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1.
Anal Methods ; 16(22): 3539-3550, 2024 Jun 06.
Article En | MEDLINE | ID: mdl-38780022

Dengue virus (DENV) is the most prevalent global arbovirus, exhibiting a high worldwide incidence with intensified severity of symptoms and alarming mortality rates. Faced with the limitations of diagnostic methods, an optical and electrochemical biosystem was developed for the detection of DENV genotypes 1 and 2, using cysteine (Cys), cadmium telluride (CdTe) quantum dots, and anti-DENV antibodies. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), surface plasmon resonance (SPR), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the immunosensor. The AFM and SPR results demonstrated discernible topographic and angular changes confirming the biomolecular recognition. Different concentrations of DENV-1 and DENV-2 were evaluated (0.05 × 106 to 2.0 × 106 PFU mL-1), resulting in a maximum anodic shift (ΔI%) of 263.67% ± 12.54 for DENV-1 and 63.36% ± 3.68 for DENV-2. The detection strategies exhibited a linear response to the increase in viral concentration. Excellent linear correlations, with R2 values of 0.95391 for DENV-1 and 0.97773 for DENV-2, were obtained across a broad concentration range. Data analysis demonstrated high reproducibility, displaying relative standard deviation values of 3.42% and 3.62% for Cys-CdTe-antibodyDENV-1-BSA and Cys-CdTe-antibodyDENV-2-BSA systems. The detection limits were 0.34 × 106 PFU mL-1 and 0.02 × 106 PFU mL-1, while the quantification limits were set at 1.49 × 106 PFU mL-1 and 0.06 × 106 PFU mL-1 for DENV-1 and DENV-2, respectively. Therefore, the biosensing apparatus demonstrates analytical effectiveness in viral screening and can be considered an innovative solution for early dengue diagnosis, contributing to global public health.


Biosensing Techniques , Dengue Virus , Dengue , Tellurium , Dengue Virus/isolation & purification , Dengue Virus/immunology , Biosensing Techniques/methods , Tellurium/chemistry , Humans , Dengue/diagnosis , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Quantum Dots/chemistry , Surface Plasmon Resonance/methods , Cysteine/chemistry , Cadmium Compounds/chemistry , Antibodies, Viral/immunology , Antibodies, Viral/analysis , Immunoassay/methods , Immunoassay/instrumentation , Limit of Detection , Microscopy, Atomic Force
2.
Braz J Microbiol ; 55(2): 1801-1809, 2024 Jun.
Article En | MEDLINE | ID: mdl-38709438

Dengue necessitates accurate diagnosis. Rapid tests such as Bioline™ DENGUE DUO have gained traction, but validation in specific populations is essential. This study aimed to evaluate the performance of the Bioline™ test, alongside assessing the socio-epidemiological profile of symptomatic patients in a Brasília Military Hospital. The serum of 404 symptomatic patients was analyzed by the Bioline™ DENGUE DUO test, followed by Dengue virus detection and discrimination of the four serotypes by RT-qPCR. Accuracy was assessed using parameters including sensitivity (S), specificity (E), positive and negative predictive values (PPV and NPV), and positive (RV +) and negative (RV-) likelihood ratios. The NS1 component exhibited a sensitivity of 70.37%, a specificity of 97.30%, and an overall efficiency of 90.10% when compared to RT-qPCR as the gold standard. The IgM component demonstrated a sensitivity of 26.85%, a specificity of 89.53%, and an overall efficiency of 72.77% when compared to RT-qPCR as the gold standard. The IgG component demonstrated a sensitivity of 23.15%, a specificity of 68.92%, and an overall efficiency of 56.68% when compared to RT-qPCR as the gold standard. Several rapid tests are commercially available. However, considering variations across regions and demographic groups, it is important to question their accuracy in specific populations. Rapid tests are important screening tools, but they can have limitations for the certainty of diagnosis. Bioline™ DENGUE DUO displayed good specificity, but sensitivity was slightly below optimal levels. While helpful for confirming dengue, improvements are needed to effectively rule out the disease.


