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1.
Nature ; 614(7946): 125-135, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36653448

RESUMEN

The human microbiome is an integral component of the human body and a co-determinant of several health conditions1,2. However, the extent to which interpersonal relations shape the individual genetic makeup of the microbiome and its transmission within and across populations remains largely unknown3,4. Here, capitalizing on more than 9,700 human metagenomes and computational strain-level profiling, we detected extensive bacterial strain sharing across individuals (more than 10 million instances) with distinct mother-to-infant, intra-household and intra-population transmission patterns. Mother-to-infant gut microbiome transmission was considerable and stable during infancy (around 50% of the same strains among shared species (strain-sharing rate)) and remained detectable at older ages. By contrast, the transmission of the oral microbiome occurred largely horizontally and was enhanced by the duration of cohabitation. There was substantial strain sharing among cohabiting individuals, with 12% and 32% median strain-sharing rates for the gut and oral microbiomes, and time since cohabitation affected strain sharing more than age or genetics did. Bacterial strain sharing additionally recapitulated host population structures better than species-level profiles did. Finally, distinct taxa appeared as efficient spreaders across transmission modes and were associated with different predicted bacterial phenotypes linked with out-of-host survival capabilities. The extent of microorganism transmission that we describe underscores its relevance in human microbiome studies5, especially those on non-infectious, microbiome-associated diseases.


Asunto(s)
Bacterias , Transmisión de Enfermedad Infecciosa , Microbioma Gastrointestinal , Ambiente en el Hogar , Microbiota , Boca , Femenino , Humanos , Lactante , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Microbioma Gastrointestinal/genética , Metagenoma , Microbiota/genética , Madres , Boca/microbiología , Transmisión Vertical de Enfermedad Infecciosa , Composición Familiar , Envejecimiento , Factores de Tiempo , Viabilidad Microbiana
2.
Emerg Infect Dis ; 30(2): 384-386, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38167202

RESUMEN

We determined that the dengue outbreak in São Tomé and Príncipe during 2022 was caused by dengue virus serotype 3 genotype III. Phylogenomic analyses showed that the outbreak strain was closely related to the newly identified GIII-American-II lineage and that the virus probably was introduced from the Americas.


Asunto(s)
Virus del Dengue , Dengue , Humanos , Santo Tomé y Príncipe , Virus del Dengue/genética , Filogenia , Genotipo , Dengue/epidemiología , Brotes de Enfermedades
3.
Trop Med Int Health ; 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38888511

RESUMEN

OBJECTIVE: Many children in sub-Saharan Africa die from infectious diseases like malaria, pneumonia, and diarrhoea that can be prevented by early diagnosis, effective and targeted treatment. This study aimed to gain insights into case management practices by parents before they present their children to hospital. METHODS: We conducted a cross-sectional study among 332 parents attending a district hospital with their under-fives symptomatic with fever and/or diarrhoea between November 2019 and July 2020 in rural Tanzania. Timely and targeted treatment was defined as seeking health care within 24 h of fever onset, and continued fluid intake in case of diarrhoea. RESULTS: The main admission diagnoses were acute respiratory infections (61.8%), malaria (25.3%), diarrhoea (18.4%) and suspected sepsis (8.1%). The majority of children (91%) received treatment prior to admission, mostly antipyretics (75.6%), local herbal medicines (26.8%), and antibiotics (17.8%)-half of them without prescription from a clinician. For diarrhoea, the use of oral rehydration solution was rare (9.0%), although perceived as easily accessible and affordable. 49.4% of the parents presented their children directly to the hospital, 23.2% went to a pharmacy/drug shop and 19.3% to a primary health facility first. Malaria symptoms began mostly 3 days before the hospital visit; only 25.4% of febrile children visited any health facility within 24 h of disease onset. Prior use of local herbal medicine (AOR = 3.2; 95% CI 1.4-7.3), visiting the pharmacy (adjusted Odds Ratio [AOR] = 3.1; 95% confidence interval [CI]: 1.0-9.8), the dispensary being the nearest health facility (AOR = 3.0; 95% CI: 1.5-6.2), and financial difficulties (AOR = 2.2; 95% CI 1.1-4.5) were associated with delayed treatment. CONCLUSION: This study suggests that antipyretics and antibiotics dispensed at pharmacies/drug shops, as well as use of local herbal medicines, delay early diagnosis and treatment, which can be life-threatening. Pharmacies/drug shops could be integrated as key focal points for sensitising community members on how to respond to paediatric illnesses and encourage the use of oral rehydration solutions.

