Accuracy of the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay from the Centers for Disease Control and Prevention (CDC Zika MAC-ELISA) for Diagnosis of Zika Virus Infection

Serological diagnosis of Zika virus (ZIKV) infection is challenging because of antigenic cross-reactivity with dengue virus (DENV). This study evaluated the accuracy of the Zika IgM antibody capture enzyme-linked immunosorbent assay (CDC Zika IgM MAC-ELISA) in differentiating between ZIKV and DENV infections. To determine sensitivity, we used acute- and convalescent-phase sera from 21 patients with RT-PCR-confirmed ZIKV infection. To determine specificity, we used acute- and convalescent-phase sera from 60 RT-PCR-confirmed dengue cases and sera from 23 blood donors. During the acute-phase of the illness, the assay presented a sensitivity of 12.5% (2/16) for samples collected 0–4 days post symptoms onset (DPSO), and of 75.0% (3/4) for samples collected 5–9 DPSO. During the convalescent-phase of the illness, the test sensitivity was 90.9% (10/11), 100% (2/2), and 0% (0/2) for samples obtained 12–102, 258–260, and 722–727 DPSO, respectively. Specificity for acute- and convalescent-phase samples from RT-PCR-confirmed dengue cases was 100% and 93.2%, respectively. Specificity for blood donor samples was 100%. The assay is an accurate method for Zika serological diagnosis and proved to be reliable for use during surveillance and outbreak investigations in settings where ZIKV and DENV cocirculate.</jats:p

Detection of Chikungunya Virus RNA in Oral Fluid and Urine: An Alternative Approach to Diagnosis?

To evaluate whether oral fluids (OF) and urine can serve as alternative, non-invasive samples to diagnose chikungunya virus (CHIKV) infection via RT-qPCR, we employed the same RNA extraction and RT-qPCR protocols on paired serum, OF and urine samples collected from 51 patients with chikungunya during the acute phase of the illness. Chikungunya patients were confirmed through RT-qPCR in acute-phase sera (N = 19), IgM seroconversion between acute- and convalescent-phase sera (N = 12), or IgM detection in acute-phase sera (N = 20). The controls included paired serum, OF and urine samples from patients with non-arbovirus acute febrile illness (N = 28) and RT-PCR-confirmed dengue (N = 16). Nine (47%) of the patients with positive RT-qPCR for CHIKV in sera and two (17%) of those with CHIKV infection confirmed solely via IgM seroconversion had OF positive for CHIKV in RT-qPCR. One (5%) patient with CHIKV infection confirmed via serum RT-qPCR was positive in the RT-qPCR performed on urine. None of the negative control group samples were positive. Although OF may serve as an alternative sample for diagnosing acute chikungunya in specific settings, a negative result cannot rule out an infection. Further research is needed to investigate whether OF and urine collected later in the disease course when serum becomes RT-qPCR-negative may be helpful in CHIKV diagnosis and surveillance, as well as to determine whether urine and OF pose any risk of CHIKV transmission

Accuracy of the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay from the Centers for Disease Control and Prevention (CDC Zika MAC-ELISA) for Diagnosis of Zika Virus Infection

Serological diagnosis of Zika virus (ZIKV) infection is challenging because of antigenic cross-reactivity with dengue virus (DENV). This study evaluated the accuracy of the Zika IgM antibody capture enzyme-linked immunosorbent assay (CDC Zika IgM MAC-ELISA) in differentiating between ZIKV and DENV infections. To determine sensitivity, we used acute- and convalescent-phase sera from 21 patients with RT-PCR-confirmed ZIKV infection. To determine specificity, we used acute- and convalescent-phase sera from 60 RT-PCR-confirmed dengue cases and sera from 23 blood donors. During the acute-phase of the illness, the assay presented a sensitivity of 12.5% (2/16) for samples collected 0&ndash;4 days post symptoms onset (DPSO), and of 75.0% (3/4) for samples collected 5&ndash;9 DPSO. During the convalescent-phase of the illness, the test sensitivity was 90.9% (10/11), 100% (2/2), and 0% (0/2) for samples obtained 12&ndash;102, 258&ndash;260, and 722&ndash;727 DPSO, respectively. Specificity for acute- and convalescent-phase samples from RT-PCR-confirmed dengue cases was 100% and 93.2%, respectively. Specificity for blood donor samples was 100%. The assay is an accurate method for Zika serological diagnosis and proved to be reliable for use during surveillance and outbreak investigations in settings where ZIKV and DENV cocirculate

Presence of dengue virus RNA in urine and oral fluid of laboratory-confirmed dengue patients: Implications for wastewater surveillance

