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1.
Nature ; 589(7841): 276-280, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33086375

RESUMO

Suppressing infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will probably require the rapid identification and isolation of individuals infected with the virus on an ongoing basis. Reverse-transcription polymerase chain reaction (RT-PCR) tests are accurate but costly, which makes the regular testing of every individual expensive. These costs are a challenge for all countries around the world, but particularly for low-to-middle-income countries. Cost reductions can be achieved by pooling (or combining) subsamples and testing them in groups1-7. A balance must be struck between increasing the group size and retaining test sensitivity, as sample dilution increases the likelihood of false-negative test results for individuals with a low viral load in the sampled region at the time of the test8. Similarly, minimizing the number of tests to reduce costs must be balanced against minimizing the time that testing takes, to reduce the spread of the infection. Here we propose an algorithm for pooling subsamples based on the geometry of a hypercube that, at low prevalence, accurately identifies individuals infected with SARS-CoV-2 in a small number of tests and few rounds of testing. We discuss the optimal group size and explain why, given the highly infectious nature of the disease, largely parallel searches are preferred. We report proof-of-concept experiments in which a positive subsample was detected even when diluted 100-fold with negative subsamples (compared with 30-48-fold dilutions described in previous studies9-11). We quantify the loss of sensitivity due to dilution and discuss how it may be mitigated by the frequent re-testing of groups, for example. With the use of these methods, the cost of mass testing could be reduced by a large factor. At low prevalence, the costs decrease in rough proportion to the prevalence. Field trials of our approach are under way in Rwanda and South Africa. The use of group testing on a massive scale to monitor infection rates closely and continually in a population, along with the rapid and effective isolation of people with SARS-CoV-2 infections, provides a promising pathway towards the long-term control of coronavirus disease 2019 (COVID-19).


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/epidemiologia , COVID-19/virologia , Vigilância da População/métodos , SARS-CoV-2/isolamento & purificação , Algoritmos , COVID-19/diagnóstico , Humanos , Prevalência , Ruanda/epidemiologia , Sensibilidade e Especificidade
2.
Int J Mol Sci ; 24(15)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37569646

RESUMO

For effective treatments and preventive measures against severe COVID-19, it is essential to determine early markers of disease severity in different populations. We analysed the cytokine kinetics of 129 COVID-19 patients with mild symptoms, 68 severe cases, and 20 healthy controls for the first time in Rwanda. Pro-inflammatory (IFNγ, IL-6, TNFα), Treg (IL-10, TGFß1, TGFß3), Th9 (IL-9), Th17 (IL-17), and Th2 (IL-4, IL-13) cytokines, total IgM and IgG, as well as gene expressions of FoxP3, STAT5+, IFNγ-R1, and ROR alpha+, were measured at day 1, day 7, day 14, day 21, and day 28 post-infection. Severe cases showed a significantly stronger increase than mild patients in levels of all cytokines (except IL-9) and all gene expression on day 1 of infection. Some cytokine levels dropped to levels comparable to mild cases at later time points. Further analysis identified IFNγ as a marker of severity throughout the disease course, while TGFß1, IL-6, and IL-17 were markers of severity only at an early phase. Importantly, this study revealed a striking low IL-9 level and high IFNγ/IL-9 ratio in the plasma of patients who later died compared to mild and severe cases who recovered, suggesting that this could be an important biomarker for predicting the severity of COVID-19 and post-COVID-19 syndrome.