4.
Trop Med Int Health ; 29(3): 206-213, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38093593

RESUMEN

BACKGROUND: Healthcare resources are often limited in areas of sub-Saharan Africa. This makes accurate and timely diagnoses challenging and delays treatment of childhood febrile illness. We explored longitudinal characteristics related to symptoms, diagnosis and treatment of hospitalised febrile children in a rural area of Ghana highly endemic for malaria. METHODS: Febrile children under 15 years, admitted to the study hospital paediatric ward, were recruited to the study and clinical data were collected throughout hospitalisation. Descriptive statistics were reported for all cases; for longitudinal analyses, a subset of visits with limited missing data was used. RESULTS: There were 801 hospitalised children included in longitudinal analyses. Malaria (n = 581, 73%) and sepsis (n = 373, 47%) were the most prevalent suspected diagnoses on admission. One-third of malaria suspected diagnoses (n = 192, 33%) were changed on the discharge diagnosis, compared to 84% (n = 315) of sepsis suspected diagnoses. Among malaria-only discharge diagnoses, 98% (n/N = 202/207) received an antimalarial and 33% (n/N = 69/207) an antibiotic; among discharge diagnoses without malaria, 28% (n/N = 108/389) received an antimalarial and 83% (n/N = 324/389) an antibiotic. CONCLUSIONS: Suspected diagnoses were largely based on clinical presentation and were frequently changed; changed diagnoses were associated with lingering symptoms, underscoring the need for faster and more accurate diagnostics. Medications were over-prescribed regardless of diagnosis stability, possibly because of a lack of confidence in suspected diagnoses. Thus, better diagnostic tools are needed for childhood febrile illnesses to enhance the accuracy of and confidence in diagnoses, and to cut down unjustified medication use, reducing the risk of antimicrobial and malaria resistance.


Asunto(s)
Antimaláricos , Malaria , Sepsis , Niño , Humanos , Lactante , Antimaláricos/uso terapéutico , Ghana/epidemiología , Fiebre/diagnóstico , Fiebre/etiología , Fiebre/tratamiento farmacológico , Malaria/diagnóstico , Malaria/tratamiento farmacológico , Malaria/epidemiología , Antibacterianos/uso terapéutico , Hospitales , Sepsis/diagnóstico , Sepsis/tratamiento farmacológico , Sepsis/epidemiología
5.
PLoS Comput Biol ; 19(11): e1011666, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38011203

RESUMEN

The extent to which dengue virus has been circulating globally and especially in Africa is largely unknown. Testing available blood samples from previous cross-sectional serological surveys offers a convenient strategy to investigate past dengue infections, as such serosurveys provide the ideal data to reconstruct the age-dependent immunity profile of the population and to estimate the average per-capita annual risk of infection: the force of infection (FOI), which is a fundamental measure of transmission intensity. In this study, we present a novel methodological approach to inform the size and age distribution of blood samples to test when samples are acquired from previous surveys. The method was used to inform SERODEN, a dengue seroprevalence survey which is currently being conducted in Ghana among other countries utilizing samples previously collected for a SARS-CoV-2 serosurvey. The method described in this paper can be employed to determine sample sizes and testing strategies for different diseases and transmission settings.


Asunto(s)
Dengue , SARS-CoV-2 , Humanos , Estudios Transversales , Estudios Seroepidemiológicos , Ghana/epidemiología , Anticuerpos Antivirales
6.
BMC Public Health ; 24(1): 1500, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38840103

RESUMEN

The East African Community (EAC) grapples with many challenges in tackling infectious disease threats and antimicrobial resistance (AMR), underscoring the importance of regional and robust pathogen genomics capacities. However, a significant disparity exists among EAC Partner States in harnessing bacterial pathogen sequencing and data analysis capabilities for effective AMR surveillance and outbreak response. This study assesses the current landscape and challenges associated with pathogen next-generation sequencing (NGS) within EAC, explicitly focusing on World Health Organization (WHO) AMR-priority pathogens. The assessment adopts a comprehensive approach, integrating a questionnaire-based survey amongst National Public Health Laboratories (NPHLs) with an analysis of publicly available metadata on bacterial pathogens isolated in the EAC countries. In addition to the heavy reliance on third-party organizations for bacterial NGS, the findings reveal a significant disparity among EAC member States in leveraging bacterial pathogen sequencing and data analysis. Approximately 97% (n = 4,462) of publicly available high-quality bacterial genome assemblies of samples collected in the EAC were processed and analyzed by external organizations, mainly in Europe and North America. Tanzania led in-country sequencing efforts, followed by Kenya and Uganda. The other EAC countries had no publicly available samples or had all their samples sequenced and analyzed outside the region. Insufficient local NGS sequencing facilities, limited bioinformatics expertise, lack of adequate computing resources, and inadequate data-sharing mechanisms are among the most pressing challenges that hinder the EAC's NPHLs from effectively leveraging pathogen genomics data. These insights emphasized the need to strengthen microbial pathogen sequencing and data analysis capabilities within the EAC to empower these laboratories to conduct pathogen sequencing and data analysis independently. Substantial investments in equipment, technology, and capacity-building initiatives are crucial for supporting regional preparedness against infectious disease outbreaks and mitigating the impact of AMR burden. In addition, collaborative efforts should be developed to narrow the gap, remedy regional imbalances, and harmonize NGS data standards. Supporting regional collaboration, strengthening in-country genomics capabilities, and investing in long-term training programs will ultimately improve pathogen data generation and foster a robust NGS-driven AMR surveillance and outbreak response in the EAC, thereby supporting global health initiatives.


