Antibody response against SARS-CoV-2 variants of concern in children infected with pre-Omicron variants: An observational cohort study.

Background: Despite that pediatric COVID-19 is usually asymptomatic or mild, SARS-CoV-2 infection typically results in the development of an antibody response. Contradictory observations have been reported when the antibody response of children and adults were compared in terms of strength, specificity and perdurability.

Methods: This observational study includes three cohorts infected with SARS-CoV-2 between March 2020-July 2021: unvaccinated infected children (n=115), unvaccinated infected adults (n=62), and vaccinated infected children (n=76).

[Leukemia associated to human T cell lymphotropic virus type 1 (HTLV-1) infection and intrafamily transmission in Santiago del Estero].

Adult T-cell leukemia/lymphoma (ATLL) is an hematological disease caused by human T-cell lymphotropic virus type 1 (HTLV-1) that develops after 20 years of incubation preferentially when the infection is acquired by vertical transmission. In cases of transmission by transfusion or organ transplant, this time is reduced from 3 months to 3 years. Acute ATLL is difficult to diagnose because it is unusual and has a rapid progression to death.

HLA-B*35 as a new marker for susceptibility to human T-cell lymphotropic virus type 1 (HTLV-1) Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) in patients living in Argentina.

Background: Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiological agent of HTLV associated myelopathy/ Tropical Spastic Paraparesis (HAM/TSP) and Adult T cell leukemia/lymphoma (ATLL), in around 2-5% of the infected individuals. Host genetic background might play a role in disease progression. Several previous studies across many countries report HLA haplotype to be one such factor.

First molecular epidemiological study of hepatitis B and D in individuals infected with human T-lymphotropic virus 1/2 from Argentina.

Human T-lymphotropic virus 1/2 (HTLV-1/2), hepatitis B virus (HBV), and hepatitis D virus (HDV) share transmission routes. Argentina shows low prevalence of HTLV-1/2, HBV, and HDV infections; however, this situation may vary according to the geographic region and group studied. The aim of this study was to estimate the prevalence of HBV and HDV infections and detect both viral genotypes in HTLV-1/2 individuals from Argentina.

Oral Pharmacokinetics of a Chitosan-Based Nano- Drug Delivery System of Interferon Alpha.

Interferon alpha (IFNα) is a protein drug used to treat viral infections and cancer diseases. Due to its poor stability in the gastrointestinal tract, only parenteral administration ensures bioavailability, which is associated with severe side effects. We hypothesized that the nanoencapsulation of IFNα within nanoparticles of the mucoadhesive polysaccharide chitosan would improve the oral bioavailability of this drug.

[Detection of Human T lymphotropic virus 1 (HTLV-1) Cosmopolitan subtype Transcontinental subgroup (Aa) and HTLV-2 subtype b in blood donors of Corrientes].

A molecular epidemiological study was conducted in a population of 9422 blood donors in the province of Corrientes, Northeastern Argentina, to determine the prevalence of Human T-cell lymphotropic virus types 1 and 2 (HTLV-1/2), the phylogenetic identification of HTLV-1 and 2 subtypes/subgroups and perform a mutation analysis. Based on the results obtained, it was shown that both HTLV-1 and HTLV-2 are circulating in a low-risk population of Corrientes, although with a similar prevalence to that of non-endemic areas. Phylogenetic studies identified the HTLV-1 Cosmopolitan subtype Transcontinental subgroup (Aa), and the HTLV-2 subtype b.

Development of a Drug Delivery System Based on Chitosan Nanoparticles for Oral Administration of Interferon-α.

Despite the good clinical efficacy of interferon-alpha (IFNα) to treat some types of cancer and viral infections, this biological drug is underused given its severe adverse effects and high dosing parenteral regimens. Aiming to achieve a breakthrough in therapy with IFNα, this work reports for the first time on the design and full characterization of a novel nanomedicine of IFNα-2b-loaded chitosan nanoparticles (IFN-CT NPs) for oral delivery. IFN-CT NPs produced by ionotropic gelation, encapsulating approximately 100% of the drug, showed a size of 36 ± 8 nm, zeta potential of +30 mV (dynamic light scattering), and spherical morphology (transmission electron microscopy).

Health care importance of Treponema pallidum, Chagas' disease and Human immunodeficiency virus 1 among Amerindians of Argentina: an observational study.

The objective of this study was to estimate the prevalence of Treponema pallidum, Trypanosoma cruzi and Human immunodeficiency virus 1 (HIV-1) in five Amerindian populations of Argentina. A retrospective study was conducted among 857 Amerindian populations (112 Kollas, 298 Mbyá-guaraníes, 79 Sagua Huarpes, 368 Wichis) from 2007 to 2010. Screening and confirmation of T.

