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Immunocompromised patients with coronavirus disease 2019 were prospectively enrolled from March to November 2022 to understand the association between antibody responses and severe acute respiratory syndrome coronavirus 2 shedding. A total of 62 patients were analyzed, and the results indicated a faster decline in genomic and subgenomic viral RNA in patients with higher neutralizing and S1-specific immunoglobulin G (IgG) antibodies (both P < .001). Notably, high neutralizing antibody levels were associated with a significantly faster decrease in viable virus cultures (P = .04). Our observations suggest the role of neutralizing antibodies in prolonged virus shedding in immunocompromised patients, highlighting the potential benefits of enhancing their humoral immune response through vaccination or monoclonal antibody treatments.
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Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19 , Huésped Inmunocomprometido , Inmunoglobulina G , SARS-CoV-2 , Esparcimiento de Virus , Humanos , COVID-19/inmunología , COVID-19/virología , SARS-CoV-2/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Masculino , Estudios Prospectivos , Femenino , Persona de Mediana Edad , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Anciano , ARN Viral , Adulto , Formación de Anticuerpos/inmunologíaRESUMEN
Although research on aspergillosis and mucormycosis confection is important to optimize antifungal therapy, data on this issue is scarce. Thus, we systematically investigated aspergillosis coinfection in patients with proven mucormycosis. Medical records of adult patients with proven mucormycosis whose formalin-fixed paraffin-embedded (FFPE) tissue sections were available, in a tertiary hospital from August 2007 to July 2023 were retrospectively reviewed to assess coinfection with aspergillosis. We noted cultures of fungi from sterile and non-sterile sites and performed polymerase chain reaction (PCR) assays on FFPE tissues to detect Aspergillus- and Mucorales-specific DNA. Sixty-seven patients with proven mucormycosis, including 12 (18%) with a positive culture of the mucormycosis agent from sterile site cultures, were enrolled. Fungal cultures from sterile and non-sterile sites revealed Aspergillus spp. growth in nine (13%) of the 67 patients, including two sterile and seven non-sterile cultures. The fungal PCR analysis from the FFPE sections was positive for Aspergillus-specific PCR in five (7%) and positive for both Aspergillus- and Mucorales-specific PCR results in eight (12%). Overall, 21 (31%) of the 67 patients with proven mucormycosis had microbiologic and/or molecular evidence of aspergillosis coinfection. Positive blood or bronchoalveolar lavage fluid galactomannan results were more common in the coinfection group (67% [14/21]) than in the mucormycosis group (37% [17/46], P = .024). No significant difference in mortality between the two groups was observed. Approximately one-third of patients with proven mucormycosis exhibited molecular and/or microbiologic evidence of aspergillosis coinfection. Further research is needed to identify patients with aspergillosis and mucormycosis coinfections, for optimal antifungal therapy.
The study aims to investigate the coinfection between mucormycosis and aspergillosis. Key findings reveal that approximately 31% of patients demonstrated evidence of coinfection, which emphasizes the importance of considering both pathogens in diagnosis and treatment decisions.
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Aspergillus , Coinfección , Mucorales , Mucormicosis , Humanos , Mucormicosis/complicaciones , Mucormicosis/microbiología , Coinfección/microbiología , Masculino , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Anciano , Mucorales/aislamiento & purificación , Mucorales/genética , Aspergillus/aislamiento & purificación , Adulto , Aspergilosis/microbiología , Aspergilosis/complicaciones , Reacción en Cadena de la Polimerasa , ADN de Hongos/genética , Centros de Atención Terciaria , Anciano de 80 o más AñosRESUMEN
There are limited data comparing the transmission rates and kinetics of viable virus shedding of the Omicron variant to those of the Delta variant. We compared these rates in hospitalized patients infected with Delta and Omicron variants. We prospectively enrolled adult patients with COVID-19 admitted to a tertiary care hospital in South Korea between September 2021 and May 2022. Secondary attack rates were calculated by epidemiologic investigation, and daily saliva samples were collected to evaluate viral shedding kinetics. Genomic and subgenomic SARS-CoV-2 RNA was measured by PCR, and virus culture was performed from daily saliva samples. A total of 88 patients with COVID-19 who agreed to daily sampling and were interviewed, were included. Of the 88 patients, 48 (59%) were infected with Delta, and 34 (41%) with Omicron; a further 5 patients gave undetectable or inconclusive RNA PCR results and 1 was suspected of being coinfected with both variants. Omicron group had a higher secondary attack rate (31% [38/124] vs. 7% [34/456], p < 0.001). Survival analysis revealed that shorter viable virus shedding period was observed in Omicron variant compared with Delta variant (median 4, IQR [1-7], vs. 8.5 days, IQR [5-12 days], p < 0.001). Multivariable analysis revealed that moderate-to-critical disease severity (HR: 1.96), and immunocompromised status (HR: 2.17) were independent predictors of prolonged viral shedding, whereas completion of initial vaccine series or first booster-vaccinated status (HR: 0.49), and Omicron infection (HR: 0.44) were independently associated with shorter viable virus shedding. Patients with Omicron infections had higher transmission rates but shorter periods of transmissible virus shedding than those with Delta infections.
