Journal Articles

Permanent URI for this collection

https://repository.daystar.ac.ke/handle/123456789/2918

Browse

Now showing 1 - 20 of 116

Effect of Surface Passivation on Electrical Properties of Pd-F:SnO2 Thin Films Prepared by Spray Pyrolysis Technique
(coatings, 2014-11) Mwathe Patrick, Musembi Robinson, Munji Mathew, Odari Victor, Munguti Lawrence, Ntilakigwa Alex, Nguu John & Muthoka Boniface
Pd-F:SnO2 thin films have been prepared by spray pyrolysis technique. Optimization has been done by doping SnO2 with palladium at varying levels of concentration and then recording sheet resistance. The sheet resistivity has been observed to decrease gradually as at% Pd concentration is increased; an optimum sheet resistivity value of 2.71 × 10−2 Ω cm has been recorded. The decrease in sheet resistivity has been attributed to presence of Pd ions which contribute in increment of charge carrier density. Using the optimum value of at% Pd doping, the same procedure has been repeated to study the effect of fluorine on Pd:SnO2; an optimum value of 1.64 × 10−4 Ω cm sheet resistivity has been recorded. This decrease has been attributed to substitution of O− with those of fluorine hence improving charge carrier density. The effect of passivation has been studied by comparing as prepared, annealed and passivated Pd-F:SnO2 thin films. Annealing has been observed to decrease the sheet resistivity to 1.21 × 10−4 Ω cm, while passivation has the effect of increasing the sheet resistivity to 1.53 × 10−4 Ω cm which is attributed to effects resulting from annealing the samples in nitrogen gas atmosphere.
Mosquito Diversity In The Nairobi – Kenya Urban Environment And Implications For Disease Transmission
(Research Gate, 2020-05) Kinuthia Geoffrey K, Ngure Veronica N, Kamau Luna, Beti Dunson, Lugalia Reuben, Wangila Agnes, Ngari Florence W, Mburu Faith W., and Kiarie Martha W
Mosquito surveillance and control efforts especially those carried out under programmatic settings by mosquito control departments of governments in many situations in Africa tend to focus on rural locales, mainly because this is where mosquito transmitted diseases have been found to be prevalent. In a recent study, we found an abundance of mosquitogenic conditions conducive for mosquito breeding in Nairobi in areas in close proximity to informal settlements, similar to previous studies. Thirteen different mosquito species were identified with Culex pipiens accounting for over 97% of the 7,605 mosquitoes sampled. Implications for disease transmission within the context of climate change and other factors are discussed. The evidence points to the need for enhanced vector surveillance and control in urban environments to minimize the risk of emergence and resurgence of mosquito-borne diseases.
Factors Encouraging The Use Of Insecticide Treated Bed-Nets By Women For Malaria Control in Ndavaya and Kinango Divisions of Kinango District of Kenya
(Journal of Sociology , Psychology and Anthropology in Practice, 2011) Mwanzo, I. Kimathi, G. and Affullo, A.
The aim of this study was to investigate and compare the factors that influence the use of Insecticide Treated Bed-Nets (ITNs) by women for malaria control in Ndavaya and Kinango Divisions of Kinango District of Kenya. A cross-sectional survey design using systematic sampling technique was applied to collect data from 204 women selected randomly from the two divisions. Semi structured questionnaire, Key Informant Interview and Focused Group Discussion were the instruments used to gather data. Data on variables such as age, educational level, incomes and source of nets were summarized using graphs. Chi-square test was applied to test whether the deviations observed were as a result of chance or due to other factors. Results indicated among others that the use of ITNs increased with the level of education and income. The government therefore should develop a communication package for malaria endemic areas, encourage further research to establish the factors that influence use of ITNs as well as explore the efficacy of indigenous malaria control mechanisms, using the appropriate government agencies.
Levels of heavy metals in wastewater and soil samples from open drainage channels in Nairobi, Kenya: community health implication
(Scientific Reports, 2020) Kinuthia Geoffrey K., Ngure Veronica, Beti Dunstone, Lugalia Reuben, Wangila Agnes & Kamau Luna
Levels of Mercury (Hg), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni) & Thallium (Tl) were established in wastewater & soil samples obtained from 8 sites in open drainage channels at Nairobi industrial area, Kenya. Ultra-trace inductively coupled plasma mass spectroscopy (ICP-MS) was used for metal analysis. Temperature, pH & turbidity of wastewater ranged from 16.75 to 26.05 °C; 7.28 to 8.78; 160.33 to 544.69 ppm respectively and within World Health Organization (WHO) allowable limits. Wastewater conductivities in 4 sites ranged from 770 to 1074 μS/cm and above WHO limits at 25 °C. The mean concentrations of the metals in wastewater ranged from 0.0001 to 0.015 ppm in an ascending order of Tl
Characterization and comparison of leishmania-like isolates from rodents, lizards and sand flies caught at Masinga location in Machakos district, Kenya
(Afr J Health Sci., 2011) Kinuthia Geoffrey K., Lugalia Reuben M., Mwanyumba Panuel J., Ngeiywa Moses M., Wishitemi Bob L., Tonui Willy K. & Anjili Christopher O.
