Comparing the performance of dengue virus IgG and IgG-capture enzyme-linked immunosorbent assays in seroprevalence study.

BACKGROUND: Dengue virus (DENV) is the leading cause of arboviral diseases in humans worldwide. Currently Dengvaxia, the first dengue vaccine licensed in 20 countries, was recommended for DENV seropositive individuals aged 9-45 years. Studying dengue seroprevalence can improve our understanding of the epidemiology and transmission dynamics of DENV, and facilitate future intervention strategies and assessment of vaccine efficacy. Several DENV envelope protein-based serological tests including IgG and IgG-capture enzyme-linked immunosorbent assays (ELISAs) have been employed in seroprevalence studies. Previously DENV IgG-capture ELISA was reported to distinguish primary and secondary DENV infections during early convalescence, however, its performance over time and in seroprevalence study remains understudied. METHODS: In this study, we used well-documented neutralization test- or reverse-transcription-polymerase-chain reaction-confirmed serum/plasma samples including DENV-naïve, primary and secondary DENV, primary West Nile virus, primary Zika virus, and Zika with previous DENV infection panels to compare the performance of three ELISAs. RESULTS: The sensitivity of the InBios IgG ELISA was higher than that of InBios IgG-capture and SD IgG-capture ELISAs. The sensitivity of IgG-capture ELISAs was higher for secondary than primary DENV infection panel. Within the secondary DENV infection panel, the sensitivity of InBios IgG-capture ELISA decreased from 77.8% at < 6 months to 41.7% at 1-1.5 years, 28.6% at 2-15 years and 0% at > 20 years (p < 0.001, Cochran-Armitage test for trend), whereas that of IgG ELISA remains 100%. A similar trend was observed for SD IgG-capture ELISA. CONCLUSIONS: Our findings demonstrate higher sensitivity of DENV IgG ELISA than IgG-capture ELISA in seroprevalence study and interpretation of DENV IgG-capture ELISA should take sampling time and primary or secondary DENV infection into consideration.

Identification of Anti-Premembrane Antibody as a Serocomplex-Specific Marker To Discriminate Zika, Dengue, and West Nile Virus Infections.

Although transmission of Zika virus (ZIKV) in the Americas has greatly declined since late 2017, recent reports of reduced risks of symptomatic Zika by prior dengue virus (DENV) infection and increased risks of severe dengue disease by previous ZIKV or DENV infection underscore a critical need for serological tests that can discriminate past ZIKV, DENV, and/or other flavivirus infections and improve our understanding of the immune interactions between these viruses and vaccine strategy in endemic regions. As serological tests for ZIKV primarily focus on envelope (E) and nonstructural protein 1 (NS1), antibodies to other ZIKV proteins have not been explored. Here, we employed Western blot analysis using antigens of 6 flaviviruses from 3 serocomplexes to investigate antibody responses following reverse transcription-PCR (RT-PCR)-confirmed ZIKV infection. Panels of 20 primary ZIKV and 20 ZIKV with previous DENV infection recognized E proteins of all 6 flaviviruses and the NS1 protein of ZIKV with some cross-reactivity to DENV. While the primary ZIKV panel recognized only the premembrane (prM) protein of ZIKV, the ZIKV with previous DENV panel recognized both ZIKV and DENV prM proteins. Analysis of antibody responses following 42 DENV and 18 West Nile virus infections revealed similar patterns of recognition by anti-E and anti-NS1 antibodies, whereas both panels recognized the prM protein of the homologous serocomplex but not others. The specificity was further supported by analysis of sequential samples. Together, these findings suggest that anti-prM antibody is a flavivirus serocomplex-specific marker and can be used to delineate current and past flavivirus infections in endemic areas. IMPORTANCE Despite a decline in Zika virus (ZIKV) transmission since late 2017, questions regarding its surveillance, potential reemergence, and interactions with other flaviviruses in regions where it is endemic remain unanswered. Recent studies have reported reduced risks of symptomatic Zika by prior dengue virus (DENV) infection and increased risks of severe dengue disease by previous ZIKV or DENV infection, highlighting a need for better serological tests to discriminate past ZIKV, DENV, and/or other flavivirus infections and improved understanding of the immune interactions and vaccine strategy for these viruses. As most serological tests for ZIKV focused on envelope and nonstructural protein 1, antibodies to other ZIKV proteins, including potentially specific antibodies, remain understudied. We employed Western blot analysis using antigens of 6 flaviviruses to study antibody responses following well-documented ZIKV, DENV, and West Nile virus infections and identified anti-premembrane antibody as a flavivirus serocomplex-specific marker to delineate current and past flavivirus infections in areas where flaviviruses are endemic.

