RESUMEN
SARS-CoV-2 caused the pandemic situation experienced since the beginning of 2020, and many countries faced the rapid spread and severe form of the disease. Mechanisms of interaction between the virus and the host were observed during acute phase, but few data are available when related to immunity dynamics in convalescents. We conducted a longitudinal study, with 51 healthy donors and 62 COVID-19 convalescent patients, which these had a 2-month follow-up after symptoms recovery. Venous blood sample was obtained from all participants to measure blood count, subpopulations of monocytes, lymphocytes, natural killer cells and dendritic cells. Serum was used to measure cytokines, chemokines, growth factors, anti-N IgG and anti-S IgG/IgM antibodies. Statistic was performed by Kruskal-Wallis test, and linear regression with days post symptoms and antibody titers. All analysis had confidence interval of 95%. Less than 35% of convalescents were anti-S IgM+, while more than 80% were IgG+ in D30. Anti-N IgG decreased along time, with loss of seroreactivity of 13%. Eosinophil count played a distinct role on both antibodies during all study, and the convalescence was orchestrated by higher neutrophil-to-lymphocyte ratio and IL-15, but initial stages were marked by increase in myeloid DCs, B1 lymphocytes, inflammatory and patrolling monocytes, G-CSF and IL-2. Later convalescence seemed to change to cytotoxicity mediated by T lymphocytes, plasmacytoid DCs, VEGF, IL-9 and CXCL10. Anti-S IgG antibodies showed the longest perseverance and may be a better option for diagnosis. The inflammatory pattern is yet present on initial stage of convalescence, but quickly shifts to a reparative dynamic. Meanwhile eosinophils seem to play a role on anti-N levels in convalescence, although may not be the major causative agent. We must highlight the importance of immunological markers on acute clinical outcomes, but their comprehension to potentialize adaptive system must be explored to improve immunizations and further preventive policies.
Asunto(s)
Anticuerpos Antivirales , COVID-19 , Convalecencia , Citocinas , Inmunoglobulina G , SARS-CoV-2 , Humanos , COVID-19/inmunología , COVID-19/sangre , Masculino , Femenino , Adulto , Persona de Mediana Edad , SARS-CoV-2/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Citocinas/sangre , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Estudios Longitudinales , Anciano , Eosinófilos/inmunología , Eosinófilos/metabolismoRESUMEN
Sporotrichosis diagnosis involves a series of analyses, including culture and antibody detection in serum samples. Serologic methods may sometimes yield false-negative or false-positive results, leading to inaccurate diagnoses. This study assessed specific patient groups in which antibody detection of different isotypes and subclasses may lack sensitivity. An enzyme-linked immunosorbent assay (ELISA) with Sporothrix brasiliensis exoantigens was used to investigate IgM, IgG, IgG1, IgG2, IgG3, IgG4, IgA, IgA1 and IgA2 antibodies in human serum samples. Eighty serum samples from patients with different sporotrichosis clinical manifestations, including cutaneous forms with and without hypersensitivity manifestations, extracutaneous forms (bone, ocular, meningeal and pulmonary), disseminated cutaneous forms and disseminated forms in individuals living with HIV/AIDS, diabetics and alcoholics, were evaluated. The ELISA sensitivities in the detection of different antibodies ranged from 0.85 to 0.60 for the detection of IgG2 and IgG3, respectively. The antibodies with higher area under ROC curves were IgG2, IgG, IgA and IgA1. There were no significant differences in the immunological reactivity of the tested antibodies among different clinical forms of sporotrichosis. The data revealed a higher likelihood of a false-negative outcome in patients with lesions in the nasal mucosa regarding the detection of IgM and a lower likelihood in patients with lymphocutaneous sporotrichosis regarding the detection of IgG3. Patients with hypersensitivity manifestations had a 3.71 odds ratio to yield negative results in total IgG detection. In conclusion, we identified specific patient groups in which antibody detection may lack sensitivity, thus contributing to a better understanding of the diagnostic challenges associated with this condition.
