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1.
N Engl J Med ; 385(12): 1104-1115, 2021 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-34525285

RESUMEN

BACKGROUND: Typhoid fever caused by multidrug-resistant H58 Salmonella Typhi is an increasing public health threat in sub-Saharan Africa. METHODS: We conducted a phase 3, double-blind trial in Blantyre, Malawi, to assess the efficacy of Vi polysaccharide typhoid conjugate vaccine (Vi-TCV). We randomly assigned children who were between 9 months and 12 years of age, in a 1:1 ratio, to receive a single dose of Vi-TCV or meningococcal capsular group A conjugate (MenA) vaccine. The primary outcome was typhoid fever confirmed by blood culture. We report vaccine efficacy and safety outcomes after 18 to 24 months of follow-up. RESULTS: The intention-to-treat analysis included 28,130 children, of whom 14,069 were assigned to receive Vi-TCV and 14,061 were assigned to receive the MenA vaccine. Blood culture-confirmed typhoid fever occurred in 12 children in the Vi-TCV group (46.9 cases per 100,000 person-years) and in 62 children in the MenA group (243.2 cases per 100,000 person-years). Overall, the efficacy of Vi-TCV was 80.7% (95% confidence interval [CI], 64.2 to 89.6) in the intention-to-treat analysis and 83.7% (95% CI, 68.1 to 91.6) in the per-protocol analysis. In total, 130 serious adverse events occurred in the first 6 months after vaccination (52 in the Vi-TCV group and 78 in the MenA group), including 6 deaths (all in the MenA group). No serious adverse events were considered by the investigators to be related to vaccination. CONCLUSIONS: Among Malawian children 9 months to 12 years of age, administration of Vi-TCV resulted in a lower incidence of blood culture-confirmed typhoid fever than the MenA vaccine. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT03299426.).


Asunto(s)
Polisacáridos Bacterianos , Fiebre Tifoidea/prevención & control , Vacunas Tifoides-Paratifoides , Niño , Preescolar , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Lactante , Análisis de Intención de Tratar , Malaui , Masculino , Vacunas Meningococicas/efectos adversos , Polisacáridos Bacterianos/efectos adversos , Salmonella typhi , Fiebre Tifoidea/epidemiología , Vacunas Tifoides-Paratifoides/efectos adversos , Vacunas Conjugadas
2.
Emerg Infect Dis ; 29(10): 1990-1998, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37640377

RESUMEN

We used national facility-level data from all government hospitals in Malawi to examine the effects of the second and third COVID-19 waves on maternal and neonatal outcomes and access to care during September 6, 2020-October 31, 2021. The COVID-19 pandemic affected maternal and neonatal health not only through direct infections but also through disruption of the health system, which could have wider indirect effects on critical maternal and neonatal outcomes. In an interrupted time series analysis, we noted a cumulative 15.4% relative increase (63 more deaths) in maternal deaths than anticipated across the 2 COVID-19 waves. We observed a 41% decrease in postnatal care visits at the onset of the second COVID-19 wave and 0.2% by the third wave, cumulative to 36,809 fewer visits than anticipated. Our findings demonstrate the need for strengthening health systems, particularly in resource-constrained settings, to prepare for future pandemic threats.


Asunto(s)
COVID-19 , Embarazo , Recién Nacido , Femenino , Humanos , Malaui/epidemiología , COVID-19/epidemiología , Pandemias , Atención Posnatal , Familia
3.
J Infect Dis ; 226(5): 871-880, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-34752631

RESUMEN

BACKGROUND: Hepatitis B is the leading cause of cirrhosis and liver cancer in sub-Saharan Africa. To reduce mortality, antiviral treatment programs are needed. We estimated prevalence, vaccine impact, and need for antiviral treatment in Blantyre, Malawi. METHODS: We conducted a household study in 2016-2018. We selected individuals from a census using random sampling and estimated age-sex-standardized hepatitis B surface antigen (HBsAg) seroprevalence. Impact of infant hepatitis B vaccination was estimated by binomial log-linear regression comparing individuals born before and after vaccine implementation. In HBsAg-positive adults, eligibility for antiviral therapy was assessed. RESULTS: Of 97386 censused individuals, 6073 (median age 18 years; 56.7% female) were sampled. HBsAg seroprevalence was 5.1% (95% confidence interval [CI], 4.3%-6.1%) among adults and 0.3% (95% CI, .1%-.6%) among children born after vaccine introduction. Estimated vaccine impact was 95.8% (95% CI, 70.3%-99.4%). Of HBsAg-positive adults, 26% were HIV-positive. Among HIV-negative individuals, 3%, 6%, and 9% were eligible for hepatitis B treatment by WHO, European, and American hepatology association criteria, respectively. CONCLUSIONS: Infant HBV vaccination has been highly effective in reducing HBsAg prevalence in urban Malawi. Up to 9% of HBsAg-positive HIV-negative adults are eligible, but have an unmet need, for antiviral therapy.


