Detection Of Measles Virus RNA Research Articles

93. Novel recombinant measles virus vaccine prevents measles virus disease in rhesus macaques

Abstract Background Measles-Mumps-Rubella (MMR) is an effective live-virus vaccine against measles virus (MeV). However, use of MMR is limited by its inability to boost MeV immunity, lack of immunogenicity in infants, and contraindication in pregnant and immunocompromised persons. Methods We evaluated a novel recombinant dimeric MeV hemagglutinin protein vaccine (rMeV) in a rhesus macaque model. Sixteen macaques were primed at day 0 and boosted at day 42 by experimental group: 1) MMR x2; 2) rMeV x2; 3) MMR prime/rMeV boost; 4) control; n=4. Macaques were challenged intratracheally with Bilthoven strain wild type MeV 8 months later. Blood, bone marrow (BM), and lymph node (LN) samples were collected over 3–28 days after challenge. Replication-competent MeV was measured in peripheral blood mononuclear cells (PBMC), BM cells, and LN cells by infectious assay; MeV RNA in PBMC and BM cells was determined by quantitative reverse transcriptase polymerase chain reaction. Plasma was evaluated for MeV-specific IgG and plaque reduction neutralization titer (PRNT). Results Six months after vaccination, mean PRNT was 2,432 in rMeV x2 (standard deviation (SD) 3,840), 3,584 in MMR-prime/rMeV boost (SD 3,072) and 5,120 in MMR x2 groups (SD 3,547). Upon infectious challenge, macaques who received any MeV-containing vaccine developed no clinical signs of measles and had no detectable infectious virus in PBMC, BM cells, or LN cells. All unvaccinated macaques had virus in PBMC that peaked at day 7 (mean 3,162 TCID50/mL, SD 4.1) and resolved by day 14 post challenge, and one macaque developed an extensive rash. Macaques who received any MeV-containing vaccine had no detectable MeV RNA in PBMC or BM cells, whereas all unvaccinated macaques had detectable MeV RNA that peaked at day 7 (1.6e5 copies, SD 10.5) in PBMC. In all experimental groups, MeV-specific IgG titers increased after MeV challenge. Conclusion Macaques who received rMeV and/or MMR were protected from rash, viremia, and detection of MeV RNA in PBMC and BM cells, unlike unvaccinated macaques. These data suggest that rMeV vaccine generates protective immune responses against measles and may be a novel candidate for future measles vaccine strategies. Study of cellular responses after rMeV vaccination and MeV challenge is warranted. Disclosures Jessica Rubens, MD, Mevox: Grant/Research Support Guillaume Stewart-Jones, PhD, Moderna: Inventor of SARS-CoV-2 vaccine sequences|Moderna: Stocks/Bonds Michael Watson, MD, MEVOX Ltd: Board Member|MEVOX Ltd: Ownership Interest|MEVOX Ltd: Stocks/Bonds Barney S. Graham, MD, PhD, BSG: BSG is an inventor on patents for the stabilization of the RSV F protein (WO2014160463A1, Prefusion RSV F proteins and their use).|National Institutes of Health: Inventor on patents for RSV vaccines|National Institutes of Health: inventor on patents for measles and other paramyxovirus vaccines Diane Griffin, MD PhD, Gilead: Grant/Research Support|GlaxoSmithKline: Advisor/Consultant|GreenLight Biosciences: Advisor/Consultant|Merck: Advisor/Consultant|MeVox: Grant/Research Support|Takeda Pharmaceuticals: Advisor/Consultant.