Asunto(s)
Brotes de Enfermedades , Genómica , Humanos , África Oriental/epidemiología , Secuenciación de Nucleótidos de Alto Rendimiento , Farmacorresistencia Bacteriana/genética , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/clasificación , Genoma Bacteriano , Pueblo de África Oriental
7.
Foodborne Pathog Dis ; 20(2): 59-66, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36779941

RESUMEN

Poultry has been suggested as an important source for extended-spectrum beta-lactamase (ESBL)-producing bacteria that can lead to difficult-to treat infections in humans. Therefore, this study aims to determine the frequency, the genetics, and antimicrobial resistance profiles of ESBL-producing Escherichia coli in domestic free-range poultry in Agogo, Ghana. The study was set up and piloted from January 2019 until June 2019. Between June and December 2019, fecal samples (N = 144) were collected from free-roaming chickens from domestic farms in the regions of Sukuumu, Bontodiase, and Freetown and cultured on ESBL screening agar. Strain identification and antibiotic susceptibility were performed using the VITEK 2 compact system. ESBL-producing E. coli were confirmed using the double disk synergy test. Molecular characterization of ESBL-associated genes (blaTEM, blaSHV, and blaCTX-M) were performed using conventional polymerase chain reaction (PCR) and further sequencing of obtained PCR amplicons. The result showed that 56.2% (n/N = 81/144) of collected fecal samples were positive for ESBL-producing E. coli. Majority of the isolates showed resistance to tetracycline (93.8%, n/N = 76/81) and trimethoprim-sulfamethoxazole (66.7, n/N = 54/81), whereas resistance to carbapenems was not found. The majority of ESBL-producing E. coli carried the blaCTX-M genes, with blaCTX-M-15 being the dominant (95.1%, n/N = 77/81) genotype. In this study, we report high frequencies of ESBL-producing E. coli in smallholder free-range poultry representing a potential source of infection, highlighting the need for control of antibiotic use and animal hygiene/sanitation measures, both important from a One Health perspective.


Asunto(s)
Infecciones por Escherichia coli , Escherichia coli , Animales , Antibacterianos/farmacología , beta-Lactamasas/genética , Pollos/microbiología , Farmacorresistencia Bacteriana/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/microbiología , Ghana/epidemiología , Aves de Corral/microbiología , Prevalencia
8.
J Hum Genet ; 67(1): 65-67, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34230590

RESUMEN

Recently, a common genetic variant E756del in the human gene PIEZO1 was associated with protection from severe malaria. Here, we performed a genetic association study of this gain-of-function variant in a large case-control study including 4149 children from the Ashanti Region in Ghana, West Africa. The statistical analysis did not indicate an association with protection from severe malaria and, thus, providing evidence against a strong protective effect of the PIEZO1 E756del variant on severe malaria susceptibility.


Asunto(s)
Resistencia a la Enfermedad/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Canales Iónicos/genética , Malaria/genética , Eliminación de Secuencia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Estudios de Casos y Controles , Niño , Femenino , Estudios de Asociación Genética/métodos , Genotipo , Ghana , Humanos , Malaria/diagnóstico , Malaria/parasitología , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Adulto Joven
9.
Malar J ; 21(1): 61, 2022 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-35193586

RESUMEN

The addition of a third anti-malarial drug matching the pharmacokinetic characteristics of the slowly eliminated partner drug in artemisinin-based combination therapy (ACT) has been proposed as new therapeutic paradigm for the treatment of uncomplicated falciparum malaria. These triple artemisinin-based combination therapy (TACT) should in theory more effectively prevent the development and spread of multidrug resistance than current ACT. Several clinical trials evaluating TACT-or other multidrug anti-malarial combination therapy (MDACT)-have been reported and more are underway. From a regulatory perspective, these clinical development programmes face a strategic dilemma: pivotal clinical trials evaluating TACT are designed to test for non-inferiority of efficacy compared to standard ACT as primary endpoint. While meeting the endpoint of non-inferior efficacy, TACT are consistently associated with a slightly higher frequency of adverse drug reactions than currently used ACT. Moreover, the prevention of the selection of specific drug resistance-one of the main reasons for TACT development-is beyond the scope of even large-scale clinical trials. This raises important questions: if equal efficacy is combined with poorer tolerability, how can then the actual benefit of these drug combinations be demonstrated? How should clinical development plans be conceived to provide objective evidence for or against an improved management of patients and effective prevention of anti-malarial drug resistance by TACT? What are the objective criteria to ultimately convince regulators to approve these new products? In this Opinion paper, the authors discuss the challenges for the clinical development of triple and multidrug anti-malarial combination therapies and the hard choices that need to be taken in the further clinical evaluation and future implementation of this new treatment paradigm.