Asunto(s)
Anticuerpos Antifúngicos , Ensayo de Inmunoadsorción Enzimática , Sensibilidad y Especificidad , Sporothrix , Esporotricosis , Humanos , Esporotricosis/inmunología , Esporotricosis/diagnóstico , Anticuerpos Antifúngicos/sangre , Sporothrix/inmunología , Sporothrix/clasificación , Masculino , Femenino , Adulto , Persona de Mediana Edad , Isotipos de Inmunoglobulinas/sangre , Isotipos de Inmunoglobulinas/inmunología , Inmunoglobulina G/sangre , Anciano , Adulto Joven , Antígenos Fúngicos/inmunología , Antígenos Fúngicos/sangre , Inmunoglobulina A/sangre , Inmunoglobulina M/sangreRESUMEN
BACKGROUND: PPE 59, which is absent from bacillus Calmette Guérin (BCG) strains, seems to induce a humoral immune response in patients with tuberculosis (TB). Additional studies are needed to better evaluate this protein in immune response to tuberculosis. OBJECTIVES: To evaluate the response of antibodies to PPE59 in TB individuals, its combination with IgG response to other, previously tested mycobacterial antigens (Ag) and with sputum smear microbiology (SM) results. METHODS: We have cloned and expressed the rv3429 gene that encodes PPE59, then IgG, IgM, and IgA against PPE59 antigens measured by enzyme-linked immunosorbent assay (ELISA) in 212 sera samples obtained from the following subject cohorts: TB residents from Italy (79) and in Brazil (52); and an all-Brazilian cohort of 55 patients with other respiratory disorders; 10 patients infected with non-tuberculous mycobacteria, and 16 asymptomatic subjects. Drawing on results from a previous study(17) of serum samples from Brazilian subjects tested for IgG by ELISA against mycobacterial antigens ESAT-6, 16kDa, MT10.3, MPT-64 and 38kDa, the results were analysed in combination with those of the PPE59 and SM tests. FINDINGS: Keeping the specificity rate at 97%, the overall PPE59 IgA sensitivity was 42.7%, while IgG and IgM showed lower performance (p < 0.0001). Combining PPE59 IgA/16kDa IgG results increased sensitivity to 71%, and even higher rates when the results were combined with SM results (86.5%, p = 0.001), at 88.9% specificity. Positive IgA was associated with pulmonary image alterations of high TB probability (p < 0.05). MAIN CONCLUSIONS: Tests with TB patients found a moderate frequency of positivity for PPE59 IgA. However, the higher level of sensitivity attained in combination with PPE59 IgA/16kDa IgG/SM results unheard of before, although imperfect, suggests that this may be a potential additional tool for rapid detection of TB in low-resource areas.
Asunto(s)
Anticuerpos Antibacterianos , Antígenos Bacterianos , Biomarcadores , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina A , Inmunoglobulina G , Inmunoglobulina M , Humanos , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Femenino , Biomarcadores/sangre , Adulto , Inmunoglobulina A/sangre , Sensibilidad y Especificidad , Persona de Mediana Edad , Mycobacterium tuberculosis/inmunología , Tuberculosis/diagnóstico , Tuberculosis/inmunología , Tuberculosis/sangre , Adulto Joven , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/sangre , Esputo/microbiología , Brasil , Proteínas Bacterianas/inmunología , Anciano , Adolescente , Estudios de CohortesRESUMEN
BACKGROUND: In Brazil, despite the increase in coverage and access to rapid testing for syphilis in primary health care, no reduction in cases of syphilis and congenital syphilis was observed. Poor and low-educated populations are disproportionately affected by infection caused by T. pallidum. This study aims to estimate the prevalence of syphilis and associated factors among people aged 18 to 49 years old in the city of Belém, brazilian amazon. METHODS: Observational, cross-sectional study carried out in a sanitary administrative district of a capital of the Brazilian Amazon, Belém, state of Pará, Brazil. Data collection was conducted from August 2021 to February 2022. The participantes consisted of residents of the Montese, Guamá and Condor neighborhoods. People aged 18 to 49 years were included. This variable was treated as dichotomous (reagent and non-reagent). The selected response event was 'reagent result'. The independent variables were the social factors and access to health services. To identify associated factors with the presence of markers of the bacteria studied, multiple logistic rules were performed. RESULTS: 178 people participated in the study; the median age was 35.0 years. The prevalence of IgG and/or IgM antibodies against T. pallidum was 7 % (13). In the final regression model, it was observed that participants who had sexual intercourse after using alcohol and drugs and those who did not know about the prevention of sexually transmitted infections were five times more likely to have tested positive for T. pallidum. CONCLUSIONS: Aspects of individual vulnerability and access to health services must be managed to reduce the exposure of poor urban populations to T. pallidum.
Asunto(s)
Sífilis , Treponema pallidum , Población Urbana , Humanos , Brasil/epidemiología , Adulto , Estudios Transversales , Masculino , Persona de Mediana Edad , Femenino , Adulto Joven , Adolescente , Prevalencia , Sífilis/epidemiología , Población Urbana/estadística & datos numéricos , Treponema pallidum/inmunología , Factores de Riesgo , Anticuerpos Antibacterianos/sangre , Pobreza , Inmunoglobulina M/sangre , Inmunoglobulina G/sangreRESUMEN
Three lateral flow immunoassay prototypes developed to detect IgM, IgG and IgM/IgG antibodies against Hantavirus were evaluated. A total of 163 samples were tested: 10 from Hantavirus patients, 103 from related diseases, and 50 from healthy controls. The prototypes exhibited 100 % sensitivity, 97.5 % to 99.3 % specificity, indicating promising improved diagnosis.