A laboratory based study was designed to characterize 43 cryo-preserved Leishmania-like flagellates. These Leishmania-like flagellates were originally obtained from non-human hosts that included spiny mice (Acomys subspinosus), plated lizards (Gerrosaurus major) and sand flies of the Genus Sergentomyia caught at Masinga location, Machakos District in Kenya. Morphological features and isoenzyme banding patterns of the flagellates were studied. The isoenzyme markers which were used for isoenzyme electrophoresis included Malate dehydrogenase (MDH), Phosphoglucomutase (PGM), Glucose phosphate isomerase (GPI), Glucose 6-phosphate dehydrogenase (G6PD), Malic enzyme (ME), 6 phosphogluconate dehydrogenase (6PGD) and Mannose phosphate isomerase (MPI). The isoenzyme banding patterns of the flagellates’ lysates were compared with those of six WHO Leishmania reference strains and those of seven well characterized reference strains of Trypanosoma, Crithidia, Herpetomonas and Leptomonas species. The results showed that the morphological changes of the Leishmania-like flagellates in the growth medium were indistinguishable from those of Leishmania WHO reference strains used. The isoenzyme profiles of the flagellates were all distinguishable from the reference strains used except for isolate NLB-1236 from G. major which had an enzyme profile identical to that of L. tropica (NLB-305) in 6 enzymes (MDH, GPI, MPI, ME, PGM, and G6PD). The banding pattern of isolate NLB-1261 from A. subspinosus was indistinguishable from that of L. major (NLB-326) in 3 enzymes only (MDH, GPI and ME) while isolate NLB-1231 from A. subspinosus had an enzyme profile identical to those of L. tropica (NLB-305) and L. arabica (NLB-664) in six enzymes (MDH, GPI, ME, PGM, MPI, and 6PGD). More than 80% of the Leishmania-like flagellates had enzyme profiles indistinguishable from each other, in all the isoenzyme markers. The morphological traits of the flagellates suggested that they were Leishmania or strains closely related to Leishmania. Isoenzyme analysis suggested that Sergentomyia sand flies most likely feed on both lizards (reptiles) and rodents (mammals). There is need to carry further investigations on NLB-1236 (from plated lizards), NLB-1261 (from wild spiny mice) and NLB-1231 (from wild spiny mice).
Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open drainage channels in Nairobi industrial area, Kenya
(BMC Ecology and Evolution, 2021) Kinuthia Geoffrey Kariuki, Ngure Veronica and Kamau Luna
Background: Industrial wastewater is a human health hazard upon exposure. Aquatic organisms in contaminated wastewater may accumulate the toxic elements with time. Human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms in open drainage channels can be key in metal exposure assessment. Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) were established in samples of wastewater, filamentous green algae (Spirogyra) and mosquitoes obtained from open drainage channels in Nairobi industrial area, Kenya. Results: Pb, Cr, & Ni levels ranged from 3.08 to 15.31 μg/l while Tl, Hg, & Cd ranged from 0.05 to 0.12 μg/l in wastewater. The Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3–2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/kg & 1.8 mg/kg respectively) were higher than in field mosquitoes (0.048 mg/kg & 0.12 mg/kg respectively). The levels of Pb, Cr, & Ni were distinctively higher in field mosquito samples than in wastewater samples from the same site. Pb, Cr, Ni, Cd & Hg levels in green filamentous Spirogyra algae were 110.62, 29.75, 14.45, 0.44, & 0.057 mg/kg respectively. Correlation for Pb & Hg (r (2) = 0.957; P < 0.05); Cd & Cr (r (2) = 0.985; P < 0.05) in algae samples was noted. The metal concentrations in the samples analyzed were highest in filamentous green algae and least in wastewater. Conclusion: Wastewater, mosquitoes, and filamentous green algae from open drainage channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Mosquitoes in urban areas and filamentous green algae in open drainage channels can play a role of metal biomonitoring in wastewater. The potential of urban mosquitoes transferring heavy metals to human population from the contaminated wastewater should be investigated.