Dengue Virus , Dengue , Hospitals, Military , Sensitivity and Specificity , Humans , Dengue/diagnosis , Dengue/blood , Dengue/virology , Brazil/epidemiology , Dengue Virus/immunology , Dengue Virus/genetics , Dengue Virus/isolation & purification , Female , Male , Adult , Middle Aged , Young Adult , Adolescent , Antibodies, Viral/blood , Child , Aged , Immunoglobulin M/blood , Child, Preschool , Reagent Kits, Diagnostic/standards
3.
Infect Dis (Lond) ; 56(7): 564-574, 2024 Jul.
Article En | MEDLINE | ID: mdl-38767622

BACKGROUND: Hantavirus and dengue virus infections lead to diseases causing economic and public health concerns. Acute hantavirus infections can lead to similar clinical haemorrhagic signs as other endemic diseases including dengue and leptospirosis. METHODS: Using a retrospective case analysis of pregnant dengue and hantavirus disease patients with clinical reports and compatible clinical laboratory information during pregnancy, we report the first evidence of dengue and hantavirus infections and a case of dual dengue and hantavirus infection among pregnant women in the Caribbean. Laboratory testing by enzyme-linked immunosorbent assay (ELISA) and non-structural protein 1 (NS1) for DENV and for hantavirus infection pseudotype focus reduction neutralisation tests (pFRNT), ELISA and immunochromatographic (ICG) strips. RESULTS: Four pregnant cases with acute DENV infections were identified; however, only one out of the four cases (25%) had a detailed medical record to permit abstraction of clinical data. Six hantavirus infected pregnant cases were identified with gestation periods ranged from 36 to 39 weeks; none of the reported patients exhibited previous pregnancy complications prior to hospitalisation and infection. Acute liver damage was observed in three of the six cases (AST readings) who were subsequently diagnosed with hepatitis in pregnancy and variable clinical outcomes were observed with term and pre-term deliveries. CONCLUSIONS: Whilst hantavirus infection in pregnancy is rare, consideration should be given to differential diagnosis with fever, kidney involvement, liver involvement, haemorrhagic symptoms and thrombocytopenia in endemic areas with clinically similar diseases such as dengue and leptospirosis.HighlightsFirst recorded case of hantavirus and dengue co-infection in a pregnant woman.First detailed report of clinical hantavirus infection in pregnant women in the Caribbean.First published report of clinical dengue infection in pregnant woman in the Caribbean.Possible complications of pregnancy following hantavirus infection.Pre-term birth and low birth weights.Clinical course of hantavirus infection in a Caribbean population.


Dengue , Hantavirus Infections , Pregnancy Complications, Infectious , Humans , Female , Pregnancy , Dengue/epidemiology , Dengue/diagnosis , Dengue/complications , Hantavirus Infections/epidemiology , Hantavirus Infections/diagnosis , Adult , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/virology , Retrospective Studies , Caribbean Region/epidemiology , Young Adult , Orthohantavirus/isolation & purification , Dengue Virus/isolation & purification , Enzyme-Linked Immunosorbent Assay , Coinfection/epidemiology , Coinfection/virology
4.
PLoS Negl Trop Dis ; 18(5): e0012184, 2024 May.
Article En | MEDLINE | ID: mdl-38768248

BACKGROUND: Dengue is a major public health concern in Reunion Island, marked by recurrent epidemics, including successive outbreaks of dengue virus serotypes 1 and 2 (DENV1 and DENV2) with over 70,000 cases confirmed since 2017. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we used Oxford Nanopore NGS technology for sequencing virologically-confirmed samples and clinical isolates collected between 2012 and 2022 to investigate the molecular epidemiology and evolution of DENV in Reunion Island. Here, we generated and analyzed a total of 499 DENV1, 360 DENV2, and 18 DENV3 sequences. By phylogenetic analysis, we show that different genotypes and variants of DENV have circulated in the past decade that likely originated from Seychelles, Mayotte and Southeast Asia and highly affected areas in Asia and Africa. CONCLUSIONS/SIGNIFICANCE: DENV sequences from Reunion Island exhibit a high genetic diversity which suggests regular introductions of new viral lineages from various Indian Ocean islands. The insights from our phylogenetic analysis may inform local health authorities about the endemicity of DENV variants circulating in Reunion Island and may improve dengue management and surveillance. This work emphasizes the importance of strong local coordination and collaboration to inform public health stakeholders in Reunion Island, neighboring areas, and mainland France.