Mobilization of Hematopoietic Stem and Progenitor Cells during Dengue Virus Infection.

Hematopoietic stem and progenitor cells (HSPCs) mobilization is the movement of HSPCs from the bone marrow to the peripheral blood or tissue induced by stress. HSPC mobilization is a well-known response to protect the host during infection through urgent differentiation of HSPCs to immune cells. Dengue virus (DENV) infection is known to cause stress in infected humans and the mobilizing capacity of HSPCs during DENV infection in affected patients has not been fully investigated. Here, we investigated whether DENV infection can induce HSPC mobilization and if the mobilized HSPCs are permissive to DENV infection. White blood cells (WBCs) were collected from dengue patients (DENV+) and healthy donors and analyzed by flow cytometry and plaque assay. Elevated HSPCs levels were found in the WBCs of the DENV+ group when compared to the healthy group. Mobilization of HSPCs and homing markers (skin and gut) expression decreased as the patients proceeded from dengue without symptoms (DWoWS) to severe dengue (SD). Mobilizing HSPCs were not only permissive to DENV infection, but infectious DENV could be recovered after coculture. Our results highlight the need for further investigation into HSPC mobilization or alterations of hematopoiesis during viral infections such as DENV in order to develop appropriate countermeasures.

Optimal initial antibiotic regimen for the treatment of acute appendicitis: a systematic review and network meta-analysis with surgical intervention as the common comparator.

BACKGROUND: The optimal antibiotic regimen for the medical management of acute appendicitis remains unknown due to a lack of head-to-head comparisons between different antibiotic regimens. METHODS: We systematically searched the PubMed, EMBASE, Scopus and Cochrane Central Register of Controlled Trials databases from their inception through to August 2020. We selected randomized controlled trials (RCTs) or observational studies comparing antibiotic therapy and appendectomy as the initial treatment for adult or paediatric patients with acute appendicitis. We performed a Bayesian network meta-analysis (NMA) to obtain the indirect comparison results between different antibiotic regimens by employing the group managed by surgery as a common comparator. Antibiotic regimens were classified into three categories: those including a carbapenem; those including a cephalosporin; and those including a ß-lactam/ß-lactamase inhibitor combination. RESULTS: A total of 9 RCTs (adults, n = 8; paediatrics, n = 1) and 12 observational studies (adults, n = 3; paediatrics, n = 9) were included in the NMA, with a total of 4551 patients. The most commonly administered regimen was a ß-lactam/ß-lactamase inhibitor combination (9/21; 43%), followed by a cephalosporin (7/21; 33%) or a carbapenem (5/21; 24%). The NMA indicated that surgery significantly increased 1 year treatment success, compared with cephalosporins [OR: 16.79; 95% credible interval: 3.8-127.64] or ß-lactam/ß-lactamase inhibitor combinations (OR: 19.99; 95% credible interval: 4.87-187.57), but not carbapenems (OR: 3.50, 95% credible interval: 0.55-38.63). In contrast, carbapenems were associated with fewer treatment-related complications compared with surgery (OR: 0.12; 95% credible interval: 0.01-0.85). CONCLUSIONS: Carbapenems might be recommended as the initial antibiotic regimen for the non-operative management of adult patients with acute appendicitis. Nevertheless, due to the imprecise estimates in our NMA, additional RCTs are needed to corroborate these findings, especially for paediatric patients.

Cytokine Signature of Dengue Patients at Different Severity of the Disease.

