Guía de Práctica Clínica para el diagnóstico temprano y la referencia oportuna del cáncer de pulmón.

OBJETIVO: Proporcionar recomendaciones para la detección temprana de pacientes con alto riesgo de desarrollar cáncer de pulmón (CP) en el primer nivel de atención y su referencia oportuna. Material y métodos. Se realizó una búsqueda detallada de la evidencia científica disponible para responder las preguntas de investigación clínica y se utilizó el Panel Delphi modificado para lograr un consenso entre expertos. RESULTADOS: Se generaron 14 recomendaciones siguiendo los estándares de una GPC. Conclusión. El CP representa un problema de salud pública en México; por ello, esta guía establece recomendaciones que apoyan la toma de decisiones sobre la detección precoz y la referencia de pacientes con sospecha de CP en el primer nivel de atención.

Clinical Impact of the COVID-19 Pandemic in Mexican Patients with Thoracic Malignancies.

BACKGROUND: Accumulated evidence indicates that patients with lung cancer are a vulnerable population throughout the pandemic. Limited information is available in Latin America regarding the impact of the pandemic on medical care. The goal of this study was to describe the clinical and social effect of COVID-19 on patients with thoracic cancer and to ascertain outcomes in those with a confirmed diagnosis. MATERIALS AND METHODS: This cohort study included patients with thoracic neoplasms within a single institution between March 1, 2020, and February 28, 2021. All variables of interest were extracted from electronic medical records. During this period, the Depression Anxiety and Stress Scale 21 (DASS-2) was applied to evaluate and identify more common psychological disorders. RESULTS: The mean age for the total cohort (n = 548) was 61.5 ± 12.9 years; non-small cell lung cancer was the most frequent neoplasm (86.9%), advanced stages predominated (80%), and most patients were under active therapy (82.8%). Any change in treatment was reported in 23.9% of patients, of which 78.6% were due to the COVID-19 pandemic. Treatment delays (≥7 days) were the most frequent modifications in 41.9% of cases, followed by treatment suspension at 37.4%. Patients without treatment changes had a more prolonged progression-free survival and overall survival (hazard ratio [HR] 0.21, p < .001 and HR 0.28, p < .001, respectively). The mean DASS-21 score was 10.45 in 144 evaluated patients, with women being more affected than men (11.41 vs. 9.08, p < .001). Anxiety was reported in 30.5% of cases, followed by depression and distress in equal proportions (18%). Depressed and stressed patients had higher odds of experiencing delays in treatment than patients without depression (odds ratio [OR] 4.5, 95% confidence interval [CI] 1.53-13.23, p = .006 and OR 3.18, 95% CI 1.2-10.06, p = .006, respectively). CONCLUSION: Treatment adjustments in patients with thoracic malignancies often occurred to avoid COVID-19 contagion with detrimental effects on survival. Psychological disorders could have a role in adherence to the original treatment regimen. IMPLICATIONS FOR PRACTICE: The pandemic has placed an enormous strain on health care systems globally. Patients with thoracic cancers represent a vulnerable population, with increased morbidity and mortality rates. In Mexico, treatment modifications were common during the pandemic, and those who experienced delays had worse survival outcomes. Most treatment modifications were related to a patient decision rather than a lockdown of health care facilities in which mental health impairment plays an essential role. Moreover, the high case fatality rate highlights the importance of improving medical care access. Likewise, to develop strategies facing future threats that may compromise health care systems in non-developed countries.

Tuberculosis patients display a high proportion of CD8+ T cells with a high cytotoxic potential.

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) and remains a major cause of morbidity and mortality worldwide. In the host's immune response system, T cells play a critical role in mediating protection against Mtb infection, but the role of CD8+ T cells is still controversial. We evaluated the phenotypical characterization and cytotoxic ability of CD8+ T cells by flow cytometry-based assay. Cytokine levels in serum were measured by multiplex cytokine assay. Our data show that cells from TB patients have an increased percentage of peripheral blood CD8+ αß+ T (p = 0.02) and CD56+ CD8+ T (p = 0.02) and a decreased frequency of NKG2D+ CD8+ T (p = 0.02) compared with healthy donors. Unlike CD8+ T cells from healthy donors, CD8+ T cells from TB patients exhibit greater cytotoxicity, mediated by HLA class I molecules, on autologous monocytes in the presence of mycobacterial antigens (p = 0.005). Finally, TB patients have a proinflammatory profile characterized by serum high level of TNF-α (p = 0.02) and IL-8 (p = 0.0001), but, interestingly, IL-4 (p = 0.002) was also increased compared with healthy donors. Our data show evidence regarding the highly cytotoxic status of CD8+ T cells in Mtb infection. These cytotoxic cells restricted to HLA-A, B, and C could be used to optimize strategies for designing new TB vaccines or for identifying markers of disease progression.

