Miguel O'Ryan - Academia.edu (original) (raw)

Papers by Miguel O'Ryan

Principles and Practice of Pediatric Infectious Diseases, 2018

Rotavirus is the most common cause of severe gastroenteritis in children younger than 3 years of ... more Rotavirus is the most common cause of severe gastroenteritis in children younger than 3 years of age worldwide. New rotavirus vaccine candidates were required to confer early protection against the most common rotavirus serotypes and to be well tolerated and not associated with intussusception. RIX4414 is a human-attenuated G1(P8) oral rotavirus vaccine administered in two doses at approximately 6–24 weeks of age. The first dose may be administered from the age of 6 weeks. There should be an interval of at least 4 weeks between doses and the vaccination course should preferably be given before 16 weeks of age and must be completed, according to the manufacturer, by the age of 24 weeks. In a worldwide development program involving more than 70,000 children in six Phase I–III field trials, this vaccine proved to be nonreactogenic, well tolerated and not associated with intussusception. The vaccine provides over 85–96% protection against moderate-to-severe gastroenteritis caused by G1 ...

Journal of Clinical Microbiology, 1998

The frequency of astrovirus infection in 456 Chilean children with diarrhea was determined by enz... more The frequency of astrovirus infection in 456 Chilean children with diarrhea was determined by enzyme-linked immunosorbent assay, reverse transcriptase PCR, and cell culture. Astrovirus was detected in 16.5% of rotavirus-negative and 7% of rotavirus-positive samples obtained from emergency rooms or hospitals and in 11% of samples from day care centers. HAst-1 was the predominant serotype identified.

F1000 - Post-publication peer review of the biomedical literature, 2020

Pediatric Infectious Disease Journal, 2018

Background: Rotaviruses (RVs) and noroviruses (NoVs) are the most common causes of severe acute g... more Background: Rotaviruses (RVs) and noroviruses (NoVs) are the most common causes of severe acute gastroenteritis in children. It is generally accepted that RVs cause severe acute gastroenteritis in a higher proportion of cases compared with NoVs. To our knowledge, there are no systematic reviews and meta-analyses comparing the severity of NoV and RV disease. Methods: We searched MEDLINE for studies reporting data for NoV and RV medically attended disease severity in children. We included studies where all children had been tested for both NoV (reverse transcription polymerase chain reaction) and RV (enzyme-linked immunosorbent assay or reverse transcription polymerase chain reaction) and that reported disease severity using the Vesikari or modified Vesikari score, or provided clinical information on severity. We generated pooled estimates of the mean with 95% confidence intervals using random effects meta-analysis. Results: We identified 266 publications, of which 31 were retained fo...

Open Forum Infectious Diseases, 2018

Background 4CMenB has been shown to be immunogenic with an acceptable safety profile in infants a... more Background 4CMenB has been shown to be immunogenic with an acceptable safety profile in infants and young adolescents. However, no data on long-term persistence after primary vaccination in adolescents are available. This is the first study to assess antibody persistence, booster response, and safety of 4CMenB in adolescents and young adults up to 7.5 years following the primary vaccination in adolescence. Methods This phase 3b, open-label, extension study (NCT02446743) assessed the antibody persistence and booster response at 4 years (Canada and Australia, NCT01423084) or 7.5 years (Chile, NCT00661713) after primary vaccination with 4CMenB (following 0 + 1-, 0 + 2-, or 0 + 6-month schedules), compared with vaccine-naïve (VN), healthy controls. Chilean follow-on (FO) and VN participants aged 18–24 years received either a booster dose of 4CMenB 7.5 years postprimary series (Group FO, N = 131) or 2 primary doses, 1 month apart (Group VN, N = 150). Immunogenicity was measured using hum...