Assuntos
COVID-19 , Citocinas , Humanos , Citocinas/genética , Interleucina-17/genética , Interleucina-9/genética , Interleucina-6 , Cinética , Síndrome de COVID-19 Pós-Aguda , Ruanda/epidemiologia , Interferon gama , Gravidade do Paciente
3.
J Interprof Care ; 37(5): 841-845, 2023 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36701263

RESUMO

Visual impairment and blindness affect an estimated 2.2 billion people worldwide. Accessible low-cost diagnostic tools and interprofessional education and collaborative practice are part of ongoing strategies to improve eye care services. This study evaluated the impact of an interprofessional Arclight workshop on undergraduate healthcare students' clinical identification skills related to eye health, and self-reported confidence in ophthalmic skills. Undergraduate students from clinical medical officer, ophthalmic clinical officer, Bachelors and Diploma nursing, and medical programs at the University of Rwanda participated in a pilot interprofessional eye health workshop. The Arclight device, a low-cost ophthalmoscope and simulation eyes were used to enable students to practice ophthalmic skills and thereafter equip them. Clinical identification skills related to common eye conditions, and self-reported confidence in ophthalmic skills were assessed pre and post workshop. Overall, students' ability to identify common eye conditions, and self-reported confidence in relation to all skills statistically improved post workshop, with some differences between professional groups in relation to eye health skills. This IPE experience used the Arclight package as a vehicle for IPE, enabling healthcare students to share and acquire new skills and confidence in relation to recognizing common eye conditions and assessing eye health.


Assuntos
Estudantes de Ciências da Saúde , Estudantes de Medicina , Humanos , Relações Interprofissionais , Pessoal de Saúde , Currículo
5.
Int J Mol Sci ; 23(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36293524

RESUMO

The proper control of Plasmodium infection requires a finely balanced immune response. Here, we evaluated the implication of TGF-ß1 and TGF-ß3 in this process using novel monoclonal antibodies to measure their plasma concentrations in comparison with other cytokines and the expression of FOXP3 mRNA. Plasma cytokine levels were measured in 80 patients with severe anaemic malaria and 186 with a mild presentation using ELISA, and rtPCR was used to measure FOXP3 mRNA expression. While no mature TGF-ß isoforms were detected in the plasma, the latent TGF-ß1 and TGF-ß3 were strongly upregulated in patients with mild malaria and nearly undetected in patients with severe disease. Similar selective upregulation in mild patients was observed for IL-9 and FOXP3 mRNA, while IL-7, IL-10, IL-17, and IL-27, although higher in mild cases, were also detected in severe disease. In contrast, a clearly skewed trend of severe cases towards higher pro-inflammatory (IL-6, IL-13, TNF-α) and Th1 (IFN-γ) responses was observed, which was associated with a higher level of parasitaemia as well as lower IgG and higher IgM responses. Together, these results suggest that the stimulation of regulatory T cells through TGF-ß1/TGF-ß3 and IL-9 is paramount to an effective and balanced protective immunity in natural human malaria infection.


Assuntos
Interleucina-27 , Malária , Humanos , Interleucina-10 , Fator de Crescimento Transformador beta1/genética , Interleucina-13 , Interleucina-17 , Interleucina-9/genética , Fator de Necrose Tumoral alfa , Regulação para Cima , Fator de Crescimento Transformador beta3 , Interleucina-6 , Interleucina-7 , Citocinas , Fator de Crescimento Transformador beta , RNA Mensageiro , Imunoglobulina M , Imunoglobulina G , Fatores de Transcrição Forkhead , Anticorpos Monoclonais
6.
J Interprof Care ; 35(4): 637-640, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32648788

RESUMO

Preventable and treatable visual impairment affects more than 1 billion people worldwide. Rwanda has an estimated visual impairment prevalence of 3.7% amongst the 12 million inhabitants. Around one third of this demand could be addressed through a more integrated and collaborative approach, particularly in primary eye care services. Healthcare students, therefore, need to be prepared for collaborative practice in eye health through interprofessional learning. Interprofessional workshops were piloted with ophthalmic clinical officer, medical clinical officer, nursing and medical students from the University of Rwanda. The aim was to promote collaborative practice by teaching students how to assess and recognize common eye conditions using the Arclight; a low cost, solar powered, portable ophthalmoscope designed for use in low resource settings. Students reported that the workshop content was relevant to all professional groups. They valued the opportunity to learn interprofessionally, share their knowledge and perspectives, and acquire new knowledge and skills together. This pilot helped to identify the most relevant skills and knowledge for future interprofessional eye health training. It enabled the facilitators to reflect on how best to maintain a balance between a quality interprofessional experience and the more specific eye health related learning objectives.


