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2.
J Genomics ; 11: 40-44, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37670735

RESUMO

Four Chlamydia psittaci isolates were recovered from clinical specimens from ill workers during a multistate outbreak at two chicken processing plants. Whole genome sequencing analyses revealed high similarity to C. psittaci genotype D. The isolates differed from each other by only two single nucleotide polymorphisms, indicating a common source.

3.
PLOS Glob Public Health ; 3(3): e0001612, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36963040

RESUMO

Each year, 2.4 million children die within their first month of life. Child Health and Mortality Prevention Surveillance (CHAMPS) established in 7 countries aims to generate accurate data on why such deaths occur and inform prevention strategies. Neonatal deaths that occurred between December 2016 and December 2021 were investigated with MITS within 24-72 hours of death. Testing included blood, cerebrospinal fluid and lung cultures, multi-pathogen PCR on blood, CSF, nasopharyngeal swabs and lung tissue, and histopathology examination of lung, liver and brain. Data collection included clinical record review and family interview using standardized verbal autopsy. The full set of data was reviewed by local experts using a standardized process (Determination of Cause of Death) to identify all relevant conditions leading to death (causal chain), per WHO recommendations. For analysis we stratified neonatal death into 24-hours of birth, early (1-<7 days) and late (7-<28 days) neonatal deaths. We analyzed 1458 deaths, 41% occurring within 24-hours, 41% early and 18% late neonatal deaths. Leading underlying causes of death were complications of intrapartum events (31%), complications of prematurity (28%), infections (17%), respiratory disorders (11%), and congenital malformations (8%). In addition to the underlying cause, 62% of deaths had additional conditions and 14% had ≥3 other conditions in the causal chain. The most common causes considering the whole causal chain were infection (40%), prematurity (32%) and respiratory distress syndrome (28%). Common maternal conditions linked to neonatal death were maternal hypertension (10%), labour and delivery complications (8%), multiple gestation (7%), placental complications (6%) obstructed labour and chorioamnionitis (5%, each). CHAMPS' findings showing the full causal chain of events that lead to death, in addition to maternal factors, highlights the complexities involved in each death along with the multiple opportunities for prevention. Highlighting improvements to prenatal and obstetric care and infection prevention are urgently needed in high-mortality settings.

4.
Ann Lab Med ; 43(4): 375-380, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-36843406

RESUMO

We developed and assessed the performance of a new multiplex real-time PCR assay for the detection of all Chlamydia species and simultaneous differentiation of Chlamydia psittaci and Chlamydia pneumoniae-two important human respiratory pathogens-in human clinical specimens. Next-generation sequencing was used to identify unique targets to design real-time PCR assays targeting all Chlamydia species, C. psittaci, and C. pneumoniae. To validate the assay, we used a panel of 49 culture isolates comprising seven C. psittaci genotypes, eight C. pneumoniae isolates, seven other Chlamydia species, and 22 near-neighbor bacterial and viral isolates, along with 22 specimens from external quality assessment (EQA) panels and 34 nasopharyngeal and oropharyngeal swabs and cerebrospinal fluid, stool, and sputum specimens previously identified as positive or negative for C. psittaci or C. pneumoniae. The assays were 100% specific, with limits of detection of 7.64- 9.02 fg/µL. The assay results matched with historical assay results for all specimens, except for one owing to the increased sensitivity of the new C. psittaci assay; the results of the EQA specimens were 100% accurate. This assay may improve the timely and accurate clinical diagnosis of Chlamydia infections and provide a greater understanding of the burden of disease caused by these agents.


Assuntos
Infecções por Chlamydia , Chlamydia , Chlamydophila psittaci , Humanos , Chlamydophila psittaci/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Chlamydia/genética , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/microbiologia
5.
BMJ Glob Health ; 7(11)2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36319031