Dengue Virus , Dengue , Genetic Variation , Genotype , Phylogeny , Dengue Virus/genetics , Dengue Virus/classification , Dengue Virus/isolation & purification , Humans , Dengue/epidemiology , Dengue/virology , Reunion/epidemiology , Molecular Epidemiology , Serogroup , Disease Outbreaks , High-Throughput Nucleotide Sequencing
5.
Euro Surveill ; 29(20)2024 05.
Article En | MEDLINE | ID: mdl-38757289

Aedes albopictus collected in 2023 in the greater Paris area (Île-de-France) were experimentally able to transmit five arboviruses: West Nile virus from 3 days post-infection (dpi), chikungunya virus and Usutu virus from 7 dpi, dengue virus and Zika virus from 21 dpi. Given the growing number of imported dengue cases reported in early 2024 in France, surveillance of Ae. albopictus should be reinforced during the Paris Olympic Games in July, when many international visitors including from endemic countries are expected.


Aedes , Chikungunya virus , Dengue Virus , Zika Virus , Animals , Aedes/virology , Humans , Zika Virus/isolation & purification , Dengue Virus/isolation & purification , Chikungunya virus/isolation & purification , Paris , Mosquito Vectors/virology , West Nile virus/isolation & purification , Arboviruses/isolation & purification , Arbovirus Infections/transmission , Flavivirus/isolation & purification , France , Dengue/transmission , Dengue/epidemiology , Zika Virus Infection/transmission
6.
Viruses ; 16(5)2024 04 29.
Article En | MEDLINE | ID: mdl-38793584

Genetic studies preceded by the observation of an unknown mosquito species in Mikolów (Poland) confirmed that it belongs to a new invasive species in Polish fauna, Aedes japonicus (Theobald, 1901), a known vector for numerous infectious diseases. Ae. japonicus is expanding its geographical presence, raising concerns about potential disease transmission given its vector competence for chikungunya virus, dengue virus, West Nile virus, and Zika virus. This first genetically confirmed identification of Ae. japonicus in Poland initiates a comprehensive review of the literature on Ae. japonicus, its biology and ecology, and the viral infections transmitted by this species. This paper also presents the circumstances of the observation of Ae. japonicus in Poland and a methodology for identifying this species.


Aedes , Mosquito Vectors , Poland , Aedes/virology , Animals , Mosquito Vectors/virology , Introduced Species , Humans , West Nile virus/genetics , Dengue Virus/genetics , Dengue Virus/isolation & purification , Dengue Virus/classification , Zika Virus/genetics , Chikungunya virus/genetics , Chikungunya virus/classification , Chikungunya virus/isolation & purification
7.
J Infect Dev Ctries ; 18(4): 495-500, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38728633

INTRODUCTION: After the Coronavirus Disease 2019 pandemic, a high number of cases and severe dengue in children were reported in some provinces in the south of Vietnam. This study aimed to determine the distribution of dengue virus serotypes and their correlation with demographic factors, disease severity, clinical manifestations, and laboratory findings. METHODOLOGY: This study employed a cross-sectional design. Ninety-six dengue-infected children admitted to Can Tho Children's Hospital between October 2022 and March 2023 were included. Confirmation of dengue infection was achieved through the real-time polymerase chain reaction (RT-PCR). RESULTS: Among the identified serotypes, DENV-2 accounted for the highest proportion (71.87%), followed by DENV-1 (23.96%), and DENV-4 (4.17%). DENV-3 was not detected. No significant demographic, disease severity, or laboratory differences were observed among the identified dengue serotypes. However, DENV-2 was associated with a higher occurrence of mucous membrane hemorrhages and gastrointestinal bleeding compared to other serotypes. CONCLUSIONS: Although DENV-2 was the most prevalent serotype responsible for dengue in children in southern Vietnam, it did not lead to more severe cases compared to other serotypes. This finding is crucial for evaluating the illness's prognosis.