Toxicity and efficacy of aqueous crude extracts from Allium sativum, Callistemon citrinus and Moringa stenopetala against L. Major
(Kabarak Journal of Research & Innovation, 2015) Kinuthia K. Geoffrey, Anjili O. Christopher, Kabiru W. Ephantus , Kigondu M. Elizabeth , Ingonga M. Johnny & Gikonyo K. Nicholas
Cutaneous leishmaniasis (CL) treatment involves pentavalent antimonials, amphotericin B, pentamidine, miltefosine among others. These drugs are toxic, costly, and require prolonged use. CL is a protozoan skin infection which may lead to disfiguring and stigmatization. In Kenya, CL is common in Baringo County where it is caused by Leishmania major and transmitted by infected female phlebotomine sand fly. Leishmaniases are common in poverty stricken areas where victims opt for local herbal therapies. Herbs used haven’t been tested scientifically to verify their toxicity and efficacy. The current study determines in vitro toxicity and in vivo efficacy of aqueous crude extracts of Moringa stenopetala, Callistemon citrinus, and Allium sativum against L. major. The IC50 of aqueous extracts against promastigotes ranged from 297μg/ml to 575μg/ml compared to Pentostam and liposomal amphotericin B with IC50 of 0.26μg/ml and 0.82μg/ml respectively. The viability of promastigotes upon exposure to extracts ranged from 52.55% to 60.57%. Similarly the IC50 of extracts against vero cells ranged between 467μg/ml to 2105μg/ml compared to 108μg/ml and 60μg/ml for pentostam and liposomal amphotericin B respectively. Orally administered A. sativum reduced L. major caused footpad lesions significantly (P < 0.05) when compared to control PBS. The efficacy of oral C. citrinus extracts (B) in reducing amastigotes in spleens of infected BALB/c mice was 82.99%, followed by oral M. stenopetala (A) at 66.96% and oral A. sativum (C) at 60.37% compared to pentostam and liposomal amphotericin B at 66.40% and 60.62% respectively. The difference between the mean total LDUs for aqueous oral C. citrinus extracts and control oral PBS was significant (P = 0.017). It was concluded that crude aqueous extracts of A. sativum, M. stenopetala, and C. citrinus show antileishmanial activity at low toxicity. Inclusion of garlic and moringa in the diets of people in leishmaniases foci should be emphasized.
Selected practices among rural residents versus the prevalence of Amoebiasis and Giardiasis in Njoro Distrct, Kenya
(African Journal of Health Sciences, 2012) Kinuthia G.K., Afolayan F.I.D., Ngure V., and Anjili C.O
The study was designed to investigate on selected practices among rural population, and their likely contribution to the spread of amoebiasis (E. histolytica) and giardiasis (G. lamblia). A cross sectional study was carried out in three villages, namely Kikapu, Piave and Belbar in Njoro District, Kenya. Questionnaire, interviews and personal observations were used to obtain data from 336 randomly selected consenting individuals in homesteads in the three villages. A retrospective study was further carried out to establish the prevalence of E. histolytica and G. lamblia among outpatients attending two randomly selected health centers in the study area. Majority of the respondents’ highest education level was basic primary school education (61%), unemployment (98%) and with a monthly expenditure of less than 2200 Kenya Shillings or 28 US Dollars (81%). Eighty percent of the respondents were classified under low economic status. Eighty two percent reported lack of piped water and boiling of drinking water was less likely to occur among the low economic status respondents (Odds ratio (OR) = 0.423, 2 = 9.88; 95% CI of -5.74 to 6.58). However, washing of hands with soap after using a latrine seemingly was not influenced by economic status of the respondents (OR = 1; 2 = 0; 95% CI = 0). The level of education seemed to influence on the adoption of risky practices, such as, failure to boil drinking water was more likely to occur among respondents who had a low academic level (OR = 0.84, 2 = 0.04, 95% CI of -2.27 to 3.95). The stool tests records at Njoro PCEA health center showed that the prevalence of E. histolytica (20.83%) and G. lamblia (20.32%) were higher than the corresponding prevalence at Njoro County Council health center which were 1.34% and 0.00% respectively. Concurrent infections of E. histolytica and G. lamblia were absent in the two health centers. The trend of E. histolytica and G. lamblia followed an alternating pattern, in which an increase in one directly corresponded to a decrease in the other and vice versa in the two health centers. It was concluded that poverty and low education levels were significant factors that influenced on the adoption of risky lifestyles that were likely to enhance parasitic infections. There is a need for reliable diagnostic methods other than direct microscopy for E. histolytica and G. lamblia stool tests in order to minimize the wide variation of the results in the two health centers. Public health education should also be enhanced to discourage the adoption of risky practices.