RESUMO

OBJECTIVE: Risk factors predisposing infants to community-acquired bacterial infections during the first 2 months of life are poorly understood in South Asia. Identifying risk factors for infection could lead to improved preventive measures and antibiotic stewardship. METHODS: Five sites in Bangladesh, India and Pakistan enrolled mother-child pairs via population-based pregnancy surveillance by community health workers. Medical, sociodemographic and epidemiological risk factor data were collected. Young infants aged 0-59 days with signs of possible serious bacterial infection (pSBI) and age-matched controls provided blood and respiratory specimens that were analysed by blood culture and real-time PCR. These tests were used to build a Bayesian partial latent class model (PLCM) capable of attributing the probable cause of each infant's infection in the ANISA study. The collected risk factors from all mother-child pairs were classified and analysed against the PLCM using bivariate and stepwise logistic multivariable regression modelling to determine risk factors of probable bacterial infection. RESULTS: Among 63 114 infants born, 14 655 were assessed and 6022 had signs of pSBI; of these, 81% (4859) provided blood samples for culture, 71% (4216) provided blood samples for quantitative PCR (qPCR) and 86% (5209) provided respiratory qPCR samples. Risk factors associated with bacterial-attributed infections included: low (relative risk (RR) 1.73, 95% credible interval (CrI) 1.42 to 2.11) and very low birth weight (RR 5.77, 95% CrI 3.73 to 8.94), male sex (RR 1.27, 95% CrI 1.07 to 1.52), breathing problems at birth (RR 2.50, 95% CrI 1.96 to 3.18), premature rupture of membranes (PROMs) (RR 1.27, 95% CrI 1.03 to 1.58) and being in the lowest three socioeconomic status quintiles (first RR 1.52, 95% CrI 1.07 to 2.16; second RR 1.41, 95% CrI 1.00 to 1.97; third RR 1.42, 95% CrI 1.01 to 1.99). CONCLUSION: Distinct risk factors: birth weight, male sex, breathing problems at birth and PROM were significantly associated with the development of bacterial sepsis across South Asian community settings, supporting refined clinical discernment and targeted use of antimicrobials.


Assuntos
Infecções Bacterianas , Infecções Comunitárias Adquiridas , Lactente , Recém-Nascido , Gravidez , Feminino , Humanos , Masculino , Estudos Longitudinais , Teorema de Bayes , Infecções Comunitárias Adquiridas/complicações , Infecções Comunitárias Adquiridas/epidemiologia , Fatores de Risco , Estudos de Coortes , Estudos de Casos e Controles , Índia/epidemiologia
6.
Clin Infect Dis ; 73(Suppl_5): S351-S359, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34910182

RESUMO

BACKGROUND: Minimally invasive tissue sampling (MITS) is an alternative to complete autopsy for determining causes of death. Multiplex molecular testing performed on MITS specimens poses challenges of interpretation, due to high sensitivity and indiscriminate detection of pathogenic, commensal, or contaminating microorganisms. METHODS: MITS was performed on 20 deceased children with respiratory illness, at 10 timepoints up to 88 hours postmortem. Samples were evaluated by multiplex molecular testing on fresh tissues by TaqMan® Array Card (TAC) and by histopathology, special stains, immunohistochemistry (IHC), and molecular testing (PCR) on formalin-fixed, paraffin-embedded (FFPE) tissues. Results were correlated to determine overall pathologic and etiologic diagnoses and to guide interpretation of TAC results. RESULTS: MITS specimens collected up to 3 days postmortem were adequate for histopathologic evaluation and testing. Seven different etiologic agents were detected by TAC in 10 cases. Three cases had etiologic agents detected by FFPE or other methods and not TAC; 2 were agents not present on TAC, and 2 were streptococci that may have been species other than those present on TAC. Result agreement was 43% for TAC and IHC or PCR, and 69% for IHC and PCR. Extraneous TAC results were common, especially when aspiration was present. CONCLUSIONS: TAC can be performed on MITS up to 3 days after death with refrigeration and provides a sensitive method for detection of pathogens but requires careful interpretation in the context of clinicoepidemiologic and histopathologic findings. Interpretation of all diagnostic tests in aggregate to establish overall case diagnoses maximizes the utility of TAC in MITS.


Assuntos
Manejo de Espécimes , Autopsia , Criança , Humanos , Imuno-Histoquímica
7.
Clin Infect Dis ; 73(Suppl_5): S360-S367, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34910183

RESUMO

BACKGROUND: We used postmortem minimally invasive tissue sampling (MITS) to assess the effect of time since death on molecular detection of pathogens among respiratory illness-associated deaths. METHODS: Samples were collected from 20 deceased children (aged 1-59 months) hospitalized with respiratory illness from May 2018 through February 2019. Serial lung and/or liver and blood samples were collected using MITS starting soon after death and every 6 hours thereafter for up to 72 hours. Bodies were stored in the mortuary refrigerator for the duration of the study. All specimens were analyzed using customized multipathogen TaqMan® array cards (TACs). RESULTS: We identified a median of 3 pathogens in each child's lung tissue (range, 1-8; n = 20), 3 pathogens in each child's liver tissue (range, 1-4; n = 5), and 2 pathogens in each child's blood specimen (range, 0-4; n = 5). Pathogens were not consistently detected across all collection time points; there was no association between postmortem interval and the number of pathogens detected (P = .43) and no change in TAC cycle threshold value over time for pathogens detected in lung tissue. Human ribonucleoprotein values indicated that specimens collected were suitable for testing throughout the study period. CONCLUSIONS: Results suggest that lung, liver, and blood specimens can be collected using MITS procedures up to 4 days after death in adequately preserved bodies. However, inconsistent pathogen detection in samples needs careful consideration before drawing definitive conclusions on the etiologic causes of death.


