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1.
Nature ; 589(7841): 276-280, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33086375

RESUMEN

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).


Asunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , COVID-19/epidemiología , COVID-19/virología , Vigilancia de la Población/métodos , SARS-CoV-2/aislamiento & purificación , Algoritmos , COVID-19/diagnóstico , Humanos , Prevalencia , Rwanda/epidemiología , Sensibilidad y Especificidad
2.
J Infect Dis ; 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39367758

RESUMEN

BACKGROUND: In Africa, the first Plasmodium falciparum artemisinin partial resistance mutation, was Kelch13 (K13) 561H - detected and validated at appreciable frequency in Rwanda in 2014. Surveillance to better define the extent of the emergence in Rwanda and neighboring countries is critical. METHODS: We used novel liquid blood drop preservation combined with pooled sequencing to provide cost-effective rapid assessment of resistance mutation frequencies at multiple collection sites across Rwanda and neighboring regions in Uganda, Tanzania, and the Democratic Republic of the Congo (DRC). Malaria-positive samples (n=5,465) from 39 health facilities collected between May 2022 and March 2023 were sequenced in 199 pools. RESULTS: In Rwanda, K13 561H and 675V were detected in 90% and 65% of sites with an average frequency of 19.0% (0-54.5%) and 5.0% (0-35.5%), respectively. In Tanzania, 561H had high frequency in multiple sites. 561H appeared at 1.6% in Uganda. 561H was absent from the DRC, although 675V was seen at low frequency. Concerningly candidate mutations were observed: 441L, 449A, and 469F co-occurred with validated mutations suggesting they are arising under the same pressures. Other markers for decreased susceptibility to artemether-lumefantrine are common: P. falciparum multidrug resistance protein 1 N86 at 98.0% (63.3-100%) and 184F at 47.0% (0-94.3%) and P. falciparum chloroquine resistance transporter 76T at 14.7% (0-58.6%). Additionally, sulfadoxine-pyrimethamine-associated mutations show high frequencies. CONCLUSION: K13 mutations are rapidly expanding in the region further endangering control efforts with the potential of engendering partner drug resistance.

3.
Malar J ; 23(1): 150, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755607

RESUMEN

BACKGROUND: Emerging artemisinin partial resistance and diagnostic resistance are a threat to malaria control in Africa. Plasmodium falciparum kelch13 (k13) propeller-domain mutations that confer artemisinin partial resistance have emerged in Africa. k13-561H was initially described at a frequency of 7.4% from Masaka in 2014-2015, but not present in nearby Rukara. By 2018, 19.6% of isolates in Masaka and 22% of isolates in Rukara contained the mutation. Longitudinal monitoring is essential to inform control efforts. In Rukara, an assessment was conducted to evaluate recent k13-561H prevalence changes, as well as other key mutations. Prevalence of hrp2/3 deletions was also assessed. METHODS: Samples collected in Rukara in 2021 were genotyped for key artemisinin and partner drug resistance mutations using molecular inversion probe assays and for hrp2/3 deletions using qPCR. RESULTS: Clinically validated k13 artemisinin partial resistance mutations continue to increase in prevalence with the overall level of mutant infections reaching 32% in Rwanda. The increase appears to be due to the rapid emergence of k13-675V (6.4%, 6/94 infections), previously not observed, rather than continued expansion of 561H (23.5% 20/85). Mutations to partner drugs and other anti-malarials were variable, with high levels of multidrug resistance 1 (mdr1) N86 (95.5%) associated with lumefantrine decreased susceptibility and dihydrofolate reductase (dhfr) 164L (24.7%) associated with a high level of antifolate resistance, but low levels of amodiaquine resistance polymorphisms with chloroquine resistance transporter (crt) 76T: at 6.1% prevalence. No hrp2 or hrp3 gene deletions associated with diagnostic resistance were found. CONCLUSIONS: Increasing prevalence of artemisinin partial resistance due to k13-561H and the rapid expansion of k13-675V is concerning for the longevity of artemisinin effectiveness in the region. False negative RDT results do not appear to be an issue with no hrp2 or hpr3 deletions detected. Continued molecular surveillance in this region and surrounding areas is needed to follow artemisinin partial resistance and provide early detection of partner drug resistance, which would likely compromise control and increase malaria morbidity and mortality in East Africa.