Clinical presentations of dengue fever (DF) are diverse and non-specific, causing unpredictable progression and outcomes. Its progression and severity have been associated with cytokine levels alteration. In this study, dengue patients were classified into groups following the 2009 WHO dengue classification scheme to investigate the cytokine signature at different severity of the disease: dengue without warning sign symptoms (A); dengue with warning signs (B); severe dengue (C); other fever (OF) and healthy (Healthy). We analyzed 23 different cytokines simultaneously, namely IL-1b, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-33, CD14, CD54, CD62E, CD62L, CD62p, CD106, CD121b, CD154, CD178, GM-CSF, IFN-g, MIF, ST2 and TNF from patients admitted to National Cheng Kung University Hospital during the 2015 Taiwan dengue outbreak. Cytokines TNF, CD54, CD62E, CD62L, CD62P, GM-CSF, IL-1b, IL-2, IL-6, IL-8, IL-10, IL-12p70, IL-17A, INF-g and MIF were elevated while CD106, CD154, IL-4 and L-33 were decreased when compared to the control. IL-10 demonstrated to be a potential diagnostic marker for DF (H and A group; AUC = 0.944, H and OF group; AUC = 0.969). CD121b demonstrated to be predictive of the SD (A and B group; AUC = 0.744, B and C group; AUC = 0.775). Our results demonstrate the cytokine profile changes during the progression of dengue and highlight possible biomarkers for optimizing effective intervention strategies.

Combination of Nonstructural Protein 1-Based Enzyme-Linked Immunosorbent Assays Can Detect and Distinguish Various Dengue Virus and Zika Virus Infections.

The recent outbreaks of Zika virus (ZIKV) and associated birth defects in regions of dengue virus (DENV) endemicity emphasize the need for sensitive and specific serodiagnostic tests. We reported previously that enzyme-linked immunosorbent assays (ELISAs) based on the nonstructural protein 1 (NS1) of DENV serotype 1 (DENV1) and ZIKV can distinguish primary DENV1, secondary DENV, and ZIKV infections. Whether ELISAs based on NS1 proteins of other DENV serotypes can discriminate various DENV and ZIKV infections remains unknown. We herein developed DENV2, DENV3, and DENV4 NS1 IgG ELISAs to test convalescent- and postconvalescent-phase samples from reverse transcription-PCR-confirmed cases, including 25 primary DENV1, 24 primary DENV2, 10 primary DENV3, 67 secondary DENV, 36 primary West Nile virus, 38 primary ZIKV, and 35 ZIKV with previous DENV infections as well as 55 flavivirus-naive samples. Each ELISA detected primary DENV infection with a sensitivity of 100% for the same serotype and 23.8% to 100% for different serotypes. IgG ELISA using a mixture of DENV1-4 NS1 proteins detected different primary and secondary DENV infections with a sensitivity of 95.6% and specificity of 89.5%. The ZIKV NS1 IgG ELISA detected ZIKV infection with a sensitivity of 100% and specificity of 82.9%. On the basis of the relative optical density ratio, the combination of DENV1-4 and ZIKV NS1 IgG ELISAs distinguished ZIKV with previous DENV and secondary DENV infections with a sensitivity of 91.7% to 94.1% and specificity of 87.0% to 95.0%. These findings have important applications to serodiagnosis, serosurveillance, and monitoring of both DENV and ZIKV infections in regions of endemicity.

Potent Neutralizing Human Monoclonal Antibodies Preferentially Target Mature Dengue Virus Particles: Implication for Novel Strategy for Dengue Vaccine.