Asunto(s)
Anticuerpos Antivirales , Infecciones por Hantavirus , Inmunoglobulina G , Inmunoglobulina M , Orthohantavirus , Sensibilidad y Especificidad , Inmunoglobulina M/sangre , Humanos , Inmunoglobulina G/sangre , Anticuerpos Antivirales/sangre , Infecciones por Hantavirus/diagnóstico , Infecciones por Hantavirus/inmunología , Orthohantavirus/inmunología , Inmunoensayo/métodosRESUMEN
PURPOSE: The current diagnostic methods for leptospirosis diagnosis are technically complex and expensive, with limited applicability to specialized laboratories. Furthermore, they lack diagnostic accuracy in the acute stage of the disease, which coincides with a period when antibiotics are highly effective. New simple and accurate tests are mandatory to decentralize and improve diagnosis. Here, we introduced a new lateral flow immunoassay (Lepto-LF) for human leptospirosis. METHODS: We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR). RESULTS: Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo). CONCLUSION: Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available.
Asunto(s)
Anticuerpos Antibacterianos , Ensayo de Inmunoadsorción Enzimática , Leptospirosis , Sensibilidad y Especificidad , Humanos , Leptospirosis/diagnóstico , Leptospirosis/sangre , Anticuerpos Antibacterianos/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoensayo/métodos , Inmunoensayo/normas , Leptospira/inmunología , Leptospira/aislamiento & purificación , Inmunoglobulina M/sangre , Masculino , Femenino , Adulto , Persona de Mediana Edad , Método Doble Ciego , Pruebas de Aglutinación/métodos , Adulto JovenRESUMEN
Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis. Firstly, a serological panel was constructed in the Brazilian Reference Laboratory for Leptospirosis using samples routinely handled by reference laboratories of six Brazilian states. It consisted of 150 positive (according to MAT and IgM-ELISA) and 250 negative samples for leptospirosis. Subsequently, the panel samples were distributed to the reference laboratories for the performance of DPP assays in triplicate. Different measures were used in the assessment of diagnostic quality. Predictive values were estimated for different pre-test probability settings. Sensitivities varied between 67.33 % and 74.00 % and specificities between 93.20 % and 98.40 % in the states, and there were adequate agreements between them. Accuracies were lower for the samples of patients with less than 7 days of symptoms. In contexts of prevalence values up to around 25 %, positive and negative predictive values were around 90 %. However, in situations of high pre-test probabilities, NPVs were low. This study improves understanding of the use of DPP in diagnosing leptospirosis, particularly its application in healthcare settings. As long as the time of symptoms onset and clinical and epidemiological contexts are adequately considered for the interpretation of results, DPP is a valid option to be used in the leptospirosis diagnostic routine.
Asunto(s)
Anticuerpos Antibacterianos , Leptospirosis , Sensibilidad y Especificidad , Humanos , Anticuerpos Antibacterianos/sangre , Brasil/epidemiología , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina M/sangre , Leptospira/aislamiento & purificación , Leptospira/inmunología , Leptospirosis/sangre , Leptospirosis/diagnóstico , Leptospirosis/inmunología , Leptospirosis/microbiología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Pruebas Serológicas/métodosRESUMEN
Neurological involvement has been widely reported in SARS-CoV-2 infection. However, viral identification in the cerebrospinal fluid (CSF) is rarely found. The aim of this study is to evaluate the accuracy of virological and immunological biomarkers in CSF for the diagnosis of neuroCOVID-19. We analyzed 69 CSF samples from patients with neurological manifestations: 14 with suspected/confirmed COVID-19, with 5 additional serial CSF samples (group A), and as a control, 50 non-COVID-19 cases (group B-26 with other neuroinflammatory diseases; group C-24 with non-inflammatory diseases). Real-time reverse-transcription polymerase chain reaction (real-time RT-PCR) was used to determine SARS-CoV-2, and specific IgG, IgM, neopterin, and protein 10 induced by gamma interferon (CXCL-10) were evaluated in the CSF samples. No samples were amplified for SARS-CoV-2 by real-time RT-PCR. The sensitivity levels of anti-SARS-CoV-2 IgG and IgM were 50% and 14.28%, respectively, with 100% specificity for both tests. CXCL-10 showed high sensitivity (95.83%) and specificity (95.83%) for detection of neuroinflammation. Serial CSF analysis showed an association between the neuroinflammatory biomarkers and outcome (death and hospital discharge) in two cases (meningoencephalitis and rhombencephalitis). The detection of SARS-CoV-2 RNA and specific immunoglobulins in the CSF can be used for neuroCOVID-19 confirmation. Additionally, CXCL-10 in the CSF may contribute to the diagnosis and monitoring of neuroCOVID-19.