Asunto(s)
Infecciones por VIH , Hepatitis B , Adolescente , Adulto , Antivirales/uso terapéutico , Niño , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Hepatitis B/tratamiento farmacológico , Hepatitis B/epidemiología , Hepatitis B/prevención & control , Antígenos de Superficie de la Hepatitis B , Vacunas contra Hepatitis B/uso terapéutico , Virus de la Hepatitis B , Humanos , Lactante , Malaui/epidemiología , Masculino , Estudios Seroepidemiológicos , Vacunación
4.
BMC Med ; 20(1): 432, 2022 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-36372899

RESUMEN

BACKGROUND: Tuberculosis remains a major public health priority and is the second leading cause of mortality from infectious disease worldwide. TB case detection rates are unacceptably low for men, the elderly and children. Disruptions in TB services due to the COVID-19 pandemic may have exacerbated these and other inequalities. METHODS: We modelled trends in age- and sex- disaggregated case notifications for all forms of new and relapse TB reported to the World Health Organization for 45 high TB, TB/HIV and MDR-TB burden countries from 2013 to 2019. We compared trend predicted notifications to observed notifications in 2020 to estimate the number of people with TB likely to have missed or delayed diagnosis. We estimated the risk ratio (RR) of missed or delayed TB diagnosis for children (aged < 15 years) or the elderly (aged ≥ 65 years) compared to adults (aged 15-64 years) and women compared to men (both aged ≥ 15 years) using a random-effects meta-analysis. RESULTS: An estimated 195,449 children (95% confidence interval, CI: 189,673-201,562, 37.8% of an expected 517,168), 1,126,133 adults (CI: 1,107,146-1,145,704, 21.8% of an expected 5,170,592) and 235,402 elderly (CI: 228,108-243,202, 28.5% of an expected 826,563) had a missed or delayed TB diagnosis in 2020. This included 511,546 women (CI: 499,623-523,869, 22.7%, of an expected 2,250,097) and 863,916 men (CI: 847,591-880,515, 23.0% of an expected 3,763,363). There was no evidence globally that the risk of having TB diagnosis missed or delayed was different for children and adults (RR: 1.09, CI: 0.41-2.91), the elderly and adults (RR: 1.40, CI: 0.62-3.16) or men and women (RR: 0.59, CI: 0.25-1.42). However, there was evidence of disparities in risk by age and/or sex in some WHO regions and in most countries. CONCLUSIONS: There is no evidence at an aggregate global level of any difference by age or sex in the risk of disruption to TB diagnosis as a result of the COVID-19 pandemic. However, in many countries, disruptions in TB services have been greater for some groups than others. It is important to recognise these context-specific inequalities when prioritising key populations for catch-up campaigns.


Asunto(s)
COVID-19 , Tuberculosis Resistente a Múltiples Medicamentos , Tuberculosis , Niño , Adulto , Masculino , Femenino , Humanos , Anciano , COVID-19/diagnóstico , COVID-19/epidemiología , Pandemias , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Organización Mundial de la Salud
5.
J Appl Microbiol ; 132(2): 1503-1517, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34324765

RESUMEN

AIMS: This study evaluated detection methods for Salmonella Typhi (S. Typhi) in the environment, to establish a novel pathway from field sampling to isolation of viable organisms and molecular confirmation from complex environmental samples, thus enabling environmental surveillance of typhoid. METHODS AND RESULTS: Multiple media were assessed using clinical isolates from the Public Health England's (PHE) Culture collection. The culture pathway selected consisted of a primary 2% bile broth and secondary Selenite F broth, followed by modified Chromogenic Agar for Salmonella Esterase (mCASE). A qPCR assay was adapted from a validated S. Typhi PCR panel for confirmation of isolates, with comparison to biochemical and serological tests showing good specificity. Sampling locations in Blantyre, Malawi were used to compare sampling methods. Viable S. Typhi were isolated from a mixture of trap and grab river water samples on six occasions. CONCLUSIONS: Culture of viable S. Typhi from environmental samples was possible using effective capture and culture techniques. SIGNIFICANCE AND IMPACT OF STUDY: Whilst several studies have attempted to detect S. Typhi from the environment, this is the first successful attempt to isolate the organism from river water since the 1980s. Supplementing clinical data with environmental screening offers the potential for enhanced surveillance, which might inform interventions and assess vaccination programmes.


