Diagnostic performances of four commercially available assays for the identification of SARS-CoV-2, influenza type A/B virus and RSV.

We evaluated the diagnostic performance of 4 commercially NAAT for detecting SARS-CoV-2 RNA, Influenza type A/B virus and RSV. Included tests were the Allplex™ SARS-CoV-2 fast PCR Assay (RNA extraction-free), Allplex™ RV Master Assay, Allplex™ SARS-CoV-2 fast MDx Assay (LAMP) and Aptima™ SARS-CoV-2/Flu Assay (RT-TMA). The assays' performance characteristics were determined using nasopharyngeal swabs from 270 patients with suspected SARS-CoV-2 infection.

Epidemiology of and in the primary health care setting in the Netherlands.

The aim of this paper is to describe the prevalence of and in patients who visited general practitioners in the Netherlands. Additionally, we describe the prevalence of resistance to azithromycin and moxifloxacin. We used data from 7,411 consecutive female patients who were screened for , , , and and data from 5,732 consecutive male patients screened for , , and .

Rapid detection of dermatophytes using the Seegene Novaplex™ dermatophyte assay.

Objectives: We assessed the performance of the Seegene Novaplex™ Dermatophyte Assay for diagnosis of dermatophytosis.

Methods: Sixty-one clinical samples from skin, nail, hair and culture were selected based on RT-PCR according to Wisselink et al. Of these samples, 26 samples were negative and 35 samples were positive with 39 dermatophytes strains.

Targeted proteomics as a tool to detect SARS-CoV-2 proteins in clinical specimens.

The rapid, sensitive and specific detection of SARS-CoV-2 is critical in responding to the current COVID-19 outbreak. In this proof-of-concept study, we explored the potential of targeted mass spectrometry (MS) based proteomics for the detection of SARS-CoV-2 proteins in both research samples and clinical specimens. First, we assessed the limit of detection for several SARS-CoV-2 proteins by parallel reaction monitoring (PRM) MS in infected Vero E6 cells.

An analysis of the predictive value of the HIV Ag/Ab screening assay within the performance characteristics of the DiaSorin LIAISON XL for the detection of blood-borne viruses.

Background: Correct identification of blood borne viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is crucial in detection and follow up of infection in patients.

Objectives: We evaluated the diagnostic performance of the DiaSorin LIAISON XL (LIAISON XL) for screening of HBV, HCV and HIV infection. In addition, we investigated the variability of the signal-to-cuttoff ratio (S/CO) of the LIAISON XL HIV Ag/Ab assay and it's predictive value in subsequent confirmation of HIV-1 infection.

Spatiotemporal dynamics of dengue epidemics, southern Vietnam.

An improved understanding of heterogeneities in dengue virus transmission might provide insights into biological and ecologic drivers and facilitate predictions of the magnitude, timing, and location of future dengue epidemics. To investigate dengue dynamics in urban Ho Chi Minh City and neighboring rural provinces in Vietnam, we analyzed a 10-year monthly time series of dengue surveillance data from southern Vietnam. The per capita incidence of dengue was lower in Ho Chi Minh City than in most rural provinces; annual epidemics occurred 1-3 months later in Ho Chi Minh City than elsewhere.

Internally controlled, generic real-time PCR for quantification and multiplex real-time PCR with serotype-specific probes for serotyping of dengue virus infections.

Dengue has become a global public health problem and a sensitive diagnostic test for early phase detection can be life saving. An internally controlled, generic real-time PCR was developed and validated by testing serial dilutions of a DENV positive control RNA in the presence of a fixed amount of IC with results showing a good linearity (R(2) = 0.9967) and a LOD of at least 1.

High-resolution analysis of intrahost genetic diversity in dengue virus serotype 1 infection identifies mixed infections.

Little is known about the rate at which genetic variation is generated within intrahost populations of dengue virus (DENV) and what implications this diversity has for dengue pathogenesis, disease severity, and host immunity. Previous studies of intrahost DENV variation have used a low frequency of sampling and/or experimental methods that do not fully account for errors generated through amplification and sequencing of viral RNAs. We investigated the extent and pattern of genetic diversity in sequence data in domain III (DIII) of the envelope (E) gene in serial plasma samples (n = 49) taken from 17 patients infected with DENV type 1 (DENV-1), totaling some 8,458 clones.

Quantifying the emergence of dengue in Hanoi, Vietnam: 1998-2009.

Background: An estimated 2.4 billion people live in areas at risk of dengue transmission, therefore the factors determining the establishment of endemic dengue in areas where transmission suitability is marginal is of considerable importance. Hanoi, Vietnam is such an area, and following a large dengue outbreak in 2009, we set out to determine if dengue is emerging in Hanoi.

