94 research outputs found
COVID-19 information dissemination in Uganda: perspectives from sub-national health workers
Background: In many places, health workers at the sub-national level are on the frontlines of disseminating information about coronavirus (COVID-19) to communities. To ensure communities are receiving timely and accurate information, it is vital health workers are kept abreast of the most recent recommendations, and guidance. Methods: An electronic survey was implemented to provide insights about the dissemination and utilisation of information and evidence related to the COVID-19 pandemic by health workers engaged at sub-national levels of the Ugandan health system. The aim of this survey was to provide insights about the dissemination and utilisation of information and evidence related to the coronavirus (COVID-19) pandemic by individuals engaged at sub-national levels of the health system. Results: Mass media and public health campaigns and outreach activities were deemed the most suitable means to reach communities with COVID-19 information. Given the reported disruption to public outreach campaigns, this is a particularly important consideration for the provision of information to communities. All materials should be adapted to the local context. The need for information on homecare of COVID-19 patients was highlighted, along with the need for updated local statistics as to COVID-19 cases to be relayed for health workers at sub-national levels. Conclusions: Understanding the sources of information used by health workers can facilitate the transfer of relevant and timely information, which in turn increases the use of such information by the Ugandan population. It is vital that these issues are continued to be monitored, and communication modes and content are actively responsive to the time- and place-specific needs of health workers and community members
Confirmed local endemicity and putative high transmission of Schistosoma mansoni in the Sesse Islands, Lake Victoria, Uganda
The Sesse Islands, in the Ugandan portion of Lake Victoria, have long been considered a low transmission zone for intestinal schistosomiasis. Based on observations of high prevalence of Schistosoma mansoni infection in the northern-most islands of this archipelago, a follow-up survey was conducted to ascertain whether transmission was endemic to this island group, combining parasitological and malacological surveys. Prevalence of intestinal schistosomiasis was again observed to be high, as was intensity of infections which, combined with low reported incidence of treatment, suggests that chemotherapy-based control initiatives are not being maximally effective in this region as high levels of population movement between islands and districts are confounding. The local disease transmission was confirmed by the observations of high abundance of Biomphalaria, as well as field-caught snails shedding S. mansoni cercariae. DNA sequencing of 12 cercariae revealed common mitochondrial cox1 haplotypes, as well as, novel ones, consistent with the high genetic diversity of this parasite in Lake Victoria. Intestinal schistosomiasis is firmly endemic in parts of the Sesse Islands and more broadly, this island group provides an insight into the future challenges to be faced by the Ugandan National Control Programme in regularly reaching these rather remote, inaccessible and largely itinerant communities
Detection of persistent Plasmodium spp. infections in Ugandan children after artemether-lumefantrine treatment
During a longitudinal study investigating the dynamics of malaria in Ugandan lakeshore communities, a consistently high malaria prevalence was observed in young children despite regular treatment. To explore the short-term performance of artemether-lumefantrine (AL), a pilot investigation into parasite carriage after treatment(s) was conducted in Bukoba village. A total of 163 children (aged 2–7 years) with a positive blood film and rapid antigen test were treated with AL; only 8·7% of these had elevated axillary temperatures. On day 7 and then on day 17, 40 children (26·3%) and 33 (22·3%) were positive by microscopy, respectively. Real-time PCR analysis demonstrated that multi-species Plasmodium infections were common at baseline, with 41·1% of children positive for Plasmodium falciparum/Plasmodium malariae, 9·2% for P. falciparum/ Plasmodium ovale spp. and 8·0% for all three species. Moreover, on day 17, 39·9% of children infected with falciparum malaria at baseline were again positive for the same species, and 9·2% of those infected with P. malariae at baseline were positive for P. malariae. Here, chronic multi-species malaria infections persisted in children after AL treatment(s). Better point-of-care diagnostics for non-falciparum infections are needed, as well as further investigation of AL performance in asymptomatic individuals
ABO Blood Groups Do Not Predict Schistosoma mansoni Infection Profiles in Highly Endemic Villages of Uganda
Schistosoma mansoni is a parasite which causes significant public-health issues, with over 240 mil-lion people infected globally. In Uganda alone, approximately 11.6 million people are affected. Despite over a decade of mass drug administration in this country, hyper-endemic hotspots persist, and individuals who are repeatedly heavily and rapidly reinfected are observed. Human blood-type antigens are known to play a role in the risk of infection for a variety of diseases, due to cross-reactivity between host antibodies and pathogenic antigens. There have been conflicting results on the effect of blood type on schistosomiasis infection and pathology. Moreover, the ef-fect of blood type as a potential intrinsic host factor on S. mansoni prevalence, intensity, clearance, and reinfection dynamics and on co-infection risk remains unknown. Therefore, the epidemio-logical link between host blood type and S. mansoni infection dynamics was assessed in three hyper-endemic communities in Uganda. Longitudinal data incorporating repeated pretreatment S. mansoni infection intensities and clearance rates were used to analyse associations between blood groups in school-aged children. Soil-transmitted helminth coinfection status and biometric parameters were incorporated in a generalised linear mixed regression model including age, gender, and body mass index (BMI), which have previously been established as significant factors influencing the prevalence and intensity of schistosomiasis. The analysis revealed no associations between blood type and S. mansoni prevalence, infection intensity, clearance, reinfection, or coinfection. Variations in infection profiles were significantly different between the villages, and egg burden significantly decreased with age. While blood type has proven to be a predictor of several diseases, the data collected in this study indicate that it does not play a significant role in S. mansoni infection burdens in these high-endemicity communities
