Richard Echodu

Richard Echodu
Gulu University (GU) · Biological Sciences

About

84
Publications
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Introduction
Skills and Expertise

Publications

Publications (84)
Article
Full-text available
Background: Tsetse flies are vectors of the genus Trypanosoma that cause African trypanosomiasis, a serious parasitic disease of people and animals. Reliable data on the vector distribution and the trypanosome species they carry is pertinent for planning sustainable control strategies. This study was carried out to estimate the spatial distributio...
Article
Full-text available
Acute stunting in children, liver cancer, and death often occur due to human exposure to aflatoxins in food. The severity of aflatoxin contamination depends on the type of Aspergillus fungus infecting the crops. In this study, Aspergillus species were isolated from households’ staple foods and were characterized for different aflatoxin chemotypes....
Article
Introduction: Trypanosomiasis is a parasitic infection caused by the protozoa Trypanosoma. It is exclusively associated with Glossina species habitats and, therefore, restricted to specific geographical settings. It affects a wide range of hosts, including humans. Animals may carry different Trypanosoma spp. while being asymptomatic. They are, ther...
Article
Full-text available
Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology: We depl...
Preprint
Full-text available
Background: Uses of indoor residual spraying (IRS), long-lasting insecticidal nets (LLINS) and treatment with artemisinin-based combination therapy (ACT) are greatly promoted in northern part of Uganda as mitigating strategies for malaria episodes. Unfortunately, the region still records the highest malaria prevalence of 63%. This study assesses ho...
Article
Full-text available
Tsetse flies ( Glossina spp.) house a population-dependent assortment of microorganisms that can include pathogenic African trypanosomes and maternally transmitted endosymbiotic bacteria, the latter of which mediate numerous aspects of their host’s metabolic, reproductive, and immune physiologies. One of these endosymbionts, Spiroplasma , was recen...
Preprint
Full-text available
Tsetse flies ( Glossina spp.) house a population-dependent assortment of microorganisms that can include pathogenic African trypanosomes and maternally transmitted endosymbiotic bacteria, the latter of which mediate numerous aspects of their host’s metabolic, reproductive, and immune physiologies. One of these endosymbionts, Spiroplasma , was recen...
Article
Full-text available
Mycotoxins are toxic metabolites of fungi that contaminate food and feed. These toxins can cause acute and chronic health threats to both humans and animals. In sub-Saharan Africa, exposure to mycotoxins is chronic and under-reported. The study explores contamination of grains (sorghum, maize, groundnut, millet) with four mycotoxins (aflatoxins, fu...
Article
Full-text available
Worldwide fungal contamination leads to both quantitative and qualitative grain losses during crop growth and/or storage. A greater proportion of grains contamination with toxins often occurs in sub-Saharan Africa, where control measures are limited. We determined fungal diversity and their toxin production ability in household grains meant for hum...
Article
Full-text available
Objective: The aim of the study was to determine the level of insecticide resistance and diversity in Anopheles mosquitoes in northern Uganda. Standard WHO insecticide susceptibility test assays were used to test for susceptibility to 0.5% malathion, 0.1% bendiocarb, 0.05% deltamethrin and 0.75% permethrin on 3-5 day old generation one progeny. We...
Preprint
Full-text available
Background: Use of indoor residual spraying (IRS), long-lasting insecticidal nets (LLINS) and treatment with artemisinin-based combination therapy (ACT) have been greatly promoted in northern Uganda but the region still records highest number of malaria cases with prevalence up to 63%. This study assesses household predicators of malaria in the reg...
Preprint
Full-text available
Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology: We deploye...
Preprint
Full-text available
Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology: We deploye...
Preprint
Full-text available
Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology: We deploye...
Preprint
Full-text available
Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. Methodology: We deploye...
