Occult Hepatitis B Virus Infection in Hepatic Diseases and Its Significance for the WHO's Elimination Plan of Viral Hepatitis.

Liver damage can progress through different stages, resulting in cirrhosis or hepatocellular carcinoma (HCC), conditions that are often associated with viral infections. Globally, 42% and 21% of cirrhosis cases correlate with HBV and HCV, respectively. In the Americas, the prevalence ranges from 1% to 44%.

Case Report of a Young Adult with Fatal COVID-19 and Abundant SARS-CoV-2 Nucleocapsid Protein and Lipofuscin Accumulation in Tissues.

This is a case report of a young adult who died of COVID-19 twelve days after admission, with coronavirus nucleocapsid protein and lipofuscin found in the heart and kidney tissues, providing further evidence of the role of SARS-CoV-2 in cellular senescence.

Dried Serum Samples for Antibody Detection in Arthropod-Borne Virus Infections Are an Effective Alternative to Serum Samples.

The disease burden of arthropod-borne infections is particularly high in low- and middle-income countries, where the availability of resources for surveillance and testing is limited. The lack of local infrastructure demands that biological samples be sent to central laboratories by refrigerated transport, which increases costs and the risk of sample degradation. Dried blood spot samples are an alternative for ensuring sample integrity during transportation and storage.

Donated Blood Screening for HIV, HCV and HBV by ID-NAT and the Residual Risk of Iatrogenic Transmission in a Tertiary Care Hospital Blood Bank in Puebla, Mexico.

Hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV) can be transmitted by blood transfusion. Most transmission occurs during the acute viremic phase (AVP), before antibody development. To reduce transmission risk, individual donor nucleic acid testing (ID-NAT) is used.

Diagnostic Accuracy of Dried Plasma Spot Specimens for HIV-1 Viral Load Testing: A Systematic Review and Meta-analysis.

Background: Dried plasma spot specimens may be a viable alternative to traditional liquid plasma in field settings, but the diagnostic accuracy is not well understood.

Methods: Standard databases (PubMed and Medline), conferences, and gray literature were searched until January 2019. The quality of evidence was evaluated using the Standards for Reporting Studies of Diagnostic Accuracy and Quality Assessment of Diagnostic Accuracy Studies-2 criteria.

Fetal and placental infection with SARS-CoV-2 in early pregnancy.

To date, mother-to-fetus transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease 2019 (COVID-19) pandemic, remains controversial. Although placental COVID-19 infection has been documented in some cases during the second- and third-trimesters, no reports are available for the first trimester of pregnancy, and no SARS-CoV-2 protein has been found in fetal tissues. We studied the placenta and fetal organs from an early pregnancy miscarriage in a COVID-19 maternal infection by immunohistochemical, reverse transcription quantitative real-time polymerase chain reaction, immunofluorescence, and electron microscopy methods.

Identification of mutations in the S gene of hepatitis B virus in HIV positive Mexican patients with occult hepatitis B virus infection.

Introduction And Aim: Occult hepatitis B virus infection (OBI) is characterized by the presence of replication-competent hepatitis B virus (HBV) DNA in the liver and/or serum of patients with undetectable levels of the HBV surface antigen (HBsAg). Due to the shared infection routes HIV positive patients are at higher risk of developing OBI, thus, the aim of this study was to determine the frequency of OBI in Mexican HIV-infected patients and to identify mutations in the HBV S gene that could be associated to the development of OBI.

Materials And Methods: Plasma samples from 50 HIV-infected patients with undetectable levels of the HBsAg were obtained and analyzed.

Natural Vertical Transmission of Zika Virus in Larval Aedes aegypti Populations, Morelos, Mexico.

We characterized natural vertical transmission of Zika virus in pools of Aedes aegypti larvae hatched from eggs collected in Jojutla, Morelos, Mexico. Of the 151 pools analyzed, 17 tested positive for Zika virus RNA; infectious Zika virus was successfully isolated from 1 of the larvae pools (31N) in C6/36 cells. Real-time quantitative PCR and indirect immunofluorescence assays confirmed the identity of the isolate, named Zika virus isolate 31N; plaque assays in Vero cells demonstrated the isolate's infectivity in a mammalian cell line.

Congenital Zika Syndrome and Extra-Central Nervous System Detection of Zika Virus in a Pre-term Newborn in Mexico.

Background: During pregnancy, the Zika virus (ZIKV) replicates in the placenta and central nervous system (CNS) of infected fetuses; nevertheless, the ability of ZIKV to replicate in other fetal tissues has not been extensively characterized.

Methods: We researched whether dissemination of congenitally-acquired ZIKV outside the CNS exists by searching for the accumulation of the viral envelope protein, ZIKV ribonucleic acid (RNA), and infectious viral particles in different organs of a deceased newborn with Congenital Zika Syndrome. A real-time qualitative polymerase chain reaction (qPCR) was used to detect ZIKV RNA in the brain, thymus, lungs, kidneys, adrenal glands, spleen, liver, and small intestine.