Assuntos
Pulmão , Manejo de Espécimes , Autopsia/métodos , Causas de Morte , Criança , Pré-Escolar , Coleta de Dados , Humanos , Lactente , Manejo de Espécimes/métodos
8.
PLoS One ; 16(4): e0249901, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33857209

RESUMO

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), evolved rapidly in the United States. This report describes the demographic, clinical, and epidemiologic characteristics of 544 U.S. persons under investigation (PUI) for COVID-19 with complete SARS-CoV-2 testing in the beginning stages of the pandemic from January 17 through February 29, 2020. METHODS: In this surveillance cohort, the U.S. Centers for Disease Control and Prevention (CDC) provided consultation to public health and healthcare professionals to identify PUI for SARS-CoV-2 testing by quantitative real-time reverse-transcription PCR. Demographic, clinical, and epidemiologic characteristics of PUI were reported by public health and healthcare professionals during consultation with on-call CDC clinicians and subsequent submission of a CDC PUI Report Form. Characteristics of laboratory-negative and laboratory-positive persons were summarized as proportions for the period of January 17-February 29, and characteristics of all PUI were compared before and after February 12 using prevalence ratios. RESULTS: A total of 36 PUI tested positive for SARS-CoV-2 and were classified as confirmed cases. Confirmed cases and PUI testing negative for SARS-CoV-2 had similar demographic, clinical, and epidemiologic characteristics. Consistent with changes in PUI evaluation criteria, 88% (13/15) of confirmed cases detected before February 12, 2020, reported travel from China. After February 12, 57% (12/21) of confirmed cases reported no known travel- or contact-related exposures. CONCLUSIONS: These findings can inform preparedness for future pandemics, including capacity for rapid expansion of novel diagnostic tests to accommodate broad surveillance strategies to assess community transmission, including potential contributions from asymptomatic and presymptomatic infections.


Assuntos
COVID-19/diagnóstico , COVID-19/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Teste de Ácido Nucleico para COVID-19 , Centers for Disease Control and Prevention, U.S. , Criança , Pré-Escolar , Estudos de Coortes , Monitoramento Epidemiológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Saúde Pública , SARS-CoV-2/isolamento & purificação , Viagem , Doença Relacionada a Viagens , Estados Unidos/epidemiologia , Adulto Jovem
9.
MMWR Morb Mortal Wkly Rep ; 70(14): 505-509, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33830980

RESUMO

Psittacosis is typically a mild febrile respiratory illness caused by infection with the bacterium Chlamydia psittaci and usually transmitted to humans by infected birds (1). On average, 11 psittacosis cases per year were reported in the United States during 2000-2017. During August-October 2018, the largest U.S. psittacosis outbreak in 30 years (82 cases identified*) occurred in two poultry slaughter plants, one each in Virginia and Georgia, that shared source farms (2). CDC used C. psittaci real-time polymerase chain reaction (PCR) to test 54 human specimens from this outbreak. This was the largest number of human specimens from a single outbreak ever tested for C. psittaci using real-time PCR, which is faster and more sensitive than commercially available serologic tests. This represented a rare opportunity to assess the utility of multiple specimen types for real-time PCR detection of C. psittaci. C. psittaci was detected more frequently in lower respiratory specimens (59% [10 of 17]) and stool (four of five) than in upper respiratory specimens (7% [two of 28]). Among six patients with sputum and nasopharyngeal swabs tested, C. psittaci was detected only in sputum in five patients. Cycle threshold (Ct) values suggested bacterial load was higher in lower respiratory specimens than in nasopharyngeal swabs. These findings support prioritizing lower respiratory specimens for real-time PCR detection of C. psittaci. Stool specimens might also have utility for diagnosis of psittacosis.