Preprint
Full-text available
Objective The aim of the study was to determine the level of insecticide resistance and diversity in Anopheles mosquitoes in northern Uganda. Standard WHO insecticide susceptibility test assays were used to test for susceptibility to 0.5% malathion, 0.1% bendiocarb, 0.05% deltamethrin and 0.75% permethrin on 3–5 day old generation one progeny. We a...
Preprint
Full-text available
Objective: The aim of the study was to determine the level of insecticide resistance and diversity in Anopheles mosquitoes in northern Uganda. Standard WHO insecticide susceptibility test assays were used to test for susceptibility to 0.5% malathion, 0.1% bendiocarb, 0.05% deltamethrin and 0.75% permethrin on 3-5 day old generation one progeny. We...
Preprint
Full-text available
Objective: The aim of the study was to determine the level of insecticide resistance and diversity in Anopheles mosquitoes in northern Uganda. Standard WHO insecticide susceptibility test assays were used to test for susceptibility to 0.5% malathion, 0.1% bendiocarb, 0.05% deltamethrin and 0.75% permethrin on 3-5 day old generation one progeny. We...
Preprint
Full-text available
Background Karamoja region of Uganda previously classified as low malaria transmission zone is currently experiencing significant upsurge of malaria incidences. Long lasting insecticidal nets (LLINs) impregnated with pyrethroids constitute a major tool for malaria control in this region. Efficacy of this tool can be hampered by resistance to the py...
Preprint
Full-text available
Background: Karamoja region of Uganda previously classified as low malaria transmission zone is currently experiencing significant upsurge of malaria incidences. Long lasting insecticidal nets (LLINs) impregnated with pyrethroids constitute a major tool for malaria control in this region. Efficacy of this tool can be hampered by resistance to the p...
Article
Full-text available
Sweet potato feathery mottle virus is a potyvirus that infect sweet potato. The genome of the virus was analysed to understand genetic diversity, evolution and gene flow. Motifs, nucleotide identity and a phylogenetic tree were used to determine phylogroup of the isolates. Gene flow and genetic diversity were tested using DnaSP v.5. Codons evolutio...
Article
Full-text available
In paper-based microfluidics, the simplest devices are colorimetric, giving qualitative results. However, getting quantitative data can be quite a bit more difficult. Distance-based devices provide a user-friendly means of obtaining quantitative data without the need for any additional equipment, simply by using an included ruler or calibrated mark...
Preprint
Objective: The aim of this cross-sectional study was to determine the prevalence, infection intensity and associated risk factors of intestinal schistosomiasis among primary school children in Lira district, Uganda. The study was conducted among 532 primary school pupils aged 6-16 years from eight randomly selected primary schools (March-May 2017)....
Preprint
Objective World Health Organisation recommends Kato-Katz technique for quantitative diagnosis of Schistosoma (S) mansoni and other soil transmitted intestinal parasites in field research. However, the prepared slides in Kato-Katz technique cannot be examined immediately and after 1 to 2 hours, the eggs of parasites with thin cell walls over clear i...
Preprint
Full-text available
Objective World Health Organisation recommends Kato-Katz technique for quantitative diagnosis of Schistosoma mansoni and other soil transmitted intestinal parasites in field research. However, for better visibility especially in hard stool specimens, the prepared slides in Kato-Katz technique are mostly examined after 1-2 hours. This longer clearin...
Article
Full-text available
Mycotoxin contamination of cereals is a significant health risk for humans and animals, particularly in developing countries. To gain insight into food safety related to agricultural practices, we assessed levels of mycotoxin contamination in 105 samples of food grains raised and stored for consumption by rural households in the post-conflict distr...
Preprint
Objective: The aim of this cross-sectional study was to determine the prevalence, infection intensity and associated risk factors of intestinal schistosomiasis among primary school children in Lira district, Uganda. The study was conducted among 532 primary school pupils aged 6-16 years from eight randomly selected primary schools (March-May 2017)....