Epidemiology and control of intestinal schistosomiasis on the Sesse Islands, Uganda: integrating malacology and parasitology to tailor local treatment recommendations
<p>Abstract</p> <p>Background</p> <p>Intestinal schistosomiasis is often widespread among the populations living around Lake Victoria and on its islands. The Sesse Island group (containing some 84 islands), however, is typically assumed to be a low prevalence zone, with limited transmission, but has never been surveyed in detail. Here, we present a rapid mapping assessment, bringing together snail and parasite information, at 23 sites for the presence of intermediate host snails and at 61 sites for the prevalence of intestinal schistosomiasis in school-aged children (N = 905). Two different diagnostic tools were used and compared at 45 of these sites: Kato-Katz thick faecal smears and circulating cathodic antigen (CCA) urine dipsticks.</p> <p>Results</p> <p><it>Biomphalaria </it>snails were found at 11 sites but in low numbers; none was found shedding schistosome cercariae. At 22 out of the 45 sites, local prevalence by urine and/or stool diagnostics was in excess of 50%, although mean prevalence of intestinal schistosomiasis overall was 34.6% (95% confidence intervals (CI) = 31.0-38.3%) by Kato-Katz and 46.5% (95% CI = 42.7-50.4%) by CCA if 'trace' reactions were considered infection-positive (if considered infection-negative, mean prevalence was 28.1% (95% CI = 24.7-31.7%)). Diagnostic congruence between CCA and Kato-Katz was poor and significant discordance in estimated prevalence by location was found, with each often inferring different mass drug administration regimes.</p> <p>Conclusions</p> <p>Accurate estimation of schistosome prevalence is important for determining present and future treatment needs with praziquantel; the wide range of schistosome prevalence across the Sesse Island group requires a treatment regime largely tailored to each island. In high prevalence locations, further malacological sampling is required to confirm the extent of local transmission, especially on the northern islands within the group. The observation that different diagnostic tests can provide varying results in terms of estimating prevalence by location, and hence change treatment recommendations, suggests that care must be taken in interpreting raw prevalence data. In particular, further research into the reasons for the differences in the poorer performance of the CCA test should be pursued.</p
Paper-based microfluidics for DNA diagnostics of malaria in low resource underserved rural communities
Rapid, low-cost, species-specific diagnosis, based upon DNA testing, is becoming important in the treatment of patients with infectious diseases. Here, we demonstrate an innovation that uses origami to enable multiplexed, sensitive assays that rival polymerase chain reactions (PCR) laboratory assays and provide high-quality, fast precision diagnostics for malaria. The paper-based microfluidic technology proposed here combines vertical flow sample-processing steps, including paper folding for whole-blood sample preparation, with an isothermal amplification and a lateral flow detection, incorporating a simple visualization system. Studies were performed in village schools in Uganda with individual diagnoses being completed in <50 min (faster than the standard laboratory-based PCR). The tests, which enabled the diagnosis of malaria species in patients from a finger prick of whole blood, were both highly sensitive and specific, detecting malaria in 98% of infected individuals in a double-blind first-in-human study. Our method was more sensitive than other field-based, benchmark techniques, including optical microscopy and industry standard rapid immunodiagnostic tests, both performed by experienced local healthcare teams (which detected malaria in 86% and 83% of cases, respectively). All assays were independently validated using a real-time double-blinded reference PCR assay. We not only demonstrate that advanced, low-cost DNA-based sensors can be implemented in underserved communities at the point of need but also highlight the challenges associated with developing and implementing new diagnostic technologies in the field, without access to laboratories or infrastructure
The impact of storage conditions on human stool 16S rRNA microbiome composition and diversity
Background: Multiple factors can influence stool sample integrity upon sample
collection. Preservation of faecal samples for microbiome studies is therefore an
important step, particularly in tropical regions where resources are limited and
high temperatures may significantly influence microbiota profiles. Freezing is the
accepted standard to preserve faecal samples however, cold chain methods are often
unfeasible in fieldwork scenarios particularly in low and middle-income countries
and alternatives are required. This study therefore aimed to address the impact of
different preservative methods, time-to-freezing at ambient tropical temperatures,
and stool heterogeneity on stool microbiome diversity and composition under
real-life physical environments found in resource-limited fieldwork conditions.