Asunto(s)
Anticuerpos Antivirales , Biomarcadores , COVID-19 , Quimiocina CXCL10 , Inmunoglobulina G , Inmunoglobulina M , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , COVID-19/líquido cefalorraquídeo , COVID-19/virología , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/genética , Masculino , Persona de Mediana Edad , Femenino , Inmunoglobulina G/líquido cefalorraquídeo , Inmunoglobulina G/sangre , Adulto , Inmunoglobulina M/líquido cefalorraquídeo , Inmunoglobulina M/sangre , Anciano , Biomarcadores/líquido cefalorraquídeo , Quimiocina CXCL10/líquido cefalorraquídeo , Anticuerpos Antivirales/líquido cefalorraquídeo , Anticuerpos Antivirales/sangre , Sensibilidad y Especificidad , Neopterin/líquido cefalorraquídeo , Anciano de 80 o más Años , Enfermedades del Sistema Nervioso/diagnóstico , Enfermedades del Sistema Nervioso/virología , Enfermedades del Sistema Nervioso/líquido cefalorraquídeo , Adulto JovenRESUMEN
The IgG response against SARS-CoV-2 infection can persist for over six months (long response; LR). However, among 30% of those infected, the duration can be as short as three months or less (short response; SR). The present study assembled serological data on the anti-SARS-CoV-2 IgG response duration of two previous studies and integrated these results with the plasmatic cytokine levels and genetic profile of 10 immune-relevant SNPs that were also previously published, along with the plasmatic total IgG, IgA, and IgM levels, allowing for the genetic, clinical, immunological, and epidemiological aspects of the post-COVID-19 IgG response duration to be understood. The SR was associated with previous mild acute COVID-19 and with an SNP (rs2228145) in IL6R related to low gene expression. Additionally, among the SR subgroup, no statistically significant Spearman correlations were observed between the plasma levels of IL-17A and the Th17 regulatory cytokines IFN-γ (rs = 0.2399; p = 0.1043), IL-4 (rs = 0.0273; p = 0.8554), and IL-2 (rs = 0.2204; p = 0.1365), while among the LR subgroup, weaker but statistically significant Spearman correlations were observed between the plasma levels of IL-17A and IFN-γ (rs = 0.3873; p = 0.0016), IL-4 (rs = 0.2671; p = 0.0328), and IL-2 (rs = 0.3959; p = 0.0012). These results suggest that the Th17 response mediated by the IL-6 pathway has a role in the prolonged IgG response to SARS-CoV-2 infection.
Asunto(s)
Anticuerpos Antivirales , COVID-19 , Inmunoglobulina G , Polimorfismo de Nucleótido Simple , SARS-CoV-2 , Humanos , COVID-19/inmunología , COVID-19/epidemiología , COVID-19/sangre , COVID-19/virología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , SARS-CoV-2/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Masculino , Femenino , Receptores de Interleucina-6/genética , Persona de Mediana Edad , Adulto , Interleucina-17/sangre , Interleucina-17/genética , Citocinas/sangre , Inmunoglobulina A/sangre , Interferón gamma/sangre , Interferón gamma/genética , Inmunoglobulina M/sangre , Interleucina-4/sangre , Interleucina-4/genética , AncianoRESUMEN
Introduction: Coronavirus Disease 2019 (COVID-19) is a severe respiratory illness caused by the RNA virus SARS-CoV-2. Globally, there have been over 759.4 million cases and 6.74 million deaths, while Ecuador has reported more than 1.06 million cases and 35.9 thousand deaths. To describe the COVID-19 pandemic impact and the vaccinations effectiveness in a low-income country like Ecuador, we aim to assess the seroprevalence of IgG and IgM antibodies against SARS-CoV-2 in a sample from healthy blood donors at the Cruz Roja Ecuatoriana. Methods: The present seroprevalence study used a lateral flow immunoassay (LFIA) to detect anti-SARS-CoV-2 IgG and IgM antibodies in months with the highest confirmed case rates (May 2020; January, April 2021; January, February, June, July 2022) and months with the highest vaccination rates (May, June, July, August, December 2021) in Quito, Ecuador. The IgG and IgM seroprevalence were also assessed based on sex, age range, blood type and RhD antigen type. The sample size was 8,159, and sampling was performed based on the availability of each blood type. Results: The results showed an overall IgG and IgM seroprevalence of 47.76% and 3.44%, respectively. There were no differences in IgG and IgM seroprevalences between blood groups and sex, whereas statistical differences were found based on months, age range groups, and RhD antigen type. For instance, the highest IgG seroprevalence was observed in February 2022 and within the 17-26 years age range group, while the highest IgM seroprevalence was in April 2021 and within the 47-56 years age range group. Lastly, only IgG seroprevalence was higher in RhD+ individuals while IgM seroprevalence was similar across RhD types. Discussion: This project contributes to limited data on IgG and IgM antibodies against SARS-CoV-2 in Ecuador. It suggests that herd immunity may have been achieved in the last evaluated months, and highlights a potential link between the RhD antigen type and COVID-19 susceptibility. These findings have implications for public health strategies and vaccine distribution not only in Ecuador but also in regions with similar characteristics.