The four serotypes of dengue virus (DENV) cause the most important mosquito-borne viral disease in humans. The envelope (E) protein is the major target of neutralizing antibodies and contains 3 domains (domain I [DI], DII, and DIII). Recent studies reported that human monoclonal antibodies (MAbs) recognizing DIII, the D1/DII hinge, the E-dimer epitope, or a quaternary epitope involving DI/DII/DIII are more potently neutralizing than those recognizing the fusion loop (FL) of DII. Due to inefficient cleavage of the premembrane protein, DENV suspensions consist of a mixture of mature, immature, and partially immature particles. We investigated the neutralization and binding of 22 human MAbs to DENV serotype 1 (DENV1) virions with differential maturation status. Compared with FL MAbs, DIII, DI/DII hinge, and E-dimer epitope MAbs showed higher maximum binding and avidity to mature particles relative to immature particles; this feature may contribute to the strong neutralizing potency of such MAbs. FL-specific MAbs required 57 to 87% occupancy on mature particles to achieve half-maximal neutralization (NT50), whereas the potently neutralizing MAbs achieved NT50 states at 20 to 38% occupancy. Analysis of the MAb repertoire and polyclonal sera from patients with primary DENV1 infection supports the immunodominance of cross-reactive anti-E antibodies over type-specific antibodies. After depletion with viral particles from a heterologous DENV serotype, the type-specific neutralizing antibodies remained and showed binding features shared by potent neutralizing MAbs. Taken together, these findings suggest that the use of homogeneous mature DENV particles as an immunogen may induce more potent neutralizing antibodies against DENV than the use of immature or mixed particles.IMPORTANCE With an estimated 390 million infections per year, the four serotypes of dengue virus (DENV) cause the most important mosquito-borne viral disease in humans. The dengue vaccine Dengvaxia was licensed; however, its low efficacy among dengue-naive individuals and increased risk of causing severe dengue in children highlight the need for a better understanding of the role of human antibodies in immunity against DENV. DENV suspensions contain mature, immature, and partially immature particles. We investigated the binding of 22 human monoclonal antibodies (MAbs) to the DENV envelope protein on particles with different maturation states. Potently neutralizing MAbs had higher relative maximum binding and avidity to mature particles than weakly neutralizing MAbs. This was supported by analysis of MAb repertoires and polyclonal sera from patients with primary DENV infection. Together, these findings suggest that mature particles may be the optimal form of presentation of the envelope protein to induce more potent neutralizing antibodies against DENV.

Use of Urea Wash ELISA to Distinguish Zika and Dengue Virus Infections.

Serologic testing remains crucial for Zika virus diagnosis. We found that urea wash in a Zika virus nonstructural protein 1 IgG ELISA distinguishes secondary dengue virus infection from Zika virus infection with previous dengue (sensitivity 87.5%, specificity 93.8%). This test will aid serodiagnosis, serosurveillance, and monitoring of Zika complications in dengue-endemic regions.

Validation of the Pockit Dengue Virus Reagent Set for Rapid Detection of Dengue Virus in Human Serum on a Field-Deployable PCR System.

Dengue virus (DENV) infection, a mosquito-borne disease, is a major public health problem in tropical countries. Point-of-care DENV detection with good sensitivity and specificity enables timely early diagnosis of DENV infection, facilitating effective disease management and control, particularly in regions of low resources. The Pockit dengue virus reagent set (GeneReach Biotech), a reverse transcription insulated isothermal PCR (RT-iiPCR), is available to detect all four serotypes of DENV on the field-deployable Pockit system, which is ready for on-site applications. In this study, analytical and clinical performances of the assay were evaluated. The index assay did not react with 14 non-DENV human viruses, indicating good specificity. Compared to the U.S. CDC DENV-1-4 real-time quantitative RT-PCR (qRT-PCR) assay, testing with serial dilutions of virus-spiked human sera demonstrated that the index assay had detection endpoints that were separately comparable with the 4 serotypes. Excellent reproducibility was observed among repeat tests done by six operators at three sites. In clinical performance, 195 clinical sera collected around Kaohsiung city in 2012 and 21 DENV-4-spiked sera were tested with the RT-iiPCR and qRT-PCR assays in parallel. The 121 (11 DENV-1, 78 DENV-2, 11 DENV-3, and 21 DENV-4) qRT-PCR-positive and 95 qRT-PCR-negative samples were all positive and negative by the RT-iiPCR reagent results, respectively, demonstrating high (100%) interrater agreement (95% confidence interval [CI95%], ∼98.81% to 100%; κ = 1). With analytical and clinical performance equivalent to those of the reference qRT-PCR assay, the index PCR assay on the field-deployable system can serve as a highly sensitive and specific on-site tool for DENV detection.