[Results of the First Mexican Consensus of Vaccination in the Adult]. / Resultados del Primer Consenso Mexicano de Vacunación en el Adulto.

For years our efforts have been focused on vaccination during childhood. Today we know that this is not enough to ensure health in the rest of the life. Childhood is as important as any other stage and, therefore, vaccination must be permanent and differentiated, according to our age, throughout life. Introducing a life course perspective in vaccination programs, with emphasis on adult vaccination, particularly in older adults, offers us the opportunity to review the performance of health programs, actions, and services in the field of immunization, as well as strengthening health promotion actions. In this context, the first Mexican Consensus on Adult Vaccination was carried out in a joint effort of the National Institute of Geriatrics, bringing together a group of specialists who worked on three central objectives: establishing vaccination guidelines throughout the life course, with emphasis on new vaccines; defining priority groups according to their risk factors; and contributing to the effort to promote healthy aging.

[First Mexican Consensus of Vaccination in Adults]. / 1º Consenso Mexicano de Vacunación en el Adulto.

For years our efforts have been focused on vaccination during childhood. Today we know that this is not enough to ensure health in the rest of the life. Childhood is as important as any other stage and, therefore, vaccination must be permanent and differentiated, according to our age, throughout life. Introducing a life course perspective in vaccination programs, with emphasis on adult vaccination, particularly in older adults, offers us the opportunity to review the performance of health programs, actions, and services in the field of immunization, as well as strengthening health promotion actions. In this context, the first Mexican Consensus on Adult Vaccination was carried out in a joint effort of the National Institute of Geriatrics, bringing together a group of specialists who worked on three central objectives: establishing vaccination guidelines throughout the life course, with emphasis on new vaccines; defining priority groups according to their risk factors; and contributing to the effort to promote healthy aging.

Community circulation patterns of oral polio vaccine serotypes 1, 2, and 3 after Mexican national immunization weeks.

BACKGROUND: With wild poliovirus nearing eradication, preventing circulating vaccine-derived poliovirus (cVDPV) by understanding oral polio vaccine (OPV) community circulation is increasingly important. Mexico, where OPV is given only during biannual national immunization weeks (NIWs) but where children receive inactivated polio vaccine (IPV) as part of their primary regimen, provides a natural setting to study OPV community circulation. METHODS: In total, 216 children and household contacts in Veracruz, Mexico, were enrolled, and monthly stool samples and questionnaires collected for 1 year; 2501 stool samples underwent RNA extraction, reverse transcription, and real-time polymerase chain reaction (PCR) to detect OPV serotypes 1, 2, and 3. RESULTS: OPV was detected up to 7 months after an NIW, but not at 8 months. In total, 35% of samples collected from children vaccinated the prior month, but only 4% of other samples, contained OPV. Although each serotype was detected in similar proportions among OPV strains shed as a result of direct vaccination, 87% of OPV acquired through community spread was serotype 2 (P < .0001). CONCLUSIONS: Serotype 2 circulates longer and is transmitted more readily than serotypes 1 or 3 after NIWs in a Mexican community primarily vaccinated with IPV. This may be part of the reason why most isolated cVDPV has been serotype 2.

S100A8/A9 proteins mediate neutrophilic inflammation and lung pathology during tuberculosis.