Asunto(s)
Salmonella typhi , Fiebre Tifoidea , Humanos , Reacción en Cadena en Tiempo Real de la Polimerasa , Salmonella , Salmonella typhi/genética , Manejo de Especímenes , Fiebre Tifoidea/diagnóstico
6.
Emerg Infect Dis ; 27(7): 1831-1839, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34152962

RESUMEN

The coronavirus disease (COVID-19) pandemic might affect tuberculosis (TB) diagnosis and patient care. We analyzed a citywide electronic TB register in Blantyre, Malawi and interviewed TB officers. Malawi did not have an official COVID-19 lockdown but closed schools and borders on March 23, 2020. In an interrupted time series analysis, we noted an immediate 35.9% reduction in TB notifications in April 2020; notifications recovered to near prepandemic numbers by December 2020. However, 333 fewer cumulative TB notifications were received than anticipated. Women and girls were affected more (30.7% fewer cases) than men and boys (20.9% fewer cases). Fear of COVID-19 infection, temporary facility closures, inadequate personal protective equipment, and COVID-19 stigma because of similar symptoms to TB were mentioned as reasons for fewer people being diagnosed with TB. Public health measures could benefit control of both TB and COVID-19, but only if TB diagnostic services remain accessible and are considered safe to attend.


Asunto(s)
COVID-19 , Tuberculosis , Control de Enfermedades Transmisibles , Femenino , Humanos , Malaui/epidemiología , Masculino , Pandemias , SARS-CoV-2 , Tuberculosis/diagnóstico , Tuberculosis/epidemiología
7.
BMC Med ; 19(1): 303, 2021 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-34794434

RESUMEN

BACKGROUND: By August 2021, the COVID-19 pandemic has been less severe in sub-Saharan Africa than elsewhere. In Malawi, there have been three subsequent epidemic waves. We therefore aimed to describe the dynamics of SARS-CoV-2 exposure in Malawi. METHODS: We measured the seroprevalence of anti-SARS-CoV-2 antibodies amongst randomly selected blood transfusion donor sera in Malawi from January 2020 to July 2021 using a cross-sectional study design. In a subset, we also assessed in vitro neutralisation against the original variant (D614G WT) and the Beta variant. RESULTS: A total of 5085 samples were selected from the blood donor database, of which 4075 (80.1%) were aged 20-49 years. Of the total, 1401 were seropositive. After adjustment for assay characteristics and applying population weights, seropositivity reached peaks in October 2020 (18.5%) and May 2021 (64.9%) reflecting the first two epidemic waves. Unlike the first wave, both urban and rural areas had high seropositivity in the second wave, Balaka (rural, 66.2%, April 2021), Blantyre (urban, 75.6%, May 2021), Lilongwe (urban, 78.0%, May 2021), and Mzuzu (urban, 74.6%, April 2021). Blantyre and Mzuzu also show indications of the start of a third pandemic wave with seroprevalence picking up again in July 2021 (Blantyre, 81.7%; Mzuzu, 71.0%). More first wave sera showed in vitro neutralisation activity against the original variant (78% [7/9]) than the beta variant (22% [2/9]), while more second wave sera showed neutralisation activity against the beta variant (75% [12/16]) than the original variant (63% [10/16]). CONCLUSION: The findings confirm extensive SARS-CoV-2 exposure in Malawi over two epidemic waves with likely poor cross-protection to reinfection from the first on the second wave. The dynamics of SARS-CoV-2 exposure will therefore need to be taken into account in the formulation of the COVID-19 vaccination policy in Malawi and across the region. Future studies should use an adequate sample size for the assessment of neutralisation activity across a panel of SARS-CoV-2 variants of concern/interest to estimate community immunity.