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Anticuerpos Antivirales , Donantes de Sangre , COVID-19 , Inmunoglobulina G , Inmunoglobulina M , SARS-CoV-2 , Humanos , COVID-19/epidemiología , COVID-19/inmunología , Ecuador/epidemiología , Inmunoglobulina G/sangre , Estudios Seroepidemiológicos , Inmunoglobulina M/sangre , Masculino , SARS-CoV-2/inmunología , Adulto , Donantes de Sangre/estadística & datos numéricos , Anticuerpos Antivirales/sangre , Femenino , Persona de Mediana Edad , Adolescente , Adulto Joven , Anciano , PandemiasRESUMEN
BACKGROUND: The indigenous population located in the central region of Brazil, is the second largest in terms of population size in the country. The Indigenous Reserve of Dourados has risk factors that increase the vulnerability of the indigenous population to infectious diseases, especially Human alphaherpesvirus (HSV-1), a neglected disease with high prevalence in priority populations in developing countries. The virus can also cause many more severe diseases, including widespread neonatal infections, herpetic keratitis, and herpes encephalitis, which can be fatal if left untreated. We estimated the prevalence of anti-HSV-1 antibodies and correlated it with the demographic and behavioral characteristics of the Indigenous population of the Jaguapirú and Bororó villages (Dourados, Mato Grosso do Sul (MS), Brazil). METHODS: Our approach was cross-sectional. From March 2017 to November 2018. Using anti-HSV-1 (Gg1) IgM and anti-HSV-1 (gG1) IgG Euroimmun and the detection and quantification of HSV-1 viral load in plasma samples, through real-time PCR. The maps were constructed using QGIS and the statistical analyses using R Studio software. RESULTS: A total of 1138 individuals (> 18 years old) were enrolled. The prevalence of anti-HSV-1 IgM and IgG were 20% and 97.5%, respectively. The prevalence of anti-HSV-1 antibodies for IgG was higher in both sexes. Anti-HSV-1 IgM antibodies were present in 17.1%, 21.2%, 12.5%, and 22% of the participants with urinary problems, genital wounds, genital warts, and urethral discharge, respectively. Real-time PCR was used for confirmatory testing; HSV-1 DNA was detected in 25.6% (54/211) of anti-HSV1 IgM-positive samples. Viral loads ranged from 5.99E + 02 to 3.36E + 13. CONCLUSIONS: The seroprevalence of HSV-1 IgM and detection of HSV-1 DNA in the Indigenous population confirmed high silent prevalence. Furthermore, the seroprevalence of HSV-1 in the Indigenous population was higher than that reported in the general adult Brazilian population. Various socioeconomic factors, drug use, and health and sexual behaviors could contribute to the facilitation of HSV-1 transmission in the Indigenous population. Our results may help develop culturally appropriate intervention programs that eliminate health access barriers and improve the implementation of public health policies aimed at promoting information regarding the prevention, treatment, and control of HSV-1 infection in Brazilian Indigenous populations.
Asunto(s)
Anticuerpos Antivirales , Herpes Simple , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Anticuerpos Antivirales/sangre , Brasil/epidemiología , Estudios Transversales , Herpes Simple/epidemiología , Herpes Simple/virología , Herpesvirus Humano 1/inmunología , Herpesvirus Humano 1/genética , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Indígenas Sudamericanos/estadística & datos numéricos , Prevalencia , Carga ViralRESUMEN
In response to the 2015 Zika virus (ZIKV) epidemic that occurred in Brazil, numerous commercial serological assays have been developed for clinical and research applications. Diagnosis of recent infection in pregnant women remains challenging. Having standardized, comparative studies of ZIKV tests is important for implementing optimal diagnostic testing and disease surveillance. This is especially important for serology tests used to detect ZIKV infection given that antibodies against ZIKV can cross-react with other arboviruses in the same virus family, such as dengue virus (DENV), yellow fever virus (YFV) and West Nile virus (WNV). We looked at the sensitivity and specificity of tests detecting ZIKV antibodies (IgM, IgG) from multiple manufacturers using panels of samples previously collected with known exposure to ZIKV and other arboviruses. We found that performance of the IgM tests was highly variable, with only one test (Inbios 2.0 IgM capture ELISA) having both high sensitivity and specificity. All IgG tests showed good sensitivity; however, specificity was highly variable, with some assays giving false-positive results on samples infected by another flavivirus. Overall, the results confirmed that accurate ZIKV antibody testing is challenging, especially in specimens from regions endemic for multiple other flaviviruses, and highlight the importance of available and suitable reference samples to evaluate ZIKV diagnostics.