RATIONALE: A hallmark of pulmonary tuberculosis (TB) is the formation of granulomas. However, the immune factors that drive the formation of a protective granuloma during latent TB, and the factors that drive the formation of inflammatory granulomas during active TB, are not well defined. OBJECTIVES: The objective of this study was to identify the underlying immune mechanisms involved in formation of inflammatory granulomas seen during active TB. METHODS: The immune mediators involved in inflammatory granuloma formation during TB were assessed using human samples and experimental models of Mycobacterium tuberculosis infection, using molecular and immunologic techniques. MEASUREMENTS AND MAIN RESULTS: We demonstrate that in human patients with active TB and in nonhuman primate models of M. tuberculosis infection, neutrophils producing S100 proteins are dominant within the inflammatory lung granulomas seen during active TB. Using the mouse model of TB, we demonstrate that the exacerbated lung inflammation seen as a result of neutrophilic accumulation is dependent on S100A8/A9 proteins. S100A8/A9 proteins promote neutrophil accumulation by inducing production of proinflammatory chemokines and cytokines, and influencing leukocyte trafficking. Importantly, serum levels of S100A8/A9 proteins along with neutrophil-associated chemokines, such as keratinocyte chemoattractant, can be used as potential surrogate biomarkers to assess lung inflammation and disease severity in human TB. CONCLUSIONS: Our results thus show a major pathologic role for S100A8/A9 proteins in mediating neutrophil accumulation and inflammation associated with TB. Thus, targeting specific molecules, such as S100A8/A9 proteins, has the potential to decrease lung tissue damage without impacting protective immunity against TB.

Glycine by enteral route does not improve major clinical outcomes in severe COVID-19: a randomized clinical pilot trial.

There is a worrying scarcity of drug options for patients with severe COVID-19. Glycine possesses anti-inflammatory, cytoprotective, endothelium-protective, and platelet-antiaggregant properties, so its use in these patients seems promising. In this open label, controlled clinical trial, inpatients with severe COVID-19 requiring mechanical ventilation randomly received usual care (control group) or usual care plus 0.5 g/kg/day glycine by the enteral route (experimental group). Major outcomes included mortality, time to weaning from mechanical ventilation, total time on mechanical ventilation, and time from study recruitment to death. Secondary outcomes included laboratory tests and serum cytokines. Patients from experimental (n = 33) and control groups (n = 23) did not differ in basal characteristics. There were no differences in mortality (glycine group, 63.6% vs control group, 52.2%, p = 0.60) nor in any other major outcome. Glycine intake was associated with lower fibrinogen levels, either evaluated per week of follow-up (p < 0.05 at weeks 1, 2, and 4) or as weighted mean during the whole hospitalization (608.7 ± 17.7 mg/dl vs control 712.2 ± 25.0 mg/dl, p = 0.001), but did not modify any other laboratory test or cytokine concentration. In summary, in severe COVID-19 glycine was unable to modify major clinical outcomes, serum cytokines or most laboratory tests, but was associated with lower serum fibrinogen concentration.Registration: ClinicalTrials.gov NCT04443673, 23/06/2020.

Association of diabetes and tuberculosis: impact on treatment and post-treatment outcomes.

OBJECTIVE: To determine the clinical consequences of pulmonary tuberculosis (TB) among patients with diabetes mellitus (DM). METHODS: We conducted a prospective study of patients with TB in Southern Mexico. From 1995 to 2010, patients with acid-fast bacilli or Mycobacterium tuberculosis in sputum samples underwent epidemiological, clinical and microbiological evaluation. Annual follow-ups were performed to ascertain treatment outcome, recurrence, relapse and reinfection. RESULTS: The prevalence of DM among 1262 patients with pulmonary TB was 29.63% (n=374). Patients with DM and pulmonary TB had more severe clinical manifestations (cavities of any size on the chest x-ray, adjusted OR (aOR) 1.80, 95% CI 1.35 to 2.41), delayed sputum conversion (aOR 1.51, 95% CI 1.09 to 2.10), a higher probability of treatment failure (aOR 2.93, 95% CI 1.18 to 7.23), recurrence (adjusted HR (aHR) 1.76, 95% CI 1.11 to 2.79) and relapse (aHR 1.83, 95% CI 1.04 to 3.23). Most of the second episodes among patients with DM were caused by bacteria with the same genotype but, in 5/26 instances (19.23%), reinfection with a different strain occurred. CONCLUSIONS: Given the growing epidemic of DM worldwide, it is necessary to add DM prevention and control strategies to TB control programmes and vice versa and to evaluate their effectiveness. The concurrence of both diseases potentially carries a risk of global spreading, with serious implications for TB control and the achievement of the United Nations Millennium Development Goals.

Variants in toll-like receptor 9 gene influence susceptibility to tuberculosis in a Mexican population.

