Duration of SARS-CoV-2 shedding: A systematic review.

Background: Positive viral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cultures indicate shedding of infectious virus and corresponding transmission risk of coronavirus disease 2019 (COVID-19). The research question of this systematic review was: Is there a discernible pattern in the timing of SARS-CoV-2 virus isolation, and what is the proportion of positive and negative results for isolation of SARS-CoV-2 virus with viral culture relative to the onset of clinical symptoms or the day of diagnosis, as indicated by longitudinal studies? Methods: We systematically searched PubMed and Embase from inception to 16 February 2023 for English-language studies with serial viral culture testing within symptomatic or asymptomatic SARS-CoV-2 infected persons during the post-vaccination period. Outcomes of interest were the daily culture status per study and the overall daily culture positivity rate of SARS-CoV-2. We critically appraised the selected studies using the Newcastle-Ottawa quality assessment scale. Results: We included 14 viral shedding studies in this systematic review. Positive viral SARS-CoV-2 cultures were detected in samples ranging from 4 days before to 18 days after symptom onset. The daily culture SARS-CoV-2 positivity rate since symptom onset or diagnosis showed a steep decline between day 5 and 9, starting with a peak ranging from 44% to 50% on days -1 to 5, decreasing to 28% on day 7 and 11% on day 9, and finally ranging between 0% and 8% on days 10-17. Conclusions: Viral shedding peaked within 5 days since symptom onset or diagnosis and the culture positivity rate rapidly declined hereafter. This systematic review provides an overview of current evidence on the daily SARS-CoV-2 culture positivity rates during the post-vaccination period. These findings could be used to estimate the effectiveness of public health control measures, including treatment and preventive strategies, to reduce the spread of COVID-19.

Análisis de la discapacidad por trastornos musculoesqueléticos en México de 1990 a 2021 / Analysis of musculoskeletal disorders-associated disability in Mexico from 1990 to 2021

Resumen Antecedentes: Los trastornos musculoesqueléticos (TME) afectan a 1710 millones de personas en todo el mundo y es la principal causa de discapacidad. Objetivo: Analizar los años vividos con discapacidad (AVD) por TME en México entre 1990 y 2021. Material y métodos: Con las estimaciones del estudio de la Carga Global de la Enfermedad 2021 se analizaron los AVD por TME y sus seis categorías: osteoartritis, artritis reumatoide, gota, dolor cervical, lumbalgia y otros TME. Se evaluaron patrones y tendencias del número, tasa cruda y tasa estandarizada por edad de los AVD a nivel nacional, estatal, por grupos de edad y sexo. Resultados: Los TME constituyeron la principal causa de AVD en México entre 1990 y 2021, con un incremento de 57.3 %; pasaron de 1458.4 a 2293.7 por 100 000 habitantes. La lumbalgia (840.6 AVD) destacó con la mayor tasa en 2021 y la osteoartritis, con el mayor incremento. Los TME se incrementaron con la edad y, con excepción de la gota, afectaron más a las mujeres. Conclusiones: De 1990 a 2021, los TME constituyeron la principal causa de AVD en México, con mayor impacto en adultos y mujeres. Los TME se evidencian desde edades tempranas, de ahí la necesidad de intervenciones continuas para preservar la calidad de vida.

Abstract Background: Musculoskeletal disorders (MSD) affect 1.71 billion people worldwide and are the leading cause of disability. Objective: To analyze the years lived with disability (YLD) attributed to MSD in Mexico between 1990 and 2021. Material and methods: With estimates from the Global Burden of Disease 2021 study, the YLDs due to MSD and their six categories were analyzed, including osteoarthritis, rheumatoid arthritis, gout, neck pain, low back pain, as well as other MSDs. Patterns and trends in the number, crude rate, and YLD age-standardized rate were evaluated at the national and state levels, as well as by age group and gender. Results: MSDs were the main cause of YLDs in Mexico between 1990 and 2021, with an increase of 57.3%, going from 1,458.4 to 2,293.7 per 100,000 population. Low back pain (840.6 YLD) showed the highest rate in 2021, while osteoarthritis had the largest increase. MSDs increased with age and, and except for gout, affected women more often. Conclusions: From 1990 to 2021, MSDs were the main cause of YLDs in Mexico, with a higher impact on adults and women. MSDs can appear early in life, hence the need for continuous interventions in order to preserve quality of life.