Assuntos
Estudantes de Medicina , Estudantes de Enfermagem , Comportamento Cooperativo , Atenção à Saúde , Humanos , Relações Interprofissionais , Ruanda
7.
J Infect Dis ; 208(1): 159-69, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23045617

RESUMO

BACKGROUND: Schistosomiasis elicits cross-regulatory immune responses, but it is unclear how antihelminthic treatment affects this balance. This study integrates data on 13 cytokines elicited by 3 schistosome to examine how praziquantel treatment alters immune polarization and whether post-treatment cytokine profiles influence reinfection status. METHODS: Venous blood from 72 Schistosoma haematobium-exposed participants was cultured with schistosome egg, adult worm, and cercaria antigens pre- and 6 weeks post-praziquantel treatment. Innate inflammatory (tumor necrosis factor α [TNF-α], interleukin(IL-)-6, IL-8), Th1 (interferon γ [IFN-γ], IL-2, IL-12p70), Th2 (IL-4, IL-5, IL-13), Th17 (IL-17A, IL-21, IL-23p19), and regulatory (IL-10) cytokines were quantified via enzyme-linked immunosorbent assay. Cytokine data was integrated using nonmetric multidimensional scaling and factor analysis. RESULTS: Egg-specific cytokine phenotypes became more proinflammatory post-treatment due to increased TNF-α, IL-6, IL-8, IFN-γ, IL-12p70, and IL-23 levels. Post-treatment cercariae-specific responses were also more proinflammatory reflecting elevated IL-8. In contrast, post-treatment adult worm-specific responses were less inflammatory, reflecting lower post-treatment IL-6. A combination of egg-induced IL-6, IL-12p70, IL-21, and IL-23 and adult worm-induced IL-5 and IL-21 post-treatment was associated with reduced reinfection risk 18 months later. CONCLUSIONS: Praziquantel treatment markedly alters polarization of schistosome-specific cytokine responses, and these changes, particularly in response to egg-stage parasites, may promote resistance to reinfection.


Assuntos
Anti-Helmínticos/uso terapêutico , Citocinas/fisiologia , Praziquantel/uso terapêutico , Esquistossomose Urinária/imunologia , Esquistossomose/imunologia , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Adolescente , Animais , Criança , Pré-Escolar , Citocinas/sangue , Feminino , Humanos , Imunidade Inata/imunologia , Interferon gama/sangue , Interleucina-10/sangue , Interleucina-12/sangue , Interleucina-13/sangue , Interleucina-17/sangue , Interleucina-2/sangue , Interleucina-23/sangue , Interleucina-4/sangue , Interleucina-5/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Interleucinas/sangue , Masculino , Schistosoma haematobium/imunologia , Esquistossomose/tratamento farmacológico , Esquistossomose Urinária/tratamento farmacológico , Fator de Necrose Tumoral alfa/sangue
8.
Int Arch Allergy Immunol ; 161(4): 333-41, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23689700

RESUMO

BACKGROUND: Protective acquired immunity against helminths and allergic sensitisation are both characterised by high IgE antibody levels. Levels of IgE antibodies are naturally tightly regulated by several mechanisms including binding of the CD23 receptor. Following observations that helminth infections and allergic sensitisation may co-present, the current study aims to investigate the relationship between the soluble CD23 (sCD23) receptor, parasite-specific IgE responses and allergic sensitisation in people exposed to the helminth parasite Schistosoma haematobium. METHODS: A cohort of 434 participants was recruited in two villages with different levels of S. haematobium infection in Zimbabwe. Serum levels of the 25-kDa fragment of sCD23 were related to levels of schistosome infection intensity, allergen (house dust mite, HDM) and schistosome-specific IgE, total IgE and skin sensitisation to HDM. RESULTS: sCD23 levels rose significantly with schistosome infection intensity but declined significantly with schistosome-specific IgE levels. Furthermore, sCD23 levels were negatively associated with skin sensitisation and IgE reactivity against HDM, but showed no relationship with total IgE. CONCLUSION: The results are consistent with the suppression of parasite and allergen-specific IgE levels by sCD23. Further mechanistic studies will determine the relevance of this potential regulatory mechanism in the development of helminth-specific immune responses in atopic individuals.


