RESUMO

This review aims to gather and disseminate updated information regarding hepatitis A virus (HAV) in Latin America (LA) in the last 11 years, including seroprevalence, post-vaccination studies, virus detection in aqueous matrices and food samples, and outbreak reports. Only 24 seroprevalence studies were published between 2012 and 2023 with 55%-100% reported prevalences of anti-HAV IgG. Among the 25 LA countries, only eight of them have introduced HAV vaccines into their immunisation programs. Outbreaks of hepatitis A occurred between 2017-2019, mainly affecting men who have sex with men in Argentina, Brazil and Chile, probably as a consequence of the abrupt decline of young adults' immunity. This could be due to that young adult have never been infected in childhood (due to socio-health improvements) and are above the cut-off ages to be included when the vaccination programs were introduced. Although scarce, studies focused on environmental and food HAV surveillance have shown viral presence in these samples. Surface waters presented HAV detections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and 70.9%. Genotypes found in all cases were IA and IC. The only wastewater-based epidemiology study showed to be a useful tool as a complement of traditional epidemiological surveillance. Only four LA countries have looked for HAV in food samples, with genome detection rates between 9% and 33%. Latin American HAV circulation scenario is changing. In countries where socioeconomic and sanitary conditions have not improved, the virus persists with high endemicity and the access to the vaccine should be re-evaluated by local governments. In countries where access to clean water, better sanitary conditions and HAV immunisation programs have been implemented, the number of cases among young adults seems to be increasing, alerting health authorities.

Assuntos

RESUMO

The genus Flavivirus comprises approximately 80 different viruses. Phylogenetic relationships among its members indicate a clear ecological separation between those viruses transmitted by mosquitoes, ticks, with no known vector, and insect-specific Flaviviruses. The diversity and phylogenetic relationships among insect-specific flaviviruses circulating in the central and northern regions of Argentina were studied by performing molecular detection and characterization of the NS5 protein gene in mosquitoes collected in Córdoba, Chaco and Tucumán provinces. Overall, 68 out of 1776 pools were positive. CxFV, KRV and CFAV circulate in the 3 studied provinces. Several mosquito species (Aedes aegypti, Culex bidens, Cx. dolosus, Cx. interfor, Cx. quinquefasciatus, Cx. saltanensis, Haemagogus spegazzini) were found infected. A wide circulation of CxFV was observed in the central-northern region of Argentina. CxFV strains detected in our study clustered with strains circulating in Santa Fe and Buenos Aires provinces (Argentina), and other countries such as Indonesia, Mexico, Uganda and Taiwan. The presence of these viruses in mosquitoes could play an important role from the public health perspective, because it has been shown that previous CxFV infection can increase or block the infection of the mosquito by other pathogenic flaviviruses.

Assuntos

RESUMO

In Argentina, circulation of hepatitis E virus (HEV) genotype 3 has been described, producing sporadic cases of acute and chronic hepatitis. Limited information is available regarding HEV infection in children, so we aimed to investigate this virus in a pediatric population from the country. Serum samples from Argentine children (0-18 years old) (n = 213) were studied for IgG anti-HEV, IgM anti-HEV and RNA-HEV: 202 samples belonged to individuals attending health-care centers for routine check-ups, and 11 samples from patients with acute hepatitis of unknown etiology. Seropositivity for IgG anti-HEV was 1.49 % (3/202). One sample from an 18-years-old female patient with acute hepatitis tested positive for IgM anti-HEV detection, negative for IgG anti-HEV and RNA-HEV, but also positive for IgM anti-EBV. The HEV prevalence was low and showed circulation among children in central Argentina.

RESUMO

Abstract The rocketing number of COVID-19 cases highlighted the critical role that diagnostic tests play in medical and public health decision-making to contain and mitigate the SARS-CoV-2 pandemic. This study reports the evaluation and implementation of different tests for the molecular detection of SARS-CoV-2 in the central region of Argentina. We evaluated 3 real time RT-PCR kits (GeneFinder COVID-19 Plus RealAmp Kit, DisCoVery SARS-CoV-2 RT-PCR Detection Kit and WGene SARS-CoV-2 RT Detection), 2 nucleic acid extraction methods [MagaBio plus Virus DNA/RNA Purification Kit II (BioFlux), 35-min vs. 9-min, a pre-analytical reagent (FlashPrep®) and 2 isothermal amplification tests (Neokit Plus and ELA CHEMSTRIP®). The order according to the best performance of the 3 real-time RT-PCR kits evaluated was: DisCoVery > GeneFinderTM> WGene. The 2 RNA extraction methods showed similar good results: MagaBio plus Virus RNA Purification Kit II (BioFlux) 9-min was selected due to its faster performance. FlashPrep® reagent showed excellent results to perform direct RNA detection. Isothermal amplification assays showed acceptable sensitivity and specificity values (>80%), except in samples with Ct> 30. Our data show optimal real time RT-PCR kits and alternative molecular methods for SARS-CoV-2 diagnostic. These alternative assays proved to be aceptable.

Resumen La explosión de casos de COVID-19 resaltó el papel fundamental que desempeñan las pruebas de diagnóstico en la toma de decisiones médicas y de salud pública para contener y mitigar la pandemia de SARS-CoV-2. Este estudio reporta la evaluación y la implementación de diferentes test para la detección molecular de SARS-CoV-2 en la región central de Argentina. Evaluamos tres kits de RT-PCR en tiempo real (GeneFinder COVID-19 Plus RealAmp Kit, DisCoVery SARS-CoV-2 RT-PCR Detection Kit y WGene SARS-CoV-2 RT Detection), dos métodos de extracción de ácidos nucleicos (MagaBio plus Virus DNA/RNA Purification Kit II [BioFlux, 35-min vs. 9-min), un reactivo pre-analítico (FlashPrep®) y dos test de amplificación isotérmica (Neokit Plus and ELA CHEMSTRIP®). El orden de rendimiento de los tres kits de RT-PCR en tiempo real evaluados fue el siguiente: DisCoVery GeneFinder™ WGene. Los dos métodos de extracción de RNA mostraron buenos y similares resultados; se seleccionó MagaBio plus Virus RNA Purification Kit II (BioFlux) 9-min debido a su rápido tiempo de procesamiento. El reactivo FlashPrep® mostró excelentes resultados para realizar detección directa de RNA. Los ensayos de amplificación isotérmica mostraron valores de sensibilidad y de especificidad aceptables (80%), excepto en muestras con Ct 30. Nuestros resultados muestran kits de RT-PCR en tiempo real óptimos, como así también métodos moleculares alternativos para el diagnóstico de SARS-CoV-2 que resultan aceptables para su uso en contextos adversos, de descentralización y en diferentes escenarios epidemiológicos, para la detección rápida y precisa del SARS-CoV-2.

RESUMO

Hepatitis E virus (HEV) is an emerging cause of viral hepatitis and pigs are considered a reservoir for the virus. HEV genotype 3 (HEV-3) has been reported in pigs, environmental matrices, and sporadic human cases in Argentina. We aimed to investigate HEV circulation in pigs from central Argentina and to assess the virus presence in pork meat and food products. Four types of samples obtained or derived from pigs collected in Córdoba province (Argentina) between 2019 and 2022, were tested: 276 serum samples were analyzed for anti-HEV antibody detection; stool (n = 20), pork meat (n = 71), and salami (n = 76) samples were studied for RNA-HEV detection, followed by sequencing and phylogenetic analyses. The positivity rate for anti-HEV antibodies was 80.1% (221/276). Eleven fecal samples (11/20) tested positive for RNA-HEV, from animals under 120 days of age. Three samples could be sequenced, and phylogenetic analyses revealed that they belonged to HEV-3 clade abchijklm, clustering close to strains previously detected in wastewater from Córdoba. None of the muscle meat or salami samples tested positive. A high HEV circulation in pigs was found, showing that these animals may play a significant role in the viral maintenance in the region, becoming a potential risk to the exposed population. Despite not detecting RNA-HEV in pork meat and salami in our study, we cannot rule out the possibility of foodborne transmission in Córdoba province.

Assuntos

RESUMO

The rocketing number of COVID-19 cases highlighted the critical role that diagnostic tests play in medical and public health decision-making to contain and mitigate the SARS-CoV-2 pandemic. This study reports the evaluation and implementation of different tests for the molecular detection of SARS-CoV-2 in the central region of Argentina. We evaluated 3 real time RT-PCR kits (GeneFinder COVID-19 Plus RealAmp Kit, DisCoVery SARS-CoV-2 RT-PCR Detection Kit and WGene SARS-CoV-2 RT Detection), 2 nucleic acid extraction methods [MagaBio plus Virus DNA/RNA Purification Kit II (BioFlux), 35-min vs. 9-min], a pre-analytical reagent (FlashPrep®) and 2 isothermal amplification tests (Neokit Plus and ELA CHEMSTRIP®). The order according to the best performance of the 3 real-time RT-PCR kits evaluated was: DisCoVery>GeneFinderTM>WGene. The 2 RNA extraction methods showed similar good results: MagaBio plus Virus RNA Purification Kit II (BioFlux) 9-min was selected due to its faster performance. FlashPrep® reagent showed excellent results to perform direct RNA detection. Isothermal amplification assays showed acceptable sensitivity and specificity values (>80%), except in samples with Ct>30. Our data show optimal real time RT-PCR kits and alternative molecular methods for SARS-CoV-2 diagnostic. These alternative assays proved to be acceptable for their use in adverse contexts, decentralization, and different epidemiological scenarios, for rapid and accurate SARS-CoV-2 detection.

Assuntos

Assuntos

RESUMO

BACKGROUND: The SARS-CoV-2 virus is responsible for the COVID-19 pandemic. To better understand the evolution of SARS-CoV-2 early in the pandemic in the Province of Cordoba, Argentina, we performed a comparative genomic analysis of SARS-CoV-2 strains detected in survivors and non-survivors of COVID-19. We also carried out an epidemiological study to find a possible association between the symptoms and comorbidities of these patients with their clinical outcomes. RESULTS: A representative sampling was performed in different cities in the Province of Cordoba. Ten and nine complete SARS-CoV-2 genomes were obtained by next-generation sequencing of nasopharyngeal specimens from non-survivors and survivors, respectively. Phylogenetic and phylodynamic analyses revealed multiple introductions of the most common lineages in South America, including B.1, B.1.1.1, B.1.499, and N.3. Fifty-six mutations were identified, with 14% of those in common between the non-survivor and survivor groups. Specific SARS-CoV-2 mutations for survivors constituted 25% whereas for non-survivors they were 41% of the repertoire, indicating partial selectivity. The non-survivors' variants showed higher diversity in 9 genes, with a majority in Nsp3, while the survivors' variants were detected in 5 genes, with a higher incidence in the Spike protein. At least one comorbidity was present in 60% of non-survivor patients and 33% of survivors. Age 75-85 years (p = 0.018) and hospitalization (p = 0.019) were associated with non-survivor patients. Related to the most common symptoms, the prevalence of fever was similar in both groups, while dyspnea was more frequent among non-survivors and cough among survivors. CONCLUSIONS: This study describes the association of clinical characteristics with the clinical outcomes of survivors and non-survivors of COVID-19 patients, and the specific mutations found in the genome sequences of SARS-CoV-2 in each patient group. Future research on the functional characterization of novel mutations should be performed to understand the role of these variations in SARS-CoV-2 pathogenesis and COVID-19 disease outcomes. These results add new genomic data to better understand the evolution of the SARS-CoV-2 variants that spread in Argentina during the first wave of the COVID-19 pandemic.

Assuntos

RESUMO

SARS-CoV-2 variants of concern (VOC) and interest (VOI) present mutations in reference to the original virus, being more transmissible. We implemented a rapid strategy for the screening of SARS-CoV-2 VOC/VOIs using real time RT-PCR and performed monitoring and surveillance of the variants in our region. Consecutive real-time RT-PCRs for detection of the relevant mutations/deletions present in the Spike protein in VOC/VOIs (TaqMan™ SARS-CoV-2 Mutation Panel, Applied Biosystems) were implemented. A total of 6,640 SARS-CoV-2 RNA samples (Cts < 30) from infected individuals in Central Argentina during 2021 were analyzed using different algorithms that were gradually adapted to the changing scenarios of local variant circulation. The strategy developed allowed the early detection and the identification of VOC/VOIs that circulated through the year, with a 100% of concordance with the WGS. The analyses of the samples showed introductions of VOCs Alpha and Gamma in February and March 2021, respectively. Gamma showed an exponential increase, with a peak of detection in July (72%), being responsible of the second wave of COVID19 in Argentina. Since VOC Delta entered into the region, it increased gradually, together with VOI Lambda, replacing VOC Gamma, until being the main variant (84.9%) on November. By December, these variants were replaced by the emergent VOC Omicron in a term of 2 weeks, producing the third wave. We report a useful tool for VOC/VOI detection, capable to quickly and cost-effectively monitor currently recognized variants in resource-limited settings, which allowed to track the recent expansion of Omicron in our region, and contributed to the implementation of public health measures to control the disease spread.

RESUMO

BACKGROUND: The hepatitis E virus (HEV) causes acute hepatitis, which can progress to chronicity in immunosuppressed patients. It is transmitted mainly by the fecal-oral or zoonotic routes, but there is current evidence that it can be transmitted by blood transfusions. The objective of the study was to investigate HEV infections in blood donors in Argentina, within the framework of a hemovigilance program. METHODS: A total of 547 samples from Argentinean blood donors, collected in 2016, 2019 and 2020 was studied for IgG and IgM anti-HEV by ELISA (Diapro) and RNA HEV by RT-real time PCR and RT-Nested-PCR. RESULTS: The prevalence of IgG anti-HEV was 3.47% (19/547). No significant differences were registered according to the year studied, sex or age. The presence of RNA HEV was observed in 0.18% (1/547) of the donors studied without serological evidence of infection. CONCLUSIONS: This is the first molecular detection in blood donors from Argentina, showing a molecular prevalence within the range described for RNA-HEV in blood donors from other non-endemic countries, in which immunocompetent RNA-HEV positive donors without serological evidence of infection were identified. The presence of viraemic donors could imply transfusion transmission, which deserves further attention and study.

Assuntos