F1000 - Post-publication peer review of the biomedical literature, 2017

Background An association between rotavirus immunisation and intussusception (IS) has been sugges... more Background An association between rotavirus immunisation and intussusception (IS) has been suggested with present rotavirus vaccines in post-licensure studies. In Finland, rotavirus vaccination programme was implemented in September 2009 using a 2, 3, and 5 months schedule with the pentavalent rotavirus vaccine. By the end of 2013, it is estimated that 719 000 rotavirus vaccine doses have been given in the national programme of which 240 000 were first doses. Nationwide register allows us to evaluate the association between rotavirus vaccination and IS. Methods and Materials Cases of IS diagnosed during 1999-2013 were identified from National Hospital Discharge Register. All cases under 250 days of age diagnosed during 2009-2013 were confirmed by reviewing medical charts. Self-controlled case-series method was used to assess the risk of IS during 1-21 days compared to 22-42 days post vaccination. Findings In register data the relative incidence of IS at 2 months of age between the post and pre vaccination era was 9.1 (95%CI 2.0-84.3). We identified 22 verified cases with date of admission less than 43 days after any of the three rotavirus vaccine doses. The incidence of IS in the risk period after the 1st dose relative to the control period was 2.0 (95% CI 0.5-8.4; p = 0.34.) Number of excess IS cases per 100 000 first vaccine doses was therefore estimated to be 1.04 (95% CI 0.0-2.5), i.e. one additional IS case per 96 000 first doses of rotavirus vaccine (95% CI 54 600 to 1). There was no risk detected after 2nd and 3rd doses. Conclusion The finding is in line with the recent published estimates. The benefits of rotavirus immunisation programme outweigh possible small risks of intussusception.

F1000 - Post-publication peer review of the biomedical literature, 2017

Regarding public health in Brazil, a new scenario emerged with the establishment of universal rot... more Regarding public health in Brazil, a new scenario emerged with the establishment of universal rotavirus (RV) vaccination programs. Herein, the data from the five years of surveillance (2007-2012) of G-and P-type RV strains isolated from individuals with acute gastroenteritis in Brazil are reported. A total of 6,196 fecal specimens were investigated by ELISA and RT-PCR. RVs were detected in 19.1% (1,181/6,196). The peak of RV incidence moved from June-August to September. RV was detected less frequently (19.5%) among children ≤ 5 years than in older children and adolescents (6-18 years) (40.6%). Genotype distribution showed a different profile for each year: G2P[4] strains were most prevalent during 2007-2010, G9P[8] in 2011, and G12P[8] in 2012. Mixed infections (G1+G2P[4], G2+G3P[4]+P[8], G2+G12P[8]), unusual combinations (G1P[4], G2P[6]), and rare strains (G3P[3]) were also identified throughout the study period. Widespread vaccination may alter the RV seasonal pattern. The finding of RV disease affecting older children and adolescents after vaccine implementation has been reported worldwide. G2P[4] emergence most likely follows a global trend seemingly unrelated to vaccination, and G12, apparently, is emerging in the Brazilian population. The rapidly changing RV genotype patterns detected during this study illustrate a dynamic population of co-circulating wildtype RVs in Brazil.

Journal of Clinical Oncology, 2001

PURPOSE: To identify clinical and laboratory parameters present at the time of a first evaluation... more PURPOSE: To identify clinical and laboratory parameters present at the time of a first evaluation that could help predict which children with cancer, fever, and neutropenia were at high risk or low risk for an invasive bacterial infection. PATIENTS AND METHODS: Over a 17-month period, all children with cancer, fever, and neutropenia admitted to five hospitals in Santiago, Chile, were enrolled onto a prospective protocol. Associations between admission parameters and risk for invasive bacterial infection were assessed by univariate and logistic regression analyses. RESULTS: A total of 447 febrile neutropenic episodes occurred in 257 children. Five parameters were statistically independent risk factors for an invasive bacterial infection. Ranked by order of significance, they were as follows: C-reactive protein levels of 90 mg/L or higher (relative risk [RR], 4.2; 95% confidence interval [CI], 3.6 to 4.8); presence of hypotension (RR, 2.7; 95% CI, 2.3 to 3.2); relapse of leukemia as c...

Revista médica de Chile, 2016

The Chilean Academy of Medicine supports the 2009 law by which all medical graduates from Chile a... more The Chilean Academy of Medicine supports the 2009 law by which all medical graduates from Chile as well as from foreign countries that wish to start their medical practice should have approved the National Board Examination in Medicine ("Eunacom"). Success in this examination of basic clinical knowledge and competences is mandatory to become attending physicians at the Public Health Care System and to apply to state-funded postgraduate education. Annually, about 90% Chilean graduates approve this examination, while no more than 20 % of foreign graduates do. Given the shortage of primary care physicians, some members of the Parliament have proposed to simplify the test or to exempt foreign medical graduates from it in order to broaden the coverage of primary care and decrease the waiting lists. The Chilean Academy of Medicine considers this shortcut strategy as dangerous for the Chilean population and unfair for our graduates. This Declaration has been send to the National Health Authorities, to Deans of all Medical Schools, and to public press media.

The Lancet, 2016

Background Replacement of the trivalent oral poliovirus vaccine (tOPV) with bivalent types 1 and ... more 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. 6-week-old full-term infants due for their fi rst polio vaccinations, who were healthy on physical examination, with no obvious medical conditions and no known chronic medical disorders, were enrolled from four investigational sites in Colombia, Dominican Republic, Guatemala, and Panama. The infants were randomly assigned by permuted block randomisation (through the use of a computer-generated list, block size 36) to nine groups, of which fi ve will be discussed in this report. These fi ve groups were randomly assigned 1:1:1:1 to four permutations of schedule: groups 1 and 2 (control groups) received bOPV at 6, 10, and 14 weeks; group 3 (also a control group, which did not count as a permutation) received tOPV at 6, 10, and 14 weeks; group 4 received bOPV plus one dose of IPV at 14 weeks; and group 5 received bOPV plus two doses of IPV at 14 and 36 weeks. Infants in all groups were challenged with monovalent type 2 vaccine (mOPV2) at 18 weeks (groups 1, 3, and 4) or 40 weeks (groups 2 and 5). The primary objective was to assess the superiority of bOPV-IPV schedules over bOPV alone, as assessed by the primary endpoints of humoral immunity (neutralising antibodies-ie, seroconversion) to all three serotypes and intestinal immunity (faecal viral shedding post-challenge) to serotype 2, analysed in the per-protocol population. Serious and medically important adverse events were monitored for up to 6 months after the study vaccination. This study is registered with ClinicalTrials.gov, number NCT01831050, and has been completed.

Emerging Infectious Diseases, 2015

(EV-D68) is an emergent viral pathogen associated with severe respiratory illness, especially in ... more (EV-D68) is an emergent viral pathogen associated with severe respiratory illness, especially in children with asthma (1). The ongoing epidemic in the United States has expanded to 47 states; as of November 25, 2014, a total of 1,121 persons were affected (http://www.cdc.gov/non-polio-enterovirus/outbreaks/EV-D68-outbreaks.html). In Chile, because of clinical suspicion of infection caused by the same EV-D68 reported in the United States, we conducted further testing. We selected 6 children who were at Clinica Las Condes (CLC), Santiago, during September-October 2014, for whom nasopharyngeal samples were enterovirus positive according to multiplex PCR (CLART PneumoVir; Genomica, Madrid, Spain) or rhinovirus/enterovirus positive according to the FilmArray Respiratory Panel (BioFire Diagnostics, Salt Lake City, UT, USA). The CLC ethics committee authorized the study. CLC is the second largest private hospital in eastern Santiago, which has a population of nearly 400,000. Since 2008, detection of respiratory viruses by CLART PneumoVir has been performed for all hospitalized CLC patients with respiratory disease. This test detects 17 respiratory viruses, including enterovirus (generic detection). Since 2014, CLC also incorporated testing with the

The Pediatric Infectious Disease Journal, 2001

Background. Because the introduction of extended spectrum cephalosporins into pediatric practice ... more Background. Because the introduction of extended spectrum cephalosporins into pediatric practice offers a number of choices for treatment, we review efficacy studies of cefepime monotherapy in the treatment of bacterial meningitis in children. Methods. Two open, randomized, comparative studies assessed the efficacy of cefepime empiric monotherapy in the treatment of bacterial meningitis in 345 pediatric patients. These studies were conducted in Latin America and compared cefepime (50 mg/kg/dose every 8 h) with either cefotaxime (50 mg/kg/dose every 6 h) or ceftriaxone (50 mg/kg/dose every 12 h). Patients 2 months to 14 years old who had clinical signs and symptoms consistent with a central nervous system infection were enrolled. Efficacy was based on clinical and bacteriologic response. Results. Integrated results from the Latin American studies indicated a 75% cure rate with cefepime vs. a 78% cure rate with comparator, among evaluable patients. Overall the rate of treatment failure was 12%. Haemophilus influenzae had the highest bacterial eradication rate (97% overall), and rates were comparable in cefepime and comparator arms. Eradication rates for Neisseria meningitidis were equally high in both treatment arms (95% overall), and the eradication rate for Streptococcus pneumoniae was 92% overall. Of the patients with S. pneumoniae isolated during pretreatment (from either cerebrospinal fluid or blood), 11 (16 isolates in total) had their isolates tested against penicillin and all were susceptible. Presence or absence of seizures, level of consciousness, Glasgow Coma Score and duration of signs and symptoms were strong predictors of outcome. Collectively no specific safety concerns were identified. Conclusion. Cefepime represents an important therapeutic option for the empiric treatment of bacterial meningitis in children, based on the good clinical response and bacteriologic eradication rates observed in this review.

Revista chilena de infectología, 2009

Revista chilena de infectología, 2002

Revista médica de Chile, 2008

Human papillomavirus vaccine. Statement of the Consultive Committee of Immunizations on behalf of... more Human papillomavirus vaccine. Statement of the Consultive Committee of Immunizations on behalf of The Chilean Infectious Diseases Society. September 2008 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.

Revista chilena de infectología, 2012

Revista chilena de pediatría, 1995

Pediatric Research, 2005

To assess iron nutrition during the first 6 months of life of infants born to iron supplemented m... more To assess iron nutrition during the first 6 months of life of infants born to iron supplemented mothers during pregnancy. Subjects and Methods: In a supplementation trial of iron plus or without zinc we followed up a group of 219 infants, during the first 6 months of life, born to iron supplemented mothers. Changes in hemoglobin (Hb) and, serum ferritin (SF) are presented. Inclusion criteria were birth at term with adequate weight for gestational age, healthy and exclusively breastfed.. Mothers received during pregnancy iron supplement (Group Aϭ103) or Iron ϩ zinc (Group Bϭ116). Results: No differences in health and nutrition status or SES indicators by group of supplementation were demonstrated. Mean Hb concentration at birth was 180.6 g/L in group A and 177.8 g/L in group B. At 3 months of age, mean Hb was 102.0 g/L and, 103.8 g/L and, at 6 months of age was 105.2 g/L and, 105.8 g/L, respectively (NS). Median SF at birth was 152.0 ug/L (group A) and 177.4 ug/L (group B), at 3 months 166.0 ug/L and 134.6 ug/L (NS) and, at 6 months this was 49.3 ug/L and, 43.3 ug/L. Hb at 3 months correlated with SF at birth (pϭ0.018). At 3 months there was no difference in SF by group of supplementation, SF correlated with SF at birth; values were higher in girls than boys (p Ͻ0.01). At 6 months of age, Hb correlated with Hb at 3 month (pϭ0.03) and with maternal education (controlling for Hb at 3 months) pϭ0.002. At 6 months of age 75% infants were exclusively breastfed, all had weight and height adequate for age and 62% had Hb Ͻ 110 g/L. Hemoglobin percentiles by age and sex are presented and related variables and anemia control strategies in infancy are discussed. Supported by USAID/OHN, Cooperative Agreement DAN-5116-8051-00 4 RECOVERY OF BONE COMPONENT IN RPC RATS TREATED WITH GH. A DISCRIMINANT ANALYSIS STUDY.

Principles and Practice of Pediatric Infectious Diseases, 2018

Rotavirus is the most common cause of severe gastroenteritis in children younger than 3 years of ... more Rotavirus is the most common cause of severe gastroenteritis in children younger than 3 years of age worldwide. New rotavirus vaccine candidates were required to confer early protection against the most common rotavirus serotypes and to be well tolerated and not associated with intussusception. RIX4414 is a human-attenuated G1(P8) oral rotavirus vaccine administered in two doses at approximately 6–24 weeks of age. The first dose may be administered from the age of 6 weeks. There should be an interval of at least 4 weeks between doses and the vaccination course should preferably be given before 16 weeks of age and must be completed, according to the manufacturer, by the age of 24 weeks. In a worldwide development program involving more than 70,000 children in six Phase I–III field trials, this vaccine proved to be nonreactogenic, well tolerated and not associated with intussusception. The vaccine provides over 85–96% protection against moderate-to-severe gastroenteritis caused by G1 ...

Journal of Clinical Microbiology, 1998

The frequency of astrovirus infection in 456 Chilean children with diarrhea was determined by enz... more The frequency of astrovirus infection in 456 Chilean children with diarrhea was determined by enzyme-linked immunosorbent assay, reverse transcriptase PCR, and cell culture. Astrovirus was detected in 16.5% of rotavirus-negative and 7% of rotavirus-positive samples obtained from emergency rooms or hospitals and in 11% of samples from day care centers. HAst-1 was the predominant serotype identified.

F1000 - Post-publication peer review of the biomedical literature, 2020

Pediatric Infectious Disease Journal, 2018

Background: Rotaviruses (RVs) and noroviruses (NoVs) are the most common causes of severe acute g... more Background: Rotaviruses (RVs) and noroviruses (NoVs) are the most common causes of severe acute gastroenteritis in children. It is generally accepted that RVs cause severe acute gastroenteritis in a higher proportion of cases compared with NoVs. To our knowledge, there are no systematic reviews and meta-analyses comparing the severity of NoV and RV disease. Methods: We searched MEDLINE for studies reporting data for NoV and RV medically attended disease severity in children. We included studies where all children had been tested for both NoV (reverse transcription polymerase chain reaction) and RV (enzyme-linked immunosorbent assay or reverse transcription polymerase chain reaction) and that reported disease severity using the Vesikari or modified Vesikari score, or provided clinical information on severity. We generated pooled estimates of the mean with 95% confidence intervals using random effects meta-analysis. Results: We identified 266 publications, of which 31 were retained fo...

Open Forum Infectious Diseases, 2018

Background 4CMenB has been shown to be immunogenic with an acceptable safety profile in infants a... more Background 4CMenB has been shown to be immunogenic with an acceptable safety profile in infants and young adolescents. However, no data on long-term persistence after primary vaccination in adolescents are available. This is the first study to assess antibody persistence, booster response, and safety of 4CMenB in adolescents and young adults up to 7.5 years following the primary vaccination in adolescence. Methods This phase 3b, open-label, extension study (NCT02446743) assessed the antibody persistence and booster response at 4 years (Canada and Australia, NCT01423084) or 7.5 years (Chile, NCT00661713) after primary vaccination with 4CMenB (following 0 + 1-, 0 + 2-, or 0 + 6-month schedules), compared with vaccine-naïve (VN), healthy controls. Chilean follow-on (FO) and VN participants aged 18–24 years received either a booster dose of 4CMenB 7.5 years postprimary series (Group FO, N = 131) or 2 primary doses, 1 month apart (Group VN, N = 150). Immunogenicity was measured using hum...

F1000 - Post-publication peer review of the biomedical literature, 2017

Background An association between rotavirus immunisation and intussusception (IS) has been sugges... more Background An association between rotavirus immunisation and intussusception (IS) has been suggested with present rotavirus vaccines in post-licensure studies. In Finland, rotavirus vaccination programme was implemented in September 2009 using a 2, 3, and 5 months schedule with the pentavalent rotavirus vaccine. By the end of 2013, it is estimated that 719 000 rotavirus vaccine doses have been given in the national programme of which 240 000 were first doses. Nationwide register allows us to evaluate the association between rotavirus vaccination and IS. Methods and Materials Cases of IS diagnosed during 1999-2013 were identified from National Hospital Discharge Register. All cases under 250 days of age diagnosed during 2009-2013 were confirmed by reviewing medical charts. Self-controlled case-series method was used to assess the risk of IS during 1-21 days compared to 22-42 days post vaccination. Findings In register data the relative incidence of IS at 2 months of age between the post and pre vaccination era was 9.1 (95%CI 2.0-84.3). We identified 22 verified cases with date of admission less than 43 days after any of the three rotavirus vaccine doses. The incidence of IS in the risk period after the 1st dose relative to the control period was 2.0 (95% CI 0.5-8.4; p = 0.34.) Number of excess IS cases per 100 000 first vaccine doses was therefore estimated to be 1.04 (95% CI 0.0-2.5), i.e. one additional IS case per 96 000 first doses of rotavirus vaccine (95% CI 54 600 to 1). There was no risk detected after 2nd and 3rd doses. Conclusion The finding is in line with the recent published estimates. The benefits of rotavirus immunisation programme outweigh possible small risks of intussusception.

F1000 - Post-publication peer review of the biomedical literature, 2017

Regarding public health in Brazil, a new scenario emerged with the establishment of universal rot... more Regarding public health in Brazil, a new scenario emerged with the establishment of universal rotavirus (RV) vaccination programs. Herein, the data from the five years of surveillance (2007-2012) of G-and P-type RV strains isolated from individuals with acute gastroenteritis in Brazil are reported. A total of 6,196 fecal specimens were investigated by ELISA and RT-PCR. RVs were detected in 19.1% (1,181/6,196). The peak of RV incidence moved from June-August to September. RV was detected less frequently (19.5%) among children ≤ 5 years than in older children and adolescents (6-18 years) (40.6%). Genotype distribution showed a different profile for each year: G2P[4] strains were most prevalent during 2007-2010, G9P[8] in 2011, and G12P[8] in 2012. Mixed infections (G1+G2P[4], G2+G3P[4]+P[8], G2+G12P[8]), unusual combinations (G1P[4], G2P[6]), and rare strains (G3P[3]) were also identified throughout the study period. Widespread vaccination may alter the RV seasonal pattern. The finding of RV disease affecting older children and adolescents after vaccine implementation has been reported worldwide. G2P[4] emergence most likely follows a global trend seemingly unrelated to vaccination, and G12, apparently, is emerging in the Brazilian population. The rapidly changing RV genotype patterns detected during this study illustrate a dynamic population of co-circulating wildtype RVs in Brazil.

Journal of Clinical Oncology, 2001

PURPOSE: To identify clinical and laboratory parameters present at the time of a first evaluation... more PURPOSE: To identify clinical and laboratory parameters present at the time of a first evaluation that could help predict which children with cancer, fever, and neutropenia were at high risk or low risk for an invasive bacterial infection. PATIENTS AND METHODS: Over a 17-month period, all children with cancer, fever, and neutropenia admitted to five hospitals in Santiago, Chile, were enrolled onto a prospective protocol. Associations between admission parameters and risk for invasive bacterial infection were assessed by univariate and logistic regression analyses. RESULTS: A total of 447 febrile neutropenic episodes occurred in 257 children. Five parameters were statistically independent risk factors for an invasive bacterial infection. Ranked by order of significance, they were as follows: C-reactive protein levels of 90 mg/L or higher (relative risk [RR], 4.2; 95% confidence interval [CI], 3.6 to 4.8); presence of hypotension (RR, 2.7; 95% CI, 2.3 to 3.2); relapse of leukemia as c...

Revista médica de Chile, 2016

The Chilean Academy of Medicine supports the 2009 law by which all medical graduates from Chile a... more The Chilean Academy of Medicine supports the 2009 law by which all medical graduates from Chile as well as from foreign countries that wish to start their medical practice should have approved the National Board Examination in Medicine ("Eunacom"). Success in this examination of basic clinical knowledge and competences is mandatory to become attending physicians at the Public Health Care System and to apply to state-funded postgraduate education. Annually, about 90% Chilean graduates approve this examination, while no more than 20 % of foreign graduates do. Given the shortage of primary care physicians, some members of the Parliament have proposed to simplify the test or to exempt foreign medical graduates from it in order to broaden the coverage of primary care and decrease the waiting lists. The Chilean Academy of Medicine considers this shortcut strategy as dangerous for the Chilean population and unfair for our graduates. This Declaration has been send to the National Health Authorities, to Deans of all Medical Schools, and to public press media.

The Lancet, 2016

Background Replacement of the trivalent oral poliovirus vaccine (tOPV) with bivalent types 1 and ... more 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. 6-week-old full-term infants due for their fi rst polio vaccinations, who were healthy on physical examination, with no obvious medical conditions and no known chronic medical disorders, were enrolled from four investigational sites in Colombia, Dominican Republic, Guatemala, and Panama. The infants were randomly assigned by permuted block randomisation (through the use of a computer-generated list, block size 36) to nine groups, of which fi ve will be discussed in this report. These fi ve groups were randomly assigned 1:1:1:1 to four permutations of schedule: groups 1 and 2 (control groups) received bOPV at 6, 10, and 14 weeks; group 3 (also a control group, which did not count as a permutation) received tOPV at 6, 10, and 14 weeks; group 4 received bOPV plus one dose of IPV at 14 weeks; and group 5 received bOPV plus two doses of IPV at 14 and 36 weeks. Infants in all groups were challenged with monovalent type 2 vaccine (mOPV2) at 18 weeks (groups 1, 3, and 4) or 40 weeks (groups 2 and 5). The primary objective was to assess the superiority of bOPV-IPV schedules over bOPV alone, as assessed by the primary endpoints of humoral immunity (neutralising antibodies-ie, seroconversion) to all three serotypes and intestinal immunity (faecal viral shedding post-challenge) to serotype 2, analysed in the per-protocol population. Serious and medically important adverse events were monitored for up to 6 months after the study vaccination. This study is registered with ClinicalTrials.gov, number NCT01831050, and has been completed.

Emerging Infectious Diseases, 2015

(EV-D68) is an emergent viral pathogen associated with severe respiratory illness, especially in ... more (EV-D68) is an emergent viral pathogen associated with severe respiratory illness, especially in children with asthma (1). The ongoing epidemic in the United States has expanded to 47 states; as of November 25, 2014, a total of 1,121 persons were affected (http://www.cdc.gov/non-polio-enterovirus/outbreaks/EV-D68-outbreaks.html). In Chile, because of clinical suspicion of infection caused by the same EV-D68 reported in the United States, we conducted further testing. We selected 6 children who were at Clinica Las Condes (CLC), Santiago, during September-October 2014, for whom nasopharyngeal samples were enterovirus positive according to multiplex PCR (CLART PneumoVir; Genomica, Madrid, Spain) or rhinovirus/enterovirus positive according to the FilmArray Respiratory Panel (BioFire Diagnostics, Salt Lake City, UT, USA). The CLC ethics committee authorized the study. CLC is the second largest private hospital in eastern Santiago, which has a population of nearly 400,000. Since 2008, detection of respiratory viruses by CLART PneumoVir has been performed for all hospitalized CLC patients with respiratory disease. This test detects 17 respiratory viruses, including enterovirus (generic detection). Since 2014, CLC also incorporated testing with the