A modern view on the clinical value of the study of oral fluid in the practice of a pediatrician

Currently, the attention of the medical community to a non-invasive method of laboratory diagnostics - the study of oral fluid (oral, saliva, saliva test) in various fields of clinical medicine and mainly in adult patients has been updated. Saliva testing has shown good results, especially in the areas of genomics, microbiomics, proteomics, metabolomics, and transcriptomics. The review presents the possibilities of using a non-invasive method for infectious and non-infectious diseases in children. Saliva contains a wide range of protein DNA and RNA biomarkers that help detect many viral infections in children. Oral fluid tests for human immunodeficiency virus, hepatitis B virus have improved access to diagnostics for infants. Both serological and molecular analyzes of the oral fluid are suitable for routine examination and early detection of measles virus RNA, polyomaviruses. Angiotensin-converting enzyme-2 receptor expression was found in the saliva of children with COVID-19, which can be used to diagnose SARS-CoV-2. The saliva test is as effective as the standard test at identifying asymptomatic individuals in contact tracing. The possibilities of saliva diagnostics are positively assessed in transplantology. New biomarkers in saliva have been identified for the diagnosis of many somatic diseases in children. The role of oral fluid as an alternative to blood serum in patients with terminal renal failure, chronic kidney disease (determination of creatinine, urea) in both adults and children is shown. The data obtained may influence the recommendations for the treatment of patients. As a non-invasive method, the study of oral fluid is promising for the diagnosis, prognosis, monitoring of diseases, large-scale typing of children, and the search for new biomarkers.

Risk factors and clinical profile of measles infection in children in Singapore

Abstract Background Measles is a highly contagious disease with potentially severe complications. A marked increase in the number of cases hospitalized for measles was observed in children in Singapore between December 2013 and February 2014. This study examined the clinical epidemiology and risk factors of children admitted for measles. Methods A retrospective study was conducted between January 2013 and May 2014 that included all children admitted for measles to KK Women's and Children's Hospital (KKH). Patients were identified from the KKH laboratory database, based on positive detection of measles virus RNA. Results A total of 68 children were identified in this study, of which 63.2% were male, 80.9% were 12 months of developing lymphopenia (OR, 0.029, 95% CI, 0.003–0.244) and conjunctivitis (OR 0.294, 95% CI 0.103–0.843) but a higher risk of developing diarrhea (OR 3.248, 95% CI 1.125–9.379). Conclusion Apart from absent or incomplete MMR vaccination, risk factors for measles infection in children included age

Detection of Measles Virus RNA in Air and Surface Specimens in a Hospital Setting

Measles virus (MeV) is known to be highly contagious, with an infectious period lasting from 4 days before to 4 days after rash onset. An unvaccinated, young, female patient with measles confirmed by direct epidemiologic link was hospitalized on day 5 after rash onset. Environmental samples were collected over the 4-day period of hospitalization in a single room. MeV RNA was detectable in air specimens, on surface specimens, and on respirators on days 5-8 after rash onset. This is the first report of environmental surveillance for MeV, and the results suggest that MeV-infected fomites may be present in healthcare settings.

Detection of measles virus RNA on SYBR green real‐time reverse transcription–polymerase chain reaction

As the coverage rate of the measles vaccine increases, not all patients present the typical symptoms of measles after exposure to the measles virus (MV). The virus loads in clinical specimens from patients with vaccine-modified non-typical measles are expected to be low compared with those of primary MV infection. A rapid and sensitive laboratory procedure is required for diagnosis of measles. SYBR Green (TaKaRa) and TaqMan (ABI) real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed to detect MV-RNA. For the real-time RT-PCR, primer sets were designed from a region of the MV H gene of the Edmonston strain (genotype A). A TaqMan probe specific for the H gene of genotype D MV was used. The minimum detectable level of MV-RNA in the SYBR Green and TaqMan real-time RT-PCR assays was evaluated using synthetic MV-RNA. The sensitivity of real-time RT-PCR was compared with that of nested RT-PCR and the virus isolation method using throat swabs and peripheral blood samples from patients with measles. The minimum detectable level of RNA was 10 and 10(2) copies for SYBR Green RT-PCR and TaqMan RT-PCR, respectively. Ten-10(6) copies of standard RNA were linearly detected on SYBR Green RT-PCR. The sensitivity of SYBR Green RT-PCR was equal to that of nested RT-PCR. MV-RNA was detected in virus isolation-negative throat swabs on SYBR Green RT-PCR. SYBR Green RT-PCR is a highly sensitive, rapid, and useful diagnostic procedure for the detection of MV.