Asunto(s)
Antimaláricos , Artemisininas , Resistencia a Medicamentos , Malaria Falciparum , Mutación , Plasmodium falciparum , Proteínas Protozoarias , Plasmodium falciparum/genética , Plasmodium falciparum/efectos de los fármacos , Artemisininas/farmacología , Antimaláricos/farmacología , Proteínas Protozoarias/genética , Resistencia a Medicamentos/genética , Rwanda , Malaria Falciparum/parasitología , Malaria Falciparum/epidemiología , Humanos , Antígenos de Protozoos/genética , Prevalencia , Niño , Adulto Joven , Adolescente , Adulto , Preescolar
4.
J Infect Dis ; 227(2): 268-277, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-35776140

RESUMEN

BACKGROUND: From 2019 to 2021, Rwandan residents of the border with the Democratic Republic of the Congo were offered the Ad26.ZEBOV (adenovirus type 26 vector vaccine encoding Ebola virus glycoprotein) and MVA-BN-Filo (modified vaccinia virus Ankara vector vaccine, encoding glycoproteins from Ebola, Sudan, Marburg, and nucleoprotein from Tai Forest viruses) Ebola vaccine regimen. METHODS: Nonpregnant persons aged ≥2 years were eligible. Unsolicited adverse events (UAEs) were reported through phone calls or visits, and serious adverse events (SAEs) were recorded per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. RESULTS: Following Ad26.ZEBOV, UAEs were reported by 0.68% of 216 113 vaccinees and were more common in younger children (aged 2-8 years, 1.2%) compared with older children (aged 9-17 years, 0.4%) and adults (aged ≥18 years, 0.7%). Fever and headache were the most reported symptoms. All 17 SAEs related to vaccine were in children aged 2-8 years (10 postvaccination febrile convulsions ± gastroenteritis and 7 fever and/or gastroenteritis). The incidence of febrile seizures was 8 of 26 062 (0.031%) prior to initiation of routine acetaminophen in December 2020 and 2 of 15 897 (0.013%) thereafter. Nonobstetric SAEs were similar in males and females. All 20 deaths were unrelated to vaccination. Young girls and adult women with UAEs were less likely to receive the second dose than those without UAEs. Seven unrelated SAEs occurred in 203 267 MVA-BN-Filo recipients. CONCLUSIONS: Postvaccination febrile convulsions in young children were rare but not previously described after Ad26.ZEBOV and were reduced with routine acetaminophen. The regimen was otherwise safe and well-tolerated.


Asunto(s)
Vacunas contra el Virus del Ébola , Ebolavirus , Fiebre Hemorrágica Ebola , Convulsiones Febriles , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Acetaminofén , Anticuerpos Antivirales , Vacunas contra el Virus del Ébola/efectos adversos , Glicoproteínas , Fiebre Hemorrágica Ebola/prevención & control , Convulsiones Febriles/inducido químicamente , Vacunación/efectos adversos , Virus Vaccinia
5.
BMC Infect Dis ; 22(1): 593, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35790903

RESUMEN

BACKGROUND: In low- and middle-income countries (LMIC) Staphylococcus aureus is regarded as one of the leading bacterial causes of neonatal sepsis, however there is limited knowledge on the species diversity and antimicrobial resistance caused by Gram-positive bacteria (GPB). METHODS: We characterised GPB isolates from neonatal blood cultures from LMICs in Africa (Ethiopia, Nigeria, Rwanda, and South Africa) and South-Asia (Bangladesh and Pakistan) between 2015-2017. We determined minimum inhibitory concentrations and performed whole genome sequencing (WGS) on Staphylococci isolates recovered and clinical data collected related to the onset of sepsis and the outcome of the neonate up to 60 days of age. RESULTS: From the isolates recovered from blood cultures, Staphylococci species were most frequently identified. Out of 100 S. aureus isolates sequenced, 18 different sequence types (ST) were found which unveiled two small epidemiological clusters caused by methicillin resistant S. aureus (MRSA) in Pakistan (ST8) and South Africa (ST5), both with high mortality (n = 6/17). One-third of S. aureus was MRSA, with methicillin resistance also detected in Staphylococcus epidermidis, Staphylococcus haemolyticus and Mammaliicoccus sciuri. Through additional WGS analysis we report a cluster of M. sciuri in Pakistan identified between July-November 2017. CONCLUSIONS: In total we identified 14 different GPB bacterial species, however Staphylococci was dominant. These findings highlight the need of a prospective genomic epidemiology study to comprehensively assess the true burden of GPB neonatal sepsis focusing specifically on mechanisms of resistance and virulence across species and in relation to neonatal outcome.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Sepsis Neonatal , Cultivo de Sangre , Países en Desarrollo , Etiopía , Humanos , Recién Nacido , Sepsis Neonatal/epidemiología , Estudios Prospectivos , Staphylococcus aureus/genética
7.
N Engl J Med ; 374(25): 2453-64, 2016 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-27332904