Asunto(s)
COVID-19 , SARS-CoV-2 , Anticuerpos Antivirales , Donantes de Sangre , Vacunas contra la COVID-19 , Estudios Transversales , Humanos , Pandemias , Estudios Seroepidemiológicos
8.
PLoS Comput Biol ; 16(12): e1008491, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33362275

RESUMEN

Insulin resistance (IR) precedes the development of type 2 diabetes (T2D) and increases cardiovascular disease risk. Although genome wide association studies (GWAS) have uncovered new loci associated with T2D, their contribution to explain the mechanisms leading to decreased insulin sensitivity has been very limited. Thus, new approaches are necessary to explore the genetic architecture of insulin resistance. To that end, we generated an iPSC library across the spectrum of insulin sensitivity in humans. RNA-seq based analysis of 310 induced pluripotent stem cell (iPSC) clones derived from 100 individuals allowed us to identify differentially expressed genes between insulin resistant and sensitive iPSC lines. Analysis of the co-expression architecture uncovered several insulin sensitivity-relevant gene sub-networks, and predictive network modeling identified a set of key driver genes that regulate these co-expression modules. Functional validation in human adipocytes and skeletal muscle cells (SKMCs) confirmed the relevance of the key driver candidate genes for insulin responsiveness.


Asunto(s)
Redes Reguladoras de Genes , Células Madre Pluripotentes Inducidas/metabolismo , Resistencia a la Insulina/genética , Insulina/metabolismo , Humanos
9.
BMC Health Serv Res ; 21(1): 150, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33588848

RESUMEN

BACKGROUND: Despite health centres being the first point of contact of care, there are challenges faced in providing care to patients at this level. In Malawi, service provision barriers reported at this level included long waiting times, high numbers of patients and erratic consultation systems which lead to mis-diagnosis and delayed referrals. Proper case management at this level of care is critical to prevent severe disease and deaths in children. We aimed to adopt Emergency, Triage, Assessment and Treatment algorithm (ETAT) to improve ability to identify severe illness in children at primary health centre (PHC) through comparison with secondary level diagnoses. METHODS: We implemented ETAT mobile Health (mHealth) at eight urban PHCs in Blantyre, Malawi between April 2017 and September 2018. Health workers and support staff were trained in mHealth ETAT. Stabilisation rooms were established and equipped with emergency equipment. All PHCs used an electronic tracking system to triage and track sick children on referral to secondary care, facilitated by a unique barcode. Support staff at PHC triaged sick children using ETAT Emergency (E), Priority (P) and Queue (Q) symptoms and clinician gave clinical diagnosis. The secondary level diagnosis was considered as a gold standard. We used statistical computing software R (v3.5.1) and used exact 95% binomial confidence intervals when estimating diagnosis agreement proportions. RESULTS: Eight-five percentage of all cases where assigned to E (9.0%) and P (75.5%) groups. Pneumonia was the most common PHC level diagnosis across all three triage groups (E, P, Q). The PHC level diagnosis of trauma was the most commonly confirmed diagnosis at secondary level facility (85.0%), while a PHC diagnosis of pneumonia was least likely to be confirmed at secondary level (39.6%). The secondary level diagnosis least likely to have been identified at PHC level was bronchiolitis 3 (5.2%). The majority of bronchiolitis cases (n = 50; (86.2%) were classified as pneumonia at the PHC level facility. CONCLUSIONS: Implementing a sustainable and consistent ETAT approach with stabilisation and treatment capacity at PHC level reinforce staff capacity to diagnose and has the potential to reduce other health system costs through fewer, timely and appropriate referrals.


Asunto(s)
Servicio de Urgencia en Hospital , Atención Primaria de Salud , Triaje , Instituciones de Atención Ambulatoria , Niño , Preescolar , Diagnóstico , Femenino , Humanos , Lactante , Recién Nacido , Malaui/epidemiología , Masculino , Población Urbana
10.
J Hepatol ; 73(3): 523-532, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32335166

