Mario Melgar

Dr. Mario Melgar


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 September 2019 in The American Journal of Tropical Medicine and Hygiene
Verified
Journal Article
Open access
PDF file
JGJames T. Gaensbauer
James T. Gaensbauer
MLMolly M Lamb
Molly M Lamb
DCDiva M. Calvimontes
Diva M. Calvimontes
EAEdwin J Asturias
Edwin J Asturias
SKSatoshi Kamidani
Satoshi Kamidani
MMMario Melgar
Mario Melgar
Multiplex polymerase chain reaction (PCR) platforms have enhanced understanding of intestinal pathogens in low- and middle-income countries (LMICs). However, few such studies have been performed in Latin America, where poverty, poor sanitation, and undernutrition persist. Multiplex PCR (BioFire, Salt Lake City, UT) was used to identify viral, bacterial, and parasitic pathogens in stool collected on day 1 and 31 from children aged 6 to 35 months with acute, non-bloody diarrhea in two locations (rural and urban) in Guatemala. We analyzed correlation between pathogens and clinical, demographic, and socioeconomic variables; described patterns of pathogen acquisition, persistence, and clearance over the 30-day period; and calculated population attributable fractions (PAFs) for diarrheal causation for individual pathogens. We analyzed 316 subjects (144 urban; 172 rural) enrolled between March 2015 and January 2016. Rural subjects had significantly more malnutrition, animal exposure, and unimproved water/sanitation infrastructure. The majority of subjects had multiple pathogens/sample (4.8 rural and 2.7 urban). Few meaningful correlates were identified between individual pathogens and clinical, demographic, or environmental variables. Escherichia coli pathotypes, Shigella, Campylobacter, and Giardia had high rates of persistence between initial and 30-day follow-up. Statistically significant adjusted PAFs were identified for Campylobacter (14.9%, 95% CI: 3.2–23.1), norovirus (10.2%, 95% CI: 0.4–17.1), sapovirus (7.6%, 95% CI: 2.3–10.9), and adenovirus 40/41 (5.6%, 95% CI: 0.3–8.7). These observations further characterize the diversity and complexity of enteric pathogens in children in LMICs. Patterns of chronic symptomatic and asymptomatic infection among Latin American children are similar to those observed in other LMIC regions. Findings have direct implications for practitioners treating individuals with acute infectious diarrhea and should inform regional public health strategies.

26 April 2024 in Antimicrobial Resistance & Infection Control
Verified
Journal Article
Open access
PDF file
VFValeria Fabre
Valeria Fabre
SCSara E. Cosgrove
Sara E. Cosgrove
FLFernanda C. Lessa
Fernanda C. Lessa
TPTwisha S. Patel
Twisha S. Patel
GRGuadalupe Reyes-Morales
Guadalupe Reyes-Morales
RQRodolfo E. Quiros
Rodolfo E. Quiros
Background: The burden of antimicrobial resistance (AMR) in Latin America is high. Little is known about healthcare workers’ (HCWs) knowledge, attitudes, and perceptions of antimicrobial stewardship (AS), AMR, and antibiotic use (AU) in the region. Methods: HCWs from 42 hospitals from 5 Latin American countries were invited to take an electronic, voluntary, anonymous survey regarding knowledge, attitudes, and perceptions of AS, AMR, and AU between March–April 2023. Findings: Overall, 996 HCWs completed the survey (52% physicians, 32% nurses, 11% pharmacists, 3% microbiologists, and 2% “other”). More than 90% of respondents indicated optimizing AU was a priority at their healthcare facility (HCF), 69% stated the importance of AS was communicated at their HCF, and 23% were unfamiliar with the term “antibiotic stewardship”. Most (> 95%) respondents acknowledged that appropriate AU can reduce AMR; however, few thought AU (< 30%) or AMR (< 50%) were a problem in their HCF. Lack of access to antibiogram and to locally endorsed guidelines was reported by 51% and 34% of HCWs, respectively. Among prescribers, 53% did not consider non-physicians’ opinions to make antibiotic-related decisions, 22% reported not receiving education on how to select antibiotics based on culture results and 60% stated patients and families influence their antibiotic decisions. Conclusions: Although HCWs perceived improving AU as a priority, they did not perceive AU or AMR as a problem in their HCF. AS opportunities include improved access to guidelines, access to AMR/AU data, teamwork, and education on AS for HCWs and patients and families.

1 May 2021 in American Journal of Infection Control
Verified
Journal Article
Open access
MRMarilyn Ramirez
Marilyn Ramirez
LMLaura Matheu
Laura Matheu
MGMiguel Gomez
Miguel Gomez
ACAlicia Chang
Alicia Chang
JFJose Ferrolino
Jose Ferrolino
MMMario Melgar
Mario Melgar
Routine manual cleaning and disinfection of the health care environment is often suboptimal. Residual contamination poses an infection risk, particularly for immunocompromised patients. This study evaluates the efficacy of dry hydrogen peroxide (DHP) on microbial surface contamination in a pediatric oncology intensive care unit. Surface samples from 5 high-touch and 2 low-touch surfaces were obtained for culture and adenosine triphosphate readings after manual cleaning on multiple days in 4 intensive care unit rooms, before and after DHP was deployed. Air samples were collected as well at the study site. Data outcomes were measured in terms of total colony-forming units for the cultures and relative light units for adenosine triphosphate. The overall mean surface microbial burden was significantly reduced in the intervention group compared to the control group (mean 5.50 vs 11.77, P<.001). These reductions in colony-forming units were seen across all sampling sites in the intervention group. A reduction in the mean relative light units levels was also noted in the intervention group when compared to the control group (172.08 vs 225.83, P <.006). Reductions with the air samples were also noted (P = .139). Study demonstrates that DHP was effective in reducing microbial surface contamination and improves quality of environmental cleaning.

3 March 2024 in Vaccine
Verified
Journal Article
Open access
TETracy Evans-Gilbert
Tracy Evans-Gilbert
JFJ Peter Figueroa
J Peter Figueroa
PBPABLO EDUARDO BONVEHI
PABLO EDUARDO BONVEHI
MMMario Melgar
Mario Melgar
DSDaniel Stecher
Daniel Stecher
NSNalora Jennifer Sanwogou
Nalora Jennifer Sanwogou
Following the COVID-19 pandemic, the Americas faced a significant decline in vaccination coverage as well as increased vaccine hesitancy. The objective of this paper is to summarize the challenges and opportunities outlined by the National Immunization Technical Advisory Groups (NITAGs) in Latin America and the Caribbean (LAC) and prioritize targeted interventions. The exploratory survey included open-ended questions on two primary components: challenges, and opportunities. Free-text comments presented by each NITAG were collated and classified using indicators and subindicators of the NITAG Maturity Assessment Tool (NMAT). Opportunities were classified thematically, and priority actions were generated from the responses. All 21 NITAGs in LAC, representing 40 countries, 76 % of which have been active for over a decade, responded to the survey. The most common challenges were establishment and composition (62 %), integration into policymaking (62 %), resources and secretariat (52 %), and stakeholder recognition (48 %). The distribution of responses was seen across the whole sample and did not suggest a more pronounced need in relation to year of establishment. Opportunities included maximizing the Regional NITAG Network of the Americas (RNA) to facilitate collaboration, information sharing, visibility, and communication; existing global, regional, and systemic analyses; the World Health Organization/Pan American Health Organization (WHO/PAHO) templates for standard operating procedures; twinning programs with mature NITAGs; and NITAGs in governance structures. Action plans were outlined to formalize the establishment of NITAGs and broaden their composition; strengthen decision-making and access to data resources; and enhance the credibility of evidence-based recommendations and their uptake by policymakers and the public. NITAG challenges are not unique to LAC. NITAGs have outlined a short-term prioritized action plan which is critical to enhancing NITAG value and importance in countries.

1 August 2022 in American Journal of Infection Control
Verified
Journal Article
Open access
MMMario Melgar
Mario Melgar
MRMarilyn Ramirez
Marilyn Ramirez
ACAlicia Chang
Alicia Chang
FAFederico Antillon
Federico Antillon
This study aims to describe the effect of Dry Hydrogen Peroxide (DHP), as an adjunct to environmental cleaning and disinfection, on the incidence of hospital-acquired infections (HAIs) at Unidad Nacional de Oncologia Pediatrica (UNOP) in Guatemala City, Guatemala. A retrospective study of all HAI data from the hospital's surveillance system, which follows Centers for Disease Control and Prevention (CDC) protocols, was conducted from January 2019 to November 2020. DHP was installed in all Pediatric Intensive Care Unit (PICU) rooms in January 2020, but nowhere else in the hospital, including the Intermediate Care Unit (IMCU). There were 189 HAI cases during the study period, with 173 occurring in either the PICU or IMCU. A statistically significant decrease in HAI incidence rates occurred in the PICU in 2020 compared to 2019 (P = .028), including Clostridiodes-associated gastroenteritis (P = .048). Logistic multivariate regression yielded a significant association between DHP exposure and reduced odds of developing an HAI during the study (OR = 0.3857, P = .029). The use of DHP as an adjunct technology for environmental cleaning and disinfection contributed to the reduction in HAIs in the PICU. Our study highlights the value of such an approach as an addition to manual cleaning to decrease the risk of infection from environmental contamination.

14 April 2025 in The Pediatric Infectious Disease Journal
Verified
Journal Article
Open access
RMRosie MBChB Mngqibisa
Rosie MBChB Mngqibisa
OFOleksandr Fofanov
Oleksandr Fofanov
CGCarlos F. Grazioso
Carlos F. Grazioso
MMMario Melgar
Mario Melgar
MBMelissa Boddicker
Melissa Boddicker
PSPamela Sears
Pamela Sears
Background: Acute bacterial skin and skin structure infections (ABSSSI) are serious infections of the skin and subcutaneous tissue that include major cutaneous abscesses, cellulitis/erysipelas, and wound infections. ABSSSI caused by Gram-positive pathogens are common in children, who tend to experience high rates of morbidity and hospitalization due to ABSSSI, including those caused by antibacterial-resistant pathogens. Methods: This phase 3 study (NCT03176134) investigated the safety of tedizolid phosphate and its ability to treat ABSSSI in pediatric participants 28 days to 90%) and comparable between groups. All participants in the tedizolid phosphate treatment group who had skin culture results at baseline experienced favorable microbiological response at the TOC visit. Conclusions: The results of this study provide evidence to support the use of tedizolid phosphate to treat ABSSSI caused by Gram-positive pathogens in pediatric patients from 28 days to <12 years of age.