Assuntos
Chlamydophila psittaci/isolamento & purificação , Surtos de Doenças , Programas de Rastreamento/métodos , Psitacose/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , Adulto , Chlamydophila psittaci/genética , Fezes/microbiologia , Feminino , Georgia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Psitacose/epidemiologia , Escarro/microbiologia , Virginia/epidemiologia , Adulto Jovem
10.
J Clin Microbiol ; 58(10)2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32727830

RESUMO

Respiratory diphtheria, characterized by a firmly adherent pseudomembrane, is caused by toxin-producing strains of Corynebacterium diphtheriae, with similar illness produced occasionally by toxigenic Corynebacterium ulcerans or, rarely, Corynebacterium pseudotuberculosis While diphtheria laboratory confirmation requires culture methods to determine toxigenicity, real-time PCR (RT-PCR) provides a faster method to detect the toxin gene (tox). Nontoxigenic tox-bearing (NTTB) Corynebacterium isolates have been described, but impact of these isolates on the accuracy of molecular diagnostics is not well characterized. Here, we describe a new triplex RT-PCR assay to detect tox and distinguish C. diphtheriae from the closely related species C. ulcerans and C. pseudotuberculosis Analytical sensitivity and specificity of the assay were assessed in comparison to culture using 690 previously characterized microbial isolates. The new triplex assay characterized Corynebacterium isolates accurately, with 100% analytical sensitivity for all targets. Analytical specificity with isolates was 94.1%, 100%, and 99.5% for tox, Diph_rpoB, and CUP_rpoB targets, respectively. Twenty-nine NTTB Corynebacterium isolates, representing 5.9% of 494 nontoxigenic isolates tested, were detected by RT-PCR. Whole-genome sequencing of NTTB isolates revealed varied mutations putatively underlying their lack of toxin production, as well as eight isolates with no mutation in tox or the promoter region. This new Corynebacterium RT-PCR method provides a rapid tool to screen isolates and identify probable diphtheria cases directly from specimens. However, the sporadic occurrence of NTTB isolates reinforces the viewpoint that diphtheria culture diagnostics continue to provide the most accurate case confirmation.


Assuntos
Corynebacterium diphtheriae , Difteria , Corynebacterium/genética , Corynebacterium diphtheriae/genética , Toxina Diftérica/genética , Humanos , Reação em Cadeia da Polimerase em Tempo Real
11.
Int J Infect Dis ; 96: 334-342, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32437937

RESUMO

OBJECTIVES: This study investigated causes of fever in the primary levels of care in Southeast Asia, and evaluated whether C-reactive protein (CRP) could distinguish bacterial from viral pathogens. METHODS: Blood and nasopharyngeal swab specimens were taken from children and adults with fever (>37.5 °C) or history of fever (<14 days) in Thailand and Myanmar. RESULTS: Of 773 patients with at least one blood or nasopharyngeal swab specimen collected, 227 (29.4%) had a target organism detected. Influenza virus type A was detected in 85/227 cases (37.5%), followed by dengue virus (30 cases, 13.2%), respiratory syncytial virus (24 cases, 10.6%) and Leptospira spp. (nine cases, 4.0%). Clinical outcomes were similar between patients with a bacterial or a viral organism, regardless of antibiotic prescription. CRP was higher among patients with a bacterial organism compared with those with a viral organism (median 18 mg/L, interquartile range [10-49] versus 10 mg/L [≤8-22], p = 0.003), with an area under the curve of 0.65 (95% CI 0.55-0.75). CONCLUSIONS: Serious bacterial infections requiring antibiotics are an exception rather than the rule in the first line of care. CRP testing could assist in ruling out such cases in settings where diagnostic uncertainty is high and routine antibiotic prescription is common. The original CRP randomised controlled trial was registered with ClinicalTrials.gov, number NCT02758821.


Assuntos
Infecções Bacterianas/complicações , Proteína C-Reativa/metabolismo , Febre/etiologia , Atenção Primária à Saúde , Adulto , Antibacterianos/uso terapêutico , Sudeste Asiático , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/tratamento farmacológico , Criança , Pré-Escolar , Feminino , Febre/diagnóstico , Febre/microbiologia , Febre/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Mianmar , Tailândia
12.
J Clin Microbiol ; 58(6)2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32269102