Asunto(s)
Antimaláricos , Malaria Falciparum , Antimaláricos/farmacología , Ensayos Clínicos como Asunto , Combinación de Medicamentos , Resistencia a Medicamentos , Humanos , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/prevención & control , Plasmodium falciparum
10.
BMC Public Health ; 22(1): 1676, 2022 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-36064368

RESUMEN

BACKGROUND: The current COVID-19 pandemic affects the entire world population and has serious health, economic and social consequences. Assessing the prevalence of COVID-19 through population-based serological surveys is essential to monitor the progression of the epidemic, especially in African countries where the extent of SARS-CoV-2 spread remains unclear. METHODS: A two-stage cluster population-based SARS-CoV-2 seroprevalence survey was conducted in Bobo-Dioulasso and in Ouagadougou, Burkina Faso, Fianarantsoa, Madagascar and Kumasi, Ghana between February and June 2021. IgG seropositivity was determined in 2,163 households with a specificity improved SARS-CoV-2 Enzyme-linked Immunosorbent Assay. Population seroprevalence was evaluated using a Bayesian logistic regression model that accounted for test performance and age, sex and neighbourhood of the participants. RESULTS: Seroprevalence adjusted for test performance and population characteristics were 55.7% [95% Credible Interval (CrI) 49·0; 62·8] in Bobo-Dioulasso, 37·4% [95% CrI 31·3; 43·5] in Ouagadougou, 41·5% [95% CrI 36·5; 47·2] in Fianarantsoa, and 41·2% [95% CrI 34·5; 49·0] in Kumasi. Within the study population, less than 6% of participants performed a test for acute SARS-CoV-2 infection since the onset of the pandemic. CONCLUSIONS: High exposure to SARS-CoV-2 was found in the surveyed regions albeit below the herd immunity threshold and with a low rate of previous testing for acute infections. Despite the high seroprevalence in our study population, the duration of protection from naturally acquired immunity remains unclear and new virus variants continue to emerge. This highlights the importance of vaccine deployment and continued preventive measures to protect the population at risk.


Asunto(s)
COVID-19 , SARS-CoV-2 , Anticuerpos Antivirales , Teorema de Bayes , Burkina Faso/epidemiología , COVID-19/epidemiología , Ghana/epidemiología , Humanos , Madagascar/epidemiología , Pandemias , Estudios Seroepidemiológicos
11.
Clin Infect Dis ; 72(8): 1358-1366, 2021 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-32150243

RESUMEN

BACKGROUND: Cryptosporidiosis has been identified as one of the major causes of diarrhea and diarrhea-associated deaths in young children in sub-Saharan Africa. This study traces back Cryptosporidium-positive children to their human and animal contacts to identify transmission networks. METHODS: Stool samples were collected from children < 5 years of age with diarrhea in Gabon, Ghana, Madagascar, and Tanzania. Cryptosporidium-positive and -negative initial cases (ICs) were followed to the community, where stool samples from households, neighbors, and animal contacts were obtained. Samples were screened for Cryptosporidium species by immunochromatographic tests and by sequencing the 18S ribosomal RNA gene and further subtyped at the 60 kDa glycoprotein gene (gp60). Transmission clusters were identified and risk ratios (RRs) calculated. RESULTS: Among 1363 pediatric ICs, 184 (13%) were diagnosed with Cryptosporidium species. One hundred eight contact networks were sampled from Cryptosporidium-positive and 68 from negative ICs. Identical gp60 subtypes were detected among 2 or more contacts in 39 (36%) of the networks from positive ICs and in 1 contact (1%) from negative ICs. In comparison to Cryptosporidium-negative ICs, positive ICs had an increased risk of having Cryptosporidium-positive household members (RR, 3.6 [95% confidence interval {CI}, 1.7-7.5]) or positive neighboring children (RR, 2.9 [95% CI, 1.6-5.1]), but no increased risk of having positive animals (RR, 1.2 [95% CI, .8-1.9]) in their contact network. CONCLUSIONS: Cryptosporidiosis in rural sub-Saharan Africa is characterized by infection clusters among human contacts, to which zoonotic transmission appears to contribute only marginally.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Animales , Niño , Preescolar , Criptosporidiosis/epidemiología , Cryptosporidium/genética , Heces , Gabón , Genotipo , Ghana , Humanos , Madagascar , Tanzanía
12.
Trop Med Int Health ; 26(6): 621-631, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33666297