RESUMEN

BACKGROUND AND AIMS: There are uncertainties about the epidemic patterns of HDV infection and its contribution to the burden of liver disease. We estimated the global prevalence of HDV infection and explored its contribution to the development of cirrhosis and hepatocellular carcinoma (HCC) among HBsAg-positive people. METHODS: We searched Pubmed, EMBASE and Scopus for studies reporting on total or IgG anti-HDV among HBsAg-positive people. Anti-HDV prevalence was estimated using a binomial mixed model, weighting for study quality and population size. The population attributable fraction (PAF) of HDV to cirrhosis and HCC among HBsAg-positive people was estimated using random effects models. RESULTS: We included 282 studies, comprising 376 population samples from 95 countries, which together tested 120,293 HBsAg-positive people for anti-HDV. The estimated anti-HDV prevalence was 4.5% (95% CI 3.6-5.7) among all HBsAg-positive people and 16.4% (14.6-18.6) among those attending hepatology clinics. Worldwide, 0.16% (0.11-0.25) of the general population, totalling 12.0 (8.7-18.7) million people, were estimated to be anti-HDV positive. Prevalence among HBsAg-positive people was highest in Mongolia, the Republic of Moldova and countries in Western and Middle Africa, and was higher in injecting drug users, haemodialysis recipients, men who have sex with men, commercial sex workers, and those with HCV or HIV. Among HBsAg-positive people, preliminary PAF estimates of HDV were 18% (10-26) for cirrhosis and 20% (8-33) for HCC. CONCLUSIONS: An estimated 12 million people worldwide have experienced HDV infection, with higher prevalence in certain geographic areas and populations. HDV is a significant contributor to HBV-associated liver disease. More quality data are needed to improve the precision of burden estimates. LAY SUMMARY: We combined all available studies to estimate how many people with hepatitis B also have hepatitis D, a viral infection that only affects people with hepatitis B. About 1 in 22 people with hepatitis B also have hepatitis D, increasing to 1 in 6 when considering people with liver disease. Hepatitis D may cause about 1 in 6 of the cases of cirrhosis and 1 in 5 of the cases of liver cancer that occur in people with hepatitis B. Hepatitis D is an important contributor to the global burden of liver disease.


Asunto(s)
Coinfección/epidemiología , Virus de la Hepatitis B/inmunología , Hepatitis B/epidemiología , Hepatitis D/epidemiología , Virus de la Hepatitis Delta/inmunología , Adulto , Carcinoma Hepatocelular/virología , Coinfección/complicaciones , Femenino , Genotipo , Anticuerpos Antihepatitis/sangre , Hepatitis B/complicaciones , Hepatitis B/virología , Antígenos de Superficie de la Hepatitis B , Hepatitis D/sangre , Hepatitis D/complicaciones , Hepatitis D/virología , Virus de la Hepatitis Delta/genética , Homosexualidad Masculina , Humanos , Inmunoglobulina G/sangre , Cirrosis Hepática/virología , Neoplasias Hepáticas/virología , Masculino , Prevalencia , ARN Viral/genética , Diálisis Renal/efectos adversos , Trabajadores Sexuales , Minorías Sexuales y de Género , Abuso de Sustancias por Vía Intravenosa/complicaciones
11.
Clin Infect Dis ; 68(Suppl 2): S50-S58, 2019 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-30845320

RESUMEN

BACKGROUND: Typhoid fever is an acute infection characterized by prolonged fever following the ingestion and subsequent invasion of Salmonella enterica serovar Typhi (S. Typhi), a human-restricted pathogen. The incidence of typhoid fever has been most reported in children 5-15 years of age, but is increasingly recognized in children younger than 5 years old. There has been a recent expansion of multidrug-resistant typhoid fever globally. Prior typhoid vaccines were not suitable for use in the youngest children in countries with a high burden of disease. This study aims to determine the efficacy of a typhoid conjugate vaccine (TCV) that was recently prequalified by the World Health Organization, by testing it in children 9 months through 12 years of age in Blantyre, Malawi. METHODS: In this Phase III, individually randomized, controlled, double-blind trial of the clinical efficacy of TCV, 28 000 children 9 months through 12 years of age will be enrolled and randomized in a 1:1 ratio to receive either Vi-TCV or a meningococcal serogroup A conjugate vaccine. A subset of 600 of these children will be further enrolled in an immunogenicity and reactogenicity sub-study to evaluate the safety profile and immune response elicited by Vi-TCV. Recruiting began in February 2018. RESULTS: All children will be under passive surveillance for at least 2 years to determine the primary outcome, which is blood culture-confirmed S. Typhi illness. Children enrolled in the immunogenicity and reactogenicity sub-study will have blood drawn before vaccination and at 2 timepoints after vaccination to measure their immune response to vaccination. They will also be followed actively for adverse events and serious adverse events. CONCLUSIONS: The introduction of a single-dose, efficacious typhoid vaccine into countries with high burden of disease or significant antimicrobial resistance could have a dramatic impact, protecting children from infection and reducing antimicrobial usage and associated health inequity in the world's poorest places. This trial, the first of a TCV in Africa, seeks to demonstrate the impact and programmatic use of TCVs within an endemic setting. CLINICAL TRIALS REGISTRATION: NCT03299426.