RESUMO

We evaluated six commercial molecular tests targeting Mycoplasma pneumoniae, namely, the BioFire FilmArray respiratory panel (RP), the Meridian Alethia Mycoplasma Direct, the GenMark ePlex respiratory pathogen panel (RPP), the Luminex NxTAG RPP, the ELITech ELITe InGenius Mycoplasma MGB research use only (RUO) PCR, and the SpeeDx Resistance Plus MP assays. Laboratory-developed PCR assays at the University of Alabama at Birmingham and the Centers for Disease Control and Prevention were used as reference standards. Among 428 specimens, 212 were designated confirmed positives for M. pneumoniae The highest clinical sensitivities were found with the InGenius PCR (99.5%) and the FilmArray RP (98.1%). The Resistance Plus MP identified 93.3% of the confirmed-positive specimens, whereas 83.6, 64.6, and 55.7% were identified by the ePlex RPP, NxTAG RPP, and Mycoplasma Direct assays, respectively. There was no significant difference between the sensitivity of the reference methods and that of the FilmArray RP and InGenius assays, but the remaining four assays detected significantly fewer positive specimens (P < 0.05). Specificities of all assays were 99.5 to 100%. The Resistance Plus MP assay detected macrolide resistance in 27/33 specimens, resulting in a sensitivity of 81.8%. This study provides the first large-scale comparison of commercial molecular assays for detection of M. pneumoniae in the United States and identified clear differences among their performance. Additional studies are necessary to explore the impact of various test performances on patient outcome.


Assuntos
Mycoplasma pneumoniae , Pneumonia por Mycoplasma , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Humanos , Macrolídeos/farmacologia , Mycoplasma pneumoniae/genética , Patologia Molecular , Pneumonia por Mycoplasma/diagnóstico
13.
Clin Infect Dis ; 69(Suppl 4): S311-S321, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31598666

RESUMO

Child Health and Mortality Prevention Surveillance (CHAMPS) laboratories are employing a variety of laboratory methods to identify infectious agents contributing to deaths of children <5 years old and stillbirths in sub-Saharan Africa and South Asia. In support of this long-term objective, our team developed TaqMan Array Cards (TACs) for testing postmortem specimens (blood, cerebrospinal fluid, lung tissue, respiratory tract swabs, and rectal swabs) for >100 real-time polymerase chain reaction (PCR) targets in total (30-45 per card depending on configuration). Multipathogen panels were configured by syndrome and customized to include pathogens of significance in young children within the regions where CHAMPS is conducted, including bacteria (57 targets covering 30 genera), viruses (48 targets covering 40 viruses), parasites (8 targets covering 8 organisms), and fungi (3 targets covering 3 organisms). The development and application of multiplex real-time PCR reactions to the TAC microfluidic platform increased the number of targets in each panel while maintaining assay efficiency and replicates for heightened sensitivity. These advances represent a substantial improvement in the utility of this technology for infectious disease diagnostics and surveillance. We optimized all aspects of the CHAMPS molecular laboratory testing workflow including nucleic acid extraction, quality assurance, and data management to ensure comprehensive molecular testing of specimens and high-quality data. Here we describe the development and implementation of multiplex TACs and associated laboratory protocols for specimen processing, testing, and data management at CHAMPS site laboratories.


Assuntos
Vigilância da População/métodos , Manejo de Espécimes/métodos , África Subsaariana , Ásia , Bactérias/genética , Criança , Saúde da Criança , Mortalidade da Criança , Doenças Transmissíveis/diagnóstico , Fungos/genética , Humanos , Laboratórios , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Vírus/genética
14.
PLoS One ; 14(4): e0214077, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30970036

RESUMO

BACKGROUND: Globally, over 400,000 neonatal deaths in 2015 were attributed to sepsis, however, the incidence and etiologies of these infections are largely unknown in low-middle income countries. We aimed to determine incidence and etiology of community-acquired early-onset (<72 hours age) sepsis (EOS) using culture and molecular diagnostics. METHODS: This was a prospective observational study, in which we conducted a surveillance for pathogens using a combination of blood culture and a polymerase chain reaction (PCR)-based test. Blood culture was performed on all neonates with suspected EOS. Among the subset fulfilling criteria for protocol-defined EOS, blood and nasopharyngeal (NP) respiratory swabs were tested by quantitative real-time reverse-transcriptase PCR using a Taqman Array Card (TAC) with 15 bacterial and 12 viral targets. Blood and NP samples from 312 healthy newborns were also tested by TAC to estimate background positivity rates. We used variant latent-class methods to attribute etiologies and calculate pathogen-specific proportions and incidence rates. RESULTS: We enrolled 2,624 neonates with suspected EOS and from these 1,231 newborns met criteria for protocol-defined EOS (incidence- 39.3/1,000 live-births). Using the partially latent-class modelling, only 26.7% cases with protocol-defined EOS had attributable etiology, and the largest pathogen proportion were Ureaplasma spp. (5.4%; 95%CI: 3.6-8.0) and group B Streptococcus (GBS) (4.8%; 95%CI: 4.1-5.8), and no etiology was attributable for 73.3% of cases. Blood cultures were positive in 99/1,231 (8.0%) with protocol-defined EOS (incidence- 3.2/1,000 live-births). Leading pathogens on blood culture included GBS (35%) and viridans streptococci (24%). Ureaplasma spp. was the most common organism identified on TAC among cases with protocol-defined EOS. CONCLUSION: Using a combination of blood culture and a PCR-based test the common pathogens isolated in neonates with sepsis were Ureaplasma spp. and GBS. Despite documenting higher rates of protocol-defined EOS and using a combination of tests, the etiology for EOS remains elusive.