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COVID-19 , SARS-CoV-2 , Adulto , Humanos , COVID-19/epidemiología , Incidencia , Estudios Prospectivos , ARN Viral/genética , SARS-CoV-2/genética , Esparcimiento de Virus , ARN Subgenómico/genéticaRESUMEN
There are limited data supporting current Centers for Disease Control and Prevention guidelines for the isolation period in moderate to severely immunocompromised patients with coronavirus disease 2019 (COVID-19). Adult COVID-19 patients who underwent solid organ transplantation (SOT) or received active chemotherapy against hematologic malignancy were enrolled and weekly respiratory samples were collected. Samples with positive genomic real-time polymerase chain reaction results underwent virus culture and rapid antigen testing (RAT). A total of 65 patients (40 with hematologic malignancy and 25 SOT) were enrolled. The median duration of viable virus shedding was 4 weeks (interquartile range: 3-7). Multivariable analysis revealed that B-cell depletion (hazard ratio [HR]: 4.76) was associated with prolonged viral shedding, and COVID-19 vaccination (≥3 doses) was negatively associated with prolonged viral shedding (HR: 0.22). The sensitivity, specificity, positive predictive value, and negative predictive value of RAT for viable virus shedding were 79%, 76%, 74%, and 81%, respectively. The negative predictive value of RAT was only 48% (95% confidence interval [CI]: 33-65) in the samples from those with symptom onset ≤20 days, but it was as high as 92% (95% CI: 85-96) in the samples from those with symptom onset >20 days. About half of immunocompromised COVID-19 patients shed viable virus for ≥4 weeks from the diagnosis, and virus shedding was prolonged especially in unvaccinated patients with B-cell-depleting therapy treatment. RAT beyond 20 days in immunocompromised patients had a relatively high negative predictive value for viable virus shedding.
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COVID-19 , Neoplasias Hematológicas , Adulto , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Estudios Prospectivos , Vacunas contra la COVID-19 , Neoplasias Hematológicas/complicaciones , Esparcimiento de Virus , ARN Viral/análisisRESUMEN
Rapid, sensitive, and specific detection of the severe acute respiratory syndrome coronavirus (SARS-CoV)- 2 during early infection is pivotal in controlling the spread and pathological progression of Coronavirus Disease 2019 (COVID-19). Thus, highly accurate, affordable, and scalable point-of-care (POC) diagnostic technologies are necessary. Herein, we developed a rapid and efficient self-directed molecular diagnostic (SdMDx) system for SARS-CoV-2. This system combines the sample preparation step, including virus enrichment and extraction processes, which involve dimethyl suberimidate dihydrochloride and diatomaceous earth functionalized with 3-aminopropyl(diethoxy)methylsilane, and the detection step using loop-mediated isothermal amplification-lateral flow assay (LAMP-LFA). Using the SdMDx system, SARS-CoV-2 could be detected within 47 min by hand without the need for any larger instruments. The SdMDx system enabled detection as low as 0.05 PFU in the culture fluid of SARS-CoV-2-infected VeroE6 cells. We validated the accuracy of the SdMDx system on 38 clinical nasopharyngeal specimens. The clinical utility of the SdMDx system for targeting the S gene of SARS-CoV-2 showed 94.4% sensitivity and 100% specificity. This system is more sensitive than antigen and antibody assays, and it minimizes the use of complicated processes and reduces contamination risks. Accordingly, we demonstrated that the SdMDx system enables a rapid, accurate, simple, efficient, and inexpensive detection of SARS-CoV-2 at home, in emergency facilities, and in low-resource sites as a pre-screening platform and POC testing through self-operation and self-diagnosis.