Survey of urban mosquitoes species (Diptera: Culicidae) with focus on waste water channels as larval habitats in Nairobi industrial area, Kenya
(African Journal of Health Sciences, 2017) Geoffrey K.K., Ngure N.V., Kamau L., Bet Di., Lugali Ra., Wangila A., Ngari W.F., Mburu W.F.,and Kiarie W.M
Background:A cross sectional study to establish the levels of heavy metals and other potentially harmful elements (PHEs)present in samples obtained from selected open waste water channels in Nairobi industrial area (Kenya) was carried out. The waste water channels selected were those near the factories or those directly discharging from factories. The samples collected included mosquitoes (larvae and adults), waste water, green algae, and soil. Unmaintained open waste water channels are among the man made features that enhance the breeding of urban mosquitoes because they tend to have overgrown vegetation and trapped solid wastes which slow or inhibit the waste water flow. Different mosquito species have previously transmitted arboviruses including those responsible for dangerous fevers such as West Nile, Rift Valley, Zika, Dengue, Yellow, and Chikungunya among others in different parts of the world. The study area (Nairobi industrial area) neighbors several densely populated informal human settlements. This paper specifically reports on composition and distribution of mosquito species obtained from the study area. Methods:The fourth instars mosquito larvae were collected from waste water channels using the standard dipping method. Adult mosquitoes were trapped using the center for disease control and prevention (CDC) light traps. Purposive random sampling for mosquito adults and larvae was carried out in industrial premises and waste water channels respectively at seven locations. This involved selecting sampling sites from which mosquito samples were likely to be obtained. The mosquitoes were then microscopically identified using taxonomic keys for the Ethiopian and East African region. Results:Out of 2,926 adult mosquitoes trapped, 12 species were identified including Cx. pipiens (95%); Cx. Vansomereni (2.6%); Cx. zombaensis (1.4%); Cx. univittatus (0.34%); Cx. theileri (0.21%); Ae. aegpti (0.14%); An. maculipalpis (0.03%); An. squamosus (0.03%) and other culicid species (0.20%). Of these adult mosquitoes,94% (2753/2926) were females and 6% (173/2926) were males giving a male: female ratio of 1: 16 when using CDC traps. Of the 4,679 mosquito larvae scooped from the waste water channels, 4 species were identified including Cx. pipiens (99.34%); Cx. vansomereni (0.51%); Toxorhynchites brevipalpis (0.13%) and Aedes mosquito (0.02%). Conclusion:The majority of mosquito species obtained were culicid, Culex pipiens for both adults and larvae. A few Anopheles and Aedes populations were obtained. Unmaintained open waste water channels seen\med to enhance the breeding of urban mosquitoes in the study area. The ecology of these mosquitoes should be studied further to enhance surveillance and controlin order to minimize the risk of mosquito borne viral infections or any other re-emerging mosquito-borne infections to the residents of Nairobi, in particular those living in the informal settlements near Nairobi industrial area, Kenya.
Selected practices among rural residents versus the prevalence of Amoebiasis and Giardiasis in Njoro Distrct, Kenya.
(African Journal of Health Sciences, 2012) Kinuthia G.K, Afolayan F.I.D, Ngure V and Anjili C.O
The study was designed to investigate on selected practices among rural population, and their likely contribution to the spread of amoebiasis (E. histolytica) and giardiasis (G. lamblia). A cross sectional study was carried out in three villages, namely Kikapu, Piave and Belbar in Njoro District, Kenya. Questionnaire, interviews and personal observations were used to obtain data from 336 randomly selected consenting individuals in homesteads in the three villages. A retrospective study was further carried out to establish the prevalence of E. histolytica and G. lamblia among outpatients attending two randomly selected health centers in the study area. Majority of the respondents’ highest education level was basic primary school education (61%), unemployment (98%) and with a monthly expenditure of less than 2200 Kenya Shillings or 28 US Dollars (81%). Eighty percent of the respondents were classified under low economic status. Eighty two percent reported lack of piped water and boiling of drinking water was less likely to occur among the low economic status respondents (Odds ratio (OR) = 0.423, 2 = 9.88; 95% CI of -5.74 to 6.58). However, washing of hands with soap after using a latrine seemingly was not influenced by economic status of the respondents (OR = 1; 2 = 0; 95% CI = 0). The level of education seemed to influence on the adoption of risky practices, such as, failure to boil drinking