Dengue Virus , Serogroup , Severe Dengue , Humans , Vietnam/epidemiology , Severe Dengue/epidemiology , Severe Dengue/virology , Cross-Sectional Studies , Male , Dengue Virus/classification , Dengue Virus/genetics , Dengue Virus/isolation & purification , Female , Child , Child, Preschool , Adolescent , Infant , Severity of Illness Index
8.
BMC Genomics ; 25(1): 433, 2024 May 01.
Article En | MEDLINE | ID: mdl-38693476

BACKGROUND: The increasing burden of dengue virus on public health due to more explosive and frequent outbreaks highlights the need for improved surveillance and control. Genomic surveillance of dengue virus not only provides important insights into the emergence and spread of genetically diverse serotypes and genotypes, but it is also critical to monitor the effectiveness of newly implemented control strategies. Here, we present DengueSeq, an amplicon sequencing protocol, which enables whole-genome sequencing of all four dengue virus serotypes. RESULTS: We developed primer schemes for the four dengue virus serotypes, which can be combined into a pan-serotype approach. We validated both approaches using genetically diverse virus stocks and clinical specimens that contained a range of virus copies. High genome coverage (>95%) was achieved for all genotypes, except DENV2 (genotype VI) and DENV 4 (genotype IV) sylvatics, with similar performance of the serotype-specific and pan-serotype approaches. The limit of detection to reach 70% coverage was 10-100 RNA copies/µL for all four serotypes, which is similar to other commonly used primer schemes. DengueSeq facilitates the sequencing of samples without known serotypes, allows the detection of multiple serotypes in the same sample, and can be used with a variety of library prep kits and sequencing instruments. CONCLUSIONS: DengueSeq was systematically evaluated with virus stocks and clinical specimens spanning the genetic diversity within each of the four dengue virus serotypes. The primer schemes can be plugged into existing amplicon sequencing workflows to facilitate the global need for expanded dengue virus genomic surveillance.


Dengue Virus , Genome, Viral , Serogroup , Whole Genome Sequencing , Dengue Virus/genetics , Dengue Virus/isolation & purification , Dengue Virus/classification , Whole Genome Sequencing/methods , Humans , Genotype , Dengue/virology , Dengue/diagnosis , High-Throughput Nucleotide Sequencing/methods , RNA, Viral/genetics
11.
J Med Virol ; 96(6): e29689, 2024 Jun.
Article En | MEDLINE | ID: mdl-38818789

Individuals infected with dengue virus (DENV) often show no symptoms, which raises the risk of DENV transfusion transmission (TT-DENV) in areas where the virus is prevalent. This study aimed to determine the evidence of DENV infection in blood donors from different geographic regions of Thailand. A cross-sectional study was conducted on blood donor samples collected from the Thai Red Cross National Blood Center and four regional blood centers between March and September 2020. Screening for DENV nonstructural protein 1 (NS1), anti-DENV immunoglobulin G (IgG), and IgM antibodies was performed on residual blood from 1053 donors using enzyme-linked immunosorbent assay kits. Positive NS1 and IgM samples indicating acute infection were verified using four different techniques, including quantitative real-time (q) RT-PCR, nested PCR, virus isolation in C6/36 cells, and mosquito amplification. DENV IgG seropositivity was identified in 89% (938/1053) of blood donors. Additionally, 0.4% (4/1053) and 2.1% (22/1053) of Thai blood donors tested positive for NS1 and IgM, respectively. The presence of asymptomatic dengue virus infection in healthy blood donors suggests a potential risk of transmission through blood transfusion, posing a concern for blood safety.


Antibodies, Viral , Blood Donors , Dengue Virus , Dengue , Immunoglobulin G , Immunoglobulin M , Humans , Thailand/epidemiology , Dengue/transmission , Dengue/epidemiology , Blood Donors/statistics & numerical data , Cross-Sectional Studies , Dengue Virus/immunology , Dengue Virus/isolation & purification , Dengue Virus/genetics , Antibodies, Viral/blood , Female , Male , Adult , Immunoglobulin M/blood , Immunoglobulin G/blood , Young Adult , Middle Aged , Adolescent , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/immunology , Blood Donation
12.
Viruses ; 16(5)2024 05 13.
Article En | MEDLINE | ID: mdl-38793650

BACKGROUND: Risk factors for severe dengue manifestations have been attributed to various factors, including specific serotypes, sex, and age. Mexico has seen the re-emergence of DENV-3, which has not circulated in a decade. OBJECTIVE: To describe dengue serotypes by age, sex, and their association with disease severity in dengue-positive serum samples from epidemiological surveillance system units. MATERIALS AND METHODS: A descriptive analysis was conducted to evaluate the frequency of dengue severity by sex, age, disease quarter, geographical location, and dengue virus serotypes. The study was conducted using laboratory samples from confirmed dengue cases through RT-qPCR from the epidemiological surveillance laboratory network of the Mexican Social Security Institute, Mexico. Simple frequencies and proportions were calculated using the z-test for proportional differences between groups. Bivariate analysis with adjusted Chi2 was performed, and binary logistic regression models were constructed using the forward Wald method considering the model's predictive capacity. The measure of association was the odds ratio, with 95% confidence intervals. Statistical significance was set to an alpha level of <0.05. RESULTS: In 2023, 10,441 samples were processed for dengue RT-qPCR at the IMSS, with a predominance of serotype DENV-3 (64.4%). The samples were mostly from women (52.0%) and outpatient cases (63.3%). The distribution of dengue severity showed significant variations by age, with a lower proportion of severe cases in young children and a higher proportion in the 5- to 14-year-old group. Hospitalizations increased significantly with severity. Warm regions had more cases overall and severity. Cases were most frequent from July to September. While DENV-2 was associated with severity, DENV-4 was not. Binary regression identified higher risk in women, age extremes, and DENV-2, with an overall predictive model of 58.5%. CONCLUSIONS: Women, age groups at the extremes of life, and the DENV-2 serotype presented severe risk of dengue in a population with social security in Mexico during 2023.


Dengue Virus , Serogroup , Severe Dengue , Humans , Mexico/epidemiology , Female , Male , Dengue Virus/genetics , Dengue Virus/classification , Dengue Virus/isolation & purification , Adolescent , Adult , Child , Middle Aged , Child, Preschool , Young Adult , Retrospective Studies , Infant , Severe Dengue/epidemiology , Severe Dengue/virology , Social Security , Aged , Risk Factors , Severity of Illness Index , Infant, Newborn
13.
J Vector Borne Dis ; 61(1): 61-71, 2024 Jan 01.
Article En | MEDLINE | ID: mdl-38648407

BACKGROUND OBJECTIVES: Dengue and chikungunya infections are one of the major health problems that have plagued the human population globally. All dengue virus (DENV) serotypes circulate within Malaysia with particular serotypes dominating in different years/outbreaks. In the state of Kelantan, an increasing number of DENV and chikungunya virus (CHIKV) new cases have been reported, including several deaths. This study aimed to isolate and detect these arboviruses from adult mosquitoes in Kelantan. METHODS: Adult mo squito samples were collected from January to August 2019 and were identified according to gender, species and locality. The isolation of the virus was done in C6/36 cells. Dengue NS1 antigen was carried out using direct mosquito lysate and mosquito culture supernatant. Detection and serotyping of the DENV was performed using multiplex RT-PCR and CHIKV detection using a one-step RT-PCR assay. RESULTS: Of 91 mosquito pools, four were positive for NS1 antigen comprising two pools (2.2%) of male Ae. albopictus (Pulau Melaka and Kubang Siput) and two pools (2.2%) of Ae. aegypti (Kampung Demit Sungai). DENV 1 was detected in one pool (0.9%) of female Ae. albopictus among 114 tested Aedes pools. Two pools of 114 pools (1.7%) from both male Aedes species were positive with double serotypes, DENV 1 and DENV 2 (Pulau Melaka). However, no pool was positive for CHIKV. INTERPRETATION CONCLUSION: The presence of DENV and the main vectors of arboviruses in Kelantan are pertinent indicators of the need to improve vector controls to reduce arbovirus infections among people in the localities.


Aedes , Chikungunya virus , Dengue Virus , Dengue , Mosquito Vectors , Animals , Malaysia , Dengue Virus/genetics , Dengue Virus/isolation & purification , Dengue Virus/classification , Chikungunya virus/genetics , Chikungunya virus/isolation & purification , Chikungunya virus/classification , Male , Female , Aedes/virology , Mosquito Vectors/virology , Dengue/virology , Chikungunya Fever/virology , Humans , Viral Nonstructural Proteins/genetics , Serogroup
14.
Viruses ; 16(4)2024 04 12.
Article En | MEDLINE | ID: mdl-38675935