Assuntos
Sepse Neonatal/sangue , Complicações Infecciosas na Gravidez/sangue , Infecções Estreptocócicas/sangue , Streptococcus agalactiae/isolamento & purificação , Idade de Início , Hemocultura , Feminino , Humanos , Recém-Nascido , Sepse Neonatal/epidemiologia , Sepse Neonatal/microbiologia , Sepse Neonatal/patologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/patologia , África do Sul , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia , Streptococcus agalactiae/genética , Streptococcus agalactiae/patogenicidade , Ureaplasma/isolamento & purificação , Ureaplasma/patogenicidade
15.
PLoS One ; 14(4): e0215753, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30998749

RESUMO

Infectious disease nucleic acid amplification technologies (NAAT) have superior sensitivity, specificity, and rapid time to result compared to traditional microbiological methods. Recovery of concentrated, high quality pathogen nucleic acid (NA) from complex specimen matrices is required for optimal performance of several NA amplification/detection technologies such as polymerase chain reaction (PCR). Fully integrated NAAT platforms that enable rapid sample-to-result workflows with minimal user input are generally restricted to larger reference lab settings, and their complexity and cost are prohibitive to widespread implementation in resource limited settings (RLS). Identification of component technologies for incorporation of reliable and affordable sample preparation with pathogen NA amplification/detection into an integrated platform suitable for RLS, is a necessary first step toward achieving the overarching goal of reducing infectious disease-associated morbidity and mortality globally. In the current study, we evaluate the performance of six novel NA extraction technologies from different developers using blinded panels of stool, sputum and blood spiked with variable amounts of quality-controlled DNA- and/or RNA-based microbes. The extraction efficiencies were semi-quantitatively assessed using validated real-time reverse transcription (RT)-PCR assays specific for each microbe and comparing target-specific RT-PCR results to those obtained with reference NA extraction methods. The technologies were ranked based on overall diagnostic accuracy (analytical sensitivity and specificity). Sample input and output volumes, total processing time, user-required manual steps and cost estimates were also examined for suitability in RLS. Together with the performance analysis, these metrics were used to select the more suitable candidate technologies for further optimization of integrated NA amplification and detection technologies for RLS.


Assuntos
DNA/isolamento & purificação , RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Transcrição Reversa , Manejo de Espécimes , DNA/química , RNA/química , Fluxo de Trabalho
16.
PLoS One ; 14(4): e0215756, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31009510

RESUMO

Nucleic acid amplification technologies (NAATs) are high-performance tools for rapidly and accurately detecting infectious agents. They are widely used in high-income countries to diagnose disease and improve patient care. The complexities associated with test methods, reagents, equipment, quality control and assurance require dedicated laboratories with trained staff, which can exclude their use in low-resource and decentralized healthcare settings. For certain diseases, fully integrated NAAT devices and assays are available for use in environmentally-controlled clinics or emergency rooms where relatively untrained staff can perform testing. However, decentralized settings in many low- and middle-income countries with large burdens of infectious disease are challenged by extreme environments, poor infrastructure, few trained staff and limited financial resources. Therefore, there is an urgent need for low-cost, integrated NAAT tools specifically designed for use in low-resource settings (LRS). Two essential components of integrated NAAT tools are: 1) efficient nucleic acid extraction technologies for diverse and complex sample types; and 2) robust and sensitive nucleic acid amplification and detection technologies. In prior work we reported the performance and workflow capacity for the nucleic acid extraction component. In the current study we evaluated performance of eight novel nucleic acid amplification and detection technologies from seven developers using blinded panels of RNA and/or DNA from three pathogens to assess both diagnostic accuracy and suitability as an essential component for low-cost NAAT in LRS. In this exercise, we noted significant differences in performance among these technologies and identified those most promising for potential further development.