water was more likely to occur among respondents who had a low academic level (OR = 0.84, 2 = 0.04, 95% CI of -2.27 to 3.95). The stool tests records at Njoro PCEA health center showed that the prevalence of E. histolytica (20.83%) and G. lamblia (20.32%) were higher than the corresponding prevalence at Njoro County Council health center which were 1.34% and 0.00% respectively. Concurrent infections of E. histolytica and G. lamblia were absent in the two health centers. The trend of E. histolytica and G. lamblia followed an alternating pattern, in which an increase in one directly corresponded to a decrease in the other and vice versa in the two health centers. It was concluded that poverty and low education levels were significant factors that influenced on the adoption of risky lifestyles that were likely to enhance parasitic infections. There is a need for reliable diagnostic methods other than direct microscopy for E. histolytica and G. lamblia stool tests in order to minimize the wide variation of the results in the two health centers. Public health education should also be enhanced to discourage the adoption of risky practices
Lifestyles and Practices that Enhance Malaria and Typhoid Fever in Njoro District, Kenya
(Journal of Community Health, 2011-07) Kinuthia Geoffrey Kariuki, Gicheru Michael Muita, Ngure Peter Kamau and Kabiru Ephantus Wanjohi
Unhygienic practices have been associated with the spread of parasitic and bacterial infections in rural areas. This study was designed to verify the link between the frequencies of malaria and typhoid fever with selected rural practices in Njoro District, Kenya. A cross-sectional study involving observations, questionnaires and interviews was conducted to determine the socio-economic variables and practices/lifestyles in 336 randomly selected homesteads. Frequencies of malaria and typhoid fever in two randomly selected health centers were determined through a retrospective study for the period from 2004 to 2009. The respondents had large families (68%), low education level (67%) and high responsibility burden (67%). Individuals who did not boil drinking water constituted 61%. Boiling drinking water was less common among the poor, Odds Ratio (OR) of 2.36, v2 = 9.88, 95% Confidence Interval (CI) of 1.38–4.03. Respondents who washed their hands in a basin after using the latrines comprised 79.8% while 4.8% did not. 18.5% of the
In vitro and in vivo activities of blends of crude aqueous extracts from Allium sativum L, Callistemon citrinus (Curtis) Skeels and Moringa stenopetala (Baker F) Cufodontis against Leishmania major
(Int. J. Med. Arom. Plants, 2013-06) KINUTHIA Geoffrey K., ANJILI Christopher O., GIKONYO Nicholas K., KIGONDU Elizabeth M., INGONGA Johnstone M., KABIRU Ephantus W.
Leishmania major caused cutaneous leishmaniasis leads to painful skin sores in humans and usual drugs are expensive, toxic, and require prolonged use. The in vitro and in vivo efficacy of aqueous crude extracts from Callistemon citrinus flowers (B), Allium sativum bulbs (C) and Moringa stenopetala leaves (A) against L. major was studied. Controls were pentostam, liposomal amphotericin B, and phosphate buffered saline (PBS). Dried and ground plant materials were soaked in distilled water at 70oC for 1.5 hours, filtered and freeze dried to obtain aqueous extracts. L. major infected BALB/c mice were treated orally or intra peritoneally (ip) with blends of the extracts. Minimum inhibitory concentrations (MICs) of single extracts ranged from 3 to 5mg/ml while IC50 from 297 to 575μg/ml compared to MICs of 12.50 and 6.25μg/ml and IC50 of 0.26 and 0.82μg/ml for pentostam and liposomal amphotericin B respectively. Blends of M. stenopetala and C. citrinus (AB), M. stenopetala and A. sativum (AC), and C. citrinus and A. sativum (BC) at concentrations based on MICs of individual extracts were active at ratios 1:1, 1:9 and 1:1 with promastigotes’ viabilities of 33.82%, 17.41% and 60.74 % respectively. IC50 for blends AB, AC, and BC ranged from 174μg/ml to 1314μg/ml against promastigotes. The individual extracts comprising blends AB, AC and BC interacted additively and synergistically in several combination ratios. Blend AC (1:1) at 125μg/ml had in vitro infection rate (IR) of 71% and multiplication index (MI) of 48.20% for L. major amastigotes compared to IR of 67% and MI of 47.51% for pentostam at 12.50μg/ml. Oral blend BC (1:1) reduced the mice footpad lesion size significantly (P < 0.05). Both oral blends BC and AC reduced mice spleen amastigotes by 48.33% and 60.94% with total LDUs of 6.35 ± 0.66 and 4.80 ± 0.95 respectively. Oral blend AB (1:1) lowered spleen amastigotes by 6.5% with total LDU of 11.49 ± 6.84. In conclusion, aqueous blends of C. citrinus, A. sativum and M. stenopetala extracts that interacted additively or synergistically were less toxic but active against L. major.