BACKGROUND: The control of Mycobacterium tuberculosis (Mtb) infection begins with the recognition of mycobacterial structural components by toll like receptors (TLRs) and other pattern recognition receptors. Our objective was to determine the influence of TLRs polymorphisms in the susceptibility to develop tuberculosis (TB) in Amerindian individuals from a rural area of Oaxaca, Mexico with high TB incidence. METHODS: We carried out a case-control association community based study, genotyping 12 polymorphisms of TLR2, TLR4, TLR6 and TLR9 genes in 90 patients with confirmed pulmonary TB and 90 unrelated exposed but asymptomatic household contacts. RESULTS: We found a significant increase in the frequency of the allele A of the TLR9 gene polymorphism rs352139 (A>G) in the group of TB patients (g.f. = 0.522) when compared with controls (g.f. = 0.383), (Pcorr = 0.01, OR = 1.75). Under the recessive model (A/G + A/A vs G/G) this polymorphism was also significantly associated with TB (Pcorr = 0.01, OR= 2.37). The association of the SNP rs352139 was statistically significant after adjustment by age, gender and comorbidities by regression logistic analysis (Dominant model: p value = 0.016, OR = 2.31; Additive model: p value = 0.023, OR = 1.68). The haplotype GAA of TLR9 SNPs was also associated with TB susceptibility (Pcorr = 0.02). Differences in the genotype or allele frequencies of TLR2, TLR4 and TLR6 polymorphisms between TB patients and healthy contacts were not detected. CONCLUSIONS: Our study suggests that the allele A of the intronic polymorphism rs352139 on TLR9 gene might contribute to the risk of developing TB in Mexican Amerindians.

[Acute respiratory infections among children and identification of alarm signs by parents and caregivers in Mexico]. / Infecciones respiratorias agudas en niños y signos de alarma identificados por padres y cuidadores en México.

OBJECTIVE: To estimate the prevalence of acute respiratory infection (ARI) during the two weeks previous to the interview among children <5 years of age and to describe the frequency of identification of alarm signs by parents or caregivers (PC). MATERIALS AND METHODS: Analysis of data from the National Health and Nutrition Surveys 2012 and 2006 and of National Health Survey 2000. RESULTS: ARI prevalence decreased from 2006 to 2012 (47.0-44.8%), particularly in the lower socioeconomic strata and children <1 year of age. 2012 Survey revealed highest prevalence for <1 year children. Fever was the main pneumonia-associated alarm sign (28.6%) in contrast to "breathes rapidly" (10.2%) or "unable to breathe" (20.9%). CONCLUSIONS: Results show that the magnitude of the problem has decreased in recent years, mainly among the more vulnerable groups, such as smaller children and those belonging to the lowest socioeconomic strata. However, training is required, particularly at the community level.

[Acute diarrheal diseases and feeding practices among children under five years in Mexico]. / Diarreas agudas y prácticas de alimentación en niños menores de cinco años en México.

OBJECTIVE: To estimate the prevalence of acute diarrheal diseases (ADD) during the two weeks previous to the interview among children <5 years of age and to describe alarm signs and feeding practices of parents and caregivers (PCG) during children's ADD. MATERIALS AND METHODS: Analysis of data from the National Health and Nutrition Surveys 2012 and 2006 and the National Health Survey 2000. RESULTS: ADD prevalence decreased significantly from 2006 (13.1%) to 2012 (11.0%), particularly in the lower socioeconomic status. "Frequent bowel movements" were the main warning sign identified by PCG (66.0%) in contrast to "crying without tears" (4.3%) and "blood in faeces" (0.5%); only 42% PCG reported administering oral rehydration therapy. Factors associated with ADD were child's age <1 year and mother's age <20 years. CONCLUSIONS: It is necessary to reinforce appropriate ADD preventive and treatment practices among PCG of children <5 years of age.

Major Depressive Disorder and Pulmonary Tuberculosis Comorbidity Exacerbates Proinflammatory Immune Response-A Preliminary Study.

