Enteropathogen Changes After Rotavirus Vaccine Scale-up.

Objectives: To inform next steps in pediatric diarrhea burden reduction by understanding the shifting enteropathogen landscape after rotavirus vaccine implementation.

Methods: We conducted a case-control study of 1788 medically attended children younger than 5 years, with and without gastroenteritis, after universal rotavirus vaccine implementation in Peru. We tested case and control stools for 5 viruses, 19 bacteria, and parasites; calculated coinfection-adjusted attributable fractions (AFs) to determine pathogen-specific burdens; and evaluated pathogen-specific gastroenteritis severity using Clark and Vesikari scales.

Echinococcus granulosus sensu stricto and E. canadensis are distributed in livestock of highly endemic area in the Peruvian highlands.

The prevalence of cystic echinococcosis is high in many livestock areas of Peru, where intermediate hosts such as sheep, cattle, and South American camelids can be infected. Several species of E. granulosus have been described in relation to its genetic diversity and distribution.

Viral intra-host evolution in immunocompetent children contributes to human norovirus diversification at the global scale.

Norovirus is a major cause of acute gastroenteritis. Human noroviruses present >30 different genotypes, with a single genotype (GII.4) predominating worldwide.

Genome-wide analyses of human noroviruses provide insights on evolutionary dynamics and evidence of coexisting viral populations evolving under recombination constraints.

Norovirus is a major cause of acute gastroenteritis worldwide. Over 30 different genotypes, mostly from genogroup I (GI) and II (GII), have been shown to infect humans. Despite three decades of genome sequencing, our understanding of the role of genomic diversification across continents and time is incomplete.

Congenital Chagas disease in Santa Cruz Department, Bolivia, is dominated by Trypanosoma cruzi lineage V.

Background: This study identified Trypanosoma cruzi discrete typing units (DTUs) in maternal and infant specimens collected from two hospitals in Bolivia, using conventional genotyping and DTU-specific serotyping.

Methods: Specimens from 142 mothers were used, including 24 seronegative and 118 seropositive individuals; 29 women transmitted T. cruzi to their infants.

Norovirus-specific immunoglobulin A in breast milk for protection against norovirus-associated diarrhea among infants.

Background: Norovirus (NV) causes acute gastroenteritis in infants. Humoral and fecal immunoglobulin A (IgA) responses have been correlated with protection against NV; however, the role of breast milk IgA against NV infection and associated diarrhea is still unknown. This study aimed to evaluate the protective role of NV-specific IgA (NV-IgA) in breast milk.

Recombinant Nontypeable Genotype II Human Noroviruses in the Americas.

We report multiple nontypeable genotype II noroviruses circulating in South America; nucleotides differed by >25% from those of other genotypes. These viruses have been circulating in the Americas for ≈20 years and show recombination with other genotypes. Clues to norovirus natural history can guide development of treatment and prevention plans.

Improved DNA extraction technique from clot for the diagnosis of Chagas disease.

Background: The detection of Trypanosoma cruzi genetic material in clinical samples is considered an important diagnostic tool for Chagas disease. We have previously demonstrated that PCR using clot samples yields greater sensitivity than either buffy coat or whole blood samples. However, phenol-chloroform DNA extraction from clot samples is difficult and toxic.

Minimally Invasive Saliva Testing to Monitor Norovirus Infection in Community Settings.

Background: Norovirus is a leading cause of acute gastroenteritis worldwide. Routine norovirus diagnosis requires stool collection. The goal of this study was to develop and validate a noninvasive method to diagnose norovirus to complement stool diagnostics and to facilitate studies on transmission.

Automatic classification of pediatric pneumonia based on lung ultrasound pattern recognition.

Pneumonia is one of the major causes of child mortality, yet with a timely diagnosis, it is usually curable with antibiotic therapy. In many developing regions, diagnosing pneumonia remains a challenge, due to shortages of medical resources. Lung ultrasound has proved to be a useful tool to detect lung consolidation as evidence of pneumonia.

Development of a Novel Protocol Based on Blood Clot to Improve the Sensitivity of qPCR Detection of in Peripheral Blood Specimens.

Quantitative polymerase chain reaction (qPCR) for multicopy genes has emerged as a promising strategy for sensitive detection of parasite DNA. qPCR can be performed from blood samples, which are minimally invasive to collect. However, there is no consensus about what type of blood specimen yields the best sensitivity.

Trypomastigote Excretory Secretory Antigen Blot Is Associated With Trypanosoma cruzi Load and Detects Congenital T. cruzi Infection in Neonates, Using Anti-Shed Acute Phase Antigen Immunoglobulin M.

Background: Congenital Trypanosoma cruzi infection accounts for an estimated 22% of new cases of Chagas disease in Latin America. However, neonatal diagnosis is challenging, as 9-month follow-up for immunoglobulin G testing is poor, quantitative polymerase chain reaction (qPCR) analysis is not routinely performed, and the micromethod misses ≥40% of congenital infections.

Methods: Biorepository samples from new mothers and their infants from Piura, Peru, (an area of nonendemicity), and Santa Cruz, Bolivia (an area of endemicity) were accessed.

Genetic diversity of human sapovirus across the Americas.

Background: Sapoviruses are responsible for sporadic and epidemic acute gastroenteritis worldwide. Sapovirus typing protocols have a success rate as low as 43% and relatively few complete sapovirus genome sequences are available to improve current typing protocols.

Objective/study Design: To increase the number of complete sapovirus genomes to better understand the molecular epidemiology of human sapovirus and to improve the success rate of current sapovirus typing methods, we used deep metagenomics shotgun sequencing to obtain the complete genomes of 68 sapovirus samples from four different countries across the Americas (Guatemala, Nicaragua, Peru and the US).

Complete Genome Sequence of a Nontypeable GII Norovirus Detected in Peru.

Norovirus, a leading cause of acute gastroenteritis in humans, is a highly diverse virus. Here, we report the complete genome sequence of a nontypeable genogroup II (GII) norovirus that was detected in a symptomatic Peruvian child in 2008. This virus showed low nucleotide sequence identities (≤82%) against all known genotypes.

Epidemiology of Sapovirus Infections in a Birth Cohort in Peru.

Background: Sapovirus is one of the primary viral causes of acute gastroenteritis (AGE), especially where rotavirus vaccination has been implemented. The characteristics and impact of natural infection at the community level, however, have not been well documented.

Methods: Stool samples were analyzed from 100 children randomly selected from a community-based birth cohort study in Peru.

Polyclonal antibodies for the detection of Trypanosoma cruzi circulating antigens.

Background: Detection of Trypanosoma cruzi antigens in clinical samples is considered an important diagnostic tool for Chagas disease. The production and use of polyclonal antibodies may contribute to an increase in the sensitivity of immunodiagnosis of Chagas disease.

Methodology/principal Findings: Polyclonal antibodies were raised in alpacas, rabbits, and hens immunized with trypomastigote excreted-secreted antigen, membrane proteins, trypomastigote lysate antigen and recombinant 1F8 to produce polyclonal antibodies.

Automatic pneumonia detection based on ultrasound video analysis.

Pneumonia is a disease which causes high mortality in children under five years old, particularly in developing countries. This paper proposes a novel application of ultrasound video analysis for the detection of pneumonia. This application is based on the processing of small video chunks, in which an image processing algorithm analyzes each frame to get some overall video statistics.

Etiological Role and Repeated Infections of Sapovirus among Children Aged Less than 2 Years in a Cohort Study in a Peri-urban Community of Peru.

Human sapovirus has been shown to be one of the most important etiologies in pediatric patients with acute diarrhea. However, very limited data are available about the causative roles and epidemiology of sapovirus in community settings. A nested matched case-control study within a birth cohort study of acute diarrhea in a peri-urban community in Peru from 2007 to 2010 was conducted to investigate the attributable fraction (AF) and genetic diversity of sapovirus.

A Comparative Study of Peripheral Immune Responses to Taenia solium in Individuals with Parenchymal and Subarachnoid Neurocysticercosis.

Background: The ability of Taenia solium to modulate the immune system likely contributes to their longevity in the human host. We tested the hypothesis that the nature of the immune response is related to the location of parasite and clinical manifestations of infection.

Methodology: Peripheral blood mononuclear cells (PBMC) were obtained from untreated patients with neurocysticercosis (NCC), categorized as having parenchymal or subarachnoid infection by the presence of cysts exclusively within the parenchyma or in subarachnoid spaces of the brain, and from uninfected (control) individuals matched by age and gender to each patient.

TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis.

Neurocysticercosis is an endemic parasitic disease caused by Taenia solium larva. Although the mechanism of infection is not completely understood, it is likely driven by proteolytic activity that degrades the intestinal wall to facilitate oncosphere penetration and further infection. We analyzed the publicly available T.

A novel Taenia solium protein that resembles troponin T proteins.

Taenia solium Linnaeus, 1758 is responsible for taeniasis and cysticercosis, which are 2 serious health problems, particularly in developing countries. The attempt to identify a 22.5kD possible protective oncospheral antigen by 2-dimensional gel-electrophoresis, micro-sequencing, and cDNA library screening produced a protein of 42kD that possesses a conserved domain similar to that of troponin T.

Nested PCR for specific diagnosis of Taenia solium taeniasis.

Taeniasis due to Taenia solium is a disease with important public health consequences, since the larval stage is not exclusive to the animal intermediate, the pig, but also infects humans, causing neurocysticercosis. Early diagnosis and treatment of T. solium tapeworm carriers is important to prevent human cysticercosis.

Characterization of a novel Taenia solium oncosphere antigen.

Infections due to Taenia solium in humans (taeniasis/cysticercosis) remain a complex health problem, particularly in developing countries. We identified two oncosphere proteins that might protect the porcine intermediate host against cysticercosis and therefore help prevent disease in humans. One of these proteins was further identified by two-dimensional gel electrophoresis and micro-sequencing.

Species identification after treatment for human taeniasis.

Identification of species of human tapeworms is crucial because the consequences of infection by Taenia solium and T saginata are very different. However, evacuation of species-identifiable tapeworms is uncommon and Taenia spp eggs are indistinguishable under the microscope. Treatment of taeniasis consists of niclosamide followed by a purgative.