In vitro activity of aqueous and methanol extracts of Callistemon citrinus (Family Myrtaceae) against Leishmania major
(African Journal of Health Sciences, 2014-04) Kinuthia, G K., Kabiru, E. W ., Gikonyo, N. K ., Ingonga, J. M ., Kigondu, E. M, Anjili, C. O
Leishmania major is a protozoan parasite that causes cutaneous leishmaniasis and the standard drugs are expensive and toxic. Cheaper and safer natural drugs are therefore needed. In this study, the in vitro efficacy of crude extracts of Callistemon citrinus were tested against L. major. Controls were anti leishmanial drugs pentostam and liposomal amphotericin B. The minimum inhibitory concentrations of C. citrinus crude aqueous and methanolic extracts were 5mg/ml and 1mg/ml respectively compared to 12.5μg/ml and 6.25μg/ml for pentostam and liposomal amphotericin B respectively. The IC50 for C. citrinus extracts against promastigotes ranged from 297.75 to 572.69μg/ml compared to 0.26 and 0.82μg/ml for pentostam and liposomal amphotericin B. The IC50 for C. citrinus extracts against vero cells ranged from 467μg/ml to 1314.65μg/ml. The promastigotes’ viability after treatment with aqueous and methanolic extracts was 69.58% and 75.74% respectively. At 125μg/ml, the aqueous and methanolic C. citrinus extracts had in vitro amastigotes’ infection rates (IRs) of 77.0±2.50 % and 77.5±3.50% respectively. The multiplication indices (MIs) and IRs of amastigotes treated with C. citrinus crude aqueous extracts and those treated with crude methanolic extracts differed insignificantly (P > 0.05). C. citrinus methanolic extracts stimulated production of about 20μM nitric oxide in BALB/c mice peritoneal macrophages suggesting immuno-modulatory role of the extracts. The crude aqueous and methanolic extracts of C. citrinus were therefore concluded to be relatively less toxic and possessed in vitro anti-leishmanial activity against L. major promastigotes and amastigotes.
Efficacy of crude methanolic extracts of Allium sativum L. and Moringa stenopetala (Baker f.) Cufod. against Leishmania major
(Int. J. Med. Arom. Plants, 2014-03) KINUTHIA Geoffrey K., KABIRU Ephantus W., ANJILI Christopher O., KIGONDU Elizabeth M., NGURE Veronica N., INGONGA Johnstone M., GIKONYO Nicholas K.
Leishmania major is a protozoan parasite responsible for cutaneous leishmaniasis (CL) in humans. CL is transmitted via a bite by infected female phlebotomine sand fly. Research on herbal therapy for leishmaniases is increasing globally because conventional drugs are costly, toxic and require a prolonged administration. In vitro and in vivo antileishmanial activities of dried Allium sativum (garlic) and Moringa stenopetala methanolic extracts against L. major were studied. Minimum inhibitory concentrations (MICs) of methanolic extracts of A. sativum (A) and M. stenopetala(M) against L. major were 3 and 5 mg/ml and IC50 of 863.12 and 1752.92 μg/ml respectively. The blend AM (1:1) hadIC50 of 372.1μg/ml and promastigotes’ viability of 71.03% compared to IC50 of 0.26 and 0.82μg/ml and promastigotes’viability of 18.41% and 12.22% for Pentostam and Liposomal amphotericin B respectively. Multiplication indices (MIs) of L. major amastigotes ranged from 43.67% to 45.93% after treatment with extracts A or M or blend AM at 125μg/ml and were significantly different (P < 0.05) from Liposomal amphotericin B at 12.5μg/ml. Oral extract A reduced significantly (P > 0.05) L. major caused foot pad lesions in BALB/c mice while oral extract M did not. Blend AM (ip) reduced the lesion sizes and its efficacy was close to Pentostam and Liposomal amphotericin B. Oral extract A had a high parasite reduction rate of 60.70% and average LDU of 0.22±0.15 compared to Pentostam at 66.40% and LDU of 0.18±0.08. In conclusion, methanolic extract of A. sativum showed anti-leishmanial activity both in vitro and in vivo and it decreased L. major caused foot pad lesions in BALB/c mice. Methanolic extracts of M. stenopetala (ip) reduced the amastigotes burden in spleens of BALB/c mice. A blend of garlic and moringa methanolic extracts (AM at 1:1) were active against L. major. The active ingredients in crude methanolic extracts of garlic and moringa plants should be established and tested against L. major when blended.
Efficacy Of Combination Therapy Using Extracts Of Aloe Secundiflora Eng L. And Callistemon Citrinus William C. In Leishmania Major Infected Balb/C Mice
(East African Medical Journal, 2016-03) NDETI C. M., KITUYI C., NDIRANGU M., INGONGA J., CHIMBEVO M. L., OCHIENG J. O., BARASA M., KINUTHIA G., MAINA E. M., NYAMBATI V. C. S. and ANJILI C. O.
