Assessment of the solar radiation potential of the Thika and Nairobi area

This assessment seeks to provide information on the solar energy resource potential of the Thika – Nairobi area essential in the dissemination of Renewable Energy Technologies which are essentially solar photovoltaic and thermal systems. To achieve this, solar radiation data for three stations (Dagoretti Corner, Thika and Jomo Kenyatta International Airport (JKIA) has been collected and analyzed with the aim of assessing the solar radiation potential. The Thika station is at an altitude of 1500 m above sea level and located at (0°, 37° 41' East). Dagoretti Corner station is at 1795 m above sea level and at (01° 18' S, 36° 45' E). The JKIA station is at 1624 m above sea level and at (1° 19’ S, 36° 55' E). The longitudinal and latitudinal difference between these stations is small and that shows how close the stations are to one another. This facilitated the ease of comparison and categorization of the two regions. Data was collected using two instruments: the Gunn – Bellani and the pyranometer. The Gunn – Bellani registers radiation in terms of the amount of liquid distilled, whereas the pyranometer used registers solar radiation in terms of counts. The raw data was first converted to MJ/m2/day and then subjected to quality control procedures. After quality control procedures, the data was analyzed in terms of the average monthly daily insolation. Extraterrestrial solar radiation was estimated using an empirical formula and by using the values of the extraterrestrial solar radiation values of parameters like diffuse solar radiation and clearness index were calculated. Statistical parameters e.g. standard deviation, Skewness and coefficient of variation, were calculated using software to show the variability in the solar energy resource. The analysis shows that the study area has reliable solar energy resources with little variability. The average monthly daily insolation ranges from 3 kWh/m2/day to 7 kWh/m2/day. The national average of 4 – 6 kWh/m2/day from earlier studies falls within this range. The transparency of the sky estimated by the formula KT = H/Ho is also encouraging as it shows that there is little obstruction to the solar radiation. Diffuse solar radiation levels are also high and this shows that incase of obstruction, the diffuse solar radiation can be relied on. The abundance of the resource shows that it is feasible for applications of both solar photovoltaic technologies and solar thermal technologies.Key words: Insolation, declination, extraterrestrial, photovoltaic

Profile Of Bacteria And Fungi On Money Coins

Objectives: To determine the quantity and quality of bacterial and fungi on money coins and to identify those that could pose a public health risk.Design: Random sampling of coins from subjects within predetermined categories.Setting: Westlands division of Nairobi Metropolitan province.Subjects: Twenty-shilling coin samples were collected from matatu (a common commuter vehicle in Kenya) taxi conductors, greengrocers, shoe shiners, butchers, food kiosk/restaurant attendants, grocery shops attendants, roast maize vendors and school children. Forty coin samples were analysed for both the total viable content and the types of bacterial and fungal organisms.Results: Average bacterial content on the coins ranged from 2.3xl03 to 25.5x103 and fungi content from 11 to 377 colony forming units. The following potentially pathogenic bacteria were among those isolated: Escherichia coli, Klebsiella, Serratia, Enterobacter, Salmonella,Acinetobacter, Enterococci, Staphylococcus and Bacillus cereus. In addition, this is the first report of potentially pathogenic fungal isolation from money coins. Penicillium spp, Aspergillus niger, Fusarium, Rhizopus, Altenaria spp, Candida spp and Cryptococcus were isolated. Conclusion: Money coins harbour potentially pathogenic bacteria and fungi that may pose a public health risk. Hand hygiene is therefore strongly recommended, especially for those who simultaneously handle food and money

Plasmid Borne Resistance in Klebsiella Isolates from Kenyatta National Hospital, Nairobi, Kenya

Eighty six Klebsiella isolates from Kenyatta National Hospital and the Centre for Microbiology, Kenya Medical Research Institute, Nairobi were screened forresistance to commonly prescribed antimicrobial agents and for their plasmidcontent. Plasmids were transferred into Esherichia coli K-12 and resultingtransconjugants screened for resistance to the antimicrobial agents used onKlebsiella donors and for their plasmid content. Plasmids from the Klebsiellaisolates were also transformed into Eschericia coli and transformants analyzedfor resistance and plasmid content. Endonuclease restriction mapping was done to characterize the plasmids from Klebsiella isolates and their Eschericia coli transformants. Resistance was found to be plasmid borne and transmissible