RESUMEN

BACKGROUND: Recent gains in reducing the global burden of malaria are threatened by the emergence of Plasmodium falciparum resistance to artemisinins. The discovery that mutations in portions of a P. falciparum gene encoding kelch (K13)-propeller domains are the major determinant of resistance has provided opportunities for monitoring such resistance on a global scale. METHODS: We analyzed the K13-propeller sequence polymorphism in 14,037 samples collected in 59 countries in which malaria is endemic. Most of the samples (84.5%) were obtained from patients who were treated at sentinel sites used for nationwide surveillance of antimalarial resistance. We evaluated the emergence and dissemination of mutations by haplotyping neighboring loci. RESULTS: We identified 108 nonsynonymous K13 mutations, which showed marked geographic disparity in their frequency and distribution. In Asia, 36.5% of the K13 mutations were distributed within two areas--one in Cambodia, Vietnam, and Laos and the other in western Thailand, Myanmar, and China--with no overlap. In Africa, we observed a broad array of rare nonsynonymous mutations that were not associated with delayed parasite clearance. The gene-edited Dd2 transgenic line with the A578S mutation, which expresses the most frequently observed African allele, was found to be susceptible to artemisinin in vitro on a ring-stage survival assay. CONCLUSIONS: No evidence of artemisinin resistance was found outside Southeast Asia and China, where resistance-associated K13 mutations were confined. The common African A578S allele was not associated with clinical or in vitro resistance to artemisinin, and many African mutations appear to be neutral. (Funded by Institut Pasteur Paris and others.).


Asunto(s)
Artemisininas/farmacología , Resistencia a Medicamentos/genética , Lactonas/farmacología , Mutación , Plasmodium falciparum/genética , Polimorfismo Genético , Proteínas Protozoarias/genética , Algoritmos , Artemisininas/uso terapéutico , Asia Sudoriental , China , Enfermedades Endémicas , Genotipo , Humanos , Lactonas/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/parasitología , Plasmodium falciparum/efectos de los fármacos , Análisis de Secuencia de ADN
8.
Trop Med Int Health ; 24(7): 879-887, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31066112

RESUMEN

OBJECTIVE: To determine prevalent MDR-TB genotypes and describe treatment outcome and bacteriology conversion in MDR-TB patients. METHODS: Review of laboratory records of 173 MDR-TB patients from all over Rwanda who initiated treatment under programmatic management of MDR-TB (PMDT) between 2014 and 2015. Fifty available archived isolates were genotyped by mycobacterial interspersed repetitive units - variable number of tandem repeats (MIRU-VNTR) genotyping. RESULT: Of the 170 patients whose outcome was known, 114 (66.3%) were cured and 36 (21%) completed the treatment, giving a successful outcome (cured and completed) of 150 (87.3%) patients. Of 20 MDR-TB patients with unfavourable treatment outcome, 18 died, one failed and one defaulted/stopped treatment. Of the 18 patients who died, 11 (61%) were HIV-coinfected. The treatment outcome was successful for 93.9% among HIV negative and 81.8% among HIV-coinfected patients (P = 0.02). Sputum smear conversion occurred in 3, 46, 57 and 78 patients before 2, 3, 4 and 6 months, respectively, with median time of sputum smear and culture conversion at 3 months. The 44 MDR-TB isolates with MIRU-VNTR result, showed high genetic diversity with low clustering rate (9.09%) and Uganda II being the most prevalent sub-family lineage detected in 68.2% of isolates. Beijing family was the least common genotype detected (2.3%, 1 isolate). CONCLUSION: The high success rates for MDR-TB treatment achieved in Rwanda were comparable to outcomes observed in resource-rich settings with HIV being an independent risk factor for poor treatment outcome. High genetic diversity and low clustering rate reported here suggest that reactivation of previous disease plays an important role in the transmission of MDR-TB in Rwanda.


OBJECTIF: Déterminer les génotypes prévalents de la TB-MDR et décrire les résultats du traitement et la conversion bactériologique chez les patients atteints de TB-MDR. MÉTHODES: Analyse des dossiers de laboratoire de 173 patients atteints de TB-MDR de l'ensemble du Rwanda qui ont débuté un traitement sous prise en charge programmatique de la TB-MDR (PMDT) entre 2014 et 2015. Cinquante isolats archivés disponibles ont été génotypés pour les unités répétitives intercalées de mycobactéries - nombre variable de tandems répétés (MIRU-VNTR). RÉSULTAT: Sur les 170 patients dont l'issue était connue, 114 (66,3%) étaient guéris et 36 (21%) avaient terminé le traitement, ce qui donne un résultat positif (guéri et complété) de 150 patients (87,3%). Sur 20 patients atteints de TB-MDR dont l'issue du traitement était défavorable, 18 sont décédés, un a eu un échec et le dernier a abandonné/arrêté le traitement. Sur les 18 patients décédés, 11 (61%) étaient coinfectés par le VIH. Le résultat du traitement a été positif pour 93,9% des personnes VIH négatives et 81,8% pour ceux coinfectées par le VIH (p = 0,02). La conversion des frottis d'expectoration est survenue chez 3, 46, 57 et 78 patients respectivement à 2, 3, 4 et 6 mois, avec une durée médiane entre le frottis d'expectoration et la conversion de culture de 3 mois. Les 44 isolats de TB-MDR avec un résultat MIRU-VNTR ont montré une diversité génétique élevée avec un faible taux de regroupement (9,09%) et la sous-famille de la lignée Ouganda II étant la plus prévalente détectée dans 68,2% des isolats. La famille Beijing était le génotype le moins fréquemment détecté (2,3%, 1 isolat). CONCLUSION: Les taux de succès élevés du traitement de la TB-MDR obtenus au Rwanda étaient comparables aux résultats observés dans les régions riches en ressources, le VIH étant un facteur de risque indépendant d'un mauvais résultat du traitement. La diversité génétique élevée et le faible taux de regroupement rapportés ici suggèrent que la réactivation d'une maladie antérieure joue un rôle important dans la transmission de la TB-MDR au Rwanda.


