Carlos Alberto Sanchez

Dr. Carlos Alberto Sanchez

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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3 May 2023 in Health Science Reports
Verified
Journal Article
Open access
CSCarlos Alberto Sanchez
Carlos Alberto Sanchez
OROriana Rivera-Lozada
Oriana Rivera-Lozada
MLMichelle Lozada-Urbano
Michelle Lozada-Urbano
PBPablo Best‐Bandenay
Pablo Best‐Bandenay
Background and Aims: Community‐acquired pneumonia is responsible for substantial mortality, and pneumococcus is commonly accepted as a major cause of pneumonia, regardless of laboratory confirmation. Child immunization programs have reported success in decreasing pneumonia mortality: directly in young children and indirectly (herd immunity) in unvaccinated adult populations in some countries. We assess changes in mortality trends for all‐cause pneumonia in older adults associated with the introduction of pneumococcal vaccination for children in Peru.Methods: This is a secondary analysis on administrative data collected periodically by the Peruvian Ministry of Health. An observational retrospective time series analysis was conducted using longitudinal population‐based data from death certificates in Peru between 2003 and 2017. The time series includes 6 years before and 9 years after the introduction of the pneumococcal‐conjugated vaccines in the national child immunization program in 2009. Monthly frequencies and annual rates for all‐cause pneumonia deaths in children under 5 years of age and adults over 65 years of age are presented. Linear and quadratic trends are analyzed.Results: Deaths among older adults accounted for 75.6% of all‐cause pneumonia mortality in Peru, with 94.4% of these reporting “pneumonia due to unspecified organism” as the underlying cause of death. Comparing pre‐ and post‐child immunization program periods, annual average mortality rates from unspecified pneumonia decreased by 22.7% in young children but increased by 19.6% in older adults. A linear trend model supports this overall tendency, but a quadratic curve explains the data better.Conclusion: Pneumococcal‐conjugated vaccines are developed using serotypes prevalent in selected countries from less common (invasive) pneumococcal disease and expected to prevent mortality worldwide from widespread (noninvasive) pneumonia. Our results do not support the presence of herd immunity from pneumococcal vaccination of children for community‐acquired pneumonia in the increasingly ageing population of Peru. This should direct future research and could influence public health policy.

7 August 2023 in BMJ Global Health
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Journal Article
Open access
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CSCarlos Alberto Sanchez
Carlos Alberto Sanchez
OROriana Rivera-Lozada
Oriana Rivera-Lozada
MLMichelle Lozada-Urbano
Michelle Lozada-Urbano
PBPablo Best
Pablo Best
Pneumonia due to Streptococcus pneumoniae (pneumococcus) is a major cause of mortality in infants (children under 1 year of age), and pneumococcal conjugate vaccines (PCVs), delivered during the first year of life, are available since the year 2000. Given those two premises, the conclusion follows logically that favourable impact reported for PCVs in preventing pneumococcal disease should be reflected in the infant mortality rates (IMRs) from all causes. Using publicly available datasets, country-level IMR estimates from UNICEF and PCV introduction status from WHO, country-specific time series analysed the temporal relationship between annual IMRs and the introduction of PCVs, providing a unique context into the long-term secular trends of IMRs in countries that included and countries that did not include PCVs in their national immunisation programmes. PCV status was available for 194 countries during the period 1950–2020: 150 (77.3%) of these countries achieved nationwide PCV coverage at some point after the year 2000, 13 (6.7%) achieved only partial or temporary PCV coverage, and 31 (15.9%) never introduced PCVs to their population. One hundred and thirty-nine (92.7%) of countries that reported a decreasing (negative) trend in IMR, also reported a strong correlation with decreasing maternal mortality rates (MMRs), suggesting an improvement in overall child/mother healthcare. Conversely, all but one of the countries that never introduced PCVs in their national immunisation programme also reported a decreasing trend in IMR that strongly correlates with MMRs. IMRs have been decreasing for decades all over the world, but this latest decrease may not be related to PCVs.

14 November 2023 in Vaccines
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Journal Article
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CSCarlos Alberto Sanchez
Carlos Alberto Sanchez
MLMichelle Lozada-Urbano
Michelle Lozada-Urbano
PBPablo Best-Bandenay
Pablo Best-Bandenay
Worldwide, conjugated pneumococcal vaccines (PCVs) have proven effective against invasive pneumococcal disease, but non-invasive pneumonia is a major cause of mortality in young children and serotypes vary geographically, affecting effectiveness. We analyze nationwide death certificate data between 2003–2017 to assess the impact of PCVs on pneumonia mortality among young children from Peru. We report descriptive statistics and perform timeseries analysis on annual mortality rates (AMRs) and monthly frequencies of pneumonia deaths. Children under 5 years of age accounted for 6.2% (n = 10,408) of all pneumonia deaths (N = 166,844), and 32.3% (n = 3363) were children between 1–4 years of age, of which 95.1% did not report pneumonia etiology. Comparing periods before and after PCV introduction in 2009, mean AMRs dropped 13.5% and 26.0% for children between 1–4 years of age (toddlers/preschoolers), and children under 1 year of age (infants), respectively. A moderate correlation (Spearman’s r = 0.546, p < 0.01) in the monthly frequency of pneumonia deaths was estimated between both age groups. Quadratic regression suggests a change in direction around 2005 (highest pneumonia mortality) for both age groups, but percentage change analysis identified an inflection point in 2013 for infants only, not for toddlers/preschoolers, suggesting that the impact of PCVs might be different for each age group.

22 November 2022 in Anales de la Facultad de Medicina
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Journal Article
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CSCarlos Alberto Sanchez
Carlos Alberto Sanchez
CDCristina Dávila
Cristina Dávila
WLWil Laura
Wil Laura
CMCiro Maguiña
Ciro Maguiña
Introducción. Es un concepto generalizado que las infecciones respiratorias son estacionales, pero pocas veces se precisan localmente estos períodos de alta frecuencia en un país con diversidad de climas. Anticipar la temporada de neumonía a nivel local puede proveer de un mejor uso de recursos críticos. Objetivo. Examinar la variabilidad estacional en defunciones mensuales por neumonía en el Perú. Métodos. Estudio observacional retrospectivo de análisis de serie de tiempo para identificar períodos de alta mortalidad por neumonía en siete ciudades del Perú. Se revisaron registros administrativos del Ministerio de Salud sobre defunciones por neumonía durante los años 2003-2017. Se calcularon estadísticas descriptivas y se analizó mediante una serie de tiempo a escala mensual la frecuencia de defunciones por neumonía, precipitación acumulada, y la temperatura ambiental máxima y mínima. Resultados. El 94,4% de las defunciones por neumonía (N = 166 844) reportaron como causa «organismo no especificado», y el 75,6% eran adultos mayores de 65 años. En Tarma, Arequipa y Cusco la temperatura mínima tiene una correlación negativa con las defunciones por neumonía en todas las edades y al menos uno de los grupos de riesgo. En Iquitos la temperatura mínima tiene una correlación positiva con las defunciones en menores de 5 años. Pucallpa y Cajamarca no tuvieron correlaciones significativas. El clima de Lima es un caso particular. La distribución durante el año de las muertes por neumonía sugiere una secuencia norte-sur, mientras que el análisis espaciotemporal del clima sugiere un patrón que va de sur-norte. Conclusión. Existen diferentes patrones estacionales en diferentes ciudades y grupos de riesgo.

2 April 2024 in F1000Research
Verified
Journal Article
Open access
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CSCarlos Alberto Sanchez
Carlos Alberto Sanchez
MLMichelle Lozada-Urbano
Michelle Lozada-Urbano
EOEstela E. Ospina
Estela E. Ospina
Background Population-based exposure assessments for heavy metals and metalloids (by governmental and private institutions) are common in Peru, but most studies generally focus on the analysis of a single chemical element, like lead or mercury, and lack an appropriate reference regarding the health impact on the exposed population. The complex/mixed chemical interactions within the human body have not yet been studied for all long-term health effects. Methods We reviewed laboratory results from five studies, between 2005-2013, that analysed multiple elements (between 13 and 17 chemical elements in each study) in spot urine samples from Peruvian communities considered exposed and not exposed. All laboratory analysis were performed using inductively coupled plasma mass spectrometry (ICP-MS) at the Environmental Health Laboratory Division of the Centers for Disease Control and Prevention (CDC) of the United States. Results Six chemical elements (total arsenic, caesium, cobalt, lead, molybdenum, and thallium) were present in almost all spot urine samples (>98% of participants), evidencing exposure (qualitative assessment). Exposure to other chemical elements like barium, cadmium, tungsten, antimony and uranium, varied among localities, while chemical elements like beryllium and platinum were rarely detected (<3% and <10% of participants, respectively) in spot urine samples. Most geometric means of urine concentration for total arsenic, lead, cadmium and mercury are higher for the Peruvian locations than for national estimates in Canada and the United States, but not in all locations. Conclusion Comparing averages across different populations can be misleading but comparing periodic values from the same population in the future could evidence an exposure trend. Future studies are needed to develop reference levels for exposed Peruvian populations. This study highlights potential health risks from exposure to environmental chemical elements and can be the first step towards understanding and mitigating human exposure to heavy metals and metalloids for known exposed populations in Peru.