Background: Leishmania major causes cutaneous leishmaniasis which leads to painful skin sores in humans. In the current study, efficacy of combination therapy of A. secundiflora and C. citrinus against L. major infected mice treated intra-peritoneally and orally was studied. Pentostam administered intra-peritoneally and phosphate buffered saline intra-peritoneally and orally were used as a controls. Objective: To determine the efficacy of combined therapy of C. citrinus and A. secundiflora extracts in Leishmania major infected BALB/c mice. Design: Experimental-Laboratory based study Setting: Kenya Medical Research Institute (Leishmania Department) Subjects: Eight weeks Male BALB/c Mice Results: The minimum inhibitory concentration (MICs) of aqueous extracts of A. secundiflora (A), and C. citrinus (B) were 2 mg/ml and 5 mg/ml respectively while the IC50 for the same extracts were 467.09μg/ml and 457.88μg/ml respectively. The combination of these extracts at ratio (1:1) supported minimal growth of L. major promastigotes and had IC50 of 58.45μg/ml as compared to MICs of 12.50μg/ml for Pentostam. The combination therapy had Infection rate (IR) of 19% and MI of 52.81% compared to Pentostam (IR=21% and MI=11.64%). The combination therapy reduced the footpad lesion size significantly (P < 0.05) just like the Pentostam control drug and no significant nitric oxide was stimulated. The oral and intra-peritoneal combination treatment reduced spleen amastigotes in mice by 73.46% and 78.12% corresponding to total LDUs of 10.87±0.64 and 8.96±0.82 respectively compared to Pentostam at 94.58% and LDU of 2.22±0.13. The difference between efficacy of Pentostam and that of combined extracts was almost significant (t= 2.653, P= 0.057). Conclusion: The combination therapy was active against L. major parasite, reduced lesion size significantly and did not prevent visceralisation but reduced spleen parasite load significantly.
SPARC the Change: What the Strategic Purchasing Africa Resource Center Has Learned about Improving Strategic Health Purchasing in Africa
(Health Systems & Reform, 2022) Cashin Cheryl , Kimathi George, Otoo Nathaniel, Bloom Danielle & Munyua Agnes Gatome
Embodied in the goals of universal health coverage (UHC) are societal norms about ethics, equity, solidarity, and social justice. As African countries work toward UHC, it is important for their governments to use all available resources, knowledge, and networks to continue to bring this goal closer to reality for their populations. The Strategic Purchasing Africa Resource Center (SPARC) was established in 2018 as a “go-to” source of Africa-based expertise in strategic health purchasing, which is a critical policy tool for making more effective use of limited funds for UHC. SPARC facilitates collaboration among governments and research partners across Africa to fill gaps in knowledge on how to make progress on strategic purchasing. The cornerstone of this work has been the development and use of the Strategic Health Purchasing Progress Tracking Framework to garner insights from each country’s efforts to make health purchasing more strategic. Application of the framework and subsequent dialogue within and between countries generated lessons on effective purchasing approaches that other countries can apply as they chart their own course to use strategic purchasing more effectively. These lessons include the need to clarify the roles of purchasing agencies, define explicit benefit packages as a precondition for other strategic purchasing functions, use contracting to set expectations, start simple with provider payment and avoid open-ended payment mechanisms, and use collaborative rather than punitive provider performance monitoring. SPARC has also facilitated learning on the “how-to” and practical steps countries can take to make progress on strategic purchasing to advance UHC.
Concentration levels of potentially harmful elements fromgold mining in Lake Victoria Region, Kenya: Environmental and health implications
(Journal of Geochemical Exploration, 2014) Ngure Veronica, Davies Theophilus, Kinuthia Geoffrey, Sitati Noah, Shisia Silvanus and Okoth Elijah Oyoo
Second only to the agricultural industry, mining is often considered to be the largest source of pollution in most mineral-rich countries. Minewastes and tailings commonly generate large concentrations of effluents containing high levels of potentially harmful elements (PHEs) which migrate into various compartments of the ecosystem with obvious undesirable health consequences. In this study, the concentrations of As Cd, Hg and Pb were determined on samples of soil, stream water and fish (Rastrineobola argentea) collected from the Migori Gold Belt (MGB) in Kenya. Maximum total concentrations of Cd, Pb, As and Hg recorded in some samples in the study area were found to be far above the World Health Organization (WHO) and the Food and Agriculture Organisation (FAO) maximum allowable concentrations (MAC), respectively, including some from the control site, 150 km away from the MGB. The calculated geometric means showed that the PHE concentrations were significantly above MAC levels (p b 0.05) in the three sample types. The PHE concentrations were as follows: in water, Cd: 1.5–10.5 μg l−1, Pb: 0.4–13.1 μg l−1, As: 0.06–23.0 μg l−1, and Hg: 0.36–52.1 μg l−1; in soil, Cd: 4.5–570 mg kg−1, Pb: 5.9–619 mg kg−1, As: 0.08–86.0 mg kg−1, and Hg: 0.51–1830 mg kg−1; and in fish; Cd, 1.9–10.1 mg kg−1, Pb: 2.0–13.1 mg kg−1, As: 0.02–1.92 mg kg−1, and Hg: 0.26–355 mg kg−1. Concentrations of PHEs were much higher in the area affected by gold mining area than at point S4 which was sampled for comparison and was 70 km away from the gold mining area. We conclude that gold mining and other human activities in the MGB have led to the release of toxic levels of Cd, Pb, As and Hg, which may lead to serious environmental health consequences in humans. We recommend that the public health sector addresses in a timely fashion, these sources of contamination (gold mining and associated human activities), in order to obviate impending health problems.