Assuntos
Hipersensibilidade/imunologia , Receptores de IgE/sangue , Schistosoma haematobium/imunologia , Esquistossomose Urinária/imunologia , Adolescente , Adulto , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Dermatophagoides/imunologia , Criança , Estudos de Coortes , Progressão da Doença , Epitopos/imunologia , Feminino , Humanos , Hipersensibilidade/complicações , Hipersensibilidade/diagnóstico , Imunoglobulina E/sangue , Masculino , Pyroglyphidae/imunologia , Schistosoma haematobium/patogenicidade , Esquistossomose Urinária/complicações , Esquistossomose Urinária/diagnóstico , Adulto Jovem , Zimbábue
9.
Trop Med Infect Dis ; 8(6)2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37368713

RESUMO

BACKGROUND: Schistosomiasis, due to S. mansoni, is prevalent in Rwanda. However, there is a paucity of information related to the abundance, species, distribution, and infectivity of Schistosoma intermediate host snails. METHODS: Snails were collected from 71 sites, including lakeshores and wetlands. Snails obtained were morphologically identified, and cercariae were shed using standard procedures. Cercariae were molecularly characterized using PCR. GPS coordinates were used to generate geospatial maps of snail distribution that were overlaid with geospatial distribution of schistosomiasis among pre-school children in the same areas. RESULTS: Overall, 3653 snails were morphologically classified as Bulinus spp. and 1449 as Biomphalaria spp. A total of 306 snails shed cercariae, 130 of which were confirmed as S. mansoni cercaria by PCR. There was no significant difference in the proportion of S. mansoni cercariae in wetlands compared to lakeshores. CONCLUSION: Rwandan water bodies harbor an important number of snails that shed S. mansoni cercariae. Furthermore, a strong spatial correlation was observed between the distribution of schistosomiasis in children and the spatial distribution of snail infectivity with S. mansoni. The presence of Bulinus spp. Suggests a potential risk of S. haematobium, although molecular analysis did not show any current transmission of this parasite.

10.
Int Arch Allergy Immunol ; 158(3): 288-98, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22398631

RESUMO

BACKGROUND: The hygiene hypothesis suggests that parasitic infections protect against allergic diseases by modulating the host's immune responses. Experimental studies indicate that this protection depends on the intensity of parasitic infection, but this observation has not been tested in human populations. The aim of this study is to investigate whether the intensity of Schistosoma haematobium infection is related to atopic responses and whether this relationship differs between populations with distinct parasite transmission dynamics. METHODS: The study was conducted in two villages with different Schistosoma haematobium transmission dynamics, i.e. high (n = 365) and low (n = 307) transmission. Allergic reactivity to the common house dust mite (Dermatophagoides pteronyssinus) was measured by skin prick tests and allergen-specific IgE and IgG4 quantified by enzyme-linked immunosorbent assay. Atopic responses were related to current infection intensity and schistosome transmission levels. RESULTS: Schistosome infection intensity was negatively associated with the skin prick reactivity, mite-specific IgE and the ratio IgE/IgG4 in the high-transmission village. However, when only low levels of infection were analyzed in the 2 villages, there was no correlation between mite-specific responses and infection intensity. CONCLUSION: The relationship between schistosome infection and atopic responses is dependent on the intensity of current schistosome infection. Thus, consistent with results from animal models, with an increasing parasite burden, the immunoregulation of immune responses to allergens appears to become more pronounced.


