Prognostic Factors Associated with Clinical and Economic Outcomes of Appendectomies in Children: A Multilevel Analysis in a National Retrospective Cohort Study.

BACKGROUND: Acute appendicitis is the most common acute surgical abdominal pathology in children, and it has a large impact on morbidity and the costs incurred by health care systems. In low- and median-income countries, national information on the clinical and economic outcomes associated with this surgery does not exist. This study aimed to identify and describe the clinical and economic outcomes for children undergoing appendectomy in Colombia's contributory system and to determine the prognostic factors associated with these outcomes. METHODS: A retrospective cohort study was conducted using administrative data from patients under 18 years of age who underwent an appendectomy between July 1, 2013, and September 30, 2015, in Colombia's contributory health system. Thirty-day mortality rates, intensive care unit (ICU) admission rates, length of stay (LOS), readmission rates and median costs were estimated for the entire country by geographic region and insurer. The prognostic factors associated with these outcomes were identified using generalized multilevel mixed models. RESULTS: A total of 21,674 children were included. The 30-day postoperative mortality rate was 0.06% [95% CI 0.02-0.9], the ICU admission rate was 8.00% [95% CI 7.63-8.36], the mean LOS was 2.48 days (SD 5.24), the readmission rate was 1.5% [95% CI 1.33-1.66] and the median cost for Colombia was 394 USD [p25-p75: 256-555]. The prognostic factors that were associated with the 30-day ICU admission rate, LOS and readmission rate were the insurer, geographic region, age, occurrence of an appendectomy with peritoneal drainage, and certain comorbidities, such as cancer and neurological, respiratory and gastrointestinal illnesses. The prognostic factors associated with costs were those previously mentioned as well as the occurrence of a laparoscopic appendectomy. CONCLUSIONS: In Colombia's contributory health system, large differences in clinical outcomes and the costs incurred by the system exist, and these differences are associated with the geographic region, the insurer, and some of the clinical characteristics of the children undergoing appendectomy.

Amazon plant diversity revealed by a taxonomically verified species list.

Recent debates on the number of plant species in the vast lowland rain forests of the Amazon have been based largely on model estimates, neglecting published checklists based on verified voucher data. Here we collate taxonomically verified checklists to present a list of seed plant species from lowland Amazon rain forests. Our list comprises 14,003 species, of which 6,727 are trees. These figures are similar to estimates derived from nonparametric ecological models, but they contrast strongly with predictions of much higher tree diversity derived from parametric models. Based on the known proportion of tree species in neotropical lowland rain forest communities as measured in complete plot censuses, and on overall estimates of seed plant diversity in Brazil and in the neotropics in general, it is more likely that tree diversity in the Amazon is closer to the lower estimates derived from nonparametric models. Much remains unknown about Amazonian plant diversity, but this taxonomically verified dataset provides a valid starting point for macroecological and evolutionary studies aimed at understanding the origin, evolution, and ecology of the exceptional biodiversity of Amazonian forests.

Chemical and odor characterization of gas emissions released during composting of solid wastes and digestates.

Hazardous and odorous gas emissions from composting and methanization plants are an issue of public concern. Odor and chemical monitoring are thus critical steps in providing suitable strategies for air pollution control at waste treatment units. In this study, 141 gas samples were extensively analyzed to characterize the odor and chemical emissions released upon the aerobic treatment of 10 raw substrates and five digestates. For this purpose, agricultural wastes, biowastes, green wastes, sewage sludge, and municipal solid waste (MSW) were composted in 300 L pilots under forced aeration. Gas exhausts were evaluated through dynamic olfactometry and analytical methods (i.e., GC/MS) to determine their odor concentration (OC in OUE m-3) and chemical composition. A total of 60 chemical compounds belonging to 9 chemical families were identified and quantified. Terpenes, oxygenated compounds, and ammonia exhibited the largest cumulative mass emission. Odor emission rates (OUE h-1) were computed based on OC measurements and related to the initial amount of organic matter composted and the process time to provide odor emission factors (OEFs in OUE g-1OM0). The composting process of solid wastes accounted for OEFs ranging from 65 to 3089 OUE g-1OM0, whereas digestates composting showed a lower odor emission potential with OEF fluctuating from 8.6 to 30.5 OUE g-1OM0. Moreover, chemical concentrations of single compounds were weighted with their corresponding odor detection thresholds (ODTs) to yield odor activities values (OAVs) and odor contribution (POi, %). Volatile sulfur compounds were the main odorants (POi = 54-99%) regardless of the operational composting conditions or substrate treated. Notably, methanethiol was the leading odorant for 73% of the composting experiments.