RESUMEN

OBJECTIVES: Specific serological tests are mandatory for reliable SARS-CoV-2 diagnostics and seroprevalence studies. Here, we assess the specificities of four commercially available SARS-CoV-2 IgG ELISAs in serum/plasma panels originating from Africa, South America, and Europe. METHODS: 882 serum/plasma samples collected from symptom-free donors before the COVID-19 pandemic in three African countries (Ghana, Madagascar, Nigeria), Colombia, and Germany were analysed with three nucleocapsid-based ELISAs (Euroimmun Anti-SARS-CoV-2-NCP IgG, EDI™ Novel Coronavirus COVID-19 IgG, Mikrogen recomWell SARS-CoV-2 IgG), one spike/S1-based ELISA (Euroimmun Anti-SARS-CoV-2 IgG), and in-house common cold CoV ELISAs. RESULTS: High specificity was confirmed for all SARS-CoV-2 IgG ELISAs for Madagascan (93.4-99.4%), Colombian (97.8-100.0%), and German (95.9-100.0%) samples. In contrast, specificity was much lower for the Ghanaian and Nigerian serum panels (Ghana: NCP-based assays 77.7-89.7%, spike/S1-based assay 94.3%; Nigeria: NCP-based assays 39.3-82.7%, spike/S1-based assay 90.7%). 15 of 600 African sera were concordantly classified as positive in both the NCP-based and the spike/S1-based Euroimmun ELISA, but did not inhibit spike/ACE2 binding in a surrogate virus neutralisation test. IgG antibodies elicited by previous infections with common cold CoVs were found in all sample panels, including those from Madagascar, Colombia, and Germany and thus do not inevitably hamper assay specificity. Nevertheless, high levels of IgG antibodies interacting with OC43 NCP were found in all 15 SARS-CoV-2 NCP/spike/S1 ELISA positive sera. CONCLUSIONS: Depending on the chosen antigen and assay protocol, SARS-CoV-2 IgG ELISA specificity may be significantly reduced in certain populations probably due to interference of immune responses to endemic pathogens like other viruses or parasites.


Asunto(s)
Anticuerpos Antivirales/sangre , COVID-19/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Adolescente , Adulto , COVID-19/virología , Niño , Preescolar , Colombia , Proteínas de la Nucleocápside de Coronavirus/inmunología , Femenino , Alemania , Ghana , Humanos , Madagascar , Masculino , Persona de Mediana Edad , Nigeria , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto Joven
13.
Liver Int ; 41(3): 449-455, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33034121

RESUMEN

BACKGROUND AND AIMS: Hepatitis E is an infectious disease of the liver caused by the hepatitis E virus (HEV). Immunocompromised patients present a particular risk group, as chronification of hepatitis E leading to life-threatening cirrhosis occurs when these patients are infected. Therefore, this study aims to estimate and compare the anti-HEV seroprevalence and the rate of HEV RNA positivity in transplant recipients and patients with human immunodeficiency virus (HIV). METHODS: This systematic review and meta-analysis involved a literature search (PubMed, Scopus; 1,138 studies) including 120 studies from 1996 to 2019, reporting anti-HEV seroprevalence and/or HEV-RNA positivity. Statistical analysis was performed using a linear mixed-effects meta regression model. RESULTS: Anti-HEV seroprevalence in 14 626 transplant recipients ranged from 6% (95% CI: 1.9-17.2) to 29.6% (95% CI: 21.6-39.) in different commercially available assays and did not differ significantly compared to 20 825 HIV positive patients (range: 3.5% (95% CI: 0.9-12.8) - 19.4% (95% CI: 13.5-26.9). In contrast, HEV-RNA positivity rate was significantly higher in transplant recipients than in HIV positive patients (1.2% (95% CI: 0.9-1.6) vs 0.39% (95% CI: 0.2-0.7); P-value = 0.0011). CONCLUSION: Anti-HEV seroprevalence did not differ significantly between transplant recipients and HIV positive patients. Interestingly, rates of HEV-RNA positivity, indicating ongoing infection, were significantly higher in transplant recipients. These findings demonstrate that transplant patients have an elevated risk of chronic infection in comparison to HIV patients at comparable risk of HEV-exposure.