AIDS-related opportunistic illnesses and early initiation of HIV care remain critical in the contemporary HAART era: a retrospective cohort study in Taiwan.

BACKGROUND: No study has reported the epidemiology of AIDS-related opportunistic illnesses (AOIs) in patients with newly diagnosed HIV infection in Taiwan in the past decade. Understanding the current trends in AOI-related morbidity/mortality is essential in improving patient care and optimizing current public health strategies to further reduce AOIs in Taiwan in the era of contemporary highly active antiretroviral therapy (HAART). METHODS: Eligible patients were evaluated at two referral centers between 2010 and 2015. The patients were stratified by date of diagnosis into three periods: 2010-2011, 2012-2013, and 2014-2015. The demographics, HIV stage at presentation according to the United States CDC 2014 case definition, laboratory variables, and the occurrence of AOIs and associated outcomes were compared among the patients. Logistic regression and Cox regression were respectively used to identify variables associated with the occurrence of AOIs within 90 days of HIV enrollment and all-cause mortality. RESULTS: Over a mean observation period of 469 days, 1264 patients with newly diagnosed HIV with a mean age of 29 years and mean CD4 count of 275 cells/µL experienced 394 AOI episodes in 290 events. At presentation, 37.7% of the patients had AIDS; the frequency did not significantly differ across groups. The overall proportion of AOIs within the study period was 21.0%, and no decline across groups was observed. The majority of AOIs (91.7%) developed within 90 days of enrollment. All-cause and AOI-related mortality did not significantly differ across groups. Throughout the three study periods, AOIs remained the main cause of death (47/56, 83.9%), especially within 180 days of enrollment (40/42, 95.2%). A CD4 cell count of < 200 cells/µL at presentation was associated with increased adjusted odds of an AOI within 90 days [adjusted odds ratio, 40.84; 95% confidence intervals (CI), 12.59-132.49] and an elevated adjusted hazard of all-cause mortality (adjusted hazard ratio, 11.03; 95% CI, 1.51-80.64). CONCLUSIONS: Despite efforts toward HIV prevention and management, early HIV care in Taiwan continues to be critically affected by AOI-related morbidity and mortality in the era of contemporary HAART. Additional targeted interventions are required for the earlier diagnosis of patients with HIV.

Distinguishing Secondary Dengue Virus Infection From Zika Virus Infection With Previous Dengue by a Combination of 3 Simple Serological Tests.

BACKGROUND: The explosive spread of Zika virus (ZIKV) and associated microcephaly present an urgent need for sensitive and specific serodiagnostic tests, particularly for pregnant women in dengue virus (DENV)-endemic regions. Recent reports of enhanced ZIKV replication by dengue-immune sera have raised concerns about the role of previous DENV infection on the risk and severity of microcephaly and other ZIKV complications. METHODS: Enzyme-linked immunosorbent assays (ELISAs) based on ZIKV and DENV nonstructural protein 1 (NS1) were established to test acute, convalescent phase, and post-convalescent phase serum/plasma samples from reverse-transcription polymerase chain reaction-confirmed cases including 20 primary ZIKV, 25 ZIKV with previous DENV, 58 secondary DENV, and 16 primary DENV1 infections. RESULTS: ZIKV-NS1 immunoglobulin M (IgM) and immunoglobulin G (IgG) ELISAs combined can detect ZIKV infection with a sensitivity of 95% and specificity of 66.7%. The ZIKV-NS1 IgG cross-reactivity by samples from secondary DENV infection cases ranged from 66.7% to 28.1% (within 1 month to 1-2 years post-illness, respectively). Addition of DENV1-NS1 IgG ELISA can distinguish primary ZIKV infection; the ratio of absorbance of ZIKV-NS1 to DENV1-NS1 IgG ELISA can distinguish ZIKV with previous DENV and secondary DENV infections with a sensitivity of 87.5% and specificity of 81.3%. These findings were supported by analysis of sequential samples. CONCLUSIONS: An algorithm for ZIKV serodiagnosis based on 3 simple ELISAs is proposed to distinguish primary ZIKV, ZIKV with previous DENV, and secondary DENV infections; this could be applied to serodiagnosis for ZIKV, serosurveillance, and monitoring ZIKV infection during pregnancy to understand the epidemiology, pathogenesis, and complications of ZIKV in dengue-endemic regions.