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BACKGROUND: Organising pneumonia (OP) is reported in patients with haematologic malignancy suspected of having invasive mould disease, yet little is known about this relationship. OBJECTIVE: To investigate molecular evidence of invasive mould pneumonia in paraffin-embedded lung tissues from histologically diagnosed OP patients with suspected invasive mould pneumonia. PATIENTS/METHODS: Patients with haematologic malignancy suspected to have invasive pulmonary mould disease who underwent lung biopsy at a tertiary hospital, Seoul, South Korea, between 2008 and 2020, were retrospectively reviewed. To find molecular evidence of fungal infection, PCR assay was used to detect Aspergillus- and Mucorales-specific DNA within OP lung tissue sections. RESULTS: Forty-seven patients with suspected invasive mould pneumonia underwent lung biopsy and 15 (32%) were histologically diagnosed as OP without any evidence of fungal hyphae. Of these 15 patients, 3 (20%) received allogenic haematopoietic stem cell transplantation prior to developing OP. Before biopsy, 2 and 13 patients had probably and possible invasive mould disease, respectively. The median antifungal treatment length was 81 [8-114] days, and the median steroid treatment dosage was 0.35 mg/kg/day for 36 days (methylprednisolone equivalent doses), respectively. After biopsy, three patients with possible invasive mould infection revealed probable invasive pulmonary aspergillosis. From the 15 paraffin-embedded lung tissues, 6 (40%) exhibited positive PCR assay results for detecting Aspergillus- and Mucorales-specific DNA. CONCLUSIONS: More than one third of OP cases in patients with suspected invasive mould pneumonia exhibited molecular evidence of invasive mould infection by fungus-specific PCR in lung tissues, likely associated with concurrent or prior fungal infection.
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Neoplasias Hematológicas , Mucorales , Micosis , Neumonía Organizada , Neumonía , Humanos , Estudios Retrospectivos , Micosis/tratamiento farmacológico , Aspergillus/genética , Neoplasias Hematológicas/complicacionesRESUMEN
BACKGROUND: There are limited data directly comparing immune responses to vaccines and to natural infections with coronavirus disease 2019 (COVID-19). This study assessed the immunogenicity of the BNT162b2 and ChAdOx1 nCoV-19 vaccines over a 3-month period and compared the immune responses with those to natural infections. METHOD: We enrolled healthcare workers who received BNT162b2 or ChAdOx1 nCoV-19 vaccines and patients with confirmed COVID-19 and then measured S1 immunoglobulin (Ig) G and neutralizing antibodies and T-cell responses. RESULTS: A total of 121 vaccinees and 26 patients with confirmed COVID-19 were analyzed. After the second dose, the BNT162b2 vaccine yielded S1 IgG antibody responses similar to those achieved with natural infections (mean IgG titer [standard deviation], 2241 [899] vs 2601 [5039]; Pâ =â .68) but significantly stronger than responses to the ChAdOx1 vaccine (174 [96]; Pâ <â .001). The neutralizing antibody titer generated by BNT162b2 was 6-fold higher than that generated by ChAdOx1 but lower than that by natural infection. T-cell responses persisted for 3 months with BNT162b2 and natural infection but decreased with ChAdOx1. CONCLUSIONS: Antibody responses after the second dose of BNT162b2 are higher than after the second dose of ChAdOx1 and like those occurring after natural infection. T-cell responses are maintained longer in BNT162b2 vaccinees than in ChAdOx1 vaccinees.
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Vacuna BNT162/inmunología , COVID-19/prevención & control , ChAdOx1 nCoV-19/inmunología , SARS-CoV-2/inmunología , Adulto , Anciano , Anticuerpos Neutralizantes/inmunología , Formación de Anticuerpos/inmunología , Vacuna BNT162/administración & dosificación , Vacuna BNT162/efectos adversos , COVID-19/epidemiología , COVID-19/inmunología , ChAdOx1 nCoV-19/administración & dosificación , ChAdOx1 nCoV-19/efectos adversos , Femenino , Humanos , Inmunoglobulina G , Masculino , Persona de Mediana Edad , VacunaciónRESUMEN
Following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, subsequent ChAdOx1 nCoV-19 vaccination induced similar neutralizing antibody levels against the original strain but significantly higher levels against the Omicron variant compared to those who were not vaccinated. Prior SARS-CoV-2 infection exhibited higher neutralization antibody titers than vaccination alone for both original strains and the Omicron variant.