Asunto(s)
Infecciones por VIH , Virus de la Hepatitis E , Hepatitis E , Anticuerpos Antihepatitis , Hepatitis E/diagnóstico , Hepatitis E/epidemiología , Virus de la Hepatitis E/genética , Humanos , Huésped Inmunocomprometido , Inmunoglobulina G , ARN Viral , Estudios Seroepidemiológicos , Viremia/epidemiología
14.
BMC Med Res Methodol ; 21(1): 165, 2021 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-34376152

RESUMEN

BACKGROUND: A considerable proportion of SARS-CoV-2 transmission occurs from asymptomatic and pre-symptomatic cases. Therefore, different polymerase chain reaction (PCR)- or rapid antigen test (RAT)-based approaches are being discussed and applied to identify infectious individuals that would have otherwise gone undetected. In this article, we provide a framework to estimate the time-dependent risk of being infectious after a negative SARS-CoV-2 test, and we simulate the number of expected infectious individuals over time in populations who initially tested negative. METHODS: A Monte Carlo approach is used to simulate asymptomatic infections over a 10-days period in populations of 1000 individuals following a negative SARS-CoV-2 test. Parameters representing the application of PCR tests or RATs are utilized, and SARS-CoV-2 cumulative 7-day incidences between 25 and 200 per 100,000 people are considered. Simulation results are compared to case numbers predicted via a mathematical equation. RESULTS: The simulations showed a continuous increase in infectious individuals over time in populations of individuals who initially tested SARS-CoV-2 negative. The interplay between false negative rates of PCR tests or RATs, and the time that has passed since testing determines the number of infectious individuals. The simulated and the mathematically predicted number of infectious individuals were comparable. However, Monte Carlo simulations highlight that, due to random variation, theoretically observed infectious individuals can considerably exceed predicted case numbers even shortly after a test was conducted. CONCLUSIONS: This study demonstrates that the number of infectious individuals in a screened group of asymptomatic people can be effectively reduced, and this effect can be described mathematically. However, the false negative rate of a test, the time since the negative test and the underlying SARS-CoV-2 incidence are critical parameters in determining the observed subsequent number of cases in tested population groups.


Asunto(s)
COVID-19 , Enfermedades Transmisibles , Simulación por Computador , Humanos , Reacción en Cadena de la Polimerasa , SARS-CoV-2
15.
Global Health ; 17(1): 49, 2021 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-33892773

RESUMEN

BACKGROUND: The emergence of SARS-CoV-2 mutants might lead to European border closures, which impact on trade and result in serious economic losses. In April 2020, similar border closures were observed during the first SARS-CoV-2 wave in East Africa. MAIN BODY: Since 2017 the East African Community EAC together with the Bernhard-Nocht-Institute for Tropical Medicine BNITM established a mobile laboratory network integrated into the National Public Health Laboratories of the six Partner States for molecular diagnosis of viral haemorrhagic fevers and SARS-CoV-2. Since May 2020, the National Public Health Laboratories of Kenya, Rwanda, Burundi, Uganda and South Sudan deployed these mobile laboratories to their respective borders, issuing a newly developed "Electronic EAC COVID-19 Digital Certificate" to SARS-CoV-2 PCR-negative truck drivers, thus assuring regional trade. CONCLUSION: Considering the large financial damages of border closures, such a mobile laboratory network as demonstrated in East Africa is cost-effective, easy to implement and feasible. The East African Community mobile laboratory network could serve as a blueprint for Europe and other countries around the globe.


Asunto(s)
Prueba de COVID-19 , COVID-19/prevención & control , Comercio/organización & administración , Laboratorios , Unidades Móviles de Salud , Viaje/legislación & jurisprudencia , África Oriental/epidemiología , COVID-19/diagnóstico , COVID-19/epidemiología , Europa (Continente)/epidemiología , Humanos
16.
J Infect Dis ; 221(7): 1098-1106, 2020 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-31701142

RESUMEN

BACKGROUND: Malaria presents with unspecific clinical symptoms that frequently overlap with other infectious diseases and is also a risk factor for coinfections, such as non-Typhi Salmonella. Malaria rapid diagnostic tests are sensitive but unable to distinguish between an acute infection requiring treatment and asymptomatic malaria with a concomitant infection. We set out to test whether cytokine profiles could predict disease status and allow the differentiation between malaria and a bacterial bloodstream infection. METHODS: We created a classification model based on cytokine concentration levels of pediatric inpatients with either Plasmodium falciparum malaria or a bacterial bloodstream infection using the Luminex platform. Candidate markers were preselected using classification and regression trees, and the predictive strength was calculated through random forest modeling. RESULTS: Analyses revealed that a combination of 7-15 cytokines exhibited a median disease prediction accuracy of 88% (95th percentile interval, 73%-100%). Haptoglobin, soluble Fas-Ligand, and complement component C2 were the strongest single markers with median prediction accuracies of 82% (with 95th percentile intervals of 71%-94%, 62%-94%, and 62%-94%, respectively). CONCLUSIONS: Cytokine profiles possess good median disease prediction accuracy and offer new possibilities for the development of innovative point-of-care tests to guide treatment decisions in malaria-endemic regions.