Epilepsy diagnosis and management of children in Kenya: review of current literature

Introduction: The growing impact of non-communicable diseases in low- to middle-income countries makes epilepsy a key research priority. We evaluated peer-reviewed published literature on childhood epilepsy specific to Kenya to identify knowledge gaps and inform future priorities. Methodology: A literature search utilizing the terms “epilepsy” OR “seizure” as exploded subject headings AND “Kenya” was conducted. Relevant databases were searched, generating 908 articles. After initial screening to remove duplications, irrelevant articles, and publications older than 15 years, 154 papers remained for full-article review, which identified 35 publications containing relevant information. Data were extracted from these reports on epidemiology, etiology, clinical features, management, and outcomes. Results: The estimated prevalence of lifetime epilepsy in children was 21–41 per 1,000, while the incidence of active convulsive epilepsy was 39–187 cases per 100,000 children per year. The incidence of acute seizures was 312–879 per 100,000 children per year and neonatal seizures 3,950 per 100,000 live births per year. Common risk factors for both epilepsy and acute seizures included adverse perinatal events, meningitis, malaria, febrile seizures, and family history of epilepsy. Electroencephalography abnormalities were documented in 20%–41% and neurocognitive comorbidities in more than half. Mortality in children admitted with acute seizures was 3%–6%, and neurological sequelae were identified in 31% following convulsive status epilepticus. Only 7%–29% children with epilepsy were on antiseizure medication. Conclusion: Active convulsive epilepsy is a common condition among Kenyan children, remains largely untreated, and leads to extremely poor outcomes. The high proportion of epilepsy attributable to preventable causes, in particular neonatal morbidity, contributes significantly to the lifetime burden of the condition. This review reaffirms the ongoing need for better public awareness of epilepsy as a treatable disease and for national-level action that targets both prevention and management

Exposure to parasitic infections determines features and phenotypes of active convulsive epilepsy in Africa

Background: Epilepsy affects 70 million people worldwide, 80% of whom are in low-and-middle income countries (LMICs). Infections of the central nervous system (CNS) contribute considerably to the burden of epilepsy in LMICs, but the nature and presentation of epilepsy following these infections is not fully understood. We examined if epilepsy foutcomes are associated with the exposure to parasitic infections. Methods: This was a case-comparison study nested in a cross-sectional survey of people with active convulsive epilepsy, with cases as those exposed to parasitic infections, and comparison as those unexposed. Associations of exposure to parasites with clinical and electroencephalographic features of epilepsy were done using a modified mixed effects Poisson regression model across five sites in Africa. Multiplicative and additive scale (RERI) interactions were explored to determine the effect of co-infections on epilepsy features. Population attributable fractions (PAF) were calculated to determine the proportion of severe clinical and electroencephalographic features of epilepsy attributable to CNS infections. Results: A total of 997 participants with active convulsive epilepsy from the five African sites were analyzed, 51% of whom were males. Exposure to parasitic infections was associated with more frequent seizures in adult epilepsy (relative risk (RR)=2.58, 95% confidence interval (95%CI):1.71-3.89). In children, exposure to any parasite was associated with convulsive status epilepticus (RR=4.68, (95%CI: 3.79-5.78), intellectual disabilities (RR=2.13, 95%CI: 1.35-3.34) and neurological deficits (RR=1.92, 95%CI: 1.42-2.61). Toxoplasma gondii and Onchocerca volvulus interacted synergistically to increase the risk of status epilepticus (RERI=0.91, 95%CI=0.48-1.35) in the data pooled across the sites. Exposure to parasitic infections contributed to 30% of severe features of epilepsy as shown by PAF. Conclusions: Parasitic infections may determine features and phenotypes of epilepsy through synergistic or antagonistic interactions, which can be different in children and adults. Interventions to control or manage infections may reduce complications and improve prognosis in epilepsy