Asunto(s)
Antituberculosos/uso terapéutico , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Adulto , Anciano , Femenino , Variación Genética , Genotipo , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Mycobacterium tuberculosis/genética , Reacción en Cadena de la Polimerasa , Rwanda , Esputo , Resultado del Tratamiento , Tuberculosis Resistente a Múltiples Medicamentos/genética , Adulto Joven
9.
Pathobiology ; 85(3): 186-191, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29131100

RESUMEN

BACKGROUND AND AIMS: A common polymorphism in the tumor suppressor gene p53 at codon 72 has been suggested to play a role in the development of a number of cancers. This polymorphism has been studied in many populations worldwide, with conflicting results. The present study was planned to assess the association of p53 codon 72 polymorphism with breast cancer development in a Rwandese population. METHODS: In this study, the polymorphism was examined by allele-specific PCR analysis in 40 patients with breast cancer and 39 healthy controls. RESULTS: The heterozygous genotype Pro/Arg prevailed in both breast cancer patients and controls, and was present in 80% (32/40) and 92.3% (36/39) of cases, respectively. No statistically significant association was observed between p53 codon 72 polymorphism and breast cancer risk. Distribution of p53 genotypes was also studied according to familial history, tumor grade, and clinical stage, and results clearly showed no statistically significant difference. CONCLUSION: These results suggest that p53 codon 72 polymorphism could not be assessed as a risk factor marker for predisposition to breast cancer in Rwanda. However, further studies using larger sample sizes are needed to provide more conclusive results and to investigate other genetic mutations affecting the activity of p53.


Asunto(s)
Neoplasias de la Mama/genética , Genes p53/genética , Polimorfismo Genético/genética , Adolescente , Adulto , Alelos , Codón/genética , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Persona de Mediana Edad , Mutación , Clasificación del Tumor , Factores de Riesgo , Rwanda , Adulto Joven
10.
Lancet ; 384(9940): 371-5, 2014 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-24703831

RESUMEN

Two decades ago, the genocide against the Tutsis in Rwanda led to the deaths of 1 million people, and the displacement of millions more. Injury and trauma were followed by the effects of a devastated health system and economy. In the years that followed, a new course set by a new government set into motion equity-oriented national policies focusing on social cohesion and people-centred development. Premature mortality rates have fallen precipitously in recent years, and life expectancy has doubled since the mid-1990s. Here we reflect on the lessons learned in rebuilding Rwanda's health sector during the past two decades, as the country now prepares itself to take on new challenges in health-care delivery.


Asunto(s)
Atención a la Salud/organización & administración , Niño , Mortalidad del Niño , Genocidio , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Infecciones por VIH/terapia , Política de Salud , Humanos , Rwanda/epidemiología , Tuberculosis Pulmonar/mortalidad , Guerra
11.
BMJ Open ; 14(10): e083410, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39353691