"Los libros y la noche", perspectiva neurológica de la ceguera de Jorge Luis Borges.

The works of Argentinian scholar Jorge Luis Borges (1899-1986) have captivated physicians. An assiduous reader, he was given, with magnificent irony, "books and the night". Borges suffered from chronic and irreversible blindness, which influenced much of his work and has been the subject of different literary and diagnostic analyses from the ophthalmological point of view. However, the characteristics of his visual impairment have escaped the neurological approach, which is why we reviewed his work looking for data suggesting a concomitant brain injury. On his autobiography, he recounts how, during an episode of septicemia, he suffered hallucinations and loss of speech; in addition, in some poems and essays he describes data that suggest "phantom chromatopsia", a lesion of cortical origin. After that accident, Borges survived with a radical change in literary style. Although a precise diagnosis is impossible, his literary work allows recognizing some elements in favor of concomitant brain involvement.

La obra del erudito argentino Jorge Luis Borges (1899-1986) ha cautivado a los médicos. Asiduo lector con magnífica ironía, le fueron dados "los libros y la noche". Borges padeció una ceguera crónica e irreversible que impulsó gran parte de su obra y ha sido objeto de distintos análisis literarios y diagnósticos desde el punto de vista oftalmológico. Sin embargo, las características de su ceguera han escapado al abordaje neurológico, por lo cual revisamos su obra en busca de datos que sugieran una lesión cerebral concomitante. En su autobiografía relata cómo durante un episodio de septicemia padeció alucinaciones y pérdida del habla; además, en algunos poemas y ensayos describe datos que sugieren "cromatopsia fantasma", lesión de origen cortical. Tras dicho accidente, Borges sobrevivió con un cambio radical en su estilo literario. Aunque un diagnóstico preciso es imposible, su obra literaria nos permite reconocer algunos elementos que sugieren involucramiento cerebral concomitante.

"The books and the night", neurological perspective on Jorge Luis Borges' blindness.

The works of Argentinian scholar Jorge Luis Borges (1899-1986) have captivated physicians. An assiduous reader, he was given, with magnificent irony, "books and the night". Borges suffered from chronic and irreversible blindness, which influenced much of his work and has been the subject of different literary and diagnostic analyses from the ophthalmological point of view. However, the characteristics of his visual impairment have escaped the neurological approach, which is why we reviewed his work looking for data suggesting a concomitant brain injury. On his autobiography, he recounts how, during an episode of septicemia, he suffered hallucinations and loss of speech; in addition, in some poems and essays he describes data that suggest "phantom chromatopsia", a lesion of cortical origin. After that accident, Borges survived with a radical change in literary style. Although a precise diagnosis is impossible, his literary work allows recognizing some elements in favor of concomitant brain involvement.

Delftia sp. LCW, a strain isolated from a constructed wetland shows novel properties for dimethylphenol isomers degradation.

BACKGROUND: Dimethylphenols (DMP) are toxic compounds with high environmental mobility in water and one of the main constituents of effluents from petro- and carbochemical industry. Over the last few decades, the use of constructed wetlands (CW) has been extended from domestic to industrial wastewater treatments, including petro-carbochemical effluents. In these systems, the main role during the transformation and mineralization of organic pollutants is played by microorganisms. Therefore, understanding the bacterial degradation processes of isolated strains from CWs is an important approach to further improvements of biodegradation processes in these treatment systems. RESULTS: In this study, bacterial isolation from a pilot scale constructed wetland fed with phenols led to the identification of Delftia sp. LCW as a DMP degrading strain. The strain was able to use the o-xylenols 3,4-DMP and 2,3-DMP as sole carbon and energy sources. In addition, 3,4-DMP provided as a co-substrate had an effect on the transformation of other four DMP isomers. Based on the detection of the genes, proteins, and the inferred phylogenetic relationships of the detected genes with other reported functional proteins, we found that the phenol hydroxylase of Delftia sp. LCW is induced by 3,4-DMP and it is responsible for the first oxidation of the aromatic ring of 3,4-, 2,3-, 2,4-, 2,5- and 3,5-DMP. The enzyme may also catalyze both monooxygenation reactions during the degradation of benzene. Proteome data led to the identification of catechol meta cleavage pathway enzymes during the growth on ortho DMP, and validated that cleavage of the aromatic rings of 2,5- and 3,5-DMPs does not result in mineralization. In addition, the tolerance of the strain to high concentrations of DMP, especially to 3,4-DMP was higher than that of other reported microorganisms from activated sludge treating phenols. CONCLUSIONS: LCW strain was able to degraded complex aromatics compounds. DMPs and benzene are reported for the first time to be degraded by a member of Delftia genus. In addition, LCW degraded DMPs with a first oxidation of the aromatic rings by a phenol hydroxylase, followed by a further meta cleavage pathway. The higher resistance to DMP toxicity, the ability to degrade and transform DMP isomers and the origin as a rhizosphere bacterium from wastewater systems, make LCW a suitable candidate to be used in bioremediation of complex DMP mixtures in CWs systems.