Asunto(s)
Inmunogenicidad Vacunal , Fiebre Tifoidea/prevención & control , Vacunas Tifoides-Paratifoides/administración & dosificación , Vacunas Tifoides-Paratifoides/inmunología , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Incidencia , Lactante , Malaui , Masculino , Salmonella typhi , Resultado del Tratamiento , Vacunación , Vacunas Conjugadas/administración & dosificación , Vacunas Conjugadas/inmunología , Organización Mundial de la Salud
12.
Brain ; 141(9): 2721-2739, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-30137212

RESUMEN

Our hypothesis is that changes in gene and protein expression are crucial to the development of late-onset Alzheimer’s disease. Previously we examined how DNA alleles control downstream expression of RNA transcripts and how those relationships are changed in late-onset Alzheimer’s disease. We have now examined how proteins are incorporated into networks in two separate series and evaluated our outputs in two different cell lines. Our pipeline included the following steps: (i) predicting expression quantitative trait loci; (ii) determining differential expression; (iii) analysing networks of transcript and peptide relationships; and (iv) validating effects in two separate cell lines. We performed all our analysis in two separate brain series to validate effects. Our two series included 345 samples in the first set (177 controls, 168 cases; age range 65–105; 58% female; KRONOSII cohort) and 409 samples in the replicate set (153 controls, 141 cases, 115 mild cognitive impairment; age range 66–107; 63% female; RUSH cohort). Our top target is heat shock protein family A member 2 (HSPA2), which was identified as a key driver in our two datasets. HSPA2 was validated in two cell lines, with overexpression driving further elevation of amyloid-β40 and amyloid-β42 levels in APP mutant cells, as well as significant elevation of microtubule associated protein tau and phosphorylated-tau in a modified neuroglioma line. This work further demonstrates that studying changes in gene and protein expression is crucial to understanding late onset disease and further nominates HSPA2 as a specific key regulator of late-onset Alzheimer’s disease processes.10.1093/brain/awy215_video1awy215media15824729224001.


Asunto(s)
Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/fisiopatología , Proteínas HSP70 de Choque Térmico/fisiología , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Mapeo Encefálico/métodos , Línea Celular , Femenino , Perfilación de la Expresión Génica/métodos , Células HEK293 , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Humanos , Masculino , Red Nerviosa/fisiopatología , Procesamiento Proteico-Postraduccional , ARN/análisis , ARN/metabolismo , Transcriptoma/genética
14.
Alzheimers Dement ; 13(9): 965-984, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28341160

RESUMEN

INTRODUCTION: The Alzheimer's Disease Research Summits of 2012 and 2015 incorporated experts from academia, industry, and nonprofit organizations to develop new research directions to transform our understanding of Alzheimer's disease (AD) and propel the development of critically needed therapies. In response to their recommendations, big data at multiple levels are being generated and integrated to study network failures in disease. We used metabolomics as a global biochemical approach to identify peripheral metabolic changes in AD patients and correlate them to cerebrospinal fluid pathology markers, imaging features, and cognitive performance. METHODS: Fasting serum samples from the Alzheimer's Disease Neuroimaging Initiative (199 control, 356 mild cognitive impairment, and 175 AD participants) were analyzed using the AbsoluteIDQ-p180 kit. Performance was validated in blinded replicates, and values were medication adjusted. RESULTS: Multivariable-adjusted analyses showed that sphingomyelins and ether-containing phosphatidylcholines were altered in preclinical biomarker-defined AD stages, whereas acylcarnitines and several amines, including the branched-chain amino acid valine and α-aminoadipic acid, changed in symptomatic stages. Several of the analytes showed consistent associations in the Rotterdam, Erasmus Rucphen Family, and Indiana Memory and Aging Studies. Partial correlation networks constructed for Aß1-42, tau, imaging, and cognitive changes provided initial biochemical insights for disease-related processes. Coexpression networks interconnected key metabolic effectors of disease. DISCUSSION: Metabolomics identified key disease-related metabolic changes and disease-progression-related changes. Defining metabolic changes during AD disease trajectory and its relationship to clinical phenotypes provides a powerful roadmap for drug and biomarker discovery.