トピックス 5号 2001年8月号

Background Few hospitals in high malaria endemic countries in Africa have the diagnostic capacity for clinically distinguishing acute bacterial meningitis (ABM) from cerebral malaria (CM). As a result, empirical use of antibiotics is necessary. A biochemical marker of ABM would facilitate precise clinical diagnosis and management of these infections and enable rational use of antibiotics. Methods We used label-free protein quantification by mass spectrometry to identify cerebrospinal fluid (CSF) markers that distinguish ABM (n=37) from CM (n=22) in Kenyan children. Fold change (FC) and false discovery rates (FDR) were used to identify differentially expressed proteins. Subsequently, potential biomarkers were assessed for their ability to discriminate between ABM and CM using receiver operating characteristic (ROC) curves. Results The host CSF proteome response to ABM (Haemophilus influenza and Streptococcus pneumoniae) is significantly different to CM. Fifty two proteins were differentially expressed (FDR&lt;0.01, Log FC≥2), of which 83% (43/52) were upregulated in ABM compared to CM. Myeloperoxidase and lactotransferrin were present in 37 (100%) and 36 (97%) of ABM cases, respectively, but absent in CM (n=22). Area under the ROC curve (AUC), sensitivity, and specificity were assessed for myeloperoxidase (1, 1, and 1; 95% CI, 1-1) and lactotransferrin (0.98, 0.97, and 1; 95% CI, 0.96-1). Conclusion Myeloperoxidase and lactotransferrin have a high potential to distinguish ABM from CM and thereby improve clinical management. Their validation requires a larger cohort of samples that includes other bacterial aetiologies of ABM.</p

Relationship between Antibody Susceptibility and Lipopolysaccharide O-Antigen Characteristics of Invasive and Gastrointestinal Nontyphoidal Salmonellae Isolates from Kenya

Background: Nontyphoidal Salmonellae (NTS) cause a large burden of invasive and gastrointestinal disease among young children in sub-Saharan Africa. No vaccine is currently available. Previous reports indicate the importance of the O-antigen of Salmonella lipopolysaccharide for virulence and resistance to antibody-mediated killing. We hypothesised that isolates with more O-antigen have increased resistance to antibody-mediated killing and are more likely to be invasive than gastrointestinal. Methodology/Principal findings: We studied 192 NTS isolates (114 Typhimurium, 78 Enteritidis) from blood and stools, mostly from paediatric admissions in Kenya 2000-2011. Isolates were tested for susceptibility to antibody-mediated killing, using whole adult serum. O-antigen structural characteristics, including O-acetylation and glucosylation, were investigated. Overall, isolates were susceptible to antibody-mediated killing, but S. Enteritidis were less susceptible and expressed more O-antigen than Typhimurium (p\u3c0.0001 for both comparisons). For S. Typhimurium, but not Enteritidis, O-antigen expression correlated with reduced sensitivity to killing (r = 0.29, 95% CI = 0.10-0.45, p = 0.002). Both serovars expressed O-antigen populations ranging 21-33 kDa average molecular weight. O-antigen from most Typhimurium were O-acetylated on rhamnose and abequose residues, while Enteritidis O-antigen had low or no O-acetylation. Both Typhimurium and Enteritidis O-antigen were approximately 20%-50% glucosylated. Amount of S. Typhimurium O-antigen and O-antigen glucosylation level were inversely related. There was no clear association between clinical presentation and antibody susceptibility, O-antigen level or other O-antigen features. Conclusion/Significance: Kenyan S. Typhimurium and Enteritidis clinical isolates are susceptible to antibody-mediated killing, with degree of susceptibility varying with level of O-antigen for S. Typhimurium. This supports the development of an antibody-inducing vaccine against NTS for Africa. No clear differences were found in the phenotype of isolates from blood and stool, suggesting that the same isolates can cause invasive disease and gastroenteritis. Genome studies are required to understand whether invasive and gastrointestinal isolates differ at the genotypic level

Differing Burden and Epidemiology of Non-Typhi Salmonella Bacteremia in Rural and Urban Kenya, 2006–2009

BACKGROUND: The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. METHODS: As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006-2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured. RESULTS: NTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy. CONCLUSIONS: NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa