RP-Department of Zoological Sciences

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A Survey of Knowledge and Attitudes towards Antibiotic Use and Resistance among Teachers in the Republic of Kenya: Implications for Using Teachers in Raising Public Awareness of Rational Antibiotic Use in School Communities
(Plos One, 2024-12) Mutua, Patrick M.; Mutiso, Joshua; Gicheru, Michael M.
Background Antimicrobial resistance is a significant public health threat. In Kenya, schools are targeted for public education to promote knowledge and attitudes towards the proper use of antimicrobials. However, there are limited studies that have investigated teachers’ knowledge and attitudes on antibiotic use. Methods We conducted an online survey from December 2023 to January 2024 which included 608 primary and secondary school teachers, representing a response rate of 93% of the estimated sample size of 653 teachers. Data on the respondents’ antibiotic knowledge score (seventeen questions) and attitude score (eleven questions) were analysed using IBM SPSS (Version 27). A binary logistic regression model was applied to analyze predicators of adequate knowledge and attitude on antibiotics. Results The average knowledge score for antibiotic use was 9.2 out of 17. Among the sampled teachers, 82% had not received public awareness information on proper antibiotic use. More than 86% of the respondents incorrectly answered that antibiotics are effective against colds. The average attitude score on antibiotic use was 6.1 out of 11. A quarter of the interviewees agreed that they gave family members antibiotics wherever they fell sick. Respondents aged 40–49 years and teaching in secondary school had higher odds for adequate knowledge in antibiotic use. Conclusions This study has identified significant knowledge and attitude gaps that need to be addressed by policy makers to ensure rational antibiotics use among teachers and in ensuring effective use of teachers in raising awareness in school communities for rational antibiotic use.
Insecticide Resistance and Its Intensity in Urban Anopheles Arabiensis in Kisumu City, Western Kenya: Implications for Malaria Control in Urban Areas
(PLoS ONE, 2024-11) MachaniI, Maxwell G.; Nzioki, Irene; Onyango, Shirley A.; Onyango, Brenda; Githure, John; Atieli, Harrysone; Wang, Chloe; Lee, Ming-Chieh; Githeko, Andrew K.
Background The rise of insecticide resistance poses a growing challenge to the effectiveness of vector control tools, particularly in rural areas. However, the urban setting has received comparatively less focus despite its significance in attracting rural to urban migration. Unplanned urbanization, often overlooked, exacerbates insecticide resistance as Anopheles mosquitoes adapt to the polluted environments of rapidly expanding cities. This study aimed to assess the insecticide susceptibility status of malaria vectors and identify potential underlying mechanisms across three distinct ecological settings characterized by differing levels of urbanization in Kisumu County, Kenya. Methods The study was conducted in 2022–2023 in Kisumu County, western Kenya. Field-derived An. gambiae (s.l.) larvae collected from a long stretch of urban-to-rural continuum were phenotyped as either resistant or susceptible to six different insecticides using the World Health Organization (WHO) susceptibility test. Polymerase chain reaction (PCR) techniques were used to identify the species of the An. gambiae complex and screened for mutations at voltage-gated sodium channels (Vgsc-1014F, Vgsc-1014S, Vgsc-1575Y) and acetylcholinesterase (Ace1) target site mutation 119S. Metabolic enzyme activities (non-specific β-esterases and monooxygenases) were evaluated in mosquitoes not exposed to insecticides using microplate assays. Additionally, during larval sampling, a retrospective questionnaire survey was conducted to determine pesticide usage by the local inhabitants. Results Anopheles arabiensis dominated in urban (96.2%) and peri-urban (96.8%) areas, while An. gambiae (s.s.) was abundant in rural settings (82.7%). Urban mosquito populations showed high resistance intensity to deltamethrin (Mortality rate: 85.2% at 10x) and suspected resistance to Pirimiphos-methyl and bendiocarb while peri-urban and rural populations exhibited moderate resistance intensity to deltamethrin (mortality rate >98% at 10x). Preexposure of mosquitoes to a synergist piperonyl butoxide (PBO) significantly increased mortality rates: from 40.7% to 88.5% in urban, 51.9% to 90.3% in peri-urban, and 55.4% to 87.6% in rural populations for deltamethrin, and from 41.4% to 78.8% in urban, 43.7% to 90.7% in peri-urban, and 35% to 84.2% in rural populations for permethrin. In contrast, 100% mortality to chlorfenapyr and clothianidin was observed in all the populations tested. The prevalence of L1014F mutation was notably higher in urban An. arabiensis (0.22) unlike the peri-urban (0.11) and rural (0.14) populations while the L1014S mutation was more prevalent in rural An. gambiae (0.93). Additionally, urban An. arabiensis exhibited elevated levels of mixed function oxidases (0.8/mg protein) and non-specific esterases (2.12/mg protein) compared to peri-urban (0.57/mg protein and 1.5/mg protein, respectively) and rural populations (0.6/mg protein and 1.8/mg protein, respectively). Pyrethroids, apart from their use in public health through LLINs, were being highly used for agricultural purposes across all ecological settings (urban 38%, peri-urban 36% and rural 37%) followed by amidine group, with organophosphates, neonicotinoids and carbamates being of secondary importance. Conclusion These findings show high resistance of An. arabiensis to insecticides commonly used for vector control, linked with increased levels of detoxification enzymes. The observed intensity of resistance underscores the pressing issue of insecticide resistance in urban areas, potentially compromising the effectiveness of vector control measures, especially pyrethroid-treated LLINs. Given the species’ unique behavior and ecology compared to An. gambiae, tailored vector control strategies are needed to address this concern in urban settings.
Moringa oleifera has the Potential to Manage HIV-1 and May Enhance the Efficacy of ARVs in Suppressing Viral Loads in HIV/AIDS Patients
(IRJPMS, 2024) Wasonga, Wilbroda; Wanyoro, Anthony; Kigondu, Mumbi Elizabeth; Gicheru, Muita Michael
Human immunodeficiency virus (HIV) infection is managed by expensive ARVs, which also have side effects, and lead to drug resistance and failure. The use of nutritional remedies in managing HIV/AIDS is becoming popular. Moringa oleifera is a nutrient-dense plant with medicinal properties resulting from its wide range of biological activities. This study investigated the beneficial effect of Moringa oleifera supplementation on the viral loads of HIV/AIDS patients receiving antiretroviral drugs (ARVs). A Quasi-Experiment of the regression discontinuity type was conducted at the Comprehensive Care Center, Mbagathi County Hospital, Nairobi, Kenya. We recruited 173 HIV seropositive participants undergoing ARV treatment and attending a regular HIV management clinic. The participants were allocated to the intervention group supplemented with Moringa oleifera leaf powder or the control group, which was not supplemented. The HIV-1 viral load measurements were assessed at the end of the third month and the sixth month of the study period. Analysis was then done to compare the two groups. The study observed that the percentage of participants with non-detectable viral load in the intervention group increased by 7.23%. In comparison, that of the control group decreased by 10.29% by the end of the study period. The study concluded that M. oleifera has the potential to inhibit HIV-1 and may enhance the efficacy of ARVs in suppressing viral loads in HIV/AIDS patients.
Molecular characterization and genotype distribution of thioester-containing protein 1 gene in Anopheles gambiae mosquitoes in western Kenya
(Malaria Journal, 2022) Onyango, Shirley A.; Ochwedo, Kevin O.; Machani, Maxwell G.; Olumeh, Julius O.; Debrah, Isaiah; Omondi, Collince J.; Ogolla, Sidney O.; Ming Chieh, Lee; Guofa, Zhou; Kokwaro, Elizabeth; Kazura, James W.; Afrane, Yaw A.; Githeko, Andrew K.; Zhong, Daibin; Yan, Guiyun
Background: Evolutionary pressures lead to the selection of efcient malaria vectors either resistant or susceptible to Plasmodium parasites. These forces may favour the introduction of species genotypes that adapt to new breeding habitats, potentially having an impact on malaria transmission. Thioester-containing protein 1 (TEP1) of Anopheles gambiae complex plays an important role in innate immune defenses against parasites. This study aims to character ize the distribution pattern of TEP1 polymorphisms among populations of An. gambiae sensu lato (s.l.) in western Kenya. Methods: Anopheles gambiae adult and larvae were collected using pyrethrum spray catches (PSC) and plastic dippers respectively from Homa Bay, Kakamega, Bungoma, and Kisumu counties between 2017 and 2020. Collected adults and larvae reared to the adult stage were morphologically identifed and then identifed to sibling species by PCR. TEP1 alleles were determined in 627 anopheles mosquitoes using restriction fragment length polymorphisms polymerase chain reaction (RFLP-PCR) and to validate the TEP1 genotyping results, a representative sample of the alleles was sequenced. Results: Two TEP1 alleles (TEP1*S1 and TEP1*R2) and three corresponding genotypes (*S1/S1, *R2/S1, and *R2/R2) were identifed. TEP1*S1 and TEP1*R2 with their corresponding genotypes, homozygous *S1/S1 and heterozygous *R2/S1 were widely distributed across all sites with allele frequencies of approximately 80% and 20%, respectively both in Anopheles gambiae and Anopheles arabiensis. There was no signifcant diference detected among the popula tions and between the two mosquito species in TEP1 allele frequency and genotype frequency. The overall low levels in population structure (FST=0.019) across all sites corresponded to an efective migration index (Nm=12.571) and low Nei’s genetic distance values (<0.500) among the subpopulation. The comparative fxation index values revealed minimal genetic diferentiation between species and high levels of gene fow among populations. Conclusion: Genotyping TEP1 has identifed two common TEP1 alleles (TEP1*S1 and TEP1*R2) and three corre sponding genotypes (*S1/S1, *R2/S1, and *R2/R2) in An. gambiae s.l. The TEP1 allele genetic diversity and population structure are low in western Kenya.
Genetic diversity and population structure of the human malaria parasite Plasmodium falciparum surface protein Pfs47 in isolates from the lowlands in Western Kenya
(PLOS ONE, 2021-11-29) Onyango, Shirley A.; Ochwedo, Kevin O.; Machani, Maxwell G.; Omondi, Collince J.; Debrah, Isaiah; Ogolla, Sidney O.; Ming-Chieh, Lee; Guofa, Zhou; Kokwaro, Elizabeth; Kazura, James W.; Afrane, Yaw A.; Githeko, Andrew K.; Daibin, Zhong; Guiyun, Yan
Plasmodium falciparum parasites have evolved genetic adaptations to overcome immune responses mounted by diverse Anopheles vectors hindering malaria control efforts. Plasmo dium falciparum surface protein Pfs47 is critical in the parasite’s survival by manipulating the vector’s immune system hence a promising target for blocking transmission in the mos quito. This study aimed to examine the genetic diversity, haplotype distribution, and popula tion structure of Pfs47 and its implications on malaria infections in endemic lowlands in Western Kenya. Cross-sectional mass blood screening was conducted in malaria endemic regions in the lowlands of Western Kenya: Homa Bay, Kombewa, and Chulaimbo. Dried blood spots and slide smears were simultaneously collected in 2018 and 2019. DNA was extracted using Chelex method from microscopic Plasmodium falciparum positive samples and used to genotype Pfs47 using polymerase chain reaction (PCR) and DNA sequencing. Thirteen observed haplotypes of the Pfs47 gene were circulating in Western Kenya. Popula tion-wise, haplotype diversity ranged from 0.69 to 0.77 and the nucleotide diversity 0.10 to 0.12 across all sites. All the study sites displayed negative Tajima’s D values although not significant. However, the negative and significant Fu’s Fs statistical values were observed across all the study sites, suggesting population expansion or positive selection. Overall genetic differentiation index was not significant (FST = -0.00891, P > 0.05) among parasite populations. All Nm values revealed a considerable gene flow in these populations. These results could have important implications for the persistence of high levels of malaria trans mission and should be considered when designing potential targeted control interventions.
The Potential for Use of Haematological and Anti-Ige Humoral Responses as Phenotypic Markers for Tick Resistance in Cattle
(Elsevier B.V, 2023-11-23) Ngetich, Collins; Kamau, Lucy; Simbauni, Jemimah; Mwendia, Charles; Owido, Milton; Kiio, Irene; Matika, Oswald; Foster, Sarah; Birkett, Michael; Djikeng, Appolinaire; Watson, Kellie Anne; Githaka, Naftaly
Approximately 80% of the global cattle population is at risk of infestation and infection by ticks and tick-borne diseases (TTBDs). The economic losses from animal mortality, reduced production, vector control costs and animal treatment are very substantial, hence there is an urgent need to develop and deploy alternative vector control strategies. Breeding for host tick resistance has the potential for sustainable large-scale TTBD control especially in cattle. The gold standard method for phenotyping tick resistance in cattle is by counting ticks on the body but is very laborious and subjective. Better methods for phenotyping tick resistance more objectively, faster and at scale, are essential for selecting host genetic resistance to ticks. This study investigated the correlation between haematological cellular profiles and immunological responses (immunoglobulin E, IgE) and full body tick counts in herds of Bos indicus and Bos taurus following artificial tick challenge with Rhipicephalus decoloratus larvae. Fifty-four Friesian and Ayrshire (Bos taurus) and 52 East African Zebu (Bos indicus) calves were each infested with ~2500 larvae. Near-replete adult female ticks (≥ 4.5 mm) were counted daily from Day 20–25. Blood and serum samples were obtained from each animal on Days 0 and 23 for cellular blood and IgE titre analysis, respectively. The indicine cattle were refractory to R. decoloratus infestation in comparison with the taurine breed (P < 0.0001). Repeated measurements of blood components pre-infestation revealed a significant (P < 0.05) association with tick count in IgE and red blood cells, haematocrit, and haemoglobin post-infestation. There was also a strong positive correlation between the tick counts and red blood cell numbers, haemoglobin, haematocrit, and IgE concentration (P < 0.0001) following tick challenge. The application of this approach to phenotype host resistance needs to be assessed using higher cattle numbers and with different tick species or genera
Community-Managed Coral Reef Restoration in Southern Kenya Initiates Reef Recovery Using Various Artificial Reef Designs
(Frontiers in Marine Science, 2023-04) Knoester, EG.; Rienstra, JJ.; Schürmann, QJF.; Wolma, AE.; Murk, AJ.; Osinga, R.
Monitoring of reef restoration efforts and artificial reefs (ARs) has typically been limited to coral fragment survival, hampering evaluation of broader objectives such as ecosystem recovery. This study aimed to determine to what extent AR design influences the ecological recovery of restored reefs by monitoring outplanted coral fragments, benthic cover, coral recruitment and fish and invertebrate communities for two years. Four AR designs (16 m2 ), unrestored controls and natural reef patches as reference (n = 10) were established in Mkwiro, Kenya. ARs consisted either of concrete disks with bottles, layered concrete disks, metal cages or a combination thereof. A mixture of 18 branching coral species (mainly Acropora spp.) was outplanted on ARs at a density of 7 corals m-2. After two years, 60% of all outplanted fragments had survived, already resulting in coral cover on most ARs comparable (though Acropora-dominated) to reference patches. Coral survival differed between ARs, with highest survival on cages due to the absence of crown-of-thorns sea star predation on this design. In total, 32 coral genera recruited on ARs and recruit densities were highest on reference patches, moderate on concrete ARs and low on cages. ARs and reference patches featured nearly twice the fish species richness and around an order of magnitude higher fish abundance and biomass compared to control patches. Fish abundance and biomass strongly correlated with coral cover on ARs. AR, reference and control patches all had distinct fish species compositions, but AR and reference patches were similar in terms of trophic structure of their fish communities. Motile invertebrates including gastropods, sea urchins, sea cucumbers and sea stars were present at ARs, but generally more abundant and diverse at natural reference patches. Taken together, all studied ecological parameters progressed towards reef ecosystem recovery, with varying influences of AR design and material. We recommend a combination of metal cages and layered concrete ARs to promote high fragment survival as well as natural coral recruitment. Ultimately, a longer period of monitoring is needed to fully determine the effectiveness reef restoration as conservation tool to support coral reef ecosystem recovery
DNA Barcoding, Dwelling Morphology, and Fecundity of the Gall-Forming Shrimp Paratypton Siebenrocki Balss, 1914 (Caridea: Palaemonidae)
(Tylor and Francis, 2023) van der Meij, Sancia E. T.; Bouwmeester, Jessica; Bähr, Susanne
Tropical coral reefs offer a wide variety of habitats to countless invertebrate species. Sessile host organisms especially are inhabited by small taxa, of which decapod crustaceans form one of the most diverse communities. Symbiotic palaemonid shrimp species associate with marine invertebrate hosts from multiple phyla, including cnidarians such as stony corals (Scleractinia). The intriguing gallforming shrimp Paratypton siebenrocki, a symbiont of Acropora corals in the Indo-Pacific, was collected in the Saudi Arabian Red Sea, Kenya, and the Maldives. Based on morphology P. siebenrocki has been considered to be most closely related to the genera Anapontonia and Metapontonia; however, no clear clustering with either palaemonid genus was observed in a phylogenetic reconstruction based on 16S and COI mtDNA. Here we photo-document the dwellings of P. siebenrocki in Acropora spp. for the first time, and furthermore we report on the reproductive output of this species. The number of eggs ranged from 345 to 909 (n = 6), and embryo volume differed strongly between early- and late-stage embryos. The carapace length ranged from 2.58 to 4.55 mm for the females and 1.51 to 2.5 mm for the males (n = 5). The number and size of the embryos, combined with their specialised, secluded lifestyle, suggest that P. siebenrocki allocates higher energy towards embryo production than free-living confamilials do.
Terminalia brownii Fresen: Stem Bark Dichloromethane Extract Alleviates Pyrogallol-Induced Suppression of Innate Immune Responses in Swiss Albino Mice
(Hindawi, 2023-02) Mbiri, Jane Wanja; Ogila, Kenneth; Kisangau, Patrick; Gicheru, Michael
Kala-azar is a parasitic disease caused by Leishmania species transmitted by sand fly. In Kenya, kala-azar is endemic in thirty subcounties spread over in eleven counties in the arid zones. Climate change-influenced seasonal weather variability and environmental alterations remain important determinants of many vector-borne diseases. The present study focused on climate change and environmental influence on kala-azar in West Pokot. A descriptive cross-sectional and retrospective research design was adapted. Study area was purposively selected. Locations were randomly selected, and households were systematically selected. Three hundred sixty-three household questionnaires, eleven key informant interviews, and five focus group discussions were undertaken. Secondary data were obtained from Kacheliba subcounty hospital records. Statistical Package for the Social Sciences version 24 was used to analyze quantitative data while qualitative data were analyzed to establish connection for interpretation. Kala-azar cases have been on the rise on aggregate and surge towards the end of dry season and just after the rains. Significant environmental factors included the presence of seasonal rain water pathways and rock piles around houses (AOR = 4.7; 95% CI = (2.3-9.6), ), presence of acacia trees in and around homesteads (AOR = 8.5; 95% CI = (2.5-28.6), ), presence of anthills around the homesteads (AOR = 5.2; 95% CI = (1.2-23.4), ), and presence of animal shed within compound (AOR = 2.8; 95% CI = (0.96-8), ). Climate change-induced seasonal weather variability, increased temperature and reduced precipitation as well as environmental alterations influence kala-azar occurrence in West Pokot. Community sensitization on disease prevalence, clearing of vector predilection sites, and improving community environmental risk perception are imperative to promote prevention.
Evaluation of the Therapeutic Potential of Warburgia ugandensis, Prunus africana, and Piliostigma thonningii against Leishmania donovani in vitro and in Balb/c Mice
(Bilingual Publishing, 2022-10) Mogaka, Maria Divinah; Mutiso, Joshua M.; Macharia, John C.; Ayako, Rebecca M.; Osero, Bernard; Gicheru, Michael M.
Leishmaniasis is a zoonotic disease caused by protozoan parasites of the genus Leishmania. Conventional chemotherapy remains to be the most preferred measure against leishmaniasis despite being associated with high toxicity and relapse rates. They are also expensive and require hospitalization. Plant-based compounds provide a better treatment alternative because they are effective, cheap, and less associated with toxicity and resistance. This study examined the therapeutic potential of Warburgia ugandensis, Prunus africana, and Piliostigma thonningii against Leishmania donovani infection in BALB/c mice. Anti-promastigote and toxicity studies were evaluated by incubating the test compound with promastigotes and Vero cells, respectively. Serum was obtained from the mice for total immunoglobulin gamma (IgG) quantification. For in vivo studies, the mice were infected with virulent Leishmania donovani then treated with methanolic extracts of Warburgia ugandensis, Prunus africana, and Piliostigma thonningii and control drug, pentostam (sodium stibogluconate). Treatment with the plant extracts and standard drug resulted to significant reduction in parasite burden. Outcomes in the mice treated with plant extracts were comparable to those treated with pentostam (P≥0.05). In the promastigote assay, all the test compounds killed more than half of the promastigotes at the highest concentration (500 µg/mL). Warburgia ugandensis, P. thonningii, and P. africana reduced the number of promastigotes from 2.0 × 106 to 7.7 × 103 , 72.0 × 103 , and 5.0 × 103 , respectively. Pentostam had the lowest IC50 (210 µg/mL), followed by Warburgia ugandensis (IC50 of 270 µg/mL). Piliostigma thonningii and P. africana were less toxic with IC50 of 720 µg/mL and 500 µg/mL, respectively. There was low production of IgG antibodies following treatment with the plant extracts and high levels in the untreated control.
Alarming Cases of Cancer in Kenya: A Case for Meru and Tharaka Nithi Counties
(Society for Science and Education, 2023-01) Mutiso, Joshua; Gitonga, Ciriaka; Abdullahi, Bulle; Simbauni, Jemimah; Gicheru, Michael
Background: Cancer is one of the leading causes of morbidity and mortality worldwide. In Kenya, cancer as a disease ranks third as a cause of death after infectious and cardiovascular diseases and the cancer cases are increasing at an alarming rate. Objective: The current study was aimed at determining the prevalence trends of cancer in Meru and Tharaka Nithi Counties with an aim of putting proper infrastructural and human capacity development to combat cancer. Methods: A random selection of patients aged between five to eighty-two years clinically diagnosed as cancer patients who were visiting Meru and Chuka General Hospitals for a period of one year were recruited for the study. The participants were requested to give a verbal consent and respond to a brief questionnaire concerning their gender, age and the type of cancer they are suffering from. This study used retrogressive approach where the trend of cancer incidences and death rate were determined for the last eight years (2011 to 2018) using the hospital data. Data were analysed using statistical package for social sciences (SPSS). Results: This study established that the prevalence of cancer in people visiting hospitals in Meru and Tharaka Nithi Counties was 0.32% and 0.38% respectively. Further, the prevalence trends of cancer cases in the two counties have been increasing over the last eight years. Conclusion: The study concludes that cancer is prevalent in Meru and Tharaka Nithi Counties. It is therefore recommended that proper infrastructural and human capacity development be put in place to combat cancer.
Differences in Malaria Vector Biting Behavior and Changing Vulnerability to Malaria Transmission in Contrasting Ecosystems of Western Kenya
(Parasites & Vectors, 2023-10) Nzioki, Irene; Machani, Maxwell G.; Onyango, Shirley A.; Kabui, Kevin K.; Githeko, Andrew K.; Ochomo, Eric; Yan, Guiyun; Afrane, Yaw A.
Background Designing, implementing, and upscaling of efective malaria vector control strategies necessitates an understanding of when and where transmission occurs. This study assessed the biting patterns of potentially infectious malaria vectors at various hours, locations, and associated human behaviors in diferent ecological settings in western Kenya. Methods Hourly indoor and outdoor catches of human-biting mosquitoes were sampled from 19:00 to 07:00 for four consecutive nights in four houses per village. The human behavior study was conducted via questionnaire surveys and observations. Species within the Anopheles gambiae complex and Anopheles funestus group were distinguished by polymerase chain reaction (PCR) and the presence of Plasmodium falciparum circumsporozoite proteins (CSP) determined by enzyme-linked immunosorbent assay (ELISA). Results Altogether, 2037 adult female anophelines were collected comprising the An. funestus group (76.7%), An. gambiae sensu lato (22.8%), and Anopheles coustani (0.5%). PCR results revealed that Anopheles arabiensis constituted 80.5% and 79% of the An. gambiae s.l. samples analyzed from the lowland sites (Ahero and Kisian, respectively). Anopheles gambiae sensu stricto (hereafter An. gambiae) (98.1%) was the dominant species in the highland site (Kimaeti). All the An. funestus s.l. analyzed belonged to An. funestus s.s. (hereafter An. funestus). Indoor biting densities of An. gambiae s.l. and An. funestus exceeded the outdoor biting densities in all sites. The peak biting occurred in early morning between 04:30 and 06:30 in the lowlands for An. funestus both indoors and outdoors. In the highlands, the peak biting of An. gambiae occurred between 01:00 and 02:00 indoors. Over 50% of the study population stayed outdoors from 18:00 to 22:00 and woke up at 05:00, coinciding with the times when the highest numbers of vectors were collected. The sporozoite rate was higher in vectors collected outdoors, with An. funestus being the main malaria vector in the lowlands and An. gambiae in the highlands. Conclusion This study shows heterogeneity of anopheline distribution, high outdoor malaria transmission, and early morning peak biting activity of An. funestus when humans are not protected by bednets in the lowland sites. Additional vector control eforts targeting the behaviors of these vectors, such as the use of non-pyrethroids for indoor residual spraying and spatial repellents outdoors, are needed.
Utilization of Reproductive Health Services and Associated Factors among Youths in Mombasa County, Kenya
(IJTDH, 2023-08) Yonge, Shadrack A.; Opiyo, Bob; Kibira, Agnes W.; Sharma, Rekha R.
Background: Reproductive health has become a global concern that is either poorly understood or not fully appreciated among the youth. Access to reproductive health services is important for protecting youth from STIs and unwanted pregnancy problems. Aim: The study sought to establish utilization of reproductive healthcare services and associated factors among youths in Mombasa County, Kenya. Study Design: A descriptive cross-sectional study was carried out between August 2018 and January 2019. Methodology: A self-administered, structured questionnaire was utilized to gather information. The information gathered was summarized using an SPSS database. The data was analyzed with SPSS version 22. Logistic regression was done to identify possible factors associated with reproductive health service utilization. p-value less than 0.05 was considered as a level of significance. Results: A total of 384 youth participated in the study, including 200 (62.2% females and 184 (37.8%) males. The media was the main source of information for modern family planning methods 200 (50. 1%). The majority of users 326 (84.9%) sought contraceptives from pharmacies. 213 (55.5%) were utilizing modern contraceptives. HIV/AIDS risk perception was significantly associated with utilization of reproductive health services [COR=2.34, 95% CI: 2.19-5.34].The condom was the most used method 134 (34.9%). Having knowledge about reproductive health services [COR=2.87; 95% CI: 1.92-3.94] was positively associated with the outcome. Male respondents were three (3) times more likely to use condoms [OR = 2.86, 95% Cl: 1.82-4.91] than female respondents. Conclusion: There was low uptake of contraceptive services among the youth who were sexually active. The condom was the most commonly used contraceptive. Strengthening urban healthcare systems is key to have equality and improve accessibility of FP services among the teenagers and young women.
Where to Fish in the Forest? Tree Characteristics and Contiguous Seagrass Features Predict Mangrove Forest Quality for Fishes and Crustaceans
(Journal of Applied Ecology, 2023) Wanjiru, Caroline; Nagelkerken, Ivan; Rueckert, Sonja; Harcourt, William; Huxham, Mark
1. Mangroves often support rich fish and crustacean communities, although faunal abundance and diversity show strong spatiotemporal variability. Consistent patterns in mangrove animal communities might be dictated by forest characteristics, by seascape context or by some combination of these factors. Predicting drivers of spatial heterogeneity in mangrove faunal communities can better support the zoning of forests for management purposes, for example by identifying sites important for fisheries nursery provision. 2. We sampled 14 sites within a large (4000 ha) mangrove forest in Kenya, quarterly over a period of 2 years. There were clear and consistent differences in the quality of sites for fish and crustacean abundance and diversity. 3. Forest characteristics (as summarised by the complexity index, CI) and seascape metrics (the presence, area and configuration of contiguous seagrass) were strong predictors of site differences. However, they showed opposite influences on dominant members of the fish and crustacean faunas, with CI correlated negatively with fishes and positively with crustaceans, and seagrass area correlated positively with fishes and negatively with crustaceans. 4. Synthesis and applications. Sites within the same mangrove forest exhibit consistent differences in fish and crustacean abundance. However, the fish and crustacean communities (and particularly dominant species within them) act differently in response to forest and seascape characteristics. Old growth, mature forest, set in a seascape of seagrass patches with bare sediment, was associated with highest crustacean abundance. In contrast, denser smaller trees and seascapes with larger, continuous areas of seagrass correlated better with fish abundance. Zoning for management, as mandated in new Kenyan policy, will need to consider these differences in seascape use between fish and crustaceans.
Forecasting the Potential Effects of Climate Change on Malaria in the Lake Victoria Basin Using Regionalized Climate Projections
(Springer Nature, 2022-08-12) Ototo, Ednah N.; Ogutu, Joseph O.; Githeko, Andrew; Said, Mohammed Y.; Kamau, Lucy; Namanya, Didacus; Simiyu, Stella; Mutimba, Stephen
Background Malaria epidemics are increasing in East Africa since the 1980s, coincident with rising temperature and widening climate variability. A projected 1–3.5 °C rise in average global temperatures by 2100 could exacerbate the epidemics by modifying disease transmission thresholds. Future malaria scenarios for the Lake Victoria Basin (LVB) are quantified for projected climate scenarios spanning 2006–2100. Methods Regression relationships are established between historical (1995–2010) clinical malaria and anaemia cases and rainfall and temperature for four East African malaria hotspots. The vector autoregressive moving average processes model, VARMAX (p,q,s), is then used to forecast malaria and anaemia responses to rainfall and temperatures projected with an ensemble of eight General Circulation Models (GCMs) for climate change scenarios defined by three Representative Concentration Pathways (RCPs 2.6, 4.5 and 8.5). Results Maximum temperatures in the long rainy (March–May) and dry (June–September) seasons will likely increase by over 2.0 °C by 2070, relative to 1971–2000, under RCPs 4.5 and 8.5. Minimum temperatures (June–September) will likely increase by over 1.5–3.0 °C under RCPs 2.6, 4.5 and 8.5. The short rains (OND) will likely increase more than the long rains (MAM) by the 2050s and 2070s under RCPs 4.5 and 8.5. Historical malaria cases are positively and linearly related to the 3–6-month running means of monthly rainfall and maximum temperature. Marked variation characterizes the patterns projected for each of the three scenarios across the eight General Circulation Models, reaffirming the importance of using an ensemble of models for projections. Conclusions The short rains (OND), wet season (MAM) temperatures and clinical malaria cases will likely increase in the Lake Victoria Basin. Climate change adaptation and mitigation strategies, including malaria control interventions could reduce the projected epidemics and cases. Interventions should reduce emerging risks, human vulnerability and environmental suitability for malaria transmission
Relationship between Infections and poverty levels in Njoro District in Kenya
(Kosin Journal of Health Sciences, 2020) Kinuthia, Geoffrey; Kiarie-Makara, Martha; Gicheru, Michael M; Kabiru, Ephantus Wanjohi
A cross-sectional study was conducted in selected rural areas of Njoro in Kenya to determine the socio-economic variables, poverty levels and disease control practices among the residents in 336 homesteads. The objective was to establish the relationship between parasitic diseases control practices, lifestyles and poverty levels among the residents in the rural areas. In addition, a retrospective study that involved recording of the frequency of parasitic and bacterial diseases diagnosed and treated in four randomly selected health centres, in the study area, from 2004 to 2009 was carried out. The results showed that the rural residents in the study area tended to have large families (68%), low education level (67%), high responsibility burden (67%) and a large number were living below poverty line (81%). The low economic status of residents coupled with certain lifestyles and practices pre-disposed the residents to infectious diseases. It was observed that ‘not boiling drinking water’ had a higher probability of occurring among the lower economic cadre of residents than in medium economic cadre [Odds Ratio (OR) = 2.36; 95% Confidence Interval (CI) of 1.38 – 4.03]. Occurrences probability of ‘not using a mosquito net’ (OR = 1.44) and ‘not using a toilet paper always’ (OR = 2.60) were higher in residents of low economic cadre. Retrospective survey showed that malaria had a higher frequency (42.75%), followed by typhoid fever (24.14%), Entamoeba histolytica (20.83%), Giardia lamblia (20.32%), intestinal worms (4.57%), Escherechia coli (3.35%) and Trichomonas hominis (1.63%). It was concluded that a combination of large family size, low education levels, high responsibility burdens, and low economic status contributed significantly to occurrence of infectious health conditions among rural residents in the study area.
Seroprevalence of non-typhoidal Salmonella disease and associated factors in children in Mukuru settlement in Nairobi County, Kenya
(PLoS ONE, 2023) PeterI, Schola K.; Mutiso, Joshua M.; Ngetich, Mercy; Mbae, Cecilia; Kariuki, Samuel
Non-typhoidal Salmonella (NTS) infections remain a significant public health challenge especially in sub-Saharan Africa. NTS disease is endemic in Kenya and is associated with sporadic fatal outbreaks in several regions of the country with poor resource setting. Data is limited on background exposure of NTS in the population in endemic areas and the general immune status of the community most affected by NTS. The aim of the study was to determine the proportion of children exposed to Salmonella Enteritidis or Salmonella Typhimurium O antigen among the apparently healthy children and patients and the associated host and environmental factors among children attending selected healthcare facilities in Mukuru, Nairobi County, Kenya. A cross-sectional case-control study was conducted among patients and apparently healthy participants aged 0–5 years. Blood was collected and centrifuged to obtain serum. The serum was used to test for the presence of antibodies (IgA, IgG, IgM) against NTS using ELISA. A questionnaire was administered to obtain relevant demographic, socio-economic and healthcare utilization information. A total of 382 children were recruited into the study. The NTS seroprevalence was 12.6%. Among the apparently healthy participants, mean age of those exposed to NTS was 36 months and those not exposed was 27 months. Among patients, the mean age was 39 months and those not exposed was 30 months. The seroprevalence of NTS infection among the apparently healthy was significantly associated with cooking water, washing water and age of the child. Treating water using chlorine or boiling method was identified as being protective against contracting Salmonella Typhimurium/Enteritidis. Among the patients, the proportion of exposure was significantly associated with keeping animals and the chicken count. There is a high exposure to NTS among young children below five years of age and the population has developed immunity to the disease.
Physicochemical Characteristics of Undrainable Water Dams Utilized For Fish Rearing in the Semi-Arid Naromoru Area, Central Kenya
(2012) Ndiwa, T. C; Mwangi, B. M; Kairu, E; Kaluli, J. W; Nyingi, D
nya. Its water sources include a few permanent rivers such as Nairobi River, intermittent streams and a large number of undrainable water reservoirs. Most of the undrainable water resources have been stocked with fish but their utilization for fish rearing has generally remained very low. The purpose of this study was therefore to examine the water quality status of the dams to assess their suitability and potential for fish production. pH, electro-conductivity and total dissoved solutes (TDS) were measured in-situ from three reservoirs (Gathathini, Lusoi and Kianda dams) differing in their habitat characteristics. Water samples were collected for determination of the ionic concentartions of the reservoirs. Water quality status differed markedly between sites, with electric conductivity ranging from 350μScm-1 at Gathathini dam to over 1350μScm-1 at Lusoi dam. pH however showed only a slight variation from 8-9.6. Water temperature and transparency varied significantly between the sites, while cationic constituents (Ca2+, K+ , Mg2+ and Na+ ), anions (SO4 2-, HCO3 2-, and Cl-1), heavy metals (Pb2- and Cu2+) and nutrients (NO3 - and PO4 2-) were all within the recommended WHO levels for fish production. Generally the water quality status was within the standards recommended for fisheries production.
Pollination and Reproductive Relationship of Four Mangroves Species in Zanzibar, Tanzania
(Mutagens, 2016) Ali, Ibrahim Abdalla; Kairu, Eunice W; Abubakar, Zakia M; Mchenga, Islam S.S
Relationship between flowers and fruits can occur as a result of several factors; including temperature, soil, rainfall, light intensity, plant resources, and genetic structure. This study was designed to investigate effect of pollination on buds, flowers, fruit sets and fruits of four mangroves species namely Rhizophora mucronata, Bruguiera gymnorhiza, Ceriops tagal and Avicennia marina. A branch free from pest and diseases have been randomly selected and observations were carried out twice a week in 9 months (July 2013 to March 2014). Results showed that, there were significant differences in the number of buds, flowers, fruit set, visitors, visits and fruits in all four mangrove species. There were variations of relationships among reproduction variables. A strong relationship was observed between buds and flowers in all species. Increase number of flowers concurrently increases number of fruit set in all species, although A. marina shown a weak relationship. We concluded that the increases number of mangroves fruits not only depends on number of fruit set and other reproduction variables, but also there was other abiotic and biotic factors required intensive investigation.
Dietary Administration of Probiotics Modulates Non-Specific Immunity and Gut Microbiota of Nile Tilapia (Oreochromis Niloticus) Cultured In Low Input Ponds
(Taylor \& Francis, 2019) Opiyo, Mary A; Jumbe, James; Ngugi, Charles C; Charo-Karisa, Harrison
Poor culture conditions in low input ponds make fish highly susceptible to infectious pathogens which lead to diseases and mortalities yet the effects of probiotics on immunity, gut microbiota and microbiological quality of fish in low input ponds are unknown. Nile tilapia, Oreochromis niloticus fingerlings (40 g) were randomly stocked at 50 fish m−3 in 1.25 m3 cages in low input ponds. The fish were fed on diets supplemented with either Saccharomyces cerevisiae (1 × 1010 CFU g−1 ) or Bacillus subtilis (1 × 109 CFU g−1 ) at six levels: Diet 0 (No probiotic); S. cerevisiae at 2 g kg−1 (Diet 1); 4 g kg−1 (Diet 2) and 6 g kg−1 (Diet 3) and B. subtilis at 5 g kg−1 (Diet 4); 10 g kg−1 (Diet 5) and 15 g kg−1 (Diet 6) for 180 days. Results indicate that hemato-immunological parameters (hemoglobin (Hb), red blood cells (RBC), white blood cells (WBC) serum protein, albumin, globulin and lysozyme activity) were significantly higher in fish fed on probiotic treated diets compared to the control (P < 0.05). On the contrary, fish fed on Diet 6 presented significantly similar Hb and globulin values compared to the control (P > 0.05). Additionally, fish fed on probiotic treated diets retained the probiotics in their guts and lower microbial load was realized in their muscle (P < 0.05). In conclusion, B. subtilis and S. cerevisiae supplementation in diets of Nile tilapia reared in low input ponds improves immunity, manipulates gut microbiota and enhances fish flesh quality

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