In 2023, Nepal faced its second largest dengue outbreak ever, following a record-breaking number of dengue cases in 2022, characterized by the expansion of infections into areas of higher altitudes. However, the characteristics of the 2023 circulating dengue virus (DENV) and the vector density remain poorly understood. Therefore, we performed DENV serotyping, clinical and laboratory assessment, and entomological analysis of the 2023 outbreak in central Nepal. A total of 396 fever cases in Dhading hospital suspected of being DENV positive were enrolled, and blood samples were collected and tested by different techniques including PCR. Of these, 278 (70.2%) had confirmed DENV infection. Multiple serotypes (DENV-1, -2, and -3) were detected. DENV-2 (97.5%) re-emerged after six years in Dhading while DENV-3 was identified for the first time. Dengue inpatients had significantly higher frequency of anorexia, myalgia, rash, diarrhea, nausea, vomiting, abdominal pain, and thrombocytopenia (p < 0.05). In this area, Aedes mosquitoes largely predominated (90.7%) with the majority being A. aegypti (60.7%). We also found high levels of Aedes index (20.0%) and container index (16.7%). We confirmed multiple DENV serotype circulation with serotype re-emergence and new serotype introduction, and high vector density in 2023. These findings call for the urgent initiation and scaling up of DENV molecular surveillance in human and mosquito populations for dengue control and prevention in Nepal.


Aedes , Dengue Virus , Dengue , Disease Outbreaks , Mosquito Vectors , Serogroup , Nepal/epidemiology , Dengue/epidemiology , Dengue/virology , Humans , Dengue Virus/genetics , Dengue Virus/classification , Dengue Virus/isolation & purification , Animals , Aedes/virology , Male , Female , Mosquito Vectors/virology , Adult , Adolescent , Middle Aged , Young Adult , Child , Serotyping , Child, Preschool , Phylogeny
15.
Viruses ; 16(4)2024 04 18.
Article En | MEDLINE | ID: mdl-38675971

The majority of cases of undifferentiated acute febrile illness (AFI) in the tropics have an undefined etiology. In Thailand, AFI accounts for two-thirds of illnesses reported to the Ministry of Public Health. To characterize the bacterial and viral causes of these AFIs, we conducted molecular pathogen screening and serological analyses in patients who sought treatment in Chum Phae Hospital, Khon Kaen province, during the period from 2015 to 2016. Through integrated approaches, we successfully identified the etiology in 25.5% of cases, with dengue virus infection being the most common cause, noted in 17% of the study population, followed by scrub typhus in 3.8% and rickettsioses in 6.8%. Further investigations targeting viruses in patients revealed the presence of Guadeloupe mosquito virus (GMV) in four patients without other pathogen co-infections. The characterization of four complete genome sequences of GMV amplified from AFI patients showed a 93-97% nucleotide sequence identity with GMV previously reported in mosquitoes. Nucleotide substitutions resulted in amino acid differences between GMV amplified from AFI patients and mosquitoes, observed in 37 positions. However, these changes had undergone purifying selection pressure and potentially had a minimal impact on protein function. Our study suggests that the GMV strains identified in the AFI patients are relatively similar to those previously reported in mosquitoes, highlighting their potential role associated with febrile illness.


Dengue , Fever , Humans , Thailand/epidemiology , Female , Male , Middle Aged , Adult , Dengue/virology , Dengue/epidemiology , Fever/virology , Young Adult , Adolescent , Phylogeny , Aged , Child , Scrub Typhus/microbiology , Scrub Typhus/epidemiology , Scrub Typhus/virology , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/classification , Child, Preschool , Coinfection/virology , Coinfection/microbiology , Coinfection/epidemiology , Viruses/genetics , Viruses/classification , Viruses/isolation & purification , Culicidae/virology , Culicidae/microbiology , Animals , Dengue Virus/genetics , Dengue Virus/classification , Dengue Virus/isolation & purification , Rickettsia Infections/epidemiology , Rickettsia Infections/microbiology , Rickettsia Infections/virology
16.
Nat Commun ; 15(1): 3508, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38664380

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.


Dengue Virus , Dengue , Disease Outbreaks , Serogroup , Travel , Dengue Virus/genetics , Dengue Virus/classification , Dengue Virus/isolation & purification , Dengue/epidemiology , Dengue/virology , Dengue/transmission , Humans , Caribbean Region/epidemiology , Travel/statistics & numerical data , Phylogeny , Epidemiological Monitoring
17.
J Vector Borne Dis ; 61(1): 117-122, 2024 Jan 01.
Article En | MEDLINE | ID: mdl-38648413