Complexity of Neutralizing Antibodies against Multiple Dengue Virus Serotypes after Heterotypic Immunization and Secondary Infection Revealed by In-Depth Analysis of Cross-Reactive Antibodies.

UNLABELLED: The four serotypes of dengue virus (DENV) cause the most important and rapidly emerging arboviral diseases in humans. The recent phase 2b and 3 studies of a tetravalent dengue vaccine reported a moderate efficacy despite the presence of neutralizing antibodies, highlighting the need for a better understanding of neutralizing antibodies in polyclonal human sera. Certain type-specific (TS) antibodies were recently discovered to account for the monotypic neutralizing activity and protection after primary DENV infection. The nature of neutralizing antibodies after secondary DENV infection remains largely unknown. In this study, we examined sera from 10 vaccinees with well-documented exposure to first and second DENV serotypes through heterotypic immunization with live-attenuated vaccines. Higher serum IgG avidities to both exposed and nonexposed serotypes were found after secondary immunization than after primary immunization. Using a two-step depletion protocol to remove different anti-envelope antibodies, including group-reactive (GR) and complex-reactive (CR) antibodies separately, we found GR and CR antibodies together contributed to more than 50% of neutralizing activities against multiple serotypes after secondary immunization. Similar findings were demonstrated in patients after secondary infection. Anti-envelope antibodies recognizing previously exposed serotypes consisted of a large proportion of GR antibodies, CR antibodies, and a small proportion of TS antibodies, whereas those recognizing nonexposed serotypes consisted of GRand CR antibodies. These findings have implications for sequential heterotypic immunization or primary immunization of DENV-primed individuals as alternative strategies for DENV vaccination. The complexity of neutralizing antibodies after secondary infection provides new insights into the difficulty of their application as surrogates of protection. IMPORTANCE: The four serotypes of dengue virus (DENV) are the leading cause of arboviral diseases in humans. Despite the presence of neutralizing antibodies, a moderate efficacy was recently reported in phase 2b and 3 trials of a dengue vaccine; a better understanding of neutralizing antibodies in polyclonal human sera is urgently needed.We studied vaccinees who received heterotypic immunization of live-attenuated vaccines, as they were known to have received the first and second DENV serotype exposures.We found anti-envelope antibodies consist of group-reactive (GR), complex-reactive (CR), and type-specific (TS) antibodies, and that both GR and CR antibodies contribute significantly to multitypic neutralizing activities after secondary DENV immunization. These findings have implications for alternative strategies for DENV vaccination. Certain TS antibodies were recently discovered to contribute to the monotypic neutralizing activity and protection after primary DENV infection; our findings of the complexity of neutralizing activities after secondary immunization/infection provide new insights for neutralizing antibodies as surrogates of protection.

The impact of HAART initiation timing on HIV-TB co-infected patients, a retrospective cohort study.