[Chronic diseases in the population affected by the armed conflict in Colombia, 2015]. / Enfermedades crónicas en población afectada por el conflicto armado en Colombia, 2015.

OBJECTIVE: The purpose of this study was to identify the most frequent non-mental chronic illnesses in the Colombian population affected by the armed conflict. METHODOLOGY: A cross-sectional study using data from the National Mental Health Survey 2015. The study population was stratified by sex and age and other general data were extracted, including education and poverty level, measured by the Multidimensional Poverty Index. Data analysis was based on information from people who reported having been victims of the Colombian armed conflict at some time in their lives; the frequency of presentation of non-mental chronic illnesses was reported as a measure of indirect relative risk. RESULTS: Information on 10,764 people over 18 years of age was described, this being a representative sample at the national level. It was found that 10.4% of subjects affected by the armed conflict have a high educational level (technical school or university), and that 43.6% are living in conditions of poverty or vulnerability. The non-mental chronic illnesses identified were: hypertension 20.4% (CI95%: 15.7-26.1); diabetes 6.7% (CI95%: 4.4-10.3); rheumatologic diseases 10.4% (CI95%: 7.1-14.9); gastrointestinal diseases 19.1% (CI95%: 14.5-24.7); and chronic pain 6.9% (CI95%: 4.2-11). CONCLUSIONS: The population affected by the armed conflict is apparently at greater risk of presenting non-mental chronic illnesses such as hypertension and diabetes, which shows the vulnerability of these communities.

Mental health in displaced children by armed conflict - National Mental Health Survey Colombia 2015.

INTRODUCTION: The armed conflict in Colombia is considered one of the most violent in Latin America. Children as a vulnerable population are most affected, increasing their risk of developing mental problems such as anxiety disorder and post-traumatic stress disorder. OBJECTIVES: To determine the prevalence of the most frequent mental problems in the Colombian children affected by armed conflict. METHODOLOGY: A cross-sectional study, using data from the National Mental Health Survey 2015. With children aged 7 to 11 years, in whom the RQC, PCL and DISC-IV-P (3.0.1) were applied. RESULTS: We described information on 100 displaced children between 7 and 11 years old due to armed conflict, being a representative sample at national level. It was found that 98.7% of this population is at school, as well as 17.8% in poverty. Mental illnesses were asked according to their appearance in the last 12 months, these were: anxiety disorder 6.5% (CI 95% 2.7-14.7) in displaced population, compared to 1.8% (CI 95% 1.1-3.1) in non-displaced; High score for post-traumatic stress was 13.2% (CI 95% 3.9-36.4) in displaced persons and 6.6% (CI 95% 4.0-10.7) in nondisplaced persons. CONCLUSIONS: Children affected by armed conflict have greater risk of presenting some mental illnesses such as anxiety disorder and post-traumatic stress, evidencing the situation of vulnerability in which they are.

Cutaneous melanoma attributable to solar radiation in Cali, Colombia.

Estimating the population attributable fraction (PAF) of melanomas due to sun exposure is challenging as there are no unexposed population nor reliable exposure data. In high incidence countries, a historic cohort of the South Thames cancer registry was used as a minimally exposed population using the formula PAF = (observed incidence-incidence in minimally exposure)/observed incidence. In this study, we apply this method, constructing a minimally exposed cohort for Colombia and also using the historical South Thames data, using melanoma incidence data from the population-based cancer registry of Cali, Colombia for the period 1967-2012. The historic cohort incidence rates were very similar to those of Thames, but cohort effects were smaller for women and nonexistent for men. Age-specific incidence rates of these minimally exposed cohorts were applied to recent population numbers. For females, PAFs were 19% using the historic Thames cohort and 25% using the historic Cali cohort, corresponding numbers for males were 62% (vs. Thames) and 0% (vs. Cali). Taking into account the incidence rates of acral melanomas, which are not sun related, the PAF increased in women to 26% (vs. Thames) and 34% (vs. Cali) and for men 77% (vs. Thames). This exercise shows the modest contribution of exposure to ultraviolet radiation in the burden of melanoma in low-incidence countries, as well as the importance to take into consideration the acral lentiginous melanomas.