RESUMEN

OBJECTIVE: To evaluate the use of antigen-based rapid diagnostic tests (Ag-RDTs) alongside a digital tool to deliver household-level COVID-19 testing by community health workers (CHWs), in line with Rwanda's ambition to decentralise COVID-19 testing. DESIGN: This was an operational pilot study to evaluate the impact and operational characteristics of using the digital e-ASCov tool combined with Ag-RDTs to support COVID-19 symptom screening and rapid testing by CHWs across eight districts in Rwanda. A total of 800 CHWs selected from both rural and urban areas were trained in delivering Ag-RDTs for COVID-19 testing and using the e-ASCOV application for data capture on a smartphone. Laboratory technicians repeated a subset of Ag-RDTs to assess the concordance of results obtained by CHWs. The study also assessed CHWs' experience of the intervention using a mixed-methods approach. SETTING: Eight rural, urban and semiurban districts in Rwanda. PARTICIPANTS: A total of 19 544 individuals were enrolled and screened for signs and symptoms of COVID-19. INTERVENTIONS: Community-based screening for COVID-19 by CHWs using the digital tool e-ASCov combined with rapid testing using Ag-RDTs. MAIN OUTCOME MEASURES: Number of participants screened and tested; concordance of Ag-RDT results between CHWs and laboratory technicians; feasibility of study procedures by CHWs and CHWs perceptions of the digital tool and Ag-RDT testing. RESULTS: From February to May 2022, CHWs screened 19 544 participants, of whom 4575 (23.4%) had COVID-19-related symptoms or a history of exposure to the infection. Among them, 86 (1.9%) were positive on Ag-RDTs. Concordance of Ag-RDT results between CHWs and laboratory technicians was 100%. Of the 800 trained CHWs, 746 (93.3%) were independently able to conduct household-based COVID-19 screening, perform the Ag-RDTs and send data to the central server. Most CHWs (>80%) found Ag-RDTs and e-ASCOV easy to use. CONCLUSIONS: This study demonstrated the feasibility of deploying a digital tool and Ag-RDTs for household-level SARS-CoV-2 detection in Rwanda. The findings support a broader roll-out of digitally supported rapid testing by CHWs to broaden access to testing for priority diseases.


Asunto(s)
COVID-19 , Agentes Comunitarios de Salud , SARS-CoV-2 , Humanos , Rwanda/epidemiología , Proyectos Piloto , COVID-19/diagnóstico , COVID-19/epidemiología , Femenino , Adulto , Masculino , SARS-CoV-2/aislamiento & purificación , Persona de Mediana Edad , Prueba de COVID-19/métodos , Tamizaje Masivo/métodos , Adulto Joven
12.
medRxiv ; 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38746440

RESUMEN

In Africa, the first Plasmodium falciparum Kelch13 (K13) artemisinin partial resistance mutation 561H was first detected and validated in Rwanda. Surveillance to better define the extent of the emergence in Rwanda and neighboring countries as other mutations arise in East Africa is critical. We employ a novel scheme of liquid blood drop preservation combined with pooled sequencing to provide a cost-effective rapid assessment of resistance mutation frequencies at multiple collection sites across Rwanda and neighboring countries. Malaria-positive samples (n=5,465) were collected from 39 health facilities in Rwanda, Uganda, Tanzania, and the Democratic Republic of the Congo (DRC) between May 2022 and March 2023 and sequenced in 199 pools. In Rwanda, K13 561H and 675V were detected in 90% and 65% of sites with an average frequency of 19.0% (0-54.5%) and 5.0% (0-35.5%), respectively. In Tanzania, 561H had high frequency in multiple sites while it was absent from the DRC although 675V was seen at low frequency. Conceringly candidate mutations were observed: 441L, 449A, and 469F co-occurred with validated mutations suggesting they are arising under the same pressures. Other resistance markers associated with artemether-lumefantrine are common: P. falciparum multidrug resistance protein 1 N86 at 98.0% and 184F at 47.0% (0-94.3%) and P. falciparum chloroquine resistance transporter 76T at 14.7% (0-58.6%). Additionally, sulfadoxine-pyrimethamine-associated mutations show high frequencies. Overall, K13 mutations are rapidly expanding in the region further endangering control efforts with the potential of engendering partner drug resistance.

13.
medRxiv ; 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38260604

RESUMEN

Background: Malaria remains a major cause of morbidity in sub-Saharan Africa. Undetected asymptomatic falciparum malaria results in a large transmission reservoir and there is evidence of increasing non-falciparum malaria as malaria is controlled in Africa, both resulting in challenges for malaria control programs. Methods: We performed quantitative real time PCR for 4 malaria species in 4,596 individuals from the 2014-2015 Rwanda Demographic Health Survey. Bivariate models were used to determine species-specific associations with risk factors. Results: Asymptomatic falciparum malaria, P. ovale spp., and P. malariae infection had broad spatial distribution across Rwanda. P. vivax infection was rare. Overall infection prevalence was 23.6% (95%CI [21.7%, 26.0%]), with falciparum and non-falciparum at 17.6% [15.9%, 19.0%] and 8.3% [7.0%, 10.0%], respectively. Parasitemias tended to be low and mixed species infections were common, especially where malaria transmission was the highest. Falciparum infection was associated with socio-econiomic status, rural residence and low altitude. Few risk factors were associated with non-falciparum malaria. Conclusions: Asymptomatic falciparum malaria and non-falciparum malaria are common and widely distributed across Rwanda. Continued molecular monitoring of Plasmodium spp. is needed to monitor these threats to malaria control in Africa.