BACKGROUND OBJECTIVES: This study reports observation on circulating serotypes and genotypes of Dengue Virus in North India. METHODS: Serum samples were obtained from suspected cases of dengue referred to the virus diagnostic laboratory during 2014 to 2022. All samples were tested for anti-dengue virus IgM antibodies and NS1Ag by ELISA. NS1Ag positive samples were processed for serotyping and genotyping. RESULTS: Total 41,476 dengue suspected cases were referred to the laboratory of which 12,292 (29.6%) tested positive. Anti-Dengue Virus IgM antibodies, NS1Ag, both IgM and NS1Ag, were positive in 7007 (57.4%); 3200 (26.0%) and 2085 (16.0%) cases respectively. Total 762 strains were serotyped during 9-year period. DENV-1, DENV-2, DENV-3 and DENV-4 serotypes were found in 79 (10.37%), 506 (66.40%), 151 (19.82%) and 26 (3.41%) cases respectively. DENV-1, DENV-2 and DENV-3 were in circulation throughout. Total 105 strains were genotyped. Genotype IV of DENV-1 serotype was circulating till 2014 which was later replaced by genotype V. A distinct seasonality with increase in number of cases in post-monsoon period was seen. INTERPRETATION CONCLUSION: DENV-1, DENV-2 and DENV-3 were found to be in circulation in North India. Predominant serotype/genotype changed at times, but not at regular intervals.


Antibodies, Viral , Dengue Virus , Dengue , Genotype , Serogroup , India/epidemiology , Dengue Virus/genetics , Dengue Virus/classification , Dengue Virus/isolation & purification , Humans , Dengue/virology , Dengue/epidemiology , Dengue/blood , Antibodies, Viral/blood , Immunoglobulin M/blood , Female , Serotyping , Male , Adult , Child , Enzyme-Linked Immunosorbent Assay , Adolescent , Middle Aged , Young Adult , Seasons , Child, Preschool
18.
Travel Med Infect Dis ; 59: 102699, 2024.
Article En | MEDLINE | ID: mdl-38452991

Dengue virus (DENV) is one of the most significant vector-borne pathogens worldwide. In this report, we describe clinical features and laboratory detection of dengue in a 45-year-old traveler to Nicaragua on return home to the United States in 2019. Clinical presentation was mild, with rash, headache, and fatigue, with only low-grade transient fever. Infection dynamics were documented by serology and PCR of serially collected body fluids. DENV serotype 2 was detected in whole blood 1 day after symptoms emerged, with viral RNA isolated to the red cell fraction, and remained detectable through day 89. DENV-2 RNA was detected in serum only on day 4, and IgM was undetectable on day 4 but evident by day 13. Viral RNA was also detected in urine. This report of DENV-2 RNA persistence in blood cells but only transient appearance in serum, supports the potential diagnostic value of whole blood over serum for PCR and opportunity of an expanded testing window. Informed testing approaches can improve diagnostic accuracy and inform strategies that preserve individual and public health.


Dengue Virus , Dengue , RNA, Viral , Travel , Humans , Dengue Virus/genetics , Dengue Virus/isolation & purification , Dengue/virology , Dengue/diagnosis , Dengue/blood , RNA, Viral/blood , Middle Aged , Nicaragua , Male , Serogroup , Immunoglobulin M/blood
19.
Braz J Microbiol ; 55(2): 1083-1090, 2024 Jun.
Article En | MEDLINE | ID: mdl-38424268

Chikungunya (CHIKV), Zika (ZIKV), and dengue viruses (DENV) are vector-borne pathogens that cause emerging and re-emerging epidemics throughout tropical and subtropical countries. The symptomatology is similar among these viruses and frequently co-circulates in the same areas, making the diagnosis arduous. Although there are different methods for detecting and quantifying pathogens, real-time reverse transcription-polymerase chain reaction (real-time RT-qPCR) has become a leading technique for detecting viruses. However, the currently developed assays frequently involve probes and high-cost reagents, limiting access in low-income countries. Therefore, this study aims to design and evaluate a quantitative one-step RT-qPCR assay to detect CHIKV, ZIKV, and DENV with high specificity, reproducibility, and low cost in multiple cell substrates. We established a DNA intercalating green dye-based RT-qPCR test that targets nsP1 of CHIKV, and NS5 gene of ZIKV, and DENV for the amplification reaction. The assay exhibited a high specificity confirmed by the melting curve analysis. No cross-reactivity was observed between the three viruses or unspecific amplification of host RNA. The sensitivity of the reaction was evaluated for each virus assay, getting a limit of detection of one RNA copy per virus. Standard curves were constructed, obtaining a reaction efficiency of ~ 100%, a correlation coefficient (R2) of ~ 0.97, and a slope of -3.3. The coefficient of variation (CV) ranged from 0.02 to 1.43. In addition, the method was optimized for viral quantification and tested in Vero, BHK-21, C6/36, LULO, and the Aedes cell lines. Thus, the DNA intercalating green dye-based RT-qPCR assay was a highly specific, sensitive, reproducible, and effective method for detecting and quantifying CHIKV, ZIKV, and DENV in different cell substrates that could also be applied in clinical samples.