BACKGROUND: Optimal timing for initiating highly active antiretroviral therapy (HAART) in HIV-TB coinfected patients is challenging for clinicians. We aim to evaluate the impact of different timing of HAART initiation on TB outcome of HIV-infected adults in Taiwan. METHODS: A population-based retrospective cohort study was conducted through linking the HIV and TB registries of Taiwan Centers for Disease Control (CDC) during 1997 to 2006. Clinical data of HIV-TB co-infected patients, including the presence of immune reconstitution inflammatory syndrome (IRIS), was collected through medical records review. The outcome of interest was all-cause mortality within 1 year following TB diagnosis. The Cox proportional hazard model was used to explore the probability of death and IRIS after TB diagnosis by adjusting for confounding factors and factors of interest. The probability of survival and TB IRIS were calculated by the Kaplan-Meier method and compared between different HAART initiation timing groups by the log-rank test. RESULTS: There were 229 HIV-TB co-infected patients included for analysis and 60 cases (26.2%) died within one year. Besides decreasing age and increasing CD4 lymphocyte count, having started HAART during TB treatment was significantly associated with better survival (adjusted Hazard Ratio was 0.11, 95% CI 0.06-0.21). As to the timing of HAART initiation, there was only non-significant benefit on survival among cases initiating HAART within 15 days, at 16-30 days and at 31-60 days of TB treatment than initiating after 60 days. Cases with HAART initiated after 30 days had lower risk in developing IRIS than cases with HAART initiated earlier. Cases with IRIS had significantly higher rate of re-hospitalization (49% vs. 4%, p < 0.001) and prolonged hospitalization (28 days vs. 18.5 days, p < 0.01). CONCLUSION: The present study found that starting HAART during TB treatment is associated with better one-year survival, although earlier initiation within 60 days of TB treatment did not show statistical differences in survival than later initiation. Initiation of HAART within 30 days appeared to increase the risk of IRIS. Deferring HAART to 31-60 days of TB treatment might be optimal after considering the risks and benefits.

Case report: dengue fever associated acute macular neuroretinopathy.

Dengue fever (DF), which is caused by the dengue virus (DENV) and transmitted through Aedes mosquitoes, is well recognized for its systemic manifestations, with its ocular involvement gaining recent attention. We present a case of a 41-year-old Taiwanese female who developed acute macular neuroretinopathy (AMN) following a DF diagnosis related to DENV-1, emphasizing the need for awareness of this complication. The patient, with a history of completely resolved optic neuritis (ON) and comorbidities, experienced blurred vision on day 10 after the onset of DF. The ophthalmic examination revealed macular edema, ellipsoid zone (EZ) infiltration, and choriocapillaris involvement. Despite pulse therapy with corticosteroids, visual disturbances persisted, highlighting the challenge of managing ocular complications. Ocular manifestations in DF include hemorrhages, inflammation, and vascular complications. DF-associated AMN, a rare presentation, poses challenges in diagnosis and treatment response evaluation. While most patients recover spontaneously, some face persistent visual impairment, especially with AMN. Our case emphasizes the importance of recognizing ocular complications in DF, necessitating a multidisciplinary approach for optimal management and further research to delineate treatment strategies and outcomes.

The epidemiology and phylogenetic trends of Omicron subvariants from BA.5 to XBB.1 in Taiwan.

BACKGROUND: Omicron, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, entered Taiwan at the end of 2021. The Taiwanese government ended its "zero-COVID" policy in March 2022. Multiple coronavirus disease 2019 (COVID-19) outbreaks began in April 2022. We monitored the replacement of Omicron subvariants after BA.1/BA.2 and analyzed their correlation with COVID-19 outbreaks. METHODS: We collected SARS-CoV-2 real-time qRTPCR-positive nasopharyngeal swabs from Kaohsiung Medical University Hospital (KMUH), Kaohsiung City, Taiwan, and performed sequencing for specimens exhibiting a cytopathic effect in Vero E6 cells to determine their clades and lineages. We analyzed the medical records of COVID-19 patients and identified hospitalization risk factor(s). We retrieved SARS-CoV-2 sequences identified in Taiwan from GISAID and analyzed their correlation with COVID-19 data from the Taiwan Centers for Disease Control. RESULTS: We analyzed the phylogenesis of KMUH-47 to KMUH-104 (SARS-CoV-2 isolates identified herein) and all of the Omicron subvariants from BA.5 to XBB.1 (n = 1930). Age and comorbidities were hospitalization risk factors. Men generally exhibited a greater fatality rate than women. COVID-19-related deaths predominantly occurred in individuals over 70 years old. The COVID-19-related case fatality rate increased as nucleotide (NT) and amino acid (AA) substitutions increased. The number of COVID-19-related cases and deaths progressively decreased with each outbreak between August 2022 and October 2023. CONCLUSION: Hospitalization was associated with age and the presence of comorbidities. COVID-19-related fatality was linked to sex, age, and the accumulation of NT and AA substitutions in emerging Omicron subvariants.