Assuntos
Dermatophagoides pteronyssinus/imunologia , Hipersensibilidade Imediata/imunologia , Schistosoma haematobium/imunologia , Esquistossomose Urinária/imunologia , Esquistossomose Urinária/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alérgenos/imunologia , Animais , Antígenos de Dermatophagoides/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Hipersensibilidade Imediata/etiologia , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Lactente , Masculino , Pessoa de Meia-Idade , Esquistossomose Urinária/parasitologia , Testes Cutâneos , Adulto Jovem , Zimbábue
11.
Microorganisms ; 10(4)2022 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-35456772

RESUMO

Malaria, caused by the Plasmodium species, is an infectious disease responsible for more than 600 thousand deaths and more than 200 million morbidity cases annually. With above 90% of those deaths and cases, sub-Saharan Africa is affected disproportionately. Malaria clinical manifestations range from asymptomatic to simple, mild, and severe disease. External factors such as the gut microbiota and helminthiases have been shown to affect malaria clinical manifestations. However, little is known about whether the gut microbiota has the potential to influence malaria clinical manifestations in humans. Similarly, many previous studies have shown divergent results on the effects of helminths on malaria clinical manifestations. To date, a few studies, mainly murine, have shown the gut microbiota's capacity to modulate malaria's prospective risk of infection, transmission, and severity. This short review seeks to summarize recent literature about possible interactions between malaria, helminthiases, and the gut microbiota. The knowledge from this exercise will inform innovation possibilities for future tools, technologies, approaches, and policies around the prevention and management of malaria in endemic countries.

12.
Trop Med Infect Dis ; 7(8)2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-36006294

RESUMO

Background. Soil-transmitted helminths (STH) are parasitic diseases with significant public health impact. Analysis is generally based on cross-sectional prevalence surveys; outcomes are mostly aggregated to larger spatial units. However, recent research demonstrates that infection levels and spatial patterns differ between STH species and tend to be localized. Methods. Incidence data of STHs including roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura) and hookworms per primary health facility for 2008 were linked to spatially delineated primary health center service areas. Prevalence data per district for individual and combined STH infections from the 2008 nationwide survey in Rwanda were also obtained. Results. A comparison of reported prevalence and incidence data indicated significant positive correlations for roundworm (R2 = 0.63) and hookworm (R2 = 0.27). Weak positive correlations were observed for whipworm (R2 = 0.02) and the three STHs combined (R2 = 0.10). Incidence of roundworm and whipworm were found to be focalized with significant spatial autocorrelation (Moran's I > 0: 0.05−0.38 and p ≤ 0.03), with (very) high incidence rates in some focal areas. In contrast, hookworm incidence is ubiquitous and randomly distributed (Moran's I > 0: 0.006 and p = 0.74) with very low incidence rates. Furthermore, an exploratory regression analysis identified relationships between helminth infection cases and potential environmental and socio-economic risk factors. Conclusions. Findings show that the spatial distribution of STH incidence is significantly associated with soil properties (sand proportion and pH), rainfall, wetlands and their uses, population density and proportion of rural residents. Identified spatial patterns are important for guiding STH prevention and control programs.