Reevaluation of Laboratory Methods for Diagnosis of Measles

The purpose of this study is to reevaluate the sensitivities of different methods used in the diagnosis of measles including virus isolation, RT-PCR, and measurement of IgM. Sixty-three throat swabs, 84 peripheral blood mononuclear cell (PBMC) samples, and 85 plasma samples were collected from 85 cases of suspected measles. The sensitivity of virus isolation using throat swabs and PBMC in comparison with RT-PCR was 58.1 and 93.5%, respectively. We defined laboratory-confirmed cases as those in which at least one of the methods was positive. The percentage of positive results by the different methods was compared among 49 laboratory-confirmed cases. The percentage of positive results from PBMC by RT-PCR and virus isolation was 100 and 91.7%, respectively. The percentage of positive results from throat swabs by RT-PCR and virus isolation was 91.2 and 52.8%, respectively. The percentage of IgM positive (79.6%) was significantly lower than that of PBMC by RT-PCR. Ten of 27 plasma samples collected within 5 days of the onset of fever were IgM negative. In contrast, all of the 21 plasma samples collected 6 days after the onset of fever were IgM positive. In conclusion, the detection of measles virus RNA in PBMC by RT-PCR was the most effective method for diagnosis of measles.

Detection of measles virus RNA in whole blood stored on filter paper

The purpose of this study was to evaluate the use of dried blood spots stored on filter paper as a means to provide specimens for virologic surveillance for measles virus (MV) in situations when the reverse cold chain is not available. Two single-step RT-PCR assays were evaluated for sensitivity of detection of MV nucleoprotein gene RNA. The more sensitive assay was then used to assess the stability of MV RNA in dried whole blood stored on filter paper. MV RNA was found to be stable in dried blood spots for up to 2 months at room temperature or 1 month at 37 degrees C. As few as 100 infected human peripheral blood mononuclear cells (PBMC) per blood spot could be detected using a single-step RT-PCR reaction and ethidium bromide detection. MV RNA was also detected in dried blood spots obtained from rhesus macaques after challenge with wild-type MV. In the rhesus samples, the single-step RT-PCR reaction could detect approximately 10(3) TCID(50) per blood spot, while nested PCR detected 3 TCID(50) per blood spot. The results of this laboratory-based study suggest that the use of dried blood spots stored on filter has the potential to improve virologic surveillance for MV in some areas, and they emphasize the need for continued testing under field conditions.

Prolonged measles virus shedding in human immunodeficiency virus-infected children, detected by reverse transcriptase-polymerase chain reaction.

A reverse transcriptase-polymerase chain reaction assay was used to detect measles virus RNA in peripheral blood mononuclear cells, urine, and nasopharyngeal specimens from Zambian children during hospitalization and approximately 1-2 months after discharge. Of 47 children, 29 (61.7%) had prolonged measles virus shedding, as defined by detection of measles virus RNA in > or =1 specimen obtained 30-61 days after rash onset. Ten (90.9%) of 11 human immunodeficiency virus (HIV)-infected children had prolonged measles virus shedding, compared with 19 (52.8%) of 36 HIV-uninfected children (P=.02). Prolonged measles virus shedding did not correlate with levels of measles virus-specific antibody. HIV-infected children with measles may have a prolonged infectious period that potentially enhances measles virus transmission and hinders measles control.

Investigation of optimal specimen type and sampling time for detection of measles virus RNA during a measles epidemic.

At various times postonset of rash, 74 patients positive for measles virus-specific immunoglobulin M provided samples for detection of measles virus RNA by a reverse transcriptase PCR. Of lymphocytes, urine, throat swab, and serum specimens, throat swab specimens were optimal for detection of measles virus RNA during the first 2 weeks after the rash.