Methods: Inner and outer stool samples collected from one specimen obtained from
three children were stored using different storage preservation methods (raw, ethanol
and RNAlater) in a Ugandan field setting. Mixed stool was also stored using these
techniques and frozen at different time-to-freezing intervals post-collection from
0–32 h. Metataxonomic profiling was used to profile samples, targeting the V1–V2
regions of 16S rRNA with samples run on a MiSeq platform. Reads were trimmed,
combined and aligned to the Greengenes database. Microbial diversity and
composition data were generated and analysed using Quantitative Insights Into
Microbial Ecology and R software.
Results: Child donor was the greatest predictor of microbiome variation between the
stool samples, with all samples remaining identifiable to their child of origin
despite the stool being stored under a variety of conditions. However, significant
differences were observed in composition and diversity between preservation
techniques, but intra-preservation technique variation was minimal for all
preservation methods, and across the time-to-freezing range (0–32 h) used. Stool
heterogeneity yielded no apparent microbiome differences.
Conclusions: Stool collected in a fieldwork setting for comparative microbiome
analyses should ideally be stored as consistently as possible using the same
preservation method throughout
ABO Blood Groups Do Not Predict Schistosoma mansoni Infection Profiles in Highly Endemic Villages of Uganda
From MDPI via Jisc Publications RouterHistory: accepted 2021-11-23, pub-electronic 2021-11-27Publication status: PublishedFunder: European Research Council; Grant(s): 680088 SCHISTO_PERSISTFunder: Wellcome Trust; Grant(s): 204820/Z/16/ZFunder: Engineering and Physical Sciences Research Council; Grant(s): EP/T003618/1, EP/R01437X/Funder: Medical Research Council; Grant(s): MR/P025447/1Schistosoma mansoni is a parasite which causes significant public-health issues, with over 240 million people infected globally. In Uganda alone, approximately 11.6 million people are affected. Despite over a decade of mass drug administration in this country, hyper-endemic hotspots persist, and individuals who are repeatedly heavily and rapidly reinfected are observed. Human blood-type antigens are known to play a role in the risk of infection for a variety of diseases, due to cross-reactivity between host antibodies and pathogenic antigens. There have been conflicting results on the effect of blood type on schistosomiasis infection and pathology. Moreover, the effect of blood type as a potential intrinsic host factor on S. mansoni prevalence, intensity, clearance, and reinfection dynamics and on co-infection risk remains unknown. Therefore, the epidemiological link between host blood type and S. mansoni infection dynamics was assessed in three hyper-endemic communities in Uganda. Longitudinal data incorporating repeated pretreatment S. mansoni infection intensities and clearance rates were used to analyse associations between blood groups in school-aged children. Soil-transmitted helminth coinfection status and biometric parameters were incorporated in a generalised linear mixed regression model including age, gender, and body mass index (BMI), which have previously been established as significant factors influencing the prevalence and intensity of schistosomiasis. The analysis revealed no associations between blood type and S. mansoni prevalence, infection intensity, clearance, reinfection, or coinfection. Variations in infection profiles were significantly different between the villages, and egg burden significantly decreased with age. While blood type has proven to be a predictor of several diseases, the data collected in this study indicate that it does not play a significant role in S. mansoni infection burdens in these high-endemicity communities
Residence time, water contact, and age-driven Schistosoma mansoni infection in hotspot communities in Uganda
Schistosomiasis is the second most important parasitic infection after malaria in terms of its socioeconomic impact and is endemic in 78 countries. It affects more than 240 million people worldwide, with 90% of cases occurring in sub-Saharan Africa. In Uganda, Schistosomamansoni is the most common species, with more than seven million people infected and 17 million living at risk despite mass drug administration (MDA) of praziquantel initiated more than 16 years ago. There has been a shift in the WHO schistosomiasis goals from controlling morbidity to elimination as a public health problem. Understanding the drivers of infection in persistent transmission hotspots despite ongoing control interventions is paramount. We conducted a cross-sectional epidemiological study of 381 individuals in Bugoto community, Mayuge district, Eastern Uganda, along with a structured survey to ascertain drivers of S. mansoni infection. Bugoto has had community-wide MDA since 2004. We detected a S. mansoni prevalence of 52% across the whole community and a prevalence of 71% in school-age children. This qualifies Bugoto as a highly endemic community according to WHO guidelines. Using a multivariate logistic regression, we found that S. mansoni infection was best explained by age group, longer residence times, and any daily contact with lake water. Schistosomamansoni infection remains a large burden across this community. This study identifies opportunities for interventions that reduce lake water contact, expand treatment eligibility to all at risk, and improve MDA coverage for long-term residents in these settings to control schistosomiasis in persistent transmission hotspots
On generalized competition index of a primitive tournament
AbstractFor positive integers k and m and a digraph D, the k-step m-competition graph Cmk(D) of D has the same set of vertices as D and an edge between vertices x and y if and only if there exist m distinct vertices v1,v2,…,vm in D such that there exist directed walks of length k from x to vi and from y to vi for 1≤i≤m. The m-competition index of a primitive digraph D is the smallest positive integer k such that Cmk(D) is a complete graph. In this paper, we study the m-competition indices of primitive tournaments and provide an upper bound for the m-competition index of a primitive tournament
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