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Anticuerpos Antivirales , Inmunoglobulina G , Inmunoglobulina M , Sensibilidad y Especificidad , Pruebas Serológicas , Infección por el Virus Zika , Virus Zika , Humanos , Virus Zika/inmunología , Infección por el Virus Zika/diagnóstico , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/sangre , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Pruebas Serológicas/métodos , Pruebas Serológicas/normas , Inmunoglobulina M/sangre , Inmunoglobulina G/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/normas , Reacciones Cruzadas/inmunología , Femenino , Embarazo , BrasilRESUMEN
The main social impact of toxoplasmosis stems from its ability to be vertically transmitted. Postnatally acquired infection is generally asymptomatic in approximately 70-90% of cases, making diagnosis often dependent on laboratory tests using serological methods to search for anti-T. gondii antibodies. This study aimed to investigate the ability of the VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays to confirm recent toxoplasmosis. In total, 341 pregnant women with suspected acute toxoplasmosis were systematically monitored in the Program for Control of Congenital Toxoplasmosis in Minas Gerais State, Brazil. We conducted an observational analytical-descriptive cross-sectional study and grouped according to clinical and laboratory criteria as having acute or chronic toxoplasmosis. The VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays were evaluated to investigate the capacity to identify acute infection. IgG avidity showed good performance in identifying acute toxoplasmosis when the IgG avidity index was lower than or equal to 0.1. Values greater than or equal to 3.16 according to the TOXO IgM kit were associated with a greater chance of acute infection. These results may contribute to a more adequate diagnosis of acute gestational toxoplasmosis and, consequently, the avoidance of inadequate or unnecessary treatments.
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Anticuerpos Antiprotozoarios , Afinidad de Anticuerpos , Inmunoglobulina G , Inmunoglobulina M , Complicaciones Parasitarias del Embarazo , Toxoplasmosis Congénita , Humanos , Femenino , Embarazo , Inmunoglobulina M/sangre , Estudios Transversales , Inmunoglobulina G/sangre , Anticuerpos Antiprotozoarios/sangre , Toxoplasmosis Congénita/diagnóstico , Toxoplasmosis Congénita/inmunología , Complicaciones Parasitarias del Embarazo/diagnóstico , Complicaciones Parasitarias del Embarazo/inmunología , Enfermedad Aguda , Adulto , Toxoplasma/inmunología , Toxoplasmosis/diagnóstico , Toxoplasmosis/inmunología , Adulto Joven , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: This study aims to develop and validate predictive models that assess the risk of leprosy development among contacts, contributing to an enhanced understanding of disease occurrence in this population. METHODS: A cohort of 600 contacts of people with leprosy treated at the National Reference Center for Leprosy and Health Dermatology at the Federal University of Uberlândia (CREDESH/HC-UFU) was followed up between 2002 and 2022. The database was divided into two parts: two-third to construct the disease risk score and one-third to validate this score. Multivariate logistic regression models were used to construct the disease score. RESULTS: Of the four models constructed, model 3, which included the variables anti-phenolic glycolipid I immunoglobulin M positive, absence of Bacillus Calmette-Guérin vaccine scar and age ≥60 years, was considered the best for identifying a higher risk of illness, with a specificity of 89.2%, a positive predictive value of 60% and an accuracy of 78%. CONCLUSIONS: Risk prediction models can contribute to the management of leprosy contacts and the systematisation of contact surveillance protocols.
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Lepra , Humanos , Lepra/epidemiología , Brasil/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Adolescente , Trazado de Contacto , Adulto Joven , Factores de Riesgo , Niño , Medición de Riesgo , Vacuna BCG , Anciano , Preescolar , Modelos Logísticos , Estudios de Cohortes , Inmunoglobulina M/sangreRESUMEN
Numerous commercial tests for the serological diagnosis of COVID-19 have been produced in recent years. However, it is important to note that these tests exhibit significant variability in their sensitivity, specificity, and accuracy of results. Therefore, the objective of this study was to utilize bioinformatics tools to map SARS-CoV-2 peptides, with the goal of developing a new serological diagnostic test for COVID-19. Two peptides from the S protein and one from the N protein were selected and characterized in silico, chemically synthesized, and used as a serological diagnostic tool to detect IgM, IgG, and IgA anti-SARS-CoV-2 antibodies through the ELISA technique, confirmed as positive and negative samples by RT-qPCR or serology by ELISA. The results showed a sensitivity, specificity, Positive Predictive Value and Negative Predictive Value of 100% (p < 00001, 95% CI) for the proposed test. Although preliminary, this study brings proof-of-concept results that are consistent with the high-performance rates of the ELISA test when compared to other well-established methods for diagnosing COVID-19.