14.
Nat Commun ; 15(1): 2758, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38553439

RESUMEN

Hospital surfaces can harbour bacterial pathogens, which may disseminate and cause nosocomial infections, contributing towards mortality in low- and middle-income countries (LMICs). During the BARNARDS study, hospital surfaces from neonatal wards were sampled to assess the degree of environmental surface and patient care equipment colonisation by Gram-negative bacteria (GNB) carrying antibiotic resistance genes (ARGs). Here, we perform PCR screening for extended-spectrum ß-lactamases (blaCTX-M-15) and carbapenemases (blaNDM, blaOXA-48-like and blaKPC), MALDI-TOF MS identification of GNB carrying ARGs, and further analysis by whole genome sequencing of bacterial isolates. We determine presence of consistently dominant clones and their relatedness to strains causing neonatal sepsis. Higher prevalence of carbapenemases is observed in Pakistan, Bangladesh, and Ethiopia, compared to other countries, and are mostly found in surfaces near the sink drain. Klebsiella pneumoniae, Enterobacter hormaechei, Acinetobacter baumannii, Serratia marcescens and Leclercia adecarboxylata are dominant; ST15 K. pneumoniae is identified from the same ward on multiple occasions suggesting clonal persistence within the same environment, and is found to be identical to isolates causing neonatal sepsis in Pakistan over similar time periods. Our data suggests persistence of dominant clones across multiple time points, highlighting the need for assessment of Infection Prevention and Control guidelines.


Asunto(s)
Países en Desarrollo , Sepsis Neonatal , Recién Nacido , Humanos , beta-Lactamasas/genética , Proteínas Bacterianas/genética , Hospitales , Antibacterianos/farmacología , Klebsiella pneumoniae/genética , Bacterias Gramnegativas/genética , Pruebas de Sensibilidad Microbiana
15.
Open Forum Infect Dis ; 10(4): ofad149, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37096145

RESUMEN

Background: Artemisinin resistance mutations in Plasmodium falciparum kelch13 (Pfk13) have begun to emerge in Africa, with Pfk13-R561H being the first reported in Rwanda in 2014, but limited sampling left questions about its early distribution and origin. Methods: We genotyped P. falciparum positive dried blood spot (DBS) samples from a nationally representative 2014-2015 Rwanda Demographic Health Surveys (DHS) HIV study. DBS were subsampled from DHS sampling clusters with >15% P. falciparum prevalence, as determined by rapid testing or microscopy done during the DHS study (n clusters = 67, n samples = 1873). Results: We detected 476 parasitemias among 1873 residual blood spots from a 2014-2015 Rwanda Demographic Health Survey. We sequenced 351 samples: 341/351 were wild-type (97.03% weighted), and 4 samples (1.34% weighted) harbored R561H that were significantly spatially clustered. Other nonsynonymous mutations found were V555A (3), C532W (1), and G533A (1). Conclusions: Our study better defines the early distribution of R561H in Rwanda. Previous studies only observed the mutation in Masaka as of 2014, but our study indicates its presence in higher-transmission regions in the southeast of the country at that time.

16.
medRxiv ; 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-38196592

RESUMEN

Background: Emerging artemisinin resistance and diagnostic resistance are a threat to malaria control in Africa. Plasmodium falciparum kelch13 (K13) propeller-domain mutations that confer artemisinin partial resistance have emerged in Africa. K13-561H was initially described at a frequency of 7.4% from Masaka in 2014-2015 but not present in nearby Rukara. By 2018, 19.6% of isolates in Masaka and 22% of isolates in Rukara contained the mutation. Longitudinal monitoring is essential to inform control efforts. In Rukara, we sought to assess recent K13-561H prevalence changes, as well as for other key mutations. Prevalence of hrp2/3 deletions was also assessed. Methods: We genotyped samples collected in Rukara in 2021 for key artemisinin and partner drug resistance mutations using molecular inversion probe assays and for hrp2/3 deletions using qPCR. Results: Clinically validated K13 artemisinin partial resistance mutations continue to increase in prevalence with the overall level of artemisinin resistance mutant infections reaching 32% in Rwanda. The increase appears to be due to the rapid emergence of K13-675V (6.4%, 6/94 infections), previously not observed, rather than continued expansion of 561H (23.5% 20/85). Mutations to partner drugs and other antimalarials were variable, with high levels of multidrug resistance 1 (MDR1) N86 (95.5%) associated with lumefantrine resistance and dihydrofolate reductase (DHFR) 164L (24.7%) associated with antifolate resistance, but low levels of amodiaquine resistance polymorphisms with chloroquine resistance transporter (CRT ) 76T: at 6.1% prevalence. No hrp2 or hrp3 gene deletions associated with diagnostic resistance were found. Conclusions: Increasing prevalence of artemisinin partial resistance due to K13-561H and the rapid expansion of K13-675V is concerning for the longevity of artemisinin effectiveness in the region. False negative mRDT results do not appear to be an issue with no hrp2 or hpr3 deletions detected. Continued molecular surveillance in this region and surrounding areas is needed to follow artemisinin resistance and provide early detection of partner drug resistance, which would likely compromise control and increase malaria morbidity and mortality in East Africa.