Comparative effectiveness of single and dual rapid diagnostic tests for syphilis and HIV in antenatal care services in Colombia.

OBJECTIVE: To assess the effectiveness of a dual rapid test compared to a single rapid test for syphilis and HIV screening. METHODS: A cluster-randomized open-label clinical trial was performed in 12 public antenatal care (ANC) centers in the cities of Bogotá and Cali, Colombia. Pregnant women who were over 14 years of age at their first antenatal visit and who had not been previously tested for HIV and syphilis during the current pregnancy were included. Pregnant women were randomized to single HIV and single syphilis rapid diagnostic tests (Arm A) or to dual HIV and syphilis rapid diagnostic tests (Arm B). The four main outcomes measured were: (1) acceptability of the test, (2) uptake in testing, (3) treatment on the same day (that is, timely treatment), and (4) treatment at any time for positive rapid test cases. Bivariate and multivariate analyses were calculated to adjust for the clustering effect and the period. RESULTS: A total of 1 048 patients were analyzed in Arm A, and 1 166 in Arm B. Acceptability of the rapid tests was 99.8% in Arm A and 99.6% in Arm B. The prevalence of positive rapid tests was 2.21% for syphilis and 0.36% for HIV. Timely treatment was provided to 20 of 29 patients (69%) in Arm A and 16 of 20 patients (80%) in Arm B (relative risk (RR), 1.10; 95% confidence interval (CI): (1.00 -1.20). Treatment at any time was given to 24 of 29 patients (83%) in Arm A and to 20 of 20 (100%) in Arm B (RR, 1.11; 95% CI: 1.01-1.22). CONCLUSIONS: There were no differences in patient acceptability, testing and timely treatment between dual rapid tests and single rapid tests for HIV and syphilis screening in the ANC centers. Same-day treatment depends also on the interpretation of and confidence in the results by the health providers.

Home-based versus clinic-based specimen collection in the management of Chlamydia trachomatis and Neisseria gonorrhoeae infections.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the most frequent causes of bacterial sexually transmitted infections (STIs). Management strategies that reduce losses in the clinical pathway from infection to cure might improve STI control and reduce complications resulting from lack of, or inadequate, treatment. OBJECTIVES: To assess the effectiveness and safety of home-based specimen collection as part of the management strategy for Chlamydia trachomatis and Neisseria gonorrhoeae infections compared with clinic-based specimen collection in sexually-active people. SEARCH METHODS: We searched the Cochrane Sexually Transmitted Infections Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and LILACS on 27 May 2015, together with the World Health Organization International Clinical Trials Registry (ICTRP) and ClinicalTrials.gov. We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) of home-based compared with clinic-based specimen collection in the management of C. trachomatis and N. gonorrhoeae infections. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. We contacted study authors for additional information. We resolved any disagreements through consensus. We used standard methodological procedures recommended by Cochrane. The primary outcome was index case management, defined as the number of participants tested, diagnosed and treated, if test positive. MAIN RESULTS: Ten trials involving 10,479 participants were included. There was inconclusive evidence of an effect on the proportion of participants with index case management (defined as individuals tested, diagnosed and treated for CT or NG, or both) in the group with home-based (45/778, 5.8%) compared with clinic-based (51/788, 6.5%) specimen collection (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.60 to 1.29; 3 trials, I² = 0%, 1566 participants, moderate quality). Harms of home-based specimen collection were not evaluated in any trial. All 10 trials compared the proportions of individuals tested. The results for the proportion of participants completing testing had high heterogeneity (I² = 100%) and were not pooled. We could not combine data from individual studies looking at the number of participants tested because the proportions varied widely across the studies, ranging from 30% to 96% in home group and 6% to 97% in clinic group (low-quality evidence). The number of participants with positive test was lower in the home-based specimen collection group (240/2074, 11.6%) compared with the clinic-based group (179/967, 18.5%) (RR 0.72, 95% CI 0.61 to 0.86; 9 trials, I² = 0%, 3041 participants, moderate quality). AUTHORS' CONCLUSIONS: Home-based specimen collection could result in similar levels of index case management for CT or NG infection when compared with clinic-based specimen collection. Increases in the proportion of individuals tested as a result of home-based, compared with clinic-based, specimen collection are offset by a lower proportion of positive results. The harms of home-based specimen collection compared with clinic-based specimen collection have not been evaluated. Future RCTs to assess the effectiveness of home-based specimen collection should be designed to measure biological outcomes of STI case management, such as proportion of participants with negative tests for the relevant STI at follow-up.

