appropriate for the GEOTRACES program, as evidenced by low blanks and detection limits relative to analyte concentrations. Analysis of bulk aerosol sample replicates were in better agreement when the processing protocol was constrained (+/- 9% RSD or better on replicate analyses by a single lab, n = 7) than when it was not (generally 20% RSD or worse among laboratories using different methodologies), suggesting that the observed variability was mainly due to methodological differences rather than sample heterogeneity. Much greater variability was observed for fractional solubility of aerosol trace elements and major anions, due to differing extraction methods. Accuracy is difficult to establish without an SRM representative of aerosols, and we are developing an SRM for this purpose. Based on these findings, we provide recommendations for the GEOTRACES program to and macro-nutrients to the open ocean (Okin et al. 2011) and is a key component of the international GEOTRACES program (GEOTRACES Planning Group 2006). A priority of the GEOTRACES program is to quantify both major and trace elements (e. g., Al, Fe, Ti, V, Zn, Pb, and Hg) and species such as nitrate and sulfate in marine aerosols. Therefore, marine aerosol samples collected during GEOTRACES cruises must follow sampling protocols that permit the collection and analysis of as many elements and compounds as possible, while meeting the constraints associated with basin-wide oceanographic cruises (e. g., space limitations, high-frequency sampling, etc.)
Testing public Bt maize events for control of stem borers in the first confined field trials in Kenya
Transgenic maize (Zea mays L), developed using modified genes from the bacterium Bacillus
thuringiensis (Bt), controls stem borers without observable negative effects to humans, livestock or
the environment, and is now sown on 134 million hectares globally. Bt maize could contribute to
increasing maize production in Kenya. Nine public Bt maize events of cry1Ab and cry1Ba genes were
tested in confined field trials site (CFTs) to assess the control of four major Kenyan stem borer
species. Leaf damage rating, number of exit holes and tunnel length were scored in the field
evaluations. Leaf area consumed and mortality rates among stem borers were scored in the leaf
bioassays in a Biosafety Level II laboratory, located at the Kenya Agricultural Research Institute
(KARI), National Agricultural Research Laboratories (NARL). Field evaluations showed that Bt maize
controlled Chilo partellus with mean damage scores of 1.2 against 2.7 for the non-Bt CML216 control.
Laboratory bioassays showed high control for Eldana saccharina and Sesamia calamistis, with mean
larval mortality of 64 and 92%, respectively. However, substantial control was not observed for
Busseola fusca. These results showed that Bt maize could control three of the four major stem borers
in Kenya with mortality records of 52.7% for B. fusca, 62.3% for E. saccharina and 85.8% for S.
calamistis. Additional Bt genes need to be sought and tested for effective stem borer control in all
maize growing ecologies in Kenya
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