Asunto(s)
Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/complicaciones , Enfermedades Metabólicas/etiología , Redes y Vías Metabólicas/fisiología , Anciano , Anciano de 80 o más Años , Envejecimiento/sangre , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/diagnóstico por imagen , Aminoácidos/sangre , Péptidos beta-Amiloides/metabolismo , Compuestos de Anilina/metabolismo , Disfunción Cognitiva/sangre , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/etiología , Estudios de Cohortes , Estudios Transversales , Ayuno , Femenino , Humanos , Masculino , Enfermedades Metabólicas/sangre , Enfermedades Metabólicas/líquido cefalorraquídeo , Enfermedades Metabólicas/diagnóstico por imagen , Metabolómica/métodos , Fragmentos de Péptidos/metabolismo , Fosfatidilcolinas/sangre , Fosfatidilcolinas/metabolismo , Esfingomielinas/sangre , Tiazoles/metabolismo , Proteínas tau/líquido cefalorraquídeo
16.
Hum Mol Genet ; 22(4): 825-31, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23184150

RESUMEN

Genome-wide association studies (GWASs) of renal cell cancer (RCC) have identified four susceptibility loci thus far. To identify an additional RCC common susceptibility locus, we conducted a GWAS and performed a meta-analysis with published GWASs (totalling 2215 cases and 8566 controls of European background) and followed up the most significant association signals [nine single nucleotide polymorphisms (SNPs) in eight genomic regions] in 3739 cases and 8786 controls. A combined analysis identified a novel susceptibility locus mapping to 2q22.3 marked by rs12105918 (P = 1.80 × 10(-8); odds ratio 1.29, 95% CI: 1.18-1.41). The signal localizes to intron 2 of the ZEB2 gene (zinc finger E box-binding homeobox 2). Our findings suggest that genetic variation in ZEB2 influences the risk of RCC. This finding provides further insights into the genetic and biological basis of inherited genetic susceptibility to RCC.


Asunto(s)
Carcinoma de Células Renales/genética , Cromosomas Humanos Par 2 , Proteínas de Homeodominio/genética , Neoplasias Renales/genética , Proteínas Represoras/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Caja Homeótica 2 de Unión a E-Box con Dedos de Zinc
17.
Lancet Microbe ; 5(3): e226-e234, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38387472

RESUMEN

BACKGROUND: Ciprofloxacin is the first-line drug for treating typhoid fever in many countries in Africa with a high disease burden, but the emergence of non-susceptibility poses a challenge to public health programmes. Through enhanced surveillance as part of vaccine evaluation, we investigated the occurrence and potential determinants of ciprofloxacin non-susceptibility in Blantyre, Malawi. METHODS: We conducted systematic surveillance of typhoid fever cases and antibiotic prescription in two health centres in Blantyre, Malawi, between Oct 1, 2016, and Oct 31, 2019, as part of the STRATAA and TyVAC studies. In addition, blood cultures were taken from eligible patients presenting at Queen Elizabeth Central Hospital, Blantyre, as part of routine diagnosis. Inclusion criteria were measured or reported fever, or clinical suspicion of sepsis. Microbiologically, we identified Salmonella enterica serotype Typhi (S Typhi) isolates with a ciprofloxacin non-susceptible phenotype from blood cultures, and used whole-genome sequencing to identify drug-resistance mutations and phylogenetic relationships. We constructed generalised linear regression models to investigate associations between the number of ciprofloxacin prescriptions given per month to study participants and the proportion of S Typhi isolates with quinolone resistance-determining region (QRDR) mutations in the following month. FINDINGS: From 46 989 blood cultures from Queen Elizabeth Central Hospital, 502 S Typhi isolates were obtained, 30 (6%) of which had either decreased ciprofloxacin susceptibility, or ciprofloxacin resistance. From 11 295 blood cultures from STRATAA and TyVAC studies, 241 microbiologically confirmed cases of typhoid fever were identified, and 198 isolates from 195 participants sequenced (mean age 12·8 years [SD 10·2], 53% female, 47% male). Between Oct 1, 2016, and Aug 31, 2019, of 177 typhoid fever cases confirmed by whole-genome sequencing, four (2%) were caused by S Typhi with QRDR mutations, compared with six (33%) of 18 cases between Sept 1 and Oct 31, 2019. This increase was associated with a preceding spike in ciprofloxacin prescriptions. Every additional prescription of ciprofloxacin given to study participants in the preceding month was associated with a 4·2% increase (95% CI 1·8-7·0) in the relative risk of isolating S Typhi with a QRDR mutation (p=0·0008). Phylogenetic analysis showed that S Typhi isolates with QRDR mutations from September and October, 2019, belonged to two distinct subclades encoding two different QRDR mutations, and were closely related (4-10 single-nucleotide polymorphisms) to susceptible S Typhi endemic to Blantyre. INTERPRETATION: We postulate a causal relationship between increased ciprofloxacin prescriptions and an increase in fluoroquinolone non-susceptibility in S Typhi. Decreasing ciprofloxacin use by improving typhoid diagnostics, and reducing typhoid fever cases through the use of an efficacious vaccine, could help to limit the emergence of resistance. FUNDING: Wellcome Trust, Bill & Melinda Gates Foundation, and National Institute for Health and Care Research (UK).


Asunto(s)
Fiebre Tifoidea , Vacunas Tifoides-Paratifoides , Humanos , Masculino , Femenino , Niño , Salmonella typhi/genética , Ciprofloxacina/farmacología , Ciprofloxacina/uso terapéutico , Fiebre Tifoidea/tratamiento farmacológico , Fiebre Tifoidea/epidemiología , Malaui/epidemiología , Filogenia
18.
PLOS Glob Public Health ; 4(4): e0002786, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38683833

RESUMEN

Providing emergency care in low resource settings relies on delivery by lower cadres of health workers (LCHW). We describe the development, implementation and mixed methods evaluation of a mobile health (mHealth) triage algorithm based on the WHO Emergency, Triage, Assessment, and Treatment (ETAT) for primary-level care. We conducted an observational study design of implementation research. Key stakeholders were engaged throughout implementation. Clinicians and LCHW at eight primary health centres in Blantyre district were trained to use an mHealth algorithm for triage. An mHealth patient surveillance system monitored patients from presentation through referral to tertiary and final outcome. A total of 209,174 children were recorded by ETAT between April 2017 and September 2018, and 155,931 had both recorded mHealth and clinician triage outcome data. Concordance between mHealth triage by lower cadres of HCW and clinician assessment was 81·6% (95% CI [81·4, 81·8]) over all outcomes (kappa: 0·535 (95% CI [0·530, 0·539]). Concordance for mHealth emergency triage was 0.31 with kappa 0.42. The most common mHealth recorded emergency sign was breathing difficulty (74·1% 95% CI [70·1, 77·9]) and priority sign was raised temperature (76·2% (95% CI [75·9, 76·6]). A total of 1,644 referrals out of 3,004 (54·7%) successfully reached the tertiary site. Both providers and carers expressed high levels of satisfaction with the mHealth ETAT pathway. An mHealth triage algorithm can be used by LCHWs with moderate concordance with clinician triage. Implementation of ETAT through an mHealth algorithm documented successful referrals from primary to tertiary, but half of referred patients did not reach the tertiary site. Potential harms of such systems, such as cases requiring referral being missed during triage, require further evaluation. The ASPIRE mHealth primary ETAT approach can be used to prioritise acute illness and support future resource planning within both district and national health system.

19.
PLoS One ; 19(5): e0291215, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38787869

RESUMEN

Tuberculosis (TB) transmission and prevalence are dynamic over time, and heterogeneous within populations. Public health programmes therefore require up-to-date, accurate epidemiological data to appropriately allocate resources, target interventions, and track progress towards End TB goals. Current methods of TB surveillance often rely on case notifications, which are biased by access to healthcare, and TB disease prevalence surveys, which are highly resource-intensive, requiring many tens of thousands of people to be tested to identify high-risk groups or capture trends. Surveys of "latent TB infection", or immunoreactivity to Mycobacterium tuberculosis (Mtb), using tests such as interferon-gamma release assays (IGRAs) could provide a way to identify TB transmission hotspots, supplementing information from disease notifications, and with greater spatial and temporal resolution than is possible to achieve in disease prevalence surveys. This cross-sectional survey will investigate the prevalence of Mtb immunoreactivity amongst young children, adolescents and adults in Blantyre, Malawi, a high HIV-prevalence city in southern Africa. Through this study we will estimate the annual risk of TB infection (ARTI) in Blantyre and explore individual- and area-level risk factors for infection, as well as investigating geospatial heterogeneity of Mtb infection (and its determinants), and comparing these to the distribution of TB disease case-notifications. We will also evaluate novel diagnostics for Mtb infection (QIAreach QFT) and sampling methodologies (convenience sampling in healthcare settings and community sampling based on satellite imagery), which may increase the feasibility of measuring Mtb infection at large scale. The overall aim is to provide high-resolution epidemiological data and provide new insights into methodologies which may be used by TB programmes globally.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Malaui/epidemiología , Humanos , Estudios Transversales , Mycobacterium tuberculosis/inmunología , Adulto , Adolescente , Tuberculosis/epidemiología , Tuberculosis/diagnóstico , Prevalencia , Niño , Femenino , Masculino , Ensayos de Liberación de Interferón gamma/métodos , Adulto Joven , Factores de Riesgo
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