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COVID-19 , Humanos , SARS-CoV-2 , Vacunas contra la COVID-19 , ChAdOx1 nCoV-19 , Anticuerpos Neutralizantes , Vacunación , Anticuerpos AntiviralesRESUMEN
BACKGROUND: Data on the clinical and virological characteristics of the Delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. This prospective cohort study compared the characteristics of the Delta variant to other variants. METHODS: Adult patients with mild coronavirus disease 2019 (COVID-19) who agreed to daily saliva sampling at a community isolation facility in South Korea between July and August 2021 were enrolled. Scores of 28 COVID-19-related symptoms were recorded daily. The genomic RNA and subgenomic RNA from saliva samples were measured by real-time reverse-transcription polymerase chain reaction (PCR). Cell cultures were performed on saliva samples with positive genomic RNA results. RESULTS: A total of 141 patients (Delta group, nâ =â 108 [77%]; non-Delta group, nâ =â 33 [23%]) were enrolled. Myalgia was more common in the Delta group than in the non-Delta group (52% vs 27%, Pâ =â .03). Total symptom scores were significantly higher in the Delta group between days 3 and 10 after symptom onset. Initial genomic RNA titers were similar between the 2 groups; however, during the late course of disease, genomic RNA titers were higher in the Delta group. Negative conversion of subgenomic RNA was slower in the Delta group (median 9 vs 5 days; Pâ <â .001). The duration of viral shedding in terms of positive viral culture was also longer in the Delta group (median 5 vs 3 days; Pâ =â .002). CONCLUSIONS: COVID-19 patients infected with the Delta variant exhibited prolonged viable viral shedding with more severe symptoms than those infected with non-Delta variants.
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COVID-19 , SARS-CoV-2 , Adulto , Humanos , Estudios Prospectivos , ARN , ARN Viral , SARS-CoV-2/genéticaRESUMEN
OBJECTIVES: This study aimed to evaluate the diagnostic usefulness of real-time (RT) polymerase chain reaction (PCR) on blood samples for diagnosis of invasive aspergillosis and mucormycosis in patients with suspected invasive mould infection. METHODS: Adult patients with suspected invasive mould infection were prospectively enrolled at a tertiary referral hospital in Seoul, South Korea between 2017 and 2020. Standard tests for diagnosis of invasive mould infection and RT-PCR for Aspergillus, Mucor and Rhizopus using blood samples were performed. We evaluated the diagnostic performance of RT-PCR tests in patients diagnosed with proven and probable invasive aspergillosis or mucormycosis infection, according to the modified definitions of the EORTC/MSG 2019. RESULTS: A total of 102 patients with suspected invasive mould infection were enrolled. Of these patients, 46 (45%) were classified as having proven (n = 13) or probable (n = 33) invasive aspergillosis, 21 (21%) as proven (n = 17) or probable (n = 4) invasive mucormycosis and 18 (18%) as possible invasive mould infection. The remaining 13 (13%) were classified as not having invasive mould infection. Patients with possible invasive mould infection (n = 18) and coinfection of aspergillosis and mucormycosis (n = 4) were excluded from the final analysis. The sensitivity and specificity of the Aspergillus PCR were 54.3% ([25/46], 95% confidence interval [CI]: 40.2-67.9%) and 94.1% ([32/34], 95% CI: 80.9-98.4%), respectively. The sensitivity and specificity of the Mucor or Rhizopus PCR were 57.1% ([12/21], 95% CI: 36.6-75.5%) and 76.3% ([45/59], 95% CI: 64.0-85.3), respectively. CONCLUSIONS: Our study suggests that blood PCR can be a useful adjunct test for diagnosing patients with suspected invasive mould infection.