Hepatitis B virus and hepatitis D virus in blood donors from Argentina: circulation of HBsAg and reverse transcriptase mutants.

In Argentina, current procedures to ensure the safety of the blood supply for transfusion include the serologic detection of specific blood-borne infections. The aim of this study was to evaluate the prevalence and the genetic diversity of hepatitis B virus (HBV) and hepatitis D virus (HDV) in blood donor populations from two distantly located Argentine regions. Data from 56,983 blood donations from the Favaloro Foundation, in the city of Buenos Aires (Central Region), and the Central Blood Bank of Misiones Province (Northeast Region) were analyzed.

HTLV-1 cosmopolitan and HTLV-2 subtype b among pregnant women of non-endemic areas of Argentina.

Objectives: The objective of this study was to estimate the prevalence of human T cell lymphotropic virus (HTLV)-1/2, HIV-1, hepatitis B virus (HBV), Trypanosoma cruzi, Treponema pallidum and Toxoplasma gondii infections and to identify the subtypes/subgroups of HTLV-1/2 among pregnant women (PW) from non-endemic provinces of Argentina.

Methods: Methods A total of 2403 samples were screened for HTLV-1/2 and confirmed by western blot and PCR. The long terminal repeat (LTR) of HTLV-1 and HTLV-2 were amplified.

HDAg-L variants in covert hepatitis D and HBV occult infection among Amerindians of Argentina: new insights.

Background: Guidelines suggest that all HBsAg-positive patients should be tested for anti-HDV IgG antibodies and to confirm active hepatitis D virus (HDV) infection by detection of HDV RNA by reverse transcriptase (RT) polymerase chain reaction (PCR).

Objectives: The aim of this study was to determine the serological prevalence and molecular features of HDV within an Amerindian community from Argentina exhibiting positivity for HBsAg and/or anti-HBc total Ig.

Study Design: Forty-six plasma samples were tested for the detection of total anti-HDV antibodies by ELISA.

New natural variants of hepatitis B virus among Amerindians from Argentina with mainly occult infections.

Background: Hepatitis B virus infection is frequent among Amerindians. In Argentina HBV genotypes A, B, C, D, E, F and H were described in different populations, while some cases of occult hepatitis B infection (OBI) were reported in human immunodeficiency virus (HIV) coinfected patients.

Objective: To determine the prevalence, genetic diversity of HBV and to analyze the deduced amino acid sequence of both S and viral polymerase (P) genes among Amerindians of Argentina.

Predominance of human lymphotropic T cell virus type 2 subtype B in urban populations of Argentina.

Human T-lymphotropic virus subtype b (HTLV-2b) infection has been described among aborigines from Northern Argentina, while HTLV-2a has been described in an injecting drug user (IDU) from a Central region, similar to the situation in Spain, the United States, and Brazil. In this study, 22 of the 26 strains analyzed from blood donors and HIV-1(+) individuals were HTLV-2b (84.6%) clustering with Amerindian references, while 4 HIV-1(+) (15.

Stable human T-cell lymphotropic virus type 1 (HTLV-1) subtype a/subgroup a endemicity in Amerindians from Northwest Argentina: a health problem to be resolved.

Jujuy province, in Northwest Argentina, is known to be endemic for HTLV-1 infection. Moreover, foci of HTLV-1 associated pathologies have also been described in this region. To gain an insight into the current situation of HTLV-1/2 in this endemic area, a seroprevalence and phylogenetic study was performed among a Kolla community from Abra Pampa city and surroundings.

Decreasing trends in HTLV-1/2 but stable HIV-1 infection among replacement donors in Argentina.

In Argentina, current procedures to ensure safety of the blood supply for transfusion include reviewing the records of blood donors with particular attention to the serologic detection of specific blood borne infections. Data of 28,483 blood donations received from January 1, 2003 to December 31, 2008 in a public hospital in Buenos Aires were analyzed. Of the 28,483 blood donations, 7,442 (26.

[Seroprevalence of HTLV-1/2 in blood donors from Misiones Province].

Human T-cell Lymphotropic viruses type 1 (HTLV-1), the first human oncoretrovirus to be discovered, is the etiologic agent of Adult T-cell Leukemia (ATL) and HTLV-1 Associated Mielopathy or Tropical Spastic Paraparesis (HAM/TSP). It is endemic worldwide, including the North of Argentina where both associated diseases have also been detected. No etiologic role has been described for HTLV-2, although it has been associated with HAM/TSP-like neurologic syndromes.