Age-period-cohort effects on incidence trends of childhood leukemia from four population-based cancer registries in Colombia.

BACKGROUND: Childhood leukemia (CL) is the most prevalent form of pediatric cancer on a global scale. However, there is a limited understanding of the dynamics of CL incidence in South America, with a specific knowledge gap in Colombia. This study aimed to identify trends in CL incidence and to analyze the effects of age, period, and birth cohort on the risk of leukemia incidence in this population. METHODS: Information on all newly diagnosed leukemia cases (in general and by subtype) among residents aged 0-18 years and living in the serving areas of population-based cancer registries of Cali (2008-2017), Bucaramanga (2000-2017), Manizales (2003-2017), and Pasto (1998-2018). Estimated annual percent changes (EAPC) in incidence over time and potential changes in the slope of these EAPCs were calculated using joinpoint regression models. The effects of age, period, and cohort in CL incidence trends were evaluated using age-period-cohort models addressing the identifiability issue through the application of double differences. RESULTS: A total of 966 childhood leukemia cases were identified. The average standardized incidence rate (ASIR) of leukemia was calculated and expressed per 100,000 person-years - observing ASIR of 4.46 in Cali, 7.27 in Bucaramanga, 3.89 in Manizales and 4.06 in Pasto. Concerning CL trends there were no statistically significant changes in EAPC throughout the different periods, however, when analyzed by leukemia subtype, statistically significant changes were observed in the EAPC for both ALL and AML. Analysis of age-period-cohort models revealed that age-related factors significantly underpin the incidence trends of childhood leukemia in these four Colombian cities. CONCLUSIONS: This study offers valuable insights into the incidence trends of childhood leukemia in four major Colombian cities. The analysis revealed stable overall CL incidence rates across varying periods, predominantly influenced by age-related factors and the absence of cohort and period effects. This information is useful for surveillance and planning purposes for CL diagnosis and treatment in Colombia.

Incidence of confusional syndrome (delirium) in a Latin American university hospital.

BACKGROUND: Little is known about the incidence of delirium and its subtypes in patients admitted to different departments of university hospitals in Latin America. OBJECTIVE: To determine the incidence of delirium and the frequency of its subtypes, as well as its associated factors, in patients admitted to different departments of a university hospital in Bogotá, Colombia. METHODS: A cohort of patients over 18 years of age admitted to the internal medicine (IM), geriatrics (GU), general surgery (GSU), orthopaedics (OU) and intensive care unit (ICU) services of a university hospital was followed up between January and June 2018. To detect the presence of delirium, we used the CAM (Confusion Assessment Method) and the CAM-ICU if the patient had decreased communication skills. The delirium subtype was characterised using the RASS (Richmond Agitation and Sedation Scale). Patients were assessed on their admission date and then every two days until discharged from the hospital. Those in whom delirium was identified were referred for specialised intra-institutional interdisciplinary management. RESULTS: A total of 531 patients admitted during the period were assessed. The overall incidence of delirium was 12% (95% CI, 0.3-14.8). They represented 31.8% of patients in the GU, 15.6% in the ICU, 8.7% in IM, 5.1% in the OU, and 3.9% in the GSU. The most frequent clinical display was the mixed subtype, at 60.9%, followed by the normoactive subtype (34.4%) and the hypoactive subtype (4.7%). The factors most associated with delirium were age (adjusted RR = 1.07; 95% CI, 1.05-1.09), the presence of four or more comorbidities (adjusted RR = 2.04; 95% CI, 1.31-3.20), and being a patient in the ICU (adjusted RR = 2.02; 95% CI, 1.22-3.35). CONCLUSIONS: The incidence of delirium is heterogeneous in the different departments of the university hospital. The highest incidence occurred in patients that were admitted to the GU. The mixed subtype was the most frequent one, and the main associated factors were age, the presence of four or more comorbidities, and being an ICU patient.

Assessment of mercury and lead contamination using the bivalve Anadara tuberculosa (Arcidae) in an estuary of the Colombian Pacific.