Measles virus RNA is not detected in inflammatory bowel disease using hybrid capture and reverse transcription followed by the polymerase chain reaction

Recent epidemiological and immunohistochemical studies have indicated a possible link between measles virus and inflammatory bowel disease (IBD). The aim of this study was to use a sensitive and robust method for the detection of measles virus RNA in IBD and control clinical samples. Peripheral blood mononuclear cells and intestinal resection tissue from IBD and control patients were studied. Two methods were used to determine the presence of measles virus RNA: hybrid capture, using measles virus-specific oligonucleotides linked to paramagnetic solid-phase supports, was carried out on total cellular RNA to enrich for measles virus RNA sequences. Reverse transcription followed by the polymerase chain reaction (RT-PCR) using rTth DNA polymerase was employed for amplification of measles virus N-gene sequences amongst the enriched species. Total RNA was also used for RT-PCR of a housekeeping mRNA species to assess RNA quality. RT-PCR for another region of the measles genome (the haemagglutinin (H) gene) was also undertaken in order to confirm the results obtained using N-gene primers for analysis of these samples. None of the samples were positive for measles N- or H-gene RNA using RT-PCR. Positive control samples confirmed the sensitivity of the methods employed. These results show that either measles virus RNA was not present in the samples, or was present below the sensitivity limits known to have been achieved.

Measles virus RNA is not detected in inflammatory bowel disease using hybrid capture and reverse transcription followed by the polymerase chain reaction

Recent epidemiological and immunohistochemical studies have indicated a possible link between measles virus and inflammatory bowel disease (IBD). The aim of this study was to use a sensitive and robust method for the detection of measles virus RNA in IBD and control clinical samples. Peripheral blood mononuclear cells and intestinal resection tissue from IBD and control patients were studied. Two methods were used to determine the presence of measles virus RNA: hybrid capture, using measles virus-specific oligonucleotides linked to paramagnetic solid-phase supports, was carried out on total cellular RNA to enrich for measles virus RNA sequences. Reverse transcription followed by the polymerase chain reaction (RT-PCR) using rTth DNA polymerase was employed for amplification of measles virus N-gene sequences amongst the enriched species. Total RNA was also used for RT-PCR of a housekeeping mRNA species to assess RNA quality. RT-PCR for another region of the measles genome (the haemagglutinin (H) gene) was also undertaken in order to confirm the results obtained using N-gene primers for analysis of these samples. None of the samples were positive for measles N- or H-gene RNA using RT-PCR. Positive control samples confirmed the sensitivity of the methods employed. These results show that either measles virus RNA was not present in the samples, or was present below the sensitivity limits known to have been achieved. J. Med. Virol. 55:305–311, 1998. © 1998 Wiley-Liss, Inc.

Detection of measles virus RNA in urine specimens from vaccine recipients.

Analysis of urine specimens by using reverse transcriptase-PCR was evaluated as a rapid assay to identify individuals infected with measles virus. For the study, daily urine samples were obtained from either 15-month-old children or young adults following measles immunization. Overall, measles virus RNA was detected in 10 of 12 children during the 2-week sampling period. In some cases, measles virus RNA was detected as early as 1 day or as late as 14 days after vaccination. Measles virus RNA was also detected in the urine samples from all four of the young adults between 1 and 13 days after vaccination. This assay will enable continued studies of the shedding and transmission of measles virus and, it is hoped, will provide a rapid means to identify measles infection, especially in mild or asymptomatic cases.

Detection of measles virus RNA in lymphocytes from peripheral-blood and brain perivascular infiltrates of patients with subacute sclerosing panencephalitis.

To clarify the relation between lymphocytes and measles virus in subacute sclerosing panencephalitis, we used in situ hybridization and a cloned measles virus DNA probe, specific for nucleocapsid protein, to detect measles virus RNA sequences in circulating lymphocytes and brain perivascular cuffs of patients with subacute sclerosing panencephalitis. Seventy to 90 per cent of peripheral mononuclear cells from three such patients were found to contain measles virus RNA sequences. In contrast, only a few infected cells were observed in four seropositive adults (0.1 to 5 per cent) and three age-matched children (10 to 15 per cent) used as controls. In one sample of brain tissue from a patient with subacute sclerosing panencephalitis, viral RNA sequences were also detected in nerve cells and in numerous cells from the perivascular infiltrates. In contrast, no hybridization was observed in brain tissue from a patient with herpetic encephalitis and from a patient with postlymphoma encephalitis. We conclude that measles virus has a strong tropism for lymphocytes and nerve cells in subacute sclerosing panencephalitis and that lymphocytes may be involved in the pathogenesis of the disease.