Article
Full-text available
Tsetse flies (Glossina spp.) are vectors of parasitic trypanosomes, which cause human (HAT) and animal African trypanosomiasis (AAT) in sub-Saharan Africa. In Uganda, Glos-sina fuscipes fuscipes (Gff) is the main vector of HAT, where it transmits Gambiense disease in the northwest and Rhodesiense disease in central, southeast and western regions. E...
Article
Full-text available
Objective: To determine the prevalence of Plasmodium falciparum multi-drug resistant gene-1 (Pfmdr-1) N86Y and D1246Y genotypes among febrile malaria outpatients attending Lira Regional Referral Hospital, Uganda. Results: Overall, 92.3% (n = 48/52) and 90% (n = 45/50) of the parasites detected carried the wild type alleles 1246D and N86, respective...
Preprint
Full-text available
Tsetse flies ( Glossina spp.) are vectors of parasitic trypanosomes, which cause human (HAT) and animal African trypanosomiasis (AAT) in sub-Saharan Africa. In Uganda, Glossina fuscipes fuscipes ( Gff ) is the main vector of HAT, where it transmits Gambiense disease in the northwest and Rhodesiense disease in central, southeast and western regions....
Article
Full-text available
The purpose of the study was to identify different viruses infecting sweetpotato and the level of co-infection and spatial distribution of the viruses within the Acholi sub-region of northern Uganda. Multiplex PCR was used to screen and determine level of co-infection in 380 sweetpotato plants. The PCR scores were computed to give overall frequency...
Article
Full-text available
Understanding the mechanisms that enforce, maintain, or reverse the process of speciation is an important challenge in evolutionary biology. This study investigates the patterns of divergence and discusses the processes that form and maintain divergent lineages of the tsetse fly Glossina fuscipes fuscipes in Uganda. We sampled 251 flies from 18 sit...
Article
Full-text available
Background The tsetse fly (Glossina sp.) midgut is colonized by maternally transmitted and environmentally acquired bacteria. Additionally, the midgut serves as a niche in which pathogenic African trypanosomes reside within infected flies. Tsetse’s bacterial microbiota impacts many aspects of the fly’s physiology. However, little is known about the...
Article
Full-text available
Viral infections greatly limit sweetpotato yields. Good farming practices are critical for effective disease management. 383 Ugandan farmers were surveyed to document symptom incidence, crop-management practices, and buyer preferences. Results showed that 89.27% farmers grow sweet potatoes yearly and 62.76% of these farmers were female. A total of...
Article
Full-text available
Objective: Nodding syndrome (NS) is a type of epilepsy characterized by repeated head-nodding seizures that appear in previously healthy children between 3 and 18 years of age. In 2012, during a WHO International Meeting on NS in Kampala, Uganda, it was recommended that fungal contamination of foods should be investigated as a possible cause of th...
Article
Full-text available
Sweetpotato (Ipomoea batatas) is a vital crop for overcoming food insecurity in sub-Saharan Africa and its production is highest in East Africa where yields are high and the growing seasons are short. This cross-country study assessed farmers’ local practices and their knowledge of the biotic constraints to sweetpotato production in Uganda, Rwanda,...
Article
Full-text available
Tsetse flies (genus Glossina) are the only vector for the parasitic trypanosomes responsible for sleeping sickness and nagana across sub‐Saharan Africa. In Uganda, the tsetse fly Glossina fuscipes fuscipes is responsible for transmission of the parasite in 90% of sleeping sickness cases, and co‐occurrence of both forms of human‐infective trypanosom...
Article
Full-text available
There is an increasing need to evaluate the impact of chemotherapeutic and vector-based interventions as onchocerciasis affected countries work towards eliminating the disease. The Esperanza Window Trap (EWT) provides a possible alternative to human landing collections (HLCs) for the collection of anthropophilic blackflies, yet it is not known whet...