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Aspergilosis , Infecciones Fúngicas Invasoras , Mucormicosis , Adulto , Aspergilosis/diagnóstico , Aspergillus/genética , Humanos , Infecciones Fúngicas Invasoras/diagnóstico , Mucor/genética , Mucormicosis/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , República de Corea , Rhizopus/genética , Sensibilidad y Especificidad , Centros de Atención TerciariaRESUMEN
We evaluated the diagnostic performance of a simple and label-free pathogen enrichment method using homobifunctional imidoesters (HI) and a microfluidic system, called the SLIM assay, followed by real-time PCR from cerebrospinal fluid (CSF) in human immunodeficiency virus (HIV)-uninfected patients with suspected tuberculous meningitis (TBM). Patients with suspected TBM were prospectively enrolled in a tertiary hospital in an intermediate tuberculosis (TB)-burden country during a 30-month period. TBM was classified according to the uniform case definition. Definite and probable TBM were regarded as the reference standards for TBM, and possible TBM and not-TBM as the reference standards for not-TBM. Of 72 HIV-uninfected patients with suspected TBM, 10 were diagnosed with definite (n = 2) and probable (n = 8) TBM by the uniform case definition. The sensitivity of the SLIM assay was 100% (95% confidence interval [CI], 69 to 100%) compared with definite or probable TBM, and it was superior to those of mycobacterial culture (20% [95% CI, 3 to 56%]) and the Xpert MTB/RIF assay (0% [95% CI, 0 to 31%]). Of 21 possible TBM and 41 not-TBM patients by the uniform case definition, 5 possible TBM and no not-TBM patients gave positive results in the SLIM assay. The specificity of the SLIM assay was 92% (95% CI, 82 to 97%; 5/62). We demonstrated that the SLIM assay had a very high sensitivity and specificity with small samples of 10 cases of definite or probable TBM. Further studies are needed to confirm this finding and to compare the SLIM assay with mycobacterial culture, Xpert MTB/RIF, and Xpert MTB/RIF Ultra assays in a larger prospective cohort of patients with suspected TBM, including both HIV-infected and HIV-uninfected cases.
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Microfluídica/métodos , Tuberculosis Meníngea/diagnóstico , Adulto , Anciano , ADN Bacteriano/genética , Femenino , Infecciones por VIH , Humanos , Imidoésteres , Masculino , Persona de Mediana Edad , Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis , Estudios Prospectivos , Sensibilidad y Especificidad , Centros de Atención Terciaria , Tuberculosis Meníngea/líquido cefalorraquídeoRESUMEN
There are no surrogate markers for the development of postherpetic neuralgia (PHN) in patients with herpes zoster (HZ). All patients with HZ were prospectively enrolled to evaluate the associations of saliva varicella zoster virus (VZV) DNA persistence and VZV-specific cell-mediated immunity (CMI) with the development of PHN. Slow clearers were defined if salivary VZV DNA persisted after day 15. Salivary VZV was detected in 60 (85.7%) of a total of 70 patients with HZ on initial presentation. Of 38 patients for whom follow-up saliva samples were available, 26 (68.4%) were classified as rapid clearers and 12 (31.6%) as slow cleares. Initial VZV-specific CMI was lower in slow clearers than rapid clearers (median 45 vs 158 spot forming cells/10 6 cells, P = .02). Of the 70 patients with HZ, 22 (31.4%) eventually developed PHN. Multivariate analysis showed that slow clearers (OR, 15.7, P = .01) and lower initial VZV-specific CMI (OR, 13.8, P = .04) were independent predictors of the development of PHN, after adjustment for age and immunocompromised status. Initial low VZV CMI response and persistence of VZV DNA in saliva may be associated with the development of PHN.