The role of climate variability and change in the transmission dynamics and geographic distribution of dengue.

The mounting evidence for anthropogenic changes in global climate raises many pressing questions about the potential effects on biological systems, and in particular the transmission of infectious diseases. Vector-borne diseases, such as dengue, may be particularly sensitive to both periodic fluctuations and sustained changes in global and local climates, because vector biology and viral replication are temperature- and moisture-dependent. This paper reviews the current state of knowledge on the associations between climate variability, climate change and dengue transmission, and the tools being used to quantify these associations.

Age-specificity of clinical dengue during primary and secondary infections.

Background: This study aims to estimate the age-specific risks of clinical dengue attack (i.e., the risk of symptomatic dengue among the total number of dengue virus (DENV) infections) during primary and secondary infections.

Dengue dynamics in Binh Thuan province, southern Vietnam: periodicity, synchronicity and climate variability.

Background: Dengue is a major global public health problem with increasing incidence and geographic spread. The epidemiology is complex with long inter-epidemic intervals and endemic with seasonal fluctuations. This study was initiated to investigate dengue transmission dynamics in Binh Thuan province, southern Vietnam.

Clinical, epidemiological and virological features of Dengue virus infections in Vietnamese patients presenting to primary care facilities with acute undifferentiated fever.

Objectives: To explore clinical and virological characteristics and describe the epidemiology of dengue in patients who presented with acute undifferentiated fever (AUF) at primary health centers (PHC) in Binh Thuan Province, Vietnam.

Methods: A prospective observational study was conducted from 2001 to 2006 to study the aetiology in AUF patients. Demographic and clinical information was obtained, and dengue polymerase chain reaction (RT-PCR) and serology were performed on a random selection of patients.

Detection of dengue nonstructural 1 (NS1) protein in Vietnamese patients with fever.

Diagnosing dengue in febrile patients is challenging. Of a total of 459 patients with acute undifferentiated fever, randomly selected from 12 primary health facilities and 1 clinic of the provincial malaria station in southern Vietnam, dengue-specific antibody (Ab) and NS1Ag enzyme-linked immunosorbent assay (ELISA) (Platelia, Bio-Rad Laboratories, Hercules, CA 94547, US) were performed on acute (t0) and convalescent (t3 weeks) sera. Polymerase chain reaction (PCR) was used for confirmation.

Seroepidemiology and serological follow-up of anti-leptospiral IgG in children in Southern Vietnam.

A follow-up study was conducted with 23 months interval to investigate the seroepidemiology and persistence of Leptospira IgG antibodies among healthy children in Binh Thuan province, Southern Vietnam. Sera from 262 children (7-13 years of age) were collected and analysed with a commercially available enzyme-linked immunosorbent assay (ELISA) for Leptospira IgG. Seroconversion was observed in 10.

Incidence of primary dengue virus infections in Southern Vietnamese children and reactivity against other flaviviruses.

Objective: To study the incidence of asymptomatic primary dengue infections among children and reactivity against other flaviviruses.

Methods: A total of 216 children, who had no dengue-specific IgG antibodies during a serosurvey in 2003 were re-examined 23 months later to determine if seroconversion had occurred. Dengue-specific IgG was demonstrated with enzyme-linked immunosorbent assay (ELISA) and reactivity patterns against other flaviviruses were assessed by using immunofluorescence assay (IFA).

Evaluation of two rapid immunochromatographic assays for diagnosis of dengue among Vietnamese febrile patients.

Results from two dengue rapid tests, the PanBio Duo cassette and the SD Bioline strip test, were compared to those of enzyme-linked immunosorbent assays (Focus Diagnostics) from sera of 200 Vietnamese febrile patients. The PanBio assay was superior, with sensitivity and specificity values for acute-phase serum samples of 54% and 70% (immunoglobulin M) and 70% and 88% (immunoglobulin G), respectively.

Seroepidemiology of leptospirosis in southern Vietnamese children.

Objective: To estimate the seroprevalence of human leptospirosis in southern Vietnam.

Methods: All pupils (n=961) of two primary schools in two communes in southern Vietnam were screened for the presence of serum Leptospira immunoglobulin (Ig)G. Leptospira IgM was tested in 92 randomly selected samples.

Seroprevalence of dengue antibodies, annual incidence and risk factors among children in southern Vietnam.

Dengue is highly endemic in southern Vietnam and all four serotypes of dengue virus have already been identified. To determine the age-specific prevalence of dengue and associated risk factors, we conducted a serological study at two primary schools and assessed risk factors by analysing children's questionnaires and household surveys. Sera were collected from 961 primary schoolchildren in Binh Thuan Province and tested for the presence of dengue virus serum antibodies using an indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA).