Publications by authors named "Miguel O'Ryan G"

Before 1990, Chile showed fewer medical schools, six in total, increasing to 13 by 2000. From then on, there was an explosive increase, reaching 29 faculties or schools by 2024. Medical students increased from 1,816 in 2010 to 3,000 by 2024.

View Article and Find Full Text PDF

Background: World Health Organization approved vaccines have demonstrated relatively high protection against moderate to severe COVID-19. Prospective vaccine effectiveness (VE) designs with first-hand data and population-based controls are nevertheless rare. Neighborhood compared to hospitalized controls, may differ in compliance to non-pharmacuetical interventions (NPI) compliance, which may influence VE results in real-world settings.

View Article and Find Full Text PDF

Objectives: Helicobacter pylori (H. pylori) is the primary cause of gastric cancer and eradication in healthy adults has proven effective in decreasing cancer incidence. H.

View Article and Find Full Text PDF

Noroviruses (NoVs) are one of the leading causes of acute gastroenteritis, including both outbreaks and endemic infections. The development of preventive strategies, including vaccines, for the most susceptible groups (children <5years of age, the elderly and individuals suffering crowding, such as military personnel and travelers) is desirable. However, NoV vaccine development has faced many difficulties, including genetic/antigenic diversity, limited knowledge on NoV immunology and viral cycle, lack of a permissive cell line for cultivation and lack of a widely available and successful animal model.

View Article and Find Full Text PDF

Background: Replacement of the trivalent oral poliovirus vaccine (tOPV) with bivalent types 1 and 3 oral poliovirus vaccine (bOPV) and global introduction of inactivated poliovirus vaccine (IPV) are major steps in the polio endgame strategy. In this study, we assessed humoral and intestinal immunity in Latin American infants after three doses of bOPV combined with zero, one, or two doses of IPV.

Methods: This open-label randomised controlled multicentre trial was part of a larger study.

View Article and Find Full Text PDF

Acute infectious gastroenteritis continues to be a leading cause of morbidity and mortality in children below 5 years of age, with the majority of deaths concentrated in 35 'low income' countries. In these countries the under five years of age mortality rates reach 100 per 1000 live births, of which a significant proportion are associated with acute diarrhea. Rotavirus, cryptosporidium, Shigella spp and enterotoxigenic Escherichia coli are the main pathogens causing disease in these settings, although other bacteria and parasites can cause moderate to severe disease in different regions and situations.

View Article and Find Full Text PDF

Outbreaks of acute gastroenteritis are a public health problem. Norovirus is known as the most common cause (50%). In Chile, immediate notification allows surveillance of these events.

View Article and Find Full Text PDF

The experience of a group of 9 doctors and 6 nurses, most of them younger than 30 years of age, whom were part of the several volunteer groups directed towards the most damaged earthquake regions, is described. The team had to overcome a number of intense personal emotions related with the magnitude of the destruction, especially in the "adobe"-constructed houses and villages, in order to provide useful medical support. Moving out of the hospital setting, reaching out to the community in schools and emergency posts proved to be important in rural communities.

View Article and Find Full Text PDF

Unlabelled: A sentinel-based outpatient and inpatient surveillance for rotavirus infection has been implemented in Chile.

Aim: Update the impact of rotavirus infections in Chile.

Methods: Ambulatory surveillance is performed in 14 centers from 8 Regions and hospital-based surveillance in 8 hospitals from three Regions (V, VIII and Metropolitan).

View Article and Find Full Text PDF

The article briefly reviews the epidemiology of human papillomavirus (HPV) infection and associated diseases in the world and in Chile and the scientific information of the licensed HPV vaccines: Gardasil and Cervarix. Considering the available information, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases, summarizes its conclusions and makes recommendations for vaccination against HPV in Chile.

View Article and Find Full Text PDF

Thimerosal is a mercury derivative included in vaccines since 1930 with the aim to prevent microbial contamination. During the last decades, the use of thimerosal has been questioned, specifically because of a potential association with neurotoxicity. After a thorough review of published studies on pediatric use of thimerosal-containing vaccines, and of position papers from international expert groups, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases concludes that there is no solid evidence of adverse events associated with the use of thimerosal containing vaccines in infants and children.

View Article and Find Full Text PDF