Chikungunya Fever , Chikungunya virus , Dengue Virus , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Zika Virus Infection , Zika Virus , Zika Virus/genetics , Zika Virus/isolation & purification , Chikungunya virus/genetics , Chikungunya virus/isolation & purification , Dengue Virus/genetics , Dengue Virus/isolation & purification , Real-Time Polymerase Chain Reaction/methods , Animals , Humans , Chikungunya Fever/diagnosis , Chikungunya Fever/virology , Zika Virus Infection/virology , Zika Virus Infection/diagnosis , Dengue/virology , Dengue/diagnosis , Chlorocebus aethiops , Reproducibility of Results , Vero Cells , RNA, Viral/genetics , Cell Line
20.
Microbiol Spectr ; 11(1): e0279622, 2023 02 14.
Article En | MEDLINE | ID: mdl-36682882

The efficient and accurate diagnosis of dengue, a major mosquito-borne disease, is of primary importance for clinical care, surveillance, and outbreak control. The identification of specific dengue virus serotype 1 (DENV-1) to DENV-4 can help in understanding the transmission dynamics and spread of dengue disease. The four rapid low-resource serotype-specific dengue tests use a simple sample preparation reagent followed by reverse transcription-isothermal recombinase polymerase amplification (RT-RPA) combined with lateral flow detection (LFD) technology. Results are obtained directly from clinical sample matrices in 35 min, requiring only a heating block and pipettes for liquid handling. In addition, we demonstrate that the rapid sample preparation step inactivates DENV, improving laboratory safety. Human plasma and serum were spiked with DENV, and DENV was detected with analytical sensitivities of 333 to 22,500 median tissue culture infectious doses (TCID50)/mL. The analytical sensitivities in blood were 94,000 to 333,000 TCID50/mL. Analytical specificity testing confirmed that each test could detect multiple serotype-specific strains but did not respond to strains of other serotypes, closely related flaviviruses, or chikungunya virus. Clinical testing on 80 human serum samples demonstrated test specificities of between 94 and 100%, with a DENV-2 test sensitivity of 100%, detecting down to 0.004 PFU/µL, similar to the sensitivity of the PCR test; the other DENV tests detected down to 0.03 to 10.9 PFU/µL. Collectively, our data suggest that some of our rapid dengue serotyping tests provide a potential alternative to conventional labor-intensive RT-quantitative PCR (RT-qPCR) detection, which requires expensive thermal cycling instrumentation, technical expertise, and prolonged testing times. Our tests provide performance and speed without compromising specificity in human plasma and serum and could become promising tools for the detection of high DENV loads in resource-limited settings. IMPORTANCE The efficient and accurate diagnosis of dengue, a major mosquito-borne disease, is of primary importance for clinical care, surveillance, and outbreak control. This study describes the evaluation of four rapid low-resource serotype-specific dengue tests for the detection of specific DENV serotypes in clinical sample matrices. The tests use a simple sample preparation reagent followed by reverse transcription-isothermal recombinase polymerase amplification (RT-RPA) combined with lateral flow detection (LFD) technology. These tests have several advantages compared to RT-qPCR detection, such as a simple workflow, rapid sample processing and turnaround times (35 min from sample preparation to detection), minimal equipment needs, and improved laboratory safety through the inactivation of the virus during the sample preparation step. The low-resource formats of these rapid dengue serotyping tests have the potential to support effective dengue disease surveillance and enhance the diagnostic testing capacity in resource-limited countries with both endemic dengue and intense coronavirus disease 2019 (COVID-19) transmission.


Dengue Virus , Dengue , Humans , Dengue/diagnosis , Dengue Virus/classification , Dengue Virus/isolation & purification , Rapid Diagnostic Tests , Recombinases , Sensitivity and Specificity , Serogroup
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