Analysis of musculoskeletal disorders-associated disability in Mexico from 1990 to 2021.

BACKGROUND: Musculoskeletal disorders (MSD) affect 1.71 billion people worldwide and are the leading cause of disability. OBJECTIVE: To analyze the years lived with disability (YLD) attributed to MSD in Mexico between 1990 and 2021. MATERIAL AND METHODS: With estimates from the Global Burden of Disease 2021 study, the YLDs due to MSD and their six categories were analyzed, including osteoarthritis, rheumatoid arthritis, gout, neck pain, low back pain, as well as other MSDs. Patterns and trends in the number, crude rate, and YLD age-standardized rate were evaluated at the national and state levels, as well as by age group and gender. RESULTS: MSDs were the main cause of YLDs in Mexico between 1990 and 2021, with an increase of 57.3%, going from 1,458.4 to 2,293.7 per 100,000 population. Low back pain (840.6 YLD) showed the highest rate in 2021, while osteoarthritis had the largest increase. MSDs increased with age and, and except for gout, affected women more often. CONCLUSIONS: From 1990 to 2021, MSDs were the main cause of YLDs in Mexico, with a higher impact on adults and women. MSDs can appear early in life, hence the need for continuous interventions in order to preserve quality of life.

ANTECEDENTES: Los trastornos musculoesqueléticos (TME) afectan a 1710 millones de personas en todo el mundo y es la principal causa de discapacidad. OBJETIVO: Analizar los años vividos con discapacidad (AVD) por TME en México entre 1990 y 2021. MATERIAL Y MÉTODOS: Con las estimaciones del estudio de la Carga Global de la Enfermedad 2021 se analizaron los AVD por TME y sus seis categorías: osteoartritis, artritis reumatoide, gota, dolor cervical, lumbalgia y otros TME. Se evaluaron patrones y tendencias del número, tasa cruda y tasa estandarizada por edad de los AVD a nivel nacional, estatal, por grupos de edad y sexo. RESULTADOS: Los TME constituyeron la principal causa de AVD en México entre 1990 y 2021, con un incremento de 57.3 %; pasaron de 1458.4 a 2293.7 por 100 000 habitantes. La lumbalgia (840.6 AVD) destacó con la mayor tasa en 2021 y la osteoartritis, con el mayor incremento. Los TME se incrementaron con la edad y, con excepción de la gota, afectaron más a las mujeres. CONCLUSIONES: De 1990 a 2021, los TME constituyeron la principal causa de AVD en México, con mayor impacto en adultos y mujeres. Los TME se evidencian desde edades tempranas, de ahí la necesidad de intervenciones continuas para preservar la calidad de vida.

sesA, sesB, sesC, sesD, sesE, sesG, sesH, and embp genes are genetic markers that differentiate commensal isolates of Staphylococcus epidermidis from isolates that cause prosthetic joint infection.

OBJECTIVES: Staphylococcus epidermidis can cause prosthetic joint infections. Strategies to differentiate between healthy skin and prosthetic joint infections isolates are relatively ineffective, which makes necessary to search for new differential biomarkers. Staphylococcus epidermidis has eleven surface proteins, denoted as Ses proteins. In this work, ses genes are used as biomarkers to differentiate between prosthetic joint infections and healthy skin isolates. METHODS: All prosthetic joint infections (n = 51) and healthy skin (n = 51) isolates were genotyped by pulsed-field gel electrophoresis. icaA, embp, sesA-I, and sdrF genes were determined by PCR. The phenotypic data included biofilm production and antibiotic resistance. RESULTS: 10 pulsed-field gel electrophoresis profiles were identified: four profiles were exclusive of prosthetic joint infections isolates, three profiles presented a higher proportion in prosthetic joint infections isolates and three profiles presented a higher proportion in healthy skin isolates. sesA, sesB, sesC, sesD, sesE, sesG, and sesH genes were more prevalent in healthy skin isolates than in prosthetic joint infections isolates (p < .05). Prosthetic joint infections isolates were more resistant to oxacillin (78%), ciprofloxacin (60%), levofloxacin (60%), and moxifloxacin (57%). The principal coordinate analysis and a discriminant analysis found that prosthetic joint infections isolates had as discriminant biomarker the biofilm formation, the icaA gene, oxacillin, ciprofloxacin, levofloxacin, moxifloxacin, and gentamicin resistance. In contrast, the healthy skin isolates had as discriminant biomarkers the embp, sesA, sesB, sesC, sesD, sesE, sesG, and sesH genes. CONCLUSIONS: These data suggest that ses genes can be considered biomarkers to differentiate between S. epidermidis commensal and prosthetic joint infections clinical.

Cost-effectiveness analysis of voriconazole, fluconazole, and amphotericin B for invasive fungal infections following allogeneic hematopoietic stem cell transplantation in Mexico.

BACKGROUND: Patients receiving allogeneic hematopoietic stem cell transplantation (alloHSCT) are at high risk of invasive fungal infections (IFIs), which are associated with high mortality and economic burden. The cost-effectiveness of prophylaxis for the prevention of IFIs in alloHSCT recipients in Mexico has not yet been assessed. METHODS: This analysis modeled a hypothetical cohort of 1,000 patients to estimate costs and outcomes for patients receiving prophylaxis for IFIs following alloHSCT, from the perspective of institutional payers in Mexico. The main prophylaxis agents currently used in Mexican clinical practice are voriconazole, fluconazole, and amphotericin B (AmB). The model accounted for event rates of IFIs during each treatment, assuming IFI causality due to invasive aspergillosis, invasive candidiasis, or other IFIs, and that the outcome for patients during follow-up was IFI-related death, death from other causes, or survival. Clinical efficacies were obtained from published literature; costs were based on local sources. Cost-effectiveness was assessed using incremental cost-effectiveness ratios (ICERs). Univariate (assessing the impact of varying each model parameter) and probabilistic sensitivity analyses were performed. RESULTS: Voriconazole was associated with the lowest number of breakthrough IFIs, IFI-related deaths, and total number of deaths. Total costs were lower for fluconazole (Mexican pesos [MXN] 72,944; US $4,079) than voriconazole (MXN 101,413; US $5,671) or AmB (MXN 110,529; US $6,180). Voriconazole had better clinical outcomes and lower costs than AmB and could be considered cost-effective compared with fluconazole in line with the local ICER threshold. Drug costs, monitoring costs, and duration of prophylaxis were most sensitive to variation from univariate sensitivity analysis. Findings from the probabilistic sensitivity analysis were consistent with the base-case results. CONCLUSION: Voriconazole had the most favorable clinical outcomes, but overall prophylaxis costs were higher than with fluconazole. Overall, based on local ICER thresholds (MXN 184,665; US $10,326), voriconazole was considered a cost-effective option for prophylaxis of IFI in Mexico.

Population Structure, Genetic Diversity, and Evolutionary History of Kleinia neriifolia (Asteraceae) on the Canary Islands.

Kleinia neriifolia Haw. is an endemic species on the Canarian archipelago, this species is widespread in the coastal thicket of all the Canarian islands. In the present study, genetic diversity and population structure of K. neriifolia were investigated using chloroplast gene sequences and nuclear SSR (simple sequence repeat). The differentiation among island populations, the historical demography, and the underlying evolutionary scenarios of this species are further tested based on the genetic data. Chloroplast diversity reveals a strong genetic divergence between eastern islands (Gran Canaria, Fuerteventura, and Lanzarote) and western islands (EI Hierro, La Palma, La Gomera, Tenerife), this west-east genetic divergence may reflect a very beginning of speciation. The evolutionary scenario with highest posterior probabilities suggests Gran Canaria as oldest population with a westward colonization path to Tenerife, La Gomera, La Palma, and EI Hierro, and eastward dispersal path to Lanzarote through Fuerteventura. In the western islands, there is a slight decrease in the effective population size toward areas of recent colonization. However, in the eastern islands, the effective population size increase in Lanzarote relative to Gran Canaria and Fuerteventura. These results further our understanding of the evolution of widespread endemic plants within Canarian archipelago.

Molecular and Phenotypic Characterization of Staphylococcus epidermidis Isolates from Healthy Conjunctiva and a Comparative Analysis with Isolates from Ocular Infection.

Staphylococcus epidermidis is a common commensal of healthy conjunctiva and it can cause endophthalmitis, however its presence in conjunctivitis, keratitis and blepharitis is unknown. Molecular genotyping of S. epidermidis from healthy conjunctiva could provide information about the origin of the strains that infect the eye. In this paper two collections of S. epidermidis were used: one from ocular infection (n = 62), and another from healthy conjunctiva (n = 45). All isolates were genotyped by pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec), detection of the genes icaA, icaD, IS256 and polymorphism type of agr locus. The phenotypic data included biofilm production and antibiotic resistance. The results displayed 61 PFGE types from 107 isolates and they were highly discriminatory. MLST analysis generated a total of 25 STs, of which 11 STs were distributed among the ocular infection isolates and lineage ST2 was the most frequent (48.4%), while 14 STs were present in the healthy conjunctiva isolates and lineage ST5 was the most abundant (24.4%). By means of a principal coordinates analysis (PCoA) and a discriminant analysis (DA) it was found that ocular infection isolates had as discriminant markers agr III or agr II, SCCmec V or SCCmec I, mecA gene, resistance to tobramycin, positive biofilm, and IS256+. In contrast to the healthy conjunctiva isolates, the discriminating markers were agr I, and resistance to chloramphenicol, ciprofloxacin, gatifloxacin and oxacillin. The discriminant biomarkers of ocular infection were examined in healthy conjunctiva isolates, and it was found that 3 healthy conjunctiva isolates [two with ST2 and another with ST9] (3/45, 6.66%) had similar genotypic and phenotypic characteristics to ocular infection isolates, therefore a small population from healthy conjunctiva could cause an ocular infection. These data suggest that the healthy conjunctiva isolates do not, in almost all cases, infect the eye due to their large genotypic and phenotypic difference with the ocular infection isolates.

Evolution of bacterial genes: evidences of positive Darwinian selection and fixation of base substitutions in virulence genes of Helicobacter pylori.

Gene diversity in Helicobacter pylori from different origins results in a phylogeographic differentiation, and this genetic variation among populations might be driven by random drift or by selective forces. However, only the selective forces would contribute to adaptation of the bacteria to the physiology and environment of its local host and to its association with gastroduodenal diseases. We studied evolutionary forces acting on variable regions of virulence genes cagA, babA and oipA, which present geographic differences among H. pylori strains from different human groups. Gene sequences in H. pylori strains from Asia, Europe and America were analysed using state of the art analytical methods like the Maximum Likelihood method. The rate and nature of polymorphisms in these virulence genes were also compared among populations using the AMOVA and McDonald-Kreitman tests. We found strong and significant positive selection acting on variable regions of cagA, babA and oipA. We found in cagA from Asian strains regions under positive selection, which localised in amino acid sites defining the Asian fingerprint for this gene and in sites with important biological activity. Different evolutionary forces are acting on the variable region of virulence genes; they partly explain the source of genetic diversity and the differences in risk for gastroduodenal diseases among different human populations.