The Pediatric Infectious Disease Journal, 2001

Background. Because the introduction of extended spectrum cephalosporins into pediatric practice ... more Background. Because the introduction of extended spectrum cephalosporins into pediatric practice offers a number of choices for treatment, we review efficacy studies of cefepime monotherapy in the treatment of bacterial meningitis in children. Methods. Two open, randomized, comparative studies assessed the efficacy of cefepime empiric monotherapy in the treatment of bacterial meningitis in 345 pediatric patients. These studies were conducted in Latin America and compared cefepime (50 mg/kg/dose every 8 h) with either cefotaxime (50 mg/kg/dose every 6 h) or ceftriaxone (50 mg/kg/dose every 12 h). Patients 2 months to 14 years old who had clinical signs and symptoms consistent with a central nervous system infection were enrolled. Efficacy was based on clinical and bacteriologic response. Results. Integrated results from the Latin American studies indicated a 75% cure rate with cefepime vs. a 78% cure rate with comparator, among evaluable patients. Overall the rate of treatment failure was 12%. Haemophilus influenzae had the highest bacterial eradication rate (97% overall), and rates were comparable in cefepime and comparator arms. Eradication rates for Neisseria meningitidis were equally high in both treatment arms (95% overall), and the eradication rate for Streptococcus pneumoniae was 92% overall. Of the patients with S. pneumoniae isolated during pretreatment (from either cerebrospinal fluid or blood), 11 (16 isolates in total) had their isolates tested against penicillin and all were susceptible. Presence or absence of seizures, level of consciousness, Glasgow Coma Score and duration of signs and symptoms were strong predictors of outcome. Collectively no specific safety concerns were identified. Conclusion. Cefepime represents an important therapeutic option for the empiric treatment of bacterial meningitis in children, based on the good clinical response and bacteriologic eradication rates observed in this review.

Revista chilena de infectología, 2009

Revista chilena de infectología, 2002

Revista médica de Chile, 2008

Human papillomavirus vaccine. Statement of the Consultive Committee of Immunizations on behalf of... more Human papillomavirus vaccine. Statement of the Consultive Committee of Immunizations on behalf of The Chilean Infectious Diseases Society. September 2008 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.

Revista chilena de infectología, 2012

Revista chilena de pediatría, 1995

Pediatric Research, 2005

To assess iron nutrition during the first 6 months of life of infants born to iron supplemented m... more To assess iron nutrition during the first 6 months of life of infants born to iron supplemented mothers during pregnancy. Subjects and Methods: In a supplementation trial of iron plus or without zinc we followed up a group of 219 infants, during the first 6 months of life, born to iron supplemented mothers. Changes in hemoglobin (Hb) and, serum ferritin (SF) are presented. Inclusion criteria were birth at term with adequate weight for gestational age, healthy and exclusively breastfed.. Mothers received during pregnancy iron supplement (Group Aϭ103) or Iron ϩ zinc (Group Bϭ116). Results: No differences in health and nutrition status or SES indicators by group of supplementation were demonstrated. Mean Hb concentration at birth was 180.6 g/L in group A and 177.8 g/L in group B. At 3 months of age, mean Hb was 102.0 g/L and, 103.8 g/L and, at 6 months of age was 105.2 g/L and, 105.8 g/L, respectively (NS). Median SF at birth was 152.0 ug/L (group A) and 177.4 ug/L (group B), at 3 months 166.0 ug/L and 134.6 ug/L (NS) and, at 6 months this was 49.3 ug/L and, 43.3 ug/L. Hb at 3 months correlated with SF at birth (pϭ0.018). At 3 months there was no difference in SF by group of supplementation, SF correlated with SF at birth; values were higher in girls than boys (p Ͻ0.01). At 6 months of age, Hb correlated with Hb at 3 month (pϭ0.03) and with maternal education (controlling for Hb at 3 months) pϭ0.002. At 6 months of age 75% infants were exclusively breastfed, all had weight and height adequate for age and 62% had Hb Ͻ 110 g/L. Hemoglobin percentiles by age and sex are presented and related variables and anemia control strategies in infancy are discussed. Supported by USAID/OHN, Cooperative Agreement DAN-5116-8051-00 4 RECOVERY OF BONE COMPONENT IN RPC RATS TREATED WITH GH. A DISCRIMINANT ANALYSIS STUDY.