13.
Front Pediatr ; 10: 906177, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35813371

RESUMO

Schistosoma mansoni is endemic in Rwanda, and control programs have been implemented with a special focus on school-age children (SAC), ignoring pre-school age children (pre-SAC) for which the actual prevalence of the disease is not well established. This study consisted of a cross-sectional quantitative mapping of the distribution of Schistosoma mansoni and identification of associated risk factors among pre-SAC throughout the country. The study covered all the 17 districts of Rwanda endemic for Schistosoma mansoni, with a total sample of 4,675 children enrolled from 80 purposively selected villages. The parasitological assessment of children's urine and stool samples was conducted using CCA and Kato Katz methods, respectively, for infection detection. A standard questionnaire was used to collect data on the risk factors, and geospatial assessment was performed using tablets and GPS to record geographic coordinates for plotting locations on maps using ArcGIS software. The overall prevalence of S. mansoni infection across the surveyed areas was 24 and 0.8% by CCA and Kato-Katz, respectively. Infection was significantly associated with bathing children in open water bodies. Furthermore, pre-SAC looked after by siblings (sisters) were two times as much likely to be infected compared to those looked after by mothers. Schistosomiasis control interventions are needed for pre-SAC to limit their exposure to open water bodies with expectations of adapted chemotherapy to be availed. Community-based deworming campaigns may be the best way to ensure good treatment coverage of pre-SAC in Rwanda.

14.
Parasitology ; 138(12): 1519-33, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21813042

RESUMO

Despite the overlapping distribution of Schistosoma haematobium and Plasmodium falciparum infections, few studies have investigated early immune responses to both parasites in young children resident in areas co-endemic for the parasites. This study measures infection levels of both parasites and relates them to exposure and immune responses in young children. Levels of IgM, IgE, IgG4 directed against schistosome cercariae, egg and adult worm and IgM, IgG directed against P. falciparum schizonts and the merozoite surface proteins 1 and 2 together with the cytokines IFN-γ, IL-4, IL-5, IL-10 and TNF-α were measured by ELISA in 95 Zimbabwean children aged 1-5 years. Schistosome infection prevalence was 14·7% and that of Plasmodium infection was 0% in the children. 43. 4% of the children showed immunological evidence of exposure to schistosome parasites and 13% showed immunological evidence of exposure to Plasmodium parasites. Schistosome-specific responses, indicative of exposure to parasite antigens, were positively associated with cercariae-specific IgE responses, while Plasmodium-specific responses, indicative of exposure to parasite antigens, were negatively associated with responses associated with protective immunity against Plasmodium. There was no significant association between schistosome-specific and Plasmodium-specific responses. Systemic cytokine levels rose with age as well as with schistosome infection and exposure. Overall the results show that (1) significantly more children are exposed to schistosome and Plasmodium infection than those currently infected and; (2) the development of protective acquired immunity commences in early childhood, although its effects on infection levels and pathology may take many years to become apparent.


Assuntos
Citocinas/análise , Imunoglobulinas/biossíntese , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Schistosoma haematobium/imunologia , Esquistossomose Urinária/imunologia , Fatores Etários , Animais , Anticorpos Anti-Helmínticos/biossíntese , Anticorpos Anti-Helmínticos/sangue , Anticorpos Antiprotozoários/biossíntese , Anticorpos Antiprotozoários/sangue , Pré-Escolar , Coinfecção , Doenças Endêmicas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulinas/sangue , Lactente , Malária Falciparum/epidemiologia , Masculino , Prevalência , Esquistossomose Urinária/epidemiologia , Zimbábue/epidemiologia
15.
Front Vet Sci ; 8: 720553, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35118148