Introduction: Dengue cases in the Americas in 2024 have reached record highs, especially in Brazil. However, surveillance remains suboptimal and new methods are needed to monitor Dengue Virus (DENV) spread. To assess whether wastewater-based epidemiology would be a useful tool, we investigated the presence of DENV RNA in dengue patients’ urine and oral fluid from an endemic area to inform how shedding in these fluids occurs and provide insight for wastewater surveillance. Methods: We examined how often DENV RNA is detected in urine and oral fluid from dengue patients confirmed by serum RT-qPCR, NS1 ELISA or IgM seroconversion in Salvador, Brazil. Results: Of 88 confirmed cases, 9.1 % were positive for DENV RNA in urine (7/88) or oral fluid (1/88). Of 53 serum RT-qPCR-positive patients, 6 (11.3 %) showed detectable DENV RNA in acute- or convalescent-phase urine. Patients with RT-qPCR-positive urine had a lower frequency of DENV IgG in acute-phase serum (a proxy for secondary infection) (57 % vs. 74 %) and a lower median serum RT-qPCR cycle threshold than those with negative urine (21.8 vs. 23.9). Conclusion: The low presence of DENV RNA in urine suggests that additional research is needed to evaluate whether using wastewater-based epidemiology to monitor DENV transmission is possible

Does immunity after Zika virus infection cross-protect against dengue?

Brazilian National Council for Scientific and Technological Development (grant 550160/2010-8 to MGR, grants 400830/2013-2 and 440891/2016-

Chikungunya chronic arthralgia: impact on general and mental health and absenteeism from work

ABSTRACT Background: This study investigated the self-rated general health, mental health, and work absenteeism among patients with laboratory-confirmed chikungunya. Methods: Telephone interviews were conducted with 63 patients ≥22 months after infection. Results: Patients who reported (N=42) or did not report (N=21) chronic arthralgia, defined by duration ≥90 days, had different frequencies for low scores for general health (68.3% vs. 30.0%, respectively; prevalence ratio, 95% confidence interval: 2.3, 1.1-4.6), symptoms of depression (31.7% vs. 15.0%; 2.1, 0.7-6.6), symptoms of anxiety (43.9% vs. 35.0%; 1.3, 0.6-2.5), and work absenteeism (76.5% and 40.0%; 1.9, 0.9-4.2). Conclusions: Chikungunya chronic arthralgia impacts long-term health and work

Density of Aedes aegypti (Diptera: Culicidae) in a low-income Brazilian urban community where dengue, Zika, and chikungunya viruses co-circulate

Abstract Background Low-income urban communities in the tropics often lack sanitary infrastructure and are overcrowded, favoring Aedes aegypti proliferation and arboviral transmission. However, as Ae. aegypti density is not spatially homogeneous, understanding the role of specific environmental characteristics in determining vector distribution is critical for planning control interventions. The objectives of this study were to identify the main habitat types for Ae. Aegypti, assess their spatial densities to identify major hotspots of arbovirus transmission over time and investigate underlying factors in a low-income urban community in Salvador, Brazil. We also tested the field-collected mosquitoes for arboviruses. Methods A series of four entomological and socio-environmental surveys was conducted in a random sample of 149 households and their surroundings between September 2019 and April 2021. The surveys included searching for potential breeding sites (water-containing habitats) and for Ae. aegypti immatures in them, capturing adult mosquitoes and installing ovitraps. The spatial distribution of Ae. aegypti density indices were plotted using kernel density-ratio maps, and the spatial autocorrelation was assessed for each index. Visual differences on the spatial distribution of the Ae. aegypti hotspots were compared over time. The association of entomological findings with socio-ecological characteristics was examined. Pools of female Ae. aegypti were tested for dengue, Zika and chikungunya virus infection. Results Overall, 316 potential breeding sites were found within the study households and 186 in the surrounding public spaces. Of these, 18 (5.7%) and 7 (3.7%) harbored a total of 595 and 283 Ae. aegypti immatures, respectively. The most productive breeding sites were water storage containers within the households and puddles and waste materials in public areas. Potential breeding sites without cover, surrounded by vegetation and containing organic matter were significantly associated with the presence of immatures, as were households that had water storage containers. None of the entomological indices, whether based on immatures, eggs or adults, detected a consistent pattern of vector clustering in the same areas over time. All the mosquito pools were negative for the tested arboviruses. Conclusions This low-income community displayed high diversity of Ae. aegypti habitats and a high degree of heterogeneity of vector abundance in both space and time, a scenario that likely reflects other low-income communities. Improving basic sanitation in low-income urban communities through the regular water supply, proper management of solid wastes and drainage may reduce water storage and the formation of puddles, minimizing opportunities for Ae. aegypti proliferation in such settings. Graphical Abstrac

Does immunity after Zika virus infection cross-protect against dengue?