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Anticuerpos Antivirales , Prueba Serológica para COVID-19 , COVID-19 , Proteínas de la Nucleocápside de Coronavirus , Ensayo de Inmunoadsorción Enzimática , SARS-CoV-2 , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus , Humanos , COVID-19/diagnóstico , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/genética , Anticuerpos Antivirales/sangre , Glicoproteína de la Espiga del Coronavirus/inmunología , Prueba Serológica para COVID-19/métodos , Ensayo de Inmunoadsorción Enzimática/métodos , Proteínas de la Nucleocápside de Coronavirus/inmunología , Fosfoproteínas/inmunología , Inmunoglobulina M/sangre , Péptidos/inmunología , Péptidos/química , Inmunoglobulina G/sangre , Biología Computacional/métodosRESUMEN
BACKGROUND AND OBJECTIVES: In Brazil, urban arboviruses, such as dengue virus (DENV), Zika virus (ZIKV) and chikungunya virus (CHIKV), constitute a major public health problem, and due to their endemicity and asymptomatic cases, they pose a potential threat to blood donations. Rio de Janeiro (RJ), Brazil, has been impacted by extensive DENV epidemics over the last 30 years and, after 2015, by CHIKV and ZIKV. MATERIALS AND METHODS: Urban arboviruses DENV, ZIKV and CHIKV were investigated in blood donations (n = 778) at the State Institute of Hematology, HEMORIO (RJ) from 2019 to 2022 by serological and molecular methods. RESULTS: An overall arbovirus exposure was observed in 26.1% of the blood donations. Anti-DENV IgM was detected in 4.0% of samples and two donations were DENV NS1 positive. Positive anti-CHIKV IgM was observed in 4.7% of the donations. Co-detection of anti-CHIKV IgM and anti-DENV IgM was observed in 1.0% of donors, and CHIKV prevalence was 21.3%. All blood donations tested were negative for the DENV, ZIKV and CHIKV RNA. CONCLUSION: IgM seroprevalence to the arboviruses analyzed here is an indicator of recent infection in asymptomatic donors, showing that the population of blood donors can be a vehicle for new infections, especially during epidemic periods.
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Donantes de Sangre , Virus del Dengue , Infección por el Virus Zika , Humanos , Donantes de Sangre/estadística & datos numéricos , Brasil/epidemiología , Femenino , Masculino , Adulto , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/sangre , Virus Zika , Inmunoglobulina M/sangre , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/sangre , Dengue/epidemiología , Dengue/sangre , Estudios Seroepidemiológicos , Anticuerpos Antivirales/sangre , Enfermedades Endémicas , Persona de Mediana Edad , Infecciones por Arbovirus/epidemiología , Infecciones por Arbovirus/sangre , Arbovirus , Virus Chikungunya , Adolescente , Adulto Joven , Donación de SangreRESUMEN
BACKGROUND: Until 2005, when a single dose of vaccine was implemented in one-year-old children, the Hepatitis A virus (HAV) was responsible for approximately 90% of acute hepatitis cases in the paediatric population in Argentina. However, despite vaccination success, sporadic outbreaks of HAV still occur among adults. This study aimed to assess the seroepidemiology of HAV in Argentina, analysing IgG and IgM antibodies against HAV in a large population, both vaccinated and unvaccinated. METHODS: The study included 16,982 patients attending a hospital from 2001 to 2023. The cohort was divided into two groups: 16,638 individuals who were not reached by the vaccination program implemented in 2005 and 344 children who were covered by the universal vaccination. RESULTS: Anti-HAV IgG was detected in 56.7% of cases. The rate was significantly higher in individuals born after 2005 (77.7%) compared to those born before (56.3%), p < 0.001. The age groups 19-40 and 41-60 years showed the anti-HAV IgG lowest rates. On the other hand, 100/3956 cases (2.5%) with suspected acute hepatitis were positive for Anti-HAVIgM. Notably, none of these were born after the mandatory vaccine rollout. CONCLUSIONS: The study of this large cohort contributes to the understanding of the seroepidemiology of HAV. Although the implementation of the vaccine achieved its main goal, the age segment between 19 and 60 years does not reach the estimated threshold to achieve herd immunity. These findings reveal the importance of targeting vaccination campaigns, provide essential insights for public health planning, and guide future immunisation strategies against HAV in Argentina.