Willingness and Ability to Pay for Sanitation in Busia
(Public Health Research, 2019) Muchangi Josphat Martin, Kimathi George, Karanja Sarah, Kuijpers Maarten and Ooijevaar Marjolein
Globally, access to improved sanitation remains a major challenge where about 2.4 billion people still lack toilets. Countries in Sub-Saharan Africa are the worst affected where about 800 million people still practice open defecation with remarkable negative health and economic effects. Diarrhoea due to poor sanitation kills more children than HIV and measles together. This study was designed to determine the willingness and ability to pay for safe sanitation by households in Busia County. A cross sectional survey was conducted on 784 households using contingent valuation method. Data was collected using structured questionnaires and both descriptive and inferential statistics were deduced. A model fit and economic modelling was performed to determine willingness and ability to pay. A total of 465(59.4%) male and 319(40.6%) were female heads were interviewed. Slightly more than a half of the respondents earned between 10-50 dollars in a month with no significant difference between male and female (P=0.924). About 487 (63%) were willing to take a sanitation loan and about 67.7% of the respondents were willing to upgrade their sanitation system. The willingness to take a loan and upgrade the existing sanitation differed significantly between male and female respondents (P=0.000). The study finds that dissatisfaction with the existing sanitation significantly affected the willingness to pay (P=0.000). The willingness to pay was high with about 68% of the population expressing interest to take a loan for sanitation. However, only about 10.1% of the population were able to pay for sanitation at the cut off price of 415 dollars. The study concludes that the market potential for sanitation is huge. We further recognize the role of various sanitation financing instruments including loans as the sustainable means of promoting access to improved sanitation
The effects of variation of contact rates between the environment, susceptible and infected population in a mathematical model of the transmission dynamics of Infectious Bursal Disease
(International Journal of Recent Research in Mathematics Computer Science and Information Technology, 2020) Omollo Emily Atieno, Kimathi George and Mwangi Isaac
We modeled a four-compartment model that explain the effects of variation of the contact rates between environment, susceptible and infected population in transmission dynamics of infectious bursal disease (IBD). We used Ordinary differential equations in formulating the model equations. Reproductive number has been derived using next generation Matrix. The disease-free equilibrium and endemic equilibrium stability are analyzed. MATLAB was used to carry out the numerical simulation. We found the higher that contact rate between the susceptible flock, infected population and the contaminated environment, the higher rate of transmission of the disease in the system
Relationship between Strategic Practices and the Performance of Tea Factories in Kenya
(International Journal of Recent Research in Interdisciplinary Sciences, 2017) Kimathi George, Nkaabu Clement and Moguche Abel
The tea industry plays an important role in Kenya’s economy providing both employment opportunities and earning the country foreign exchange. However, global competition in the industry demands that tea producers in the country improve efficiency. Over the years, achieving international competitiveness among tea factories in Kenya for better financial performance is a major challenge. This study investigated strategic practices and how they relate to the performance of tea factories in Kenya. The objective of this study was to determine how brand equity, management efficiency, costs of production and quality of raw materials related to the performance of tea factories in Kenya. The study adopted a descriptive research design approach because it explored and described the relationship between variables in their natural setting without manipulating them. The research was limited to 8 tea factories in Embu and Kirinyaga Counties. A population of 152 possible respondents comprising factory directors, factory managers, and factory supervisors were used to collect the necessary data required for this study. A sample of 47 respondents was selected using simple random sampling from different strata. Questionnaires were instruments of data collection. A pilot test was conducted to test the validity and reliability of the research instruments. Multiple regression analysis method was used to establish the statistical relationship between variables quantitatively while content analysis helped to analyze published content qualitatively. The study also established that there was a positive statistical relationship between strategic practices and performance of KTDA managed factories. The study recommended that KTDA factories should embrace on marketing, research and development, change management and technology integration for them to survive in the turbulent business environment.

Browse

Recent Submissions