Detection of anti-premembrane antibody as a specific marker of four flavivirus serocomplexes and its application to serosurveillance in endemic regions.

In the past few decades, several emerging/re-emerging mosquito-borne flaviviruses have resulted in disease outbreaks of public health concern in the tropics and subtropics. Due to cross-reactivities of antibodies recognizing the envelope protein of different flaviviruses, serosurveillance remains a challenge. Previously we reported that anti-premembrane (prM) antibody can discriminate between three flavivirus infections by Western blot analysis. In this study, we aimed to develop a serological assay that can discriminate infection or exposure with flaviviruses from four serocomplexes, including dengue (DENV), Zika (ZIKV), West Nile (WNV) and yellow fever (YFV) viruses, and explore its application for serosurveillance in flavivirus-endemic countries. We employed Western blot analysis including antigens of six flaviviruses (DENV1, 2 and 4, WNV, ZIKV and YFV) from four serocomplexes. We tested serum samples from YF-17D vaccinees, and from DENV, ZIKV and WNV panels that had been confirmed by RT-PCR or by neutralization assays. The overall sensitivity/specificity of anti-prM antibodies for DENV, ZIKV, WNV, and YFV infections/exposure were 91.7%/96.4%, 91.7%/99.2%, 88.9%/98.3%, and 91.3%/92.5%, respectively. When testing 48 samples from Brazil, we identified multiple flavivirus infections/exposure including DENV and ZIKV, DENV and YFV, and DENV, ZIKV and YFV. When testing 50 samples from the Philippines, we detected DENV, ZIKV, and DENV and ZIKV infections with a ZIKV seroprevalence rate of 10%, which was consistent with reports of low-level circulation of ZIKV in Asia. Together, these findings suggest that anti-prM antibody is a flavivirus serocomplex-specific marker and can be employed to delineate four flavivirus infections/exposure in regions where multiple flaviviruses co-circulate.

Role of cognitive parameters in dengue hemorrhagic fever and dengue shock syndrome.

Dengue is becoming recognized as one of the most important vector-borne human diseases. It is predominant in tropical and subtropical zones but its geographical distribution is progressively expanding, making it an escalating global health problem of today. Dengue presents with spectrum of clinical manifestations, ranging from asymptomatic, undifferentiated mild fever, dengue fever (DF), to dengue hemorrhagic fever (DHF) with or without shock (DSS), a life-threatening illness characterized by plasma leakage due to increased vascular permeability. Currently, there are no antiviral modalities or vaccines available to treat and prevent dengue. Supportive care with close monitoring is the standard clinical practice. The mechanisms leading to DHF/DSS remains poorly understood. Multiple factors have been attributed to the pathological mechanism, but only a couple of these hypotheses are popular in scientific circles. The current discussion focuses on underappreciated factors, temperature, natural IgM, and endotoxin, which may be critical components playing roles in dengue pathogenesis.

Mortality from septic shock in a dengue infected patient: a case report.

Dengue infection can be associated with secondary infections which may be challenging to recognize due to the overlap with the symptoms of dengue infection. We report here the case of a 48 year old Chinese female with dengue fever with a fatal secondary bacterial infection due to Enterococcus faecium.

Spondyloarthritis and nonbacterial thrombotic endocarditis as paraneoplastic manifestations in treatment-naive Burkitt lymphoma.

Non-radiographic axial spondyloarthropathy (nr-axSpA) is a clinical diagnosis of symptoms matching inflammatory back pain criteria without radiological lesions at the sacroiliac joint. The frequency of an early nr-axSpA-like presentation in lymphoma patients has not been clarified. Here we report a woman in her 20s with a fever and musculoskeletal discomfort. Detailed investigations revealed that she was suffering from Burkitt lymphoma in which nr-axSpA-like symptoms were a musculoskeletal manifestation of the disease, irrelevant to the anti-neoplastic treatment.