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ADN Viral/análisis , Herpes Zóster/complicaciones , Inmunidad Celular , Neuralgia Posherpética/etiología , Saliva/virología , Adulto , Anciano , Biomarcadores/análisis , Femenino , Herpes Zóster/inmunología , Herpesvirus Humano 3 , Humanos , Masculino , Persona de Mediana Edad , Neuralgia Posherpética/diagnóstico , Neuralgia Posherpética/virología , Estudios ProspectivosRESUMEN
OBJECTIVE: To investigate the accuracy of immunohistochemistry (IHC) tests for distinguishing between mucormycosis and aspergillosis and compare the clinical characteristics of mucormycosis patients according to galactomannan (GM) results. METHODS: We evaluated diagnostic performance of IHC test with tissue sections of patients with culture-proven invasive fungal infection. In addition, we conducted PCR assay with tissue sections of mucormycosis patients with positive GM results to evaluate the possibility of co-infection. RESULTS: In culture-proven mucormycosis (n = 13) and aspergillosis (n = 20), the sensitivity and specificity of IHC test were both 100% for mucormycosis and 85% and 100%, respectively, for aspergillosis. Among the 53 patients who met the modified criteria for proven mucormycosis and had GM assay results, 24 (45%) were positive. Compared with those with negative GM results (n = 29), mucormycosis patients with positive GM results had significantly higher incidence of gastrointestinal tract infections (6/24 [25%] vs 0/29 [0%], P = .006) and were more likely to be histomorphologically diagnosed as aspergillosis (7/24 [29%] vs 2/29 [7%], P = .06). PCR assay amplified both Aspergillus- and Mucorales-specific DNA in 6 of these 24 cases. CONCLUSIONS: Immunohistochemistry tests seem useful for compensating for the limitations of histomorphologic diagnosis in distinguishing between mucormycosis and aspergillosis. Some proven mucormycosis patients with positive GM results had histopathology consistent with aspergillosis and gastrointestinal mucormycosis. In addition, about one quarter of these patients revealed the evidence of co-infection with aspergillosis by PCR assay.
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Aspergilosis/diagnóstico , Inmunohistoquímica , Mucormicosis/diagnóstico , Adulto , Anciano , Aspergilosis/sangre , Aspergillus , Líquido del Lavado Bronquioalveolar/microbiología , ADN de Hongos/sangre , Femenino , Galactosa/análogos & derivados , Humanos , Infecciones Fúngicas Invasoras/diagnóstico , Masculino , Mananos/análisis , Persona de Mediana Edad , Mucorales , Mucormicosis/sangre , Juego de Reactivos para Diagnóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Scrub typhus and severe fever with thrombocytopenia syndrome (SFTS) are the most common tick-borne illnesses in South Korea. Early differentiation of SFTS from scrub typhus in emergency departments is essential but difficult because of their overlapping epidemiology, shared risk factors, and similar clinical manifestations. METHODS: We compared the diagnostic performance of one-step isothermal nucleic acid amplification with bio-optical sensor detection (iNAD) under isothermal conditions, which is rapid (20-30 min), with that of real-time PCR, in patients with a confirmed tick-borne illness. Fifteen patients with confirmed SFTS who provided a total of 15 initial blood samples and 5 follow-up blood samples, and 21 patients with confirmed scrub typhus, were evaluated. RESULTS: The clinical sensitivity of iNAD (100%; 95% CI, 83-100) for SFTS was significantly higher than that of real-time PCR (75%; 95% CI, 51-91; P = 0.047), while its clinical specificity (86%; 95% CI, 65-97) was similar to that of real-time PCR (95%; 95% CI, 77-99; P = 0.61). The clinical sensitivity of iNAD for scrub typhus (100%; 95% CI, 81-100) was significantly higher than that of real-time PCR for scrub typhus (67%; 95% CI, 43-85; P = 0.009), while its clinical specificity (90%; 95% CI, 67-98) was similar to that of real-time PCR (95%; 95% CI, 73-100; P > 0.99). CONCLUSIONS: iNAD is a valuable, rapid method of detecting SFTS virus and Orientia tsutsugamushi with high clinical sensitivity and specificity.
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Técnicas de Amplificación de Ácido Nucleico/métodos , Fiebre por Flebótomos/diagnóstico , Tifus por Ácaros/diagnóstico , Enfermedades por Picaduras de Garrapatas/diagnóstico , Anciano , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , Óptica y Fotónica/instrumentación , Óptica y Fotónica/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa , República de Corea , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
Background: We evaluated the diagnostic usefulness of polymerase chain reaction (PCR) analysis for detecting varicella-zoster virus (VZV) infection and reactivation of VZV, using DNA extracted from saliva and plasma specimens obtained from subjects with suspected herpes zoster and from healthy volunteers during stressful and nonstressful conditions. Methods: There were 52 patients with a diagnosis of herpes zoster (group 1), 30 with a diagnosis of zoster-mimicking disease (group 2), and 27 healthy volunteers (group 3). Saliva and plasma samples were evaluated for VZV DNA by real-time PCR analysis. Results: Among patients with suspected herpes zoster (ie, patients in groups 1 and 2), the sensitivity of PCR analysis of salivary DNA for detecting VZV (88%; 95% confidence interval [CI], 74%-95%) was significantly higher than that of PCR analysis of plasma DNA (28%; 95% CI, 16%-44%; P < .001), whereas the specificity of PCR analysis of salivary DNA (100%; 95% CI, 88%-100%) was similar to that of PCR analysis of plasma DNA (100%; 95% CI, 78%-100%; P > .99). VZV DNA was not detected in saliva and plasma samples from group 3 (0%; 95% CI, 0%-14%). Conclusions: Real-time PCR analysis of salivary DNA is more sensitive than that of plasma DNA for detecting VZV among patients with suspected herpes zoster. We found no subclinical reactivation of VZV in group 3 following exposure to common stressful conditions.