BACKGROUND: Major depressive disorders (MDDs) occurs frequently in patients with tuberculosis (TB). Elevated serum pro-inflammatory cytokine levels in MDD patients is a well-established fact. Therefore, an integrated clinical practice should be considered. However, the inflammatory status of MDD-TB patients is unknown. In this study, we analyze cytokines in activated-cells and sera from MDD-TB, TB, MDD patients, and healthy controls. METHODS: Flow cytometry was used to evaluate the intracellular production of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-12, and IL-10 by peripheral blood mononuclear cells after a polyclonal stimulation. A Bio-Plex Luminex system was used to measure serum cytokine and chemokine levels in the study groups. RESULTS: We observed a 40.6% prevalence of MDD in TB patients. The proportion of IFN-gamma-producing cells was higher in MDD-TB patients than other pathological groups. Nevertheless, the percentage of TNF-alpha- and IL-12-producing cells was similar between MDD-TB and TB patients. Likewise, MDD-TB and TB patients showed similar serum pro-inflammatory cytokine and chemokine levels, which were significantly lower than those in MDD patients. By multiple correspondence analyses, we observed that low levels of serum IL-4, IL-10, and IL-13 were powerfully associated with TB comorbidities with MDD. CONCLUSIONS: A high frequency of IFN-γ-producing cells is associated with low levels of serum anti-inflammatory cytokines in MDD-TB patients.

Trimethoprim-Sulfamethoxazole-associated early neutropenia in Mexican adults living with HIV: A cohort study.

INTRODUCTION: Trimethoprim/sulfamethoxazole (TMP/SMX) is the antimicrobial of first choice in the treatment and prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients, particularly in people living with human immunodeficiency virus (HIV). TMP/SMX use entails different adverse effects, and its association with early neutropenia is minimally documented. This study aimed to identify the risk of early neutropenia associated with TMP/SMX use in adults living with HIV in Mexico. METHODS: A prospective cohort study was conducted in TMP/SMX-naïve adults living with HIV admitted to a third-level hospital between August 2019 and March 2020. Socio-demographic, clinical, and laboratory data were collected. According to patients' diagnostic, if they required treatment or prophylaxis against PCP, medical staff decided to prescribe TMP/SMX, as it is the first-line treatment. The risk of TMP/SMX induced early neutropenia, as well as associated factors were analyzed through a bivariate model and a multivariate Poisson regression model. The strength of association was measured by incidence rate ratio (IRR) with 95% confidence interval. RESULTS: 57 patients were enrolled in the study, of whom 40 patients were in the TMP/SMX treatment-group for treatment or prophylaxis of PCP (204.8 person-years of observation, median 26.5 days) and 17 patients were in the non-treatment group because they did not need the drug for treatment or prophylaxis of PCP (87.0 person-years of observation, median 21 days). The incidence rate of early neutropenia in the TMP/SMX-treatment group versus non-treatment group was 7.81 and 1.15 cases per 100 person-years, respectively. After adjusting for stage 3 of HIV infection and neutrophil count <1,500 cells/mm3 at hospital admission, the current use of TMP/SMX was not associated with an increase in the incidence rate ratio of early neutropenia (adjusted IRR: 3.46; 95% CI: 0.25-47.55; p = 0.352). CONCLUSIONS: The current use of TMP/SMX in Mexican adults living with HIV was not associated with an increase in the incidence rate ratio of early neutropenia.

Molecular transition of SARS-CoV-2 from critical patients during the first year of the COVID-19 pandemic in Mexico City.

Background: The SARS-CoV-2 virus has caused unprecedented mortality since its emergence in late 2019. The continuous evolution of the viral genome through the concerted action of mutational forces has produced distinct variants that became dominant, challenging human immunity and vaccine development. Aim and methods: In this work, through an integrative genomic approach, we describe the molecular transition of SARS-CoV-2 by analyzing the viral whole genome sequences from 50 critical COVID-19 patients recruited during the first year of the pandemic in Mexico City. Results: Our results revealed differential levels of the evolutionary forces across the genome and specific mutational processes that have shaped the first two epidemiological waves of the pandemic in Mexico. Through phylogenetic analyses, we observed a genomic transition in the circulating SARS-CoV-2 genomes from several lineages prevalent in the first wave to a dominance of the B.1.1.519 variant (defined by T478K, P681H, and T732A mutations in the spike protein) in the second wave. Conclusion: This work contributes to a better understanding of the evolutionary dynamics and selective pressures that act at the genomic level, the prediction of more accurate variants of clinical significance, and a better comprehension of the molecular mechanisms driving the evolution of SARS-CoV-2 to improve vaccine and drug development.

Monocytes from tuberculosis patients that exhibit cleaved caspase 9 and denaturalized cytochrome c are more susceptible to death mediated by Toll-like receptor 2.