17.
J Pers Med ; 13(12)2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38138934

RESUMEN

INTRODUCTION: Precision medicine (PM) or personalized medicine is an innovative approach that aims to tailor disease prevention and treatment to consider the differences in people's genes, environments, and lifestyles. Although many efforts have been made to accelerate the universal adoption of PM, several challenges need to be addressed in order to advance PM in Africa. Therefore, our study aimed to establish baseline data on the knowledge and perceptions of the implementation of PM in the Rwandan healthcare setting. METHOD: A descriptive qualitative study was conducted in five hospitals offering diagnostics and oncology services to cancer patients in Rwanda. To understand the existing policies regarding PM implementation in the country, two additional institutions were surveyed: the Ministry of Health (MOH), which creates and sets policies for the overall vision of the health sector, and the Rwanda Biomedical Center (RBC), which coordinates the implementation of health sector policies in the country. The researchers conducted 32 key informant interviews and assessed the functionality of available PM equipment in the 5 selected health facilities. The data were thematically categorized and analyzed. RESULTS: The study revealed that PM is perceived as a complex and expensive program by most health managers and health providers. The most cited challenges to implementing PM included the following: the lack of policies and guidelines; the lack of supportive infrastructures and limited suppliers of required equipment and laboratory consumables; financial constraints; cultural, behavioral, and religious beliefs; and limited trained, motivated, and specialized healthcare providers. Regarding access to health services for cancer treatment, patients with health insurance pay 10% of their medical costs, which is still too expensive for Rwandans. CONCLUSION: The study participants highlighted the importance of PM to enhance healthcare delivery if the identified barriers are addressed. For instance, Rwandan health sector leadership might consider the creation of specialized oncology centers in all or some referral hospitals with all the necessary genomic equipment and trained staff to serve the needs of the country and implement a PM program.

18.
J Clin Tuberc Other Mycobact Dis ; 27: 100299, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35146133

RESUMEN

SUMMARY BACKGROUND: Multidrug-resistant (MDR) tuberculosis (TB) poses an important challenge in TB management and control. Rifampicin resistance (RR) is a solid surrogate marker of MDR-TB. We investigated the RR-TB clustering rates, bacterial population dynamics to infer transmission dynamics, and the impact of changes to patient management on these dynamics over 27 years in Rwanda. METHODS: We analysed whole genome sequences of a longitudinal collection of nationwide RR-TB isolates. The collection covered three important periods: before programmatic management of MDR-TB (PMDT; 1991-2005), the early PMDT phase (2006-2013), in which rifampicin drug-susceptibility testing (DST) was offered to retreatment patients only, and the consolidated phase (2014-2018), in which all bacteriologically confirmed TB patients had rifampicin DST done mostly via Xpert MTB/RIF assay. We constructed clusters based on a 5 SNP cut-off and resistance conferring SNPs. We used Bayesian modelling for dating and population size estimations, TransPhylo to estimate the number of secondary cases infected by each patient, and multivariable logistic regression to assess predictors of being infected by the dominant clone. RESULTS: Of 308 baseline RR-TB isolates considered for transmission analysis, the clustering analysis grouped 259 (84.1%) isolates into 13 clusters. Within these clusters, a single dominant clone was discovered containing 213 isolates (82.2% of clustered and 69.1% of all RR-TB), which we named the "Rwanda Rifampicin-Resistant clone" (R3clone). R3clone isolates belonged to Ugandan sub-lineage 4.6.1.2 and its rifampicin and isoniazid resistance were conferred by the Ser450Leu mutation in rpoB and Ser315Thr in katG genes, respectively. All R3clone isolates had Pro481Thr, a putative compensatory mutation in the rpoC gene that likely restored its fitness. The R3clone was estimated to first arise in 1987 and its population size increased exponentially through the 1990s', reaching maximum size (∼84%) in early 2000 s', with a declining trend since 2014. Indeed, the highest proportion of R3clone (129/157; 82·2%, 95%CI: 75·3-87·8%) occurred between 2000 and 13, declining to 64·4% (95%CI: 55·1-73·0%) from 2014 onward. We showed that patients with R3clone detected after an unsuccessful category 2 treatment were more likely to generate secondary cases than patients with R3clone detected after an unsuccessful category 1 treatment regimen. CONCLUSIONS: RR-TB in Rwanda is largely transmitted. Xpert MTB/RIF assay as first diagnostic test avoids unnecessary rounds of rifampicin-based TB treatment, thus preventing ongoing transmission of the dominant R3clone. As PMDT was intensified and all TB patients accessed rifampicin-resistance testing, the nationwide R3clone burden declined. To our knowledge, our findings provide the first evidence supporting the impact of universal DST on the transmission of RR-TB.