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ADN Viral/aislamiento & purificación , Herpes Zóster/diagnóstico , Herpesvirus Humano 3/aislamiento & purificación , Técnicas de Diagnóstico Molecular/métodos , Plasma/virología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Saliva/virología , Adulto , Anciano , Anciano de 80 o más Años , ADN Viral/genética , Femenino , Herpesvirus Humano 3/genética , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Adulto JovenRESUMEN
The isolation of nucleic acids in the lab on a chip is crucial to achieve the maximal effectiveness of point-of-care testing for detection in clinical applications. Here, we report on the use of a simple and versatile single-channel microfluidic platform that combines dimethyl pimelimidate (DMP) for nucleic acids (both RNA and DNA) extraction without electricity using a thin-film system. The system is based on the adaption of DMP into nonchaotropic-based nucleic acids and the capture of reagents into a low-cost thin-film platform for use as a microfluidic total analysis system, which can be utilized for sample processing in clinical diagnostics. Moreover, we assessed the use of the DMP system for the extraction of nucleic acids from various samples, including mammalian cells, bacterial cells, and viruses from human disease, and we also confirmed that the quality and quantity of the nucleic acids extracted were sufficient to allow for the robust detection of biomarkers and/or pathogens in downstream analysis. Furthermore, this DMP system does not require any instruments and electricity, and has improved time efficiency, portability, and affordability. Thus, we believe that the DMP system may change the paradigm of sample processing in clinical diagnostics.
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We report the enhancement in the obtained signal and penetration depth of 2-D depth-resolved images that were taken by shaping the incident wavefront in optical coherence tomography (OCT). Limitations in the penetration depth and signal to noise ratio (SNR) in OCT are mainly due to multiple scattering, which have been effectively suppressed by controlling the incident wavefront using a digital mirror device (DMD) in combination with spectral-domain OCT. The successful enhancements in the penetration depth and SNR are demonstrated in a wide-range of tissue phantoms, reaching depth enhancement of up to 92%. The hidden structures inside a tissue phantom that could not be seen in conventional OCT are clearly revealed through our proposed system. Its 2-D imaging capability, assisted by further optimization of the system for real-time acquisition speed will boost wide-spread use of OCT for in-vivo tissue diagnosis.
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Aumento de la Imagen/instrumentación , Fantasmas de Imagen , Tomografía de Coherencia Óptica/instrumentación , Diseño de Equipo , HumanosRESUMEN
BACKGROUND: This study describes the first multiplex real-time polymerase chain reaction assay developed, as a multipurpose assessment, for the simultaneous quantification of total bacteria and three Vibrio spp. (V. parahaemolyticus, V. vulnificus and V. anguillarum) in fish and seawater. The consumption of raw finfish as sushi or sashimi has been increasing the chance of Vibrio outbreaks in consumers. Freshness and quality of fishery products also depend on the total bacterial populations present. RESULTS: The detection sensitivity of the specific targets for the multiplex assay was 1 CFU mL⻹ in pure culture and seawater, and 10 CFU g⻹ in fish. While total bacterial counts by the multiplex assay were similar to those obtained by cultural methods, the levels of Vibrio detected by the multiplex assay were generally higher than by cultural methods of the same populations. Among the natural samples without Vibrio spp. inoculation, eight out of 10 seawater and three out of 20 fish samples were determined to contain Vibrio spp. CONCLUSION: Our data demonstrate that this multiplex assay could be useful for the rapid detection and quantification of Vibrio spp. and total bacteria as a multipurpose tool for surveillance of fish and water quality as well as diagnostic method.