RESUMO

Rwanda has a fast growing pig production sector projected to continue expansion, due to rising local and regional demand. We undertook a value chain analysis to establish the flows of pigs and pork in Rwanda and the roles of various actors involved, and to understand governance and sanitary risks in the value chain. Cross-sectional qualitative data were collected through focus group discussions and key informant interviews with farmers, brokers, butchers, abattoir managers, and veterinarians. Data were collected on pig production methods and inputs, the source and destination of live and slaughtered pigs, value-adding infrastructures (abattoirs and processing factories), the people involved and interactions between them, governance, and challenges. Pig production in Rwanda is dominated by smallholders, mainly as a source of supplementary income and secondarily for manure. Emerging medium-sized and large pig farms were also identified, located mainly around urban areas. Live pig markets are the main mechanism allowing various actors to buy/sell pigs. Brokers have an important role in pig transactions: they are key in setting prices at markets, examining pigs for disease, organising the supply of pigs for abattoirs and for export. Only a few formal pig abattoirs were identified, which mainly supply to pork processing factories based in Kigali and/or export to customers. Local consumers rely on informal slaughtering at farm or bar/restaurant backyards, with irregular veterinary inspection. Formal abattoirs were attended by a veterinary inspector, however a lack of record keeping was noted. Sanitary risks identified were a lack of biosecurity throughout the chain and poor hygiene at slaughter places. Lingual palpation was practised in pig markets to identify cysticercosis infection, however cyst-positive pigs were not destroyed, but were sold for reduced prices in the same market or later informally sold by the owner. There are few veterinarians attending farms, with most services provided by less qualified technicians or self-treatment of pigs by farmers. Overall, this production system is characterised by a high degree of informality at all nodes, combined with the rapid growth trajectory in the sector. These findings provide a basis to plan interventions tailored to vulnerabilities identified in the Rwanda pig value chain.

16.
Nat Commun ; 12(1): 5705, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588460

RESUMO

COVID-19 transmission rates are often linked to locally circulating strains of SARS-CoV-2. Here we describe 203 SARS-CoV-2 whole genome sequences analyzed from strains circulating in Rwanda from May 2020 to February 2021. In particular, we report a shift in variant distribution towards the emerging sub-lineage A.23.1 that is currently dominating. Furthermore, we report the detection of the first Rwandan cases of the B.1.1.7 and B.1.351 variants of concern among incoming travelers tested at Kigali International Airport. To assess the importance of viral introductions from neighboring countries and local transmission, we exploit available individual travel history metadata to inform spatio-temporal phylogeographic inference, enabling us to take into account infections from unsampled locations. We uncover an important role of neighboring countries in seeding introductions into Rwanda, including those from which no genomic sequences were available. Our results highlight the importance of systematic genomic surveillance and regional collaborations for a durable response towards combating COVID-19.


Assuntos
COVID-19/virologia , Genoma Viral/genética , SARS-CoV-2/genética , Doença Relacionada a Viagens , Adulto , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/transmissão , Monitoramento Epidemiológico , Feminino , Humanos , Masculino , Filogenia , Filogeografia , RNA Viral/genética , RNA Viral/isolamento & purificação , Ruanda/epidemiologia , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/patogenicidade , Sequenciamento Completo do Genoma
17.
AAS Open Res ; 2: 7, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-36419723

RESUMO

Background: Schistosomiasis is prevalent in many sub-Saharan African countries and transmission is through waters contaminated by infected snails. In Rwanda, although schistosomiasis is endemic, very few epidemiological studies exist; of these, schoolchildren have been the focus, neglecting pre-school-aged children (PSAC). Furthermore, malacological surveys to indicate the potential for transmission are scarce in the country. The aim of this study was to determine the prevalence of schistosomiasis among PSAC living on Nkombo Island in Lake Kivu and to map the distribution and infectivity of snails in the area. Methods: Stool and urine samples were collected from children aged 1 to 4 years and tested for schistosomiasis using the Kato Katz and the point-of-care circulating cathodic antigen (POC-CCA) diagnostic techniques respectively. Snails were collected along the shores at five different locations with human-water contact activities and cercaria shedding was microscopically examined. GPS receivers were used to collect geographical coordinates and snail distribution maps were generated using ArcGIS. A questionnaire was used to assess water contact activities and frequency.     Results: A total of 278 PSAC were recruited. Overall, 9.5% (excluding traces) of the tested children reacted positively to the POC-CCA, although there were no ova detected in their stool via Kato Katz. The questionnaire revealed that 48.2% of parents/guardians use Lake Kivu's water for household activities while 42.4% children are taken to the Lake shores daily. Overall, 13.5% of collected snails shed cercariae. Conclusions: PSAC of Nkombo Island are exposed to Schistosoma parasites through contact with Lake Kivu, which hosts a number of snails shedding cercaria. Exposure is through recreational activities but also through bathing as safe water is scarce in the area. Health education of parents/guardians of these young children should be promoted and the national schistosomiasis control program should be integrated into water supply projects.