19.
Lancet Glob Health ; 10(5): e661-e672, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35427523

RESUMEN

BACKGROUND: Neonatal sepsis is a primary cause of neonatal mortality and is an urgent global health concern, especially within low-income and middle-income countries (LMICs), where 99% of global neonatal mortality occurs. The aims of this study were to determine the incidence and associations with neonatal sepsis and all-cause mortality in facility-born neonates in LMICs. METHODS: The Burden of Antibiotic Resistance in Neonates from Developing Societies (BARNARDS) study recruited mothers and their neonates into a prospective observational cohort study across 12 clinical sites from Bangladesh, Ethiopia, India, Pakistan, Nigeria, Rwanda, and South Africa. Data for sepsis-associated factors in the four domains of health care, maternal, birth and neonatal, and living environment were collected for all mothers and neonates enrolled. Primary outcomes were clinically suspected sepsis, laboratory-confirmed sepsis, and all-cause mortality in neonates during the first 60 days of life. Incidence proportion of livebirths for clinically suspected sepsis and laboratory-confirmed sepsis and incidence rate per 1000 neonate-days for all-cause mortality were calculated. Modified Poisson regression was used to investigate factors associated with neonatal sepsis and parametric survival models for factors associated with all-cause mortality. FINDINGS: Between Nov 12, 2015 and Feb 1, 2018, 29 483 mothers and 30 557 neonates were enrolled. The incidence of clinically suspected sepsis was 166·0 (95% CI 97·69-234·24) per 1000 livebirths, laboratory-confirmed sepsis was 46·9 (19·04-74·79) per 1000 livebirths, and all-cause mortality was 0·83 (0·37-2·00) per 1000 neonate-days. Maternal hypertension, previous maternal hospitalisation within 12 months, average or higher monthly household income, ward size (>11 beds), ward type (neonatal), living in a rural environment, preterm birth, perinatal asphyxia, and multiple births were associated with an increased risk of clinically suspected sepsis, laboratory-confirmed sepsis, and all-cause mortality. The majority (881 [72·5%] of 1215) of laboratory-confirmed sepsis cases occurred within the first 3 days of life. INTERPRETATION: Findings from this study highlight the substantial proportion of neonates who develop neonatal sepsis, and the high mortality rates among neonates with sepsis in LMICs. More efficient and effective identification of neonatal sepsis is needed to target interventions to reduce its incidence and subsequent mortality in LMICs. FUNDING: Bill & Melinda Gates Foundation.


Asunto(s)
Sepsis Neonatal , Nacimiento Prematuro , Sepsis , Países en Desarrollo , Femenino , Humanos , Mortalidad Infantil , Recién Nacido , Sepsis Neonatal/epidemiología , Embarazo , Estudios Prospectivos , Sepsis/epidemiología
20.
Am J Trop Med Hyg ; 105(1): 47-53, 2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-33999845

RESUMEN

Tuberculosis (TB), including multidrug-resistant (MDR; i.e., resistant to at least rifampicin and isoniazid)/rifampicin-resistant (MDR/RR) TB, is the most important opportunistic infection among people living with HIV (PLHIV). In 2005, Rwanda launched the programmatic management of MDR/RR-TB. The shorter MDR/RR-TB treatment regimen (STR) has been implemented since 2014. We analyzed predictors of MDR/RR-TB mortality, including the effect of using the STR overall and among PLHIV. This retrospective study included data from patients diagnosed with RR-TB in Rwanda between July 2005 and December 2018. Multivariable logistic regression was used to assess predictors of mortality. Of 898 registered MDR/RR-TB patients, 861 (95.9%) were included in this analysis, of whom 360 (41.8%) were HIV coinfected. Overall, 86 (10%) patients died during MDR/RR-TB treatment. Mortality was higher among HIV-coinfected compared with HIV-negative TB patients (13.3% versus 7.6%). Among HIV-coinfected patients, patients aged ≥ 55 years (adjusted odds ratio = 5.89) and those with CD4 count ≤ 100 cells/mm3 (adjusted odds ratio = 3.77) had a higher likelihood of dying. Using either the standardized longer MDR/RR-TB treatment regimen or the STR was not correlated with mortality overall or among PLHIV. The STR was as effective as the long MDR/RR-TB regimen. In conclusion, older age and advanced HIV disease were strong predictors of MDR/RR-TB mortality. Therefore, special care for elderly and HIV-coinfected patients with ≤ 100 CD4 cells/mL might further reduce MDR/RR-TB mortality.


Asunto(s)
Antituberculosos/uso terapéutico , Farmacorresistencia Bacteriana , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/mortalidad , Rifampin/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Predicción , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
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