Assuntos
Doenças Transmissíveis/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Ácidos Nucleicos/genética , Sistemas Automatizados de Assistência Junto ao Leito/economia , Chlamydia/genética , Doenças Transmissíveis/microbiologia , Doenças Transmissíveis/virologia , Análise Custo-Benefício , HIV-1/genética , Recursos em Saúde/economia , Humanos , Neisseria gonorrhoeae/genética , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Reprodutibilidade dos Testes , Zika virus/genética
17.
Clin Infect Dis ; 68(1): 5-12, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29788037

RESUMO

Background: The epidemiology of Mycoplasma pneumoniae (Mp) among US children (<18 years) hospitalized with community-acquired pneumonia (CAP) is poorly understood. Methods: In the Etiology of Pneumonia in the Community study, we prospectively enrolled 2254 children hospitalized with radiographically confirmed pneumonia from January 2010-June 2012 and tested nasopharyngeal/oropharyngeal swabs for Mp using real-time polymerase chain reaction (PCR). Clinical and epidemiological features of Mp PCR-positive and -negative children were compared using logistic regression. Macrolide susceptibility was assessed by genotyping isolates. Results: One hundred and eighty two (8%) children were Mp PCR-positive (median age, 7 years); 12% required intensive care and 26% had pleural effusion. No in-hospital deaths occurred. Macrolide resistance was found in 4% (6/169) isolates. Of 178 (98%) Mp PCR-positive children tested for copathogens, 50 (28%) had ≥1 copathogen detected. Variables significantly associated with higher odds of Mp detection included age (10-17 years: adjusted odds ratio [aOR], 10.7 [95% confidence interval {CI}, 5.4-21.1] and 5-9 years: aOR, 6.4 [95% CI, 3.4-12.1] vs 2-4 years), outpatient antibiotics ≤5 days preadmission (aOR, 2.3 [95% CI, 1.5-3.5]), and copathogen detection (aOR, 2.1 [95% CI, 1.3-3.3]). Clinical characteristics were non-specific. Conclusions: Usually considered as a mild respiratory infection, Mp was the most commonly detected bacteria among children aged ≥5 years hospitalized with CAP, one-quarter of whom had codetections. Although associated with clinically nonspecific symptoms, there was a need for intensive care in some cases. Mycoplasma pneumoniae should be included in the differential diagnosis for school-aged children hospitalized with CAP.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/patologia , Hospitalização , Mycoplasma pneumoniae/isolamento & purificação , Pneumonia por Mycoplasma/epidemiologia , Pneumonia por Mycoplasma/patologia , Adolescente , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mycoplasma pneumoniae/efeitos dos fármacos , Pneumonia por Mycoplasma/microbiologia , Estudos Prospectivos , Estados Unidos/epidemiologia
18.
Lancet ; 392(10142): 145-159, 2018 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-30025808

RESUMO

BACKGROUND: More than 500 000 neonatal deaths per year result from possible serious bacterial infections (pSBIs), but the causes are largely unknown. We investigated the incidence of community-acquired infections caused by specific organisms among neonates in south Asia. METHODS: From 2011 to 2014, we identified babies through population-based pregnancy surveillance at five sites in Bangladesh, India, and Pakistan. Babies were visited at home by community health workers up to ten times from age 0 to 59 days. Illness meeting the WHO definition of pSBI and randomly selected healthy babies were referred to study physicians. The primary objective was to estimate proportions of specific infectious causes by blood culture and Custom TaqMan Array Cards molecular assay (Thermo Fisher, Bartlesville, OK, USA) of blood and respiratory samples. FINDINGS: 6022 pSBI episodes were identified among 63 114 babies (95·4 per 1000 livebirths). Causes were attributed in 28% of episodes (16% bacterial and 12% viral). Mean incidence of bacterial infections was 13·2 (95% credible interval [CrI] 11·2-15·6) per 1000 livebirths and of viral infections was 10·1 (9·4-11·6) per 1000 livebirths. The leading pathogen was respiratory syncytial virus (5·4, 95% CrI 4·8-6·3 episodes per 1000 livebirths), followed by Ureaplasma spp (2·4, 1·6-3·2 episodes per 1000 livebirths). Among babies who died, causes were attributed to 46% of pSBI episodes, among which 92% were bacterial. 85 (83%) of 102 blood culture isolates were susceptible to penicillin, ampicillin, gentamicin, or a combination of these drugs. INTERPRETATION: Non-attribution of a cause in a high proportion of patients suggests that a substantial proportion of pSBI episodes might not have been due to infection. The predominance of bacterial causes among babies who died, however, indicates that appropriate prevention measures and management could substantially affect neonatal mortality. Susceptibility of bacterial isolates to first-line antibiotics emphasises the need for prudent and limited use of newer-generation antibiotics. Furthermore, the predominance of atypical bacteria we found and high incidence of respiratory syncytial virus indicated that changes in management strategies for treatment and prevention are needed. Given the burden of disease, prevention of respiratory syncytial virus would have a notable effect on the overall health system and achievement of Sustainable Development Goal. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Infecções Bacterianas/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Países em Desenvolvimento , Viroses/epidemiologia , Adolescente , Adulto , Infecções Bacterianas/etiologia , Infecções Bacterianas/mortalidade , Bangladesh , Causalidade , Pré-Escolar , Estudos de Coortes , Infecções Comunitárias Adquiridas/etiologia , Infecções Comunitárias Adquiridas/mortalidade , Feminino , Humanos , Incidência , Índia , Lactente , Recém-Nascido , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/etiologia , Masculino , Pessoa de Meia-Idade , Paquistão , Vigilância da População , Gravidez , Resultado da Gravidez/epidemiologia , Fatores de Risco , Viroses/etiologia , Viroses/mortalidade , Adulto Jovem
19.
Emerg Infect Dis ; 24(3): 506-513, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29460736