Asunto(s)
Bacteriemia/diagnóstico , Citocinas/sangre , Malaria Falciparum/diagnóstico , Parasitemia/diagnóstico , Bacteriemia/epidemiología , Bacteriemia/metabolismo , Biomarcadores/sangre , Estudios de Casos y Controles , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Lactante , Malaria Falciparum/epidemiología , Malaria Falciparum/metabolismo , Masculino , Parasitemia/epidemiología , Parasitemia/metabolismo
17.
BMC Public Health ; 20(1): 947, 2020 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-32546159

RESUMEN

INTRODUCTION: Chikungunya and Zika Virus are vector-borne diseases responsible for a substantial disease burden in the Americas. Between 2013 and 2016, no cases of Chikungunya or Zika Virus were reported by the Venezuelan Ministry of Health. However, peaks of undiagnosed fever cases have been observed during the same period. In the context of scarce data, alternative surveillance methods are needed. Assuming that unusual peaks of acute fever cases correspond to the incidences of both diseases, this study aims to evaluate the use of Google Trends as an indicator of the epidemic behavior of Chikungunya and Zika. METHODS: Time-series cross-correlations of acute fever cases reported by the Venezuelan Ministry of Health and data on Google search queries related to Chikungunya and Zika were calculated. RESULTS: A temporal distinction has been made so that acute febrile cases occurring between 25th of June 2014 and 23rd of April 2015 were attributed to the Chikungunya virus, while cases occurring between 30th of April 2015 and 29th of April 2016 were ascribed to the Zika virus. The highest cross-correlations for each disease were shown at a lag of 0 (r = 0.784) for Chikungunya and at + 1 (r = 0.754) for Zika. CONCLUSION: The strong positive correlation between Google search queries and official data on acute febrile cases suggests that this resource can be used as an indicator of endemic urban arboviruses activity. In the Venezuelan context, Internet search queries might help to overcome some of the gaps that exist in the national surveillance system.


Asunto(s)
Arbovirus , Fiebre Chikungunya/epidemiología , Fiebre/etiología , Conducta en la Búsqueda de Información , Internet , Vigilancia de la Población/métodos , Infección por el Virus Zika/epidemiología , Fiebre Chikungunya/complicaciones , Fiebre Chikungunya/virología , Virus Chikungunya , Dengue/epidemiología , Dengue/virología , Virus del Dengue , Epidemias , Fiebre/virología , Agencias Gubernamentales , Humanos , Incidencia , Motor de Búsqueda/tendencias , Población Urbana , Venezuela/epidemiología , Virus Zika , Infección por el Virus Zika/complicaciones , Infección por el Virus Zika/virología
18.
Clin Infect Dis ; 69(Suppl 6): S449-S458, 2019 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-31665776

RESUMEN

BACKGROUND: Antimicrobial resistance (AMR) is a major global health concern, yet, there are noticeable gaps in AMR surveillance data in regions such as sub-Saharan Africa. We aimed to measure the prevalence of extended-spectrum ß-lactamase (ESBL) producing Gram-negative bacteria in bloodstream infections from 12 sentinel sites in sub-Saharan Africa. METHODS: Data were generated during the Typhoid Fever Surveillance in Africa Program (TSAP), in which standardized blood cultures were performed on febrile patients attending 12 health facilities in 9 sub-Saharan African countries between 2010 and 2014. Pathogenic bloodstream isolates were identified at the sites and then subsequently confirmed at a central reference laboratory. Antimicrobial susceptibility testing, detection of ESBL production, and conventional multiplex polymerase chain reaction (PCR) testing for genes encoding for ß-lactamase were performed on all pathogens. RESULTS: Five hundred and five pathogenic Gram-negative bloodstream isolates were isolated during the study period and available for further characterization. This included 423 Enterobacteriaceae. Phenotypically, 61 (12.1%) isolates exhibited ESBL activity, and genotypically, 47 (9.3%) yielded a PCR amplicon for at least one of the screened ESBL genes. Among specific Gram-negative isolates, 40 (45.5%) of 88 Klebsiella spp., 7 (5.7%) of 122 Escherichia coli, 6 (16.2%) of 37 Acinetobacter spp., and 2 (1.3%) of 159 of nontyphoidal Salmonella (NTS) showed phenotypic ESBL activity. CONCLUSIONS: Our findings confirm the presence of ESBL production among pathogens causing bloodstream infections in sub-Saharan Africa. With few alternatives for managing ESBL-producing pathogens in the African setting, measures to control the development and proliferation of AMR organisms are urgently needed.