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Anticuerpos de Hepatitis A , Vacunas contra la Hepatitis A , Hepatitis A , Inmunoglobulina G , Inmunoglobulina M , Humanos , Argentina/epidemiología , Estudios Seroepidemiológicos , Hepatitis A/epidemiología , Hepatitis A/prevención & control , Adulto , Masculino , Femenino , Persona de Mediana Edad , Adulto Joven , Anticuerpos de Hepatitis A/sangre , Niño , Vacunas contra la Hepatitis A/administración & dosificación , Vacunas contra la Hepatitis A/inmunología , Adolescente , Preescolar , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Lactante , Vacunación/estadística & datos numéricos , Virus de la Hepatitis A/inmunología , Anciano , Programas de InmunizaciónRESUMEN
Leptospirosis is a globally distributed infectious disease caused by pathogenic spirochetes of the Leptospira genus, often overlooked. It is estimated that the disease affects approximately one million people annually, resulting in more than 58,900 deaths. The gold standard for serodiagnosis of leptospirosis is the Microscopic Agglutination Test (MAT). However, the limitations of this technique necessitate the exploration of alternative diagnostic methods. In this study, we evaluated the ErpY-like recombinant protein (rErpY-like) in the development of a serologic diagnostic assay for human leptospirosis. Eighty-six human sera samples, characterized by MAT, underwent evaluation through indirect IgM-ELISA and IgG-ELISA. The sensitivity and specificity values obtained from IgM-ELISA were 60% and 76%, respectively, while those from IgG-ELISA were 96.4% and 100%, respectively. The use of the rErpY-like protein in both IgM-ELISA and IgG-ELISA proves to be a sensitive and specific method for antibody detection. This could potentially serve as a valuable alternative tool in the diagnosis of human leptospirosis.
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Anticuerpos Antibacterianos , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina G , Inmunoglobulina M , Leptospira , Leptospirosis , Sensibilidad y Especificidad , Pruebas Serológicas , Leptospirosis/diagnóstico , Leptospirosis/inmunología , Leptospirosis/microbiología , Leptospirosis/sangre , Humanos , Anticuerpos Antibacterianos/sangre , Inmunoglobulina M/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Leptospira/inmunología , Pruebas Serológicas/métodos , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/genética , Antígenos Bacterianos/inmunologíaRESUMEN
BACKGROUND: Plasmodium falciparum malaria is a public health issue mostly seen in tropical countries. Until now, there is no effective malaria vaccine against antigens specific to the blood-stage of P. falciparum infection. Because the pathogenesis of malarial disease results from blood-stage infection, it is essential to identify the most promising blood-stage vaccine candidate antigens under natural exposure to malaria infection. METHODS: A cohort of 400 pregnant women and their infants was implemented in South Benin. An active and passive protocol of malaria surveillance was established during pregnancy and infancy to precisely ascertain malaria infections during the follow-up. Twenty-eight antibody (Ab) responses specific to seven malaria candidate vaccine antigens were repeatedly quantified during pregnancy (3 time points) and infancy (6 time points) in order to study the Ab kinetics and their protective role. Abs were quantified by ELISA and logistic, linear and cox-proportional hazard model were performed to analyse the associations between Ab responses and protection against malaria in mothers and infants, taking into account socio-economic factors and for infants an environmental risk of exposure. RESULTS: The levels of IgM against MSP1, MSP2 and MSP3 showed an early protective response against the onset of symptomatic malaria infections starting from the 18th month of life, whereas no association was found for IgG responses during infancy. In women, some IgG responses tend to be associated with a protection against malaria risk along pregnancy and at delivery, among them IgG3 against GLURP-R0 and IgG2 against MSP1. CONCLUSION: The main finding suggests that IgM should be considered in vaccine designs during infanthood. Investigation of the functional role played by IgM in malaria protection needs further attention.
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Anticuerpos Antiprotozoarios , Antígenos de Protozoos , Inmunoglobulina G , Inmunoglobulina M , Malaria Falciparum , Plasmodium falciparum , Humanos , Femenino , Plasmodium falciparum/inmunología , Malaria Falciparum/prevención & control , Malaria Falciparum/inmunología , Embarazo , Lactante , Inmunoglobulina M/sangre , Inmunoglobulina G/sangre , Anticuerpos Antiprotozoarios/sangre , Benin , Antígenos de Protozoos/inmunología , Adulto , Adulto Joven , Ensayo de Inmunoadsorción Enzimática , Recién Nacido , Complicaciones Parasitarias del Embarazo/prevención & control , Complicaciones Parasitarias del Embarazo/inmunología , Estudios de CohortesRESUMEN
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.