Buenaventura Bay is considered the main estuary on the Pacific coast of Colombia, because of port and industrial activities. Mining and agriculture are major sources of contamination in the estuary. This study used the bivalve Anadara tuberculosa to evaluate the presence of mercury and lead in the Dagua River estuary (Colombia), one of the main tributaries coming into the bay. Five samplings for sediments and six for tissues of A. tuberculosa were carried out between 2016 and 2017. Additionally, a series of bioassays were conducted to determine its ability to bioaccumulate metals. A mean mercury concentration of 0.57 ± 0.74 mg*kg-1 and lead concentration of 0.87 ± 0.68 mg*kg-1 in sediment were found. Bioassays allowed us to conclude that at low mercury exposure concentrations (0.25 mg*kg-1), lesions are generated in animal tissue, mainly in sexual cells. The high concentrations of mercury found in organisms exceed the maximum permitted concentration established in Colombia. In addition, the contamination factors for mercury and lead were considered very high. This research aims at contributing to the use of Anadara tuberculosa, as prospective bioindicator for pollution biomonitoring in mangrove coastal ecosystems.

Design and analysis of a mechanical ventilation system based on cams.

Low-cost mechanical ventilators have been developed in order to deal with the shortage of traditional ventilators whose quantity is not sufficient in an emergency context in Perú. Protofy, a company from Spain, designed one of the first low-cost mechanical ventilation systems OxyGEN which was approved by a medicine agency in its country in special context of COVID 19. Therefore, as main of this article, a redesign of this system named OxygenIP.PE was carried out according to local requirements and available technology, but maintaining its working concept based on compression mechanism by cams. Sensors were added and a control algorithm of the respiratory rate was developed. Ventilation curves monitoring over time was implemented; in this sense, a mathematical model of the whole system was developed. OxygenIP.PE was redesigned, fabricated, and tested measuring its ventilation curves over time. Results indicate that this redesign provides a sturdy equipment able to work during a longer lifetime than the original. The replicability of the ventilation curves behavior is ensured, while the mechanism dimensions are adapted for a particular airbag resuscitator. The mathematical model of the whole system can satisfactorily determine the ventilation curves over time and is used to show the air pressure, volume, and flow as a function of the compression arm's angular position and differential pressure through the breathing circuit measurement, furthermore the algorithms designed as a consequence of the mathematical model were implemented for Raspberry and ARDUINO microcontrollers. There were obtained parameters of pressure 10-65 cmH2O, airflow 50-65 l/m, volume 0-0.5 l, at two values of beat per minute (BPM) 15 and 25.

Phylogenomic Evidence of Reinfection and Persistence of SARS-CoV-2: First Report from Colombia.

The continuing evolution of SARS-CoV-2 and the emergence of novel variants have raised concerns about possible reinfection events and potential changes in the coronavirus disease 2019 (COVID-19) transmission dynamics. Utilizing Oxford Nanopore technologies, we sequenced paired samples of three patients with positive RT-PCR results in a 1-2-month window period, and subsequent phylogenetics and genetic polymorphism analysis of these genomes was performed. Herein, we report, for the first time, genomic evidence of one case of reinfection in Colombia, exhibiting different SARS-CoV-2 lineage classifications between samples (B.1 and B.1.1.269). Furthermore, we report two cases of possible viral persistence, highlighting the importance of deepening our understanding on the evolutionary intra-host traits of this virus throughout different timeframes of disease progression. These results emphasize the relevance of genomic surveillance as a tool for understanding SARS-CoV-2 infection dynamics, and how this may translate effectively to future control and mitigations efforts, such as the national vaccination program.

Case of neuromyelitis optica: bilateral sensorineural hearing loss and transverse myelopathy following intrathecal chemotherapy.

Neurotoxicity from intrathecally administered chemotherapeutic drugs is frequent, particularly with some agents like methotrexate, which are more prone to developing adverse effects. Myelopathy ranks among the most frequently reported neurological entities; with the diagnosis being straightforward, after ruling out infectious, metabolic, autoimmune or paraneoplastic causes. Scarcity of cases precludes evidence-based recommendations for the management of these complications. The most common therapeutic approach consists of the suspension of chemotherapy, exclusion of infectious and neoplastic causes, with prompt administration of high-dose steroids. We report a 21-year-old patient with acute lymphoblastic leukaemia, who developed acute transverse myelitis and bilateral sensorineural hearing loss, after five rounds of intrathecal methotrexate and cytarabine. Although neurotoxicity from both agents has been documented, this combination has not been previously reported.