Divergent strains of human T-lymphotropic virus type 1 (HTLV-1) within the Cosmopolitan subtype in Argentina.

HTLV-1 Cosmopolitan subtype Transcontinental subgroup A has been described among aboriginal communities from the northwest endemic area of Argentina. Moreover, Transcontinental subgroup A and the Japanese subgroup B were reported among blood donors from the nonendemic central region of the country. We carried out the first HTLV-1 phylogenetic study in individuals residing in Buenos Aires capital city.

Human immunodeficiency virus and tuberculosis in Argentina: prevalence, genotypes and risk factors.

The objective of this study was to determine the prevalence and genetic variability of human immunodeficiency virus type 1 (HIV-1) and other sexually transmitted infections (STIs) among 205 patients with clinical diagnosis of tuberculosis (TB) in Buenos Aires in 2001. Infections with hepatitis B virus (HBV), HIV-1, hepatitis C virus (HCV), Treponema pallidum and human T-cell lymphotropic virus types I/II were diagnosed in 37/187 (19.8 %), 35/205 (17.

Comparison of four commercial screening assays for the diagnosis of human T-cell lymphotropic virus types 1 and 2.

Serological assays for human T-cell lymphotropic virus types 1 and 2 (HTLV-1/2) are widely used in routine screening of blood donors. The aim of this study was to compare the performance of four commercial screening assays for HTLV-1/2 infection frequently used in South America. A total of 142 HTLV-1 and HTLV-2 seropositive and 336 seronegative samples were analyzed by using four commercial tests (BioKit, Vironostika, Murex and Fujirebio).

HTLV-1/2 among high-risk groups in Argentina: molecular diagnosis and prevalence of different sexual transmitted infections.

The objectives of this study were to estimate the prevalence and characterize the epidemiologic patterns of HTLV-1/2 infections and co-infections with HIV, HBV (hepatitis B), HCV (hepatitis C), and Treponema Pallidum in five different high-risk groups, including injecting drug users (IDUs), female sex workers (FSWs), men who have sex with men (MSM), patients with tuberculosis (TB), and patients attending clinics for sexually transmitted infections (STIs) in Buenos Aires, Argentina. The HTLV-1/2 prevalence was 19.1% (33/173) for IDUs, 2.

Human T-cell lymphotropic virus types I and II (HTLV-I and -II) infection among seroindeterminate cases in Argentina.

Human T-cell lymphotropic virus (HTLV) seroindeterminate cases have been reported among blood donors (BD) and in at-risk populations worldwide, including Argentina. The objective of the present work was to study the presence of HTLV-I/II infection and its association to specific Western blot (WB) patterns among healthy BD and at-risk populations in Argentina. We analyzed 83 HTLV-I/II seroindeterminate WB cases diagnosed among BD (n = 49) and in different at-risk populations (n = 34) for human retroviruses infections.

Epidemiology of human immunodeficiency virus, viral hepatitis (B and C), treponema pallidum, and human T-cell lymphotropic I/II virus among men who have sex with men in Buenos Aires, Argentina.

Background: Human immunodeficiency virus (HIV) and sexually transmitted infections (STI) are prevalent among men who have sex with men (MSM).

Goal: To estimate the prevalence of HIV and STIs in this group.

Study: A total of 694 MSM were tested for HIV, hepatitis B (HBV), hepatitis C (HCV), human T-cell lymphotropic (HTLV-I/II) viruses and Treponema pallidum infection.

High prevalence of HTLV-I and HTLV-II among blood donors in Argentina: a South American health concern.

After an HTLV-I endemic area was discovered in Jujuy, a northwestern province in Argentina, to detect other possible foci of HTLV-I/II we started in 1997 a multicentric study to estimate the seroprevalence of HTLV-I/II including blood banks from different regions of the country. Out of 123,233 samples from nine different provinces, 68 proved seropositive with a final prevalence of 0.05% (95% CI = 0.

[Prevalence of HTLV-I/II infection among blood donors in Santa Fe Province, Argentina].

Subsequent to the National Epidemiologic Surveillance Program developed in 1997 by the National AIDS Program, anti-HTLV-I/II antibodies among blood donors in Santa Fe Province started to be detected. On the basis of this initial finding, it was regarded of interest to evaluate the true HTLV-I/II seroprevalence in this population during a four-year survey. Thus, from 1997 up to 2002, 9425 samples were studied from 17 out of the 19 provincial departments.