Experimental models have shown that lipoproteins from Mycobacterium tuberculosis induce apoptosis via Toll-like receptor 2 (TLR2) in the THP-1 cell line and in monocyte-derived macrophages from healthy volunteers. We found an increased percentage of circulating monocytes in patients with tuberculosis (TB) in comparison to healthy controls. Patients with TB showed a higher TLR2 and TLR4 expression density on monocytes, and a higher proportion of TLR2(+) monocytes, as well as increased serum tumour necrosis factor-α level. In culture, monocytes from TB patients were more susceptible to death than monocytes from healthy controls. Moreover, death-susceptible monocytes were positive to both TLR2 and TLR4 at the start of culture. Freshly obtained monocytes from TB patients exhibited cleaved caspase 9 and denaturalized cytochrome c. For levels of caspase 8, apoptosis-regulating signal kinase 1, and phospho-p38 mitogen-activated protein kinase there was no difference between samples from TB patients and from healthy controls. The culture filtrate antigen extract from M. tuberculosis H37Rv strain induced the death of monocytes from patient with TB after a 4-hr incubation, which was abrogated by neutralizing antibodies for TLR2 but not TLR4. Similarly, Pam3CSK4, a synthetic agonist triacylated ligand to TLR2, also induced the death of monocytes, although it did not increase levels of cleaved caspase 9. Our findings suggest that monocytes from TB patients are more susceptible to death, probably through mitochondrial damage, and that cell death increases in the presence of mycobacterial antigen by a TLR2-dependent pathway.

Tuberculosis in ageing: high rates, complex diagnosis and poor clinical outcomes.

BACKGROUND: worldwide, the frequency of tuberculosis among older people almost triples that observed among young adults. OBJECTIVE: to describe clinical and epidemiological consequences of pulmonary tuberculosis among older people. METHODS: we screened persons with a cough lasting more than 2 weeks in Southern Mexico from March 1995 to February 2007. We collected clinical and mycobacteriological information (isolation, identification, drug-susceptibility testing and IS6110-based genotyping and spoligotyping) from individuals with bacteriologically confirmed pulmonary tuberculosis. Patients were treated in accordance with official norms and followed to ascertain treatment outcomes, retreatment, and vital status. RESULTS: eight hundred ninety-three tuberculosis patients were older than 15 years of age; of these, 147 (16.5%) were 65 years of age or older. Individuals ≥ 65 years had significantly higher rates of recently transmitted and reactivated tuberculosis. Older age was associated with treatment failure (OR=5.37; 95% CI: 1.06-27.23; P=0.042), and death due to tuberculosis (HR=3.52; 95% CI: 1.78-6.96; P<0.001) adjusting for sociodemographic and clinical variables. CONCLUSIONS: community-dwelling older individuals participate in chains of transmission indicating that tuberculosis is not solely due to the reactivation of latent disease. Untimely and difficult diagnosis and a higher risk of poor outcomes even after treatment completion emphasise the need for specific strategies for this vulnerable group.

Use of a novel real-time PCR assay to detect oral polio vaccine shedding and reversion in stool and sewage samples after a mexican national immunization day.

During replication, oral polio vaccine (OPV) can revert to neurovirulence and cause paralytic poliomyelitis. In individual vaccinees, it can acquire specific revertant point mutations, leading to vaccine-associated paralytic poliomyelitis (VAPP). With longer replication, OPV can mutate into vaccine-derived poliovirus (VDPV), which causes poliomyelitis outbreaks similar to those caused by wild poliovirus. After wild poliovirus eradication, safely phasing out vaccination will likely require global use of inactivated polio vaccine (IPV) until cessation of OPV circulation. Mexico, where children receive routine IPV but where OPV is given biannually during national immunization days (NIDs), provides a natural setting to study the duration of OPV circulation in a population primarily vaccinated with IPV. We developed a real-time PCR assay to detect and distinguish revertant and nonrevertant OPV serotype 1 (OPV-1), OPV-2, and OPV-3 from RNA extracted directly from stool and sewage. Stool samples from 124 children and 8 1-liter sewage samples from Orizaba, Veracruz, Mexico, collected 6 to 13 weeks after a NID were analyzed. Revertant OPV-1 was found in stool at 7 and 9 weeks, and nonrevertant OPV-2 and OPV-3 were found in stool from two children 10 weeks after the NID. Revertant OPV-1 and nonrevertant OPV-2 and -3 were detected in sewage at 6 and 13 weeks after the NID. Our real-time PCR assay was able to detect small amounts of OPV in both stool and sewage and to distinguish nonrevertant and revertant serotypes and demonstrated that OPV continues to circulate at least 13 weeks after a NID in a Mexican population routinely immunized with IPV.

Parapneumonic effusion and thoracic empyema in adults. Clinical aspects, microbiology and frequency of surgical outcome.

BACKGROUND: To date, information about the outcome of patients with parapneumonic effusion and empyema is limited. OBJECTIVE: To describe the clinical characteristics, the microbiological study and the frequency and type of surgical treatment in adult patients with parapneumonic effusion or empyema. METHOD: A prospective cross-sectional study of patients admitted with parapneumonic effusion or empyema, from August 2011 to July 2014, in a reference hospital for respiratory diseases in Mexico City, was conducted. Clinical characteristics, microbiology, risk categories for poor prognosis in empyema and frequency and type of surgical treatment were studied. RESULTS: We studied 284 patients whose median age was 47 years, 75% were men, and 57.7% were transferred from other hospitals. In 38.5% of the cases a microorganism was identified and there was a predominance of Gram negative. 153 (53.9%) required surgical treatment, of which 90% were thoracotomy with decortication. Hospital mortality was 5.63%. CONCLUSIONS: Most of the patients arrived in advanced stages of the disease, so more than half required surgery, of which 90% was decortication. It is desirable to favor mechanisms for early diagnosis and treatment to reduce the need for surgical treatment.

ANTECEDENTES: La información sobre el tipo y la frecuencia del tratamiento quirúrgico en los casos de empiema torácico es escasa. OBJETIVO: Describir las características clínicas, el estudio microbiológico y la frecuencia y el tipo de tratamiento quirúrgico en pacientes adultos con derrame pleural paraneumónico o empiema. MÉTODO: Estudio transversal prospectivo de pacientes con diagnóstico de derrame pleural paraneumónico o empiema, de agosto de 2011 a julio de 2014, en un hospital de referencia para enfermedades respiratorias en la Ciudad de México. Se estudiaron las características clínicas, las categorías de riesgo para mal pronóstico en empiema y la frecuencia y el tipo de tratamiento quirúrgico. RESULTADOS: Se estudiaron 284 pacientes cuya mediana de edad fue de 47 años y el 75% eran hombres. El 57.7% fueron traslados de otros hospitales. En el 38.8% de los casos se identificó un microorganismo, con predominio de gramnegativos. Requirieron tratamiento quirúrgico 153 pacientes (53.9%), de los cuales en el 90% fue toracotomía con lavado y decorticación. La mortalidad hospitalaria fue del 5.63%. CONCLUSIONES: La mayor parte de los pacientes llegaron en etapas avanzadas de la enfermedad, y por ello más de la mitad requirieron cirugía, de los cuales en el 90% fue lavado y decorticación. Es deseable favorecer mecanismos para realizar un diagnóstico y un tratamiento tempranos con el fin de disminuir la necesidad de tratamiento quirúrgico.

Case-control study about magnitude of exposure to wood smoke and risk of developing lung cancer.

INTRODUCTION: Exposure to biomass combustion products, particularly firewood, has been considered as a potential carcinogen for developing lung cancer. In this regard, current evidence is widely heterogeneous; besides, in most studies, wood smoke exposure is not appropriately quantified, which further complicates the analysis of wood smoke as a potential carcinogen. The aim of the present study was to estimate the risk of developing lung cancer according to the degree of exposure to wood smoke in patients who use firewood for cooking. MATERIAL AND METHODS: We performed a case-control study that included 482 patients with lung cancer (cases) and 592 hospital controls. Exposure to wood smoke was evaluated as a dichotomous variable (i.e. yes or no); in patients with prior wood smoke exposure, an index of exposure in hours per year was calculated (WSEI). Using bivariate and multivariate logistic regression analyses, the odds ratio (OR) between wood smoke exposure and lung cancer were calculated. RESULTS: The ORs for developing lung cancer (raw and adjusted) for a WSEI > 100 h/year were OR 1.55 [95% confidence interval (CI), 1.06-2.26) and OR 2.26 (95% CI, 1.50-3.40), respectively; the ORs (raw and adjusted) for WSEI >300 h/year were OR 1.76 (95% CI, 1.06-2.91) and OR 3.19 (95% CI, 1.83-5.55), respectively. CONCLUSIONS: Exposure to wood smoke is a risk factor for lung cancer; furthermore, this effect maintains a dose-response relationship which has a multiplicative effect with smoking.