18.
Pan Afr Med J ; 32: 11, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31143316

RESUMO

INTRODUCTION: This study aimed to assess the prevalence and associated risk factors of intestinal parasite infections among children less than two years of age in Rutsiro, Rwanda. METHODS: A cross-sectional parasitological survey was conducted in Rutsiro in June 2016. Fresh stool samples were collected from 353 children and examined using microscopy to detect parasite. A questionnaire was administered to collect data on hygiene, sanitation, socio-demographic and economic characteristics. RESULTS: Approximately one in two children (44.8%) were found to be infected with at least one intestinal parasite. Ascaris (28.5%) was the most prevalent infection followed by Entamoeba histolytica (25.95%) and Giardia lamblia (19.6%). Infection with more than one pathogen was noted e.g. presence of Ascaris and yeasts (8.9%), and amoeba with Trichocephale (4.4%), respectively. Children from non-farming families were less likely to be at risk of intestinal parasite infections (AOR = 0.41, p = 0.028) compared to children from farming families. Children from households with access to treated drinking water were less likely to contract intestinal parasite infections (AOR = 0.44, p = 0.021) compared with those who used untreated water. Children from families with improved sources of water were twice as likely to be diagnosed with intestinal parasitoses compared to those who did not. We postulate that the majority of families (50.1%) who have access to improved water sources do not treat water before consumption. CONCLUSION: The high prevalence of intestinal parasitoses in children warrants strict control measures for improved sanitation, while treatment of drinking water should be considered.


Assuntos
Água Potável/normas , Enteropatias Parasitárias/epidemiologia , Microscopia/métodos , População Rural/estatística & dados numéricos , Estudos Transversais , Feminino , Humanos , Higiene/normas , Lactente , Enteropatias Parasitárias/diagnóstico , Enteropatias Parasitárias/parasitologia , Masculino , Prevalência , Fatores de Risco , Ruanda/epidemiologia , Saneamento/normas , Fatores Socioeconômicos , Inquéritos e Questionários
20.
Infect Dis Poverty ; 6(1): 8, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28245883

RESUMO

Even though Rwanda lies within a region that has a high prevalence of schistosomiasis and soil-transmitted helminth (STH) infections, epidemiological information regarding these infections in the country remains scarce. The present review attempts to compile the available data on schistosomiasis and STHs, from 1940 to 2014, to provide an insight on the epidemiological profile of these infections. This information will, in turn, support the design and implementation of sustainable control measures. The available records indicate that only Schistosoma mansoni and all the major species of STHs are endemic in Rwanda. In 2008, the national prevalence of S. mansoni was reported to be 2.7%, ranging from 0 to 69.5%, and that of STH infections was 65.8% (diagnosed using the Kato-Katz technique). The prevalence of these infections varies from one district to another, with schoolchildren remaining a highly affected group. The main control approach is mass drug administration using albendazole and praziquantel, mostly targeting school-aged children in school environments. In 2008, adult individuals living in areas with a prevalence of S. mansoni ≥30% were also included in the mass drug administration programme. However, despite Rwanda achieving an almost 100% coverage of this programme in 2008-2010, the transmission of S. mansoni and STHs continues to take place, as illustrated by the most recent surveys. If Rwanda is to achieve sustainable control and elimination of schistosomiasis and STHs, there is a need to revise the country's control strategy and adopt an integrated control approach that involves a combination of measures.


Assuntos
Controle de Doenças Transmissíveis/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Doenças Endêmicas , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Albendazol/administração & dosagem , Animais , Anti-Helmínticos/administração & dosagem , Helmintíase/tratamento farmacológico , Helmintíase/transmissão , Humanos , Praziquantel/administração & dosagem , Prevalência , Ruanda/epidemiologia
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