Data
Laboratory production of CO2. (PDF)
Data
Semi-field production of CO2. (PDF)
Article
Full-text available
Uganda is the only country where the chronic and acute forms of human African Trypanosomiasis (HAT) or sleeping sickness both occur and are separated by < 100 km in areas north of Lake Kyoga. In Uganda, Glossina fuscipes fuscipes is the main vector of the Trypanosoma parasites responsible for these diseases as well for the animal African Trypanosom...
Data
Linear regression of allelic richness (microsatellite loci) and haplotype diversity (mtDNA) over longitude produced using JMP V11.0 (SAS Institute Inc., Cary, NC, USA, 1989–2007). Triangles, diamonds, and squares identify sampling sites within the Northwest, Transition Zone, Northeast genetic units, respectively. (PDF)
Data
Pairwise DEST for 42 populations averaged over 16 loci. The first two columns show the sampling site pairs, while the third and fourth columns report their mean DEST values and the Benjamini-Hochberg corrected significance p-values, respectively. Estimates were made in the R package DEMEtics [60]. (XLSX)
Data
Results of tests for isolation by distance where geographic distance between sampling sites (km) were linear-regressed over nuclear microsatellites based genetic distance (FST /(1-FST)) and mtDNA sequence based genetic distance (ΦST/(1-ΦST)). Results for the Northwest, Transition Zone, Northeast, West units, and all samples combined (Overall) are s...
Data
Effective population size and bottleneck tests. Estimates of effective population size (Ne) were computed for each of the 42 sampling sites across the geographic regions in northern Uganda using three methods: LD, modified temporal method of Waples [66] based on [67] and heterozygote excess method. Estimates are provided together with their 95% CI....
Data
Table showing list and frequency of distribution of haplotypes recovered from the G. f. fuscipes samples mtDNA sequences analyzed from northern Uganda. (XLSX)
Data
Discriminant Analysis of Principal Components (DAPC) based on genetic diversity at 16 microsatellite loci in 42 populations and obtained using the adegenet package [52] in R [53]. Two linear discriminants (LD1 and LD2) were used, following selection of principal components using a-score optimization, to plot G. f. fuscipes genotypes. Color codes ar...
Data
Total number of microsatellite alleles by locus. (DOCX)
Data
Table shows the probability of assignment (q-values) of individuals to each of the 3 genetic units, individual mtDNA haplotype, home region of individual, and if it’s a migrant the origin of migration, as well as comparison between microsatellite and mtDNA genetic assignment. (XLSX)
Data
Pairwise FST and ɸST comparisons for microsatellites (A) and mtDNA (B) respectively. FST values are reported in the lower diagonal. Since most values are significant, we highlight those that are non-significant in bold. All computations were done in ARLEQUIN. Significance was calculated based on a P<0.05. (XLSX)
Data
Table showing the total number of migrants based on GENECLASS and FLOCK. General information is displayed (population, closest village, drainage basin). Total, female, and male migrants are shown as counts from each unit based on both analyses. (XLSX)
Data
Sample information and molecular diversity indices. Sample geographic locations, sample sizes, and genetic diversity statistics for 16 microsatellite loci and for a 490bp mtDNA COI-COII gene fragment in 42 populations of G. f. fuscipes. ** Indicates samples collected prior to 2014, N = number of individuals analyzed, AR = Allelic richness, Ho = Obs...
Data
Microsatellite loci information. The table reports loci names followed by the forward (F) and reverse (R) primers names and sequences. The last column reports its source. M13 tails are marked with an asterisk (*). (DOCX)
Data
Wilcoxon signed rank test results comparing STRUCTURE results from the real data to the hybrid swarm model and the mechanical mixing model. (XLSX)
Article
Full-text available
Background - Glossina fuscipes fuscipes is a tsetse species of high economic importance in Uganda where it is responsible for transmitting animal African trypanosomiasis (AAT) and both the chronic and acute forms of human African trypanosomiasis (HAT). We used genotype data from 17 microsatellites and a mitochondrial DNA marker to assess temporal c...