Serum Dried Samples to Detect Dengue Antibodies: A Field Study.

Background: Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance.

Complete Genome Sequences, before and after Mammalian Cell Culture, of Zika Virus Isolated from the Serum of a Symptomatic Male Patient from Oaxaca, Mexico.

Zika virus (ZIKV) is an emerging arthropod-borne flavivirus associated with severe congenital malformations and neurological complications. Although the ZIKV genome is well characterized, there is limited information regarding changes after cell isolation and culture adaptation. We isolated, and passaged in Vero cells, ZIKV from the serum of a symptomatic male patient and compared the viral genomes before and after culture.

Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients.

Monitoring antiretroviral therapy using measurements of viral load (VL) and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS) samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM) in a group of HIV-1 patients.

[Cytomegalovirus: congenital infection and clinical presentation in infants with respiratory distress syndrome].

Background: Respiratory distress syndrome (RDS) is a multifactorial and common disease that varies from 15 to 50 % in the newborn, causing 50 % of mortality. The RDS may be associated with bacterial and viral infections, and one of the most common viral agents is the cytomegalovirus (CMV). In the neonatal period the virus incidence goes from 0.

Occult hepatitis B virus co-infection in human immunodeficiency virus-positive patients: A review of prevalence, diagnosis and clinical significance.

The prevalence of human immunodeficiency virus (HIV) and hepatitis B virus (HBV) co-infection is high as they share similar mechanisms of transmission. The development and widespread use of highly sensitive tests for HBV diagnosis has demonstrated that a significant proportion of apparently healthy individuals with evidence of exposure to HBV continue to carry fully functional HBV DNA in their hepatocytes, a situation that predisposes them to the development of progressive liver disease and hepatocellular carcinoma. The presence of co-infections frequently influences the natural evolution of each of the participating infections present by either facilitating their virulence or competing for resources.

Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients.

Aim: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico.

Methods: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes.

Putrescine is required for the expression of eif-5a in Trichomonas vaginalis.

Recently, we found that Trichomonas vaginalis contains a eukaryotic translation initiation factor 5A (TveIF-5A) with unknown function in this parasite. eIF-5A is the only cellular protein dependent of polyamines to form a hypusine residue, an unusual basic amino acid that is post-translationally formed by modification of a single specific lysine residue in an eIF-5A precursor protein. The purpose of this study was to determine the effect of a putrescine analogue, 1,4-diamino-2-butanone (DAB), on tveif-5a mRNA and TveIF-5A protein expression.

Genotypic testing for HIV-1 drug resistance using dried blood samples.

In third-world countries, dried blood samples (DBS) are a convenient alternative to plasma for monitoring viral load during HIV-1 therapy. In this study, we evaluated the feasibility of using DBS to perform HIV-1 drug resistance genotyping in a ViroSeq assay in which the protease and reverse transcriptase regions of the pol gene are analyzed. Fifty-seven antiretroviral genotypes from plasma samples were tested, and drug resistance genotypes were determined.

Use of dried blood samples for monitoring hepatitis B virus infection.

Background: Hepatitis B virus (HBV) infection is a problem in several regions of the world with limited resources. Blood samples dried on filter paper (DBS) have been successfully used to diagnose and monitor several infectious diseases. In Mexico there is an urgent need for an affordable and easy sampling method for viral load (VL) testing and monitoring of chronic HBV infection.

IL-10 and TGF-beta control the establishment of persistent and transmissible infections produced by Leishmania tropica in C57BL/6 mice.

Leishmania tropica is the causative agent of Old World anthroponotic cutaneous leishmaniasis, which is characterized by lesions that take an extended period of time to heal, often resulting in disfiguring scars, and are more refractory to treatment than leishmaniasis caused by Leishmania major. Immunologic studies involving experimental animal models of L. tropica infection are virtually nonexistent.

The relative contribution of IL-4 receptor signaling and IL-10 to susceptibility to Leishmania major.

The roles of IL-10 and IL-4 receptor signaling were evaluated in a murine model of Leishmania major infection. In previous studies the L. major substrain LV39 caused progressive, nonhealing lesions in BALB/c mice deficient for IL-4R alpha-chain (IL-4R alpha), while substrain IR173 was highly controlled.

Leishmania priming of human dendritic cells for CD40 ligand-induced interleukin-12p70 secretion is strain and species dependent.

A major question in the study of leishmaniasis is what dictates clinical disease expression produced by different Leishmania species, i.e., cutaneous versus systemic and healing versus nonhealing.

CD8+ T cells are required for primary immunity in C57BL/6 mice following low-dose, intradermal challenge with Leishmania major.

Standard murine models of cutaneous leishmaniasis, involving s.c. inoculation of large numbers of Leishmania major promastigotes, have not supported an essential role for CD8(+) T cells in the control of primary infection.