Asunto(s)
Bacterias Gramnegativas/patogenicidad , Infecciones por Bacterias Gramnegativas/sangre , Infecciones por Bacterias Gramnegativas/epidemiología , Adolescente , Adulto , África del Sur del Sahara/epidemiología , Antibacterianos/farmacología , Niño , Preescolar , Farmacorresistencia Bacteriana Múltiple/genética , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/enzimología , Humanos , Lactante , Recién Nacido , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Prevalencia , Vigilancia de Guardia , Adulto Joven , beta-Lactamasas
19.
Foodborne Pathog Dis ; 16(5): 352-358, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30907631

RESUMEN

Salmonella and Campylobacter are important gastroenteric pathogens. Arcobacter butzleri is an emerging enteric pathogen. Data on the frequencies of these poultry-associated pathogens on meat products sold in sub-Saharan Africa are scarce. This study aimed to analyze the frequency of Salmonella, Campylobacter, and Arcobacter antibiotic resistance and underlying mechanisms of resistance to fluoroquinolones in locally produced and imported poultry sold in urban Ghana. Chicken meat was collected and cultured on standard media. Bacterial strains were identified by biochemical methods and by mass spectrometry. Antibiotic susceptibility was tested by disk diffusion. Ciprofloxacin-resistant strains were assessed for molecular mechanisms of resistance. Among 200 samples, comprising 34% (n = 68) from the Ghanaian poultry industry and 66% (n = 132) from imports, 9% (n = 17) contained Salmonella, 11% (n = 22) Campylobacter, and 26.5% (n = 53) A. butzleri. Higher overall contamination frequencies were found in local meat. Most common Salmonella serovars identified were Kentucky (n/N = 5/16; 31%) and Poona (n/N = 4/16; 25%). Campylobacter were C. coli (n/N = 10/19; 53%) and C. jejuni (n/N = 9/19; 47%). Resistance to fluoroquinolones was high with 63% (n = 10), 75% (n = 15), and 52% (n = 25) in Salmonella, Campylobacter, and Arcobacter, respectively. A link between Salmonella Kentucky [sequence type (ST) 198] and a ciprofloxacin minimum inhibitory concentration of 16 µg/mL was found. Salmonella Poona-ST308 revealed transferable qnrB2 fluoroquinolone resistance genes. Markedly high frequencies of resistant Salmonella, Campylobacter, and Arcobacter predominant in locally produced meat represent a probable transmission reservoir for human infections. These findings highlight the need for implementation of surveillance systems that focus on food hygiene, use of antibiotics in animal husbandry, and continuous monitoring of the quality of meat products from imports.


Asunto(s)
Arcobacter/aislamiento & purificación , Campylobacter/aislamiento & purificación , Farmacorresistencia Bacteriana Múltiple , Fluoroquinolonas/farmacología , Productos de la Carne/microbiología , Salmonella enterica/aislamiento & purificación , Animales , Antibacterianos/farmacología , Ciprofloxacina/farmacología , Microbiología de Alimentos , Ghana , Infecciones por Bacterias Gramnegativas/epidemiología , Infecciones por Bacterias Gramnegativas/veterinaria , Pruebas de Sensibilidad Microbiana , Aves de Corral/microbiología
20.
J Infect Dis ; 218(suppl_5): S496-S503, 2018 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-30101349

RESUMEN

Background: The pathophysiology of Ebola virus disease (EVD) is still poorly understood. This study aimed at identifying soluble biomarkers that inform on disease mechanisms. Methods: Fifty-four soluble mediators of the immune, coagulation, and endothelial system were measured in baseline and follow-up samples from hospitalized patients with EVD, using Luminex technology. Cross-sectional expression levels and changes over time were correlated with outcome. Results: Levels of circulating proinflammatory cytokines and chemokines, as well as markers of endothelial dysfunction and coagulopathy, were elevated on admission to hospital in patients who died from EVD as compared to survivors. These markers further increased in patients who died and/or decreased over time in survivors. In contrast, markers of gut integrity and T-cell response were higher in survivors and increased until discharge. Conclusions: Inflammatory response, endothelial integrity, gastric tissue protection, and T cell immunity play a role in EVD pathophysiology.


Asunto(s)
Fiebre Hemorrágica Ebola/inmunología , Adulto , Biomarcadores/análisis , Quimiocinas/sangre , Estudios Transversales , Citocinas/sangre , Endotelio Vascular/fisiopatología , Femenino , Fiebre Hemorrágica Ebola/mortalidad , Fiebre Hemorrágica Ebola/fisiopatología , Humanos , Cinética , Masculino , Persona de Mediana Edad , Sobrevivientes , Linfocitos T/inmunología
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