RESUMO

During 2012-2015, we tested respiratory specimens from patients with severe respiratory illness (SRI), patients with influenza-like illness (ILI), and controls in South Africa by real-time PCR for Mycoplasma pneumoniae, followed by culture and molecular characterization of positive samples. M. pneumoniae prevalence was 1.6% among SRI patients, 0.7% among ILI patients, and 0.2% among controls (p<0.001). Age <5 years (adjusted odd ratio 7.1; 95% CI 1.7-28.7) and HIV infection (adjusted odds ratio 23.8; 95% CI 4.1-138.2) among M. pneumonia-positive persons were associated with severe disease. The detection rate attributable to illness was 93.9% (95% CI 74.4%-98.5%) in SRI patients and 80.7% (95% CI 16.7%-95.6%) in ILI patients. The hospitalization rate was 28 cases/100,000 population. We observed the macrolide-susceptible M. pneumoniae genotype in all cases and found P1 types 1, 2, and a type 2 variant with multilocus variable number tandem repeat types 3/6/6/2, 3/5/6/2, and 4/5/7/2.


Assuntos
Mycoplasma pneumoniae , Pneumonia por Mycoplasma/epidemiologia , Pneumonia por Mycoplasma/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/história , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Genótipo , História do Século XXI , Hospitalização , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mycoplasma pneumoniae/classificação , Mycoplasma pneumoniae/genética , Pneumonia por Mycoplasma/história , Vigilância da População , Prevalência , Fatores de Risco , África do Sul/epidemiologia , Adulto Jovem
20.
MMWR Morb Mortal Wkly Rep ; 66(42): 1144-1147, 2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-29073124

RESUMO

On April 25, 2017, a cluster of unexplained illness and deaths among persons who had attended a funeral during April 21-22 was reported in Sinoe County, Liberia (1). Using a broad initial case definition, 31 cases were identified, including 13 (42%) deaths. Twenty-seven cases were from Sinoe County (1), and two cases each were from Grand Bassa and Monsterrado counties, respectively. On May 5, 2017, initial multipathogen testing of specimens from four fatal cases using the Taqman Array Card (TAC) assay identified Neisseria meningitidis in all specimens. Subsequent testing using direct real-time polymerase chain reaction (PCR) confirmed N. meningitidis in 14 (58%) of 24 patients with available specimens and identified N. meningitidis serogroup C (NmC) in 13 (54%) patients. N. meningitidis was detected in specimens from 11 of the 13 patients who died; no specimens were available from the other two fatal cases. On May 16, 2017, the National Public Health Institute of Liberia and the Ministry of Health of Liberia issued a press release confirming serogroup C meningococcal disease as the cause of this outbreak in Liberia.


Assuntos
Surtos de Doenças , Meningite Meningocócica/epidemiologia , Meningite Meningocócica/microbiologia , Neisseria meningitidis Sorogrupo C/isolamento & purificação , Serviços de Laboratório Clínico/estatística & dados numéricos , Análise por Conglomerados , Humanos , Libéria/epidemiologia , Meningite Meningocócica/mortalidade , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Tempo
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