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2018-03-15T13:47:18Z No. of bitstreams: 1 Ribeiro GS Does immunity after Zika virus infection....pdf: 349909 bytes, checksum: 6c4e81ba8f9ba41c4283097fe22dcc18 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2018-03-15T14:12:33Z (GMT) No. of bitstreams: 1 Ribeiro GS Does immunity after Zika virus infection....pdf: 349909 bytes, checksum: 6c4e81ba8f9ba41c4283097fe22dcc18 (MD5)Made available in DSpace on 2018-03-15T14:12:33Z (GMT). No. of bitstreams: 1 Ribeiro GS Does immunity after Zika virus infection....pdf: 349909 bytes, checksum: 6c4e81ba8f9ba41c4283097fe22dcc18 (MD5) Previous issue date: 2018Brazilian National Council for Scientific and Technological Development (grant 550160/2010-8 to MGR, grants 400830/2013-2 and 440891/2016-7Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Secretaria Municipal de Saúde de Salvador. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Yale University. New Haven, CT, USAEmory University. Atlanta, GA, USA / University of Texas Medical Branch. Galveston, TX, USAFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, BrasilFundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasi

Evaluation of two commercially available chikungunya virus IgM enzyme-linked immunoassays (ELISA) in a setting of concomitant transmission of chikungunya, dengue and Zika viruses

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2019-12-10T17:38:28Z No. of bitstreams: 1 Kikuti M Evaluation...pdf: 366431 bytes, checksum: 068dafd1d3db10c2333615678a271257 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2019-12-10T17:51:29Z (GMT) No. of bitstreams: 1 Kikuti M Evaluation...pdf: 366431 bytes, checksum: 068dafd1d3db10c2333615678a271257 (MD5)Made available in DSpace on 2019-12-10T17:51:29Z (GMT). No. of bitstreams: 1 Kikuti M Evaluation...pdf: 366431 bytes, checksum: 068dafd1d3db10c2333615678a271257 (MD5) Previous issue date: 2019-01-05Brazilian National Council for Scientific and Technological Development (grants 400830/2013-2 and 440891/2016-7 to GSR; and scholarships to UK, MGR, and GSR); the Bahia Foundation for Research Support (grants PET0026/ 2013, APP0044/2016, and PET0022/2016 to GSR); the Coordination for the Improvement of Higher Education Personnel, Brazilian Ministry of Education (grant 88887.130746/2016-00 to GSR and scholarship to MK); the Oswaldo Cruz Foundation; the Federal University of Bahia; and the Department of Science and Technology, Secretariat of Science, Technology and Strategic Inputs, Brazilian Ministry of Health.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Instituto de Biología Subtropical. Nodo Iguazú. Puerto Iguazu, Misiones, Argentina.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Universidade Federal da Bahia. Salvador, BA, Brasil.University of Texas Medical Branch. Galveston, TX, USA.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Emory University. Atlanta, GA, USA.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Salvador, BA, Brasil.To evaluate the diagnostic performance of the Inbios (Seattle, US) and Euroimmun (Luebeck, Germany) chikungunya virus (CHIKV) IgM enzyme-linked immunoassays (ELISAs). Methods: We evaluated the tests’ accuracy on sera from 372 patients enrolled in an acute febrile illness surveillance study performed in Salvador, Brazil from Sept/2014 to Jul/2016, a period of simultaneous CHIKV, dengue (DENV), and Zika (ZIKV) virus transmission. We assessed the sensitivity on acute and paired convalescent sera from RT-PCR-confirmed CHIKV cases (collected at median one and 19 days postonset of symptoms, respectively), and the specificity on sera of RT-PCR-confirmed DENV and ZIKV cases, and on negative patients. Results: The Inbios and Euroimmun tests’ sensitivities for acute samples were 4.0% and 10.3%, while for convalescent samples they were 92.4% and 96.9%, respectively. Overall, Inbios IgM ELISA specificities for acute and convalescent samples were 97.7% and 90.5%, respectively, and Euroimmun specificities were 88.5% and 83.9%, respectively. Conclusions: Both tests presented high sensitivity for convalescent samples. However, the Euroimmun test returned more equivocal results and presented a slightly lower specificity, which might result in a higher rate of false positives if the test is used in scenarios of low CHIKV transmission, when the chance of CHIKV infection is lower