Serological follow up of positive SARS-CoV-2 cases / Seguimiento serológico de casos positivos a SARS-CoV-2

Abstract: Objective: To describe the humoral response in a cohort with mild and asymptomatic SARS-CoV-2 infection previously identified in a community-based serological survey. Materials and methods: This study was an observational follow up of 193 subjects previously identified with positive anti-SARS-CoV-2 antibodies invited for a second test 112 days after the first sampling. All completed a standardized electronic questionnaire. IgM/IgG antibodies were determined using a qualitative IgM/IgG chemiluminescent immunoassay. Results: Among the 193 eligible subjects, a total of 174 (90%) attended the follow-up visit, and their serum samples were tested. Of the samples, 171 (98.3%) were still positive, and 3 (1.7%) were negative. Also, the cut-off index (COI) value of the immunoassay significantly increased from the first to the second test (P <0.001). Conclusions: Our findings support a sustained humoral response in individuals with mild and asymptomatic SARS-CoV-2 infection up to 112 days after a positive serologic baseline test, accompanied by increasing antibody titers.

Resumen: Objetivo: Describir la respuesta humoral en una cohorte con una infección leve o asintomática por SARS-CoV-2, previamente identificada en una encuesta serológica comunitaria. Material y métodos: Se realizó un seguimiento observacional de 193 individuos previamente identificados con anticuerpos IgM/IgG anti-SARS-CoV-2 invitados 112 días después de una determinación serológica inicial. Todos los participantes completaron un cuestionario electrónico estandarizado. Se determinaron los anticuerpos IgM/IgG mediante un inmunoensayo quimioluminiscente cualitativo. Resultados: De entre los 193 sujetos elegibles, 174 (90%) acudieron al seguimiento. De las muestras, 171 (98.3%) eran positivas y 3 (1.7%) negativas. Además, el valor de COI del inmunoenasayo se incrementó al comparar la primera y segunda determinación (P <0.001). Conclusiones: Los presentes resultados apoyan una respuesta humoral sostenida en individuos con infección por SARS-CoV-2 con síntomas leves o asintomática hasta 112 días después de una prueba serológica positiva, acompañada de incremento en los títulos de anticuerpos.

Will environmental changes in temperature affect the course of COVID-19?

ABSTRACT While the outbreak has reached every region of the world, it is undeniable that countries in the southern hemisphere seem to be less affected, where cases have been reported, these have been imported and travel related. We analyzed the climate temperature from various regions according to their current ongoing human-to-human transmission status. We studied 3 groups; Group 1, 10 provinces from China with majority of COVID-19 cases; Group 2, areas where continuous horizontal transmission outside of China had been reported; and group 3, areas where imported cases had been detected and no horizontal transmission had been documented after at least seven days since the first case was reported. The regions without ongoing human-to-human transmission showed significantly higher temperatures when compared to China and countries with ongoing human-to-human transmission, with over an 11-degree difference. The average rainfall during the study period was significantly higher in those regions without OHHT when compared to the Chinese provinces with ongoing human-to-human transmission and the regions with active transmission of SARS-CoV-2. Our findings show statistically significant differences between regions with ongoing human-to-human transmission of COVID-19 cases compared to those regions without horizontal transmission. This phenomenon could have implications in the behavior of the ongoing COVID-19 outbreak in the following months.

Monetary costs and hospital burden associated with the management of invasive fungal infections in Mexico: a multicenter study

ABSTRACT Background: Invasive fungal infections (IFIs) affect >1.5 million people per year. Nevertheless, IFIs are usually neglected and underdiagnosed. IFIs should be considered as a public-health problem and major actions should be taken to tackle them and their associated costs. Aim To report the incidence of IFIs in four Mexican hospitals, to describe the economic cost associated with IFIs therapy and the impact of adverse events such as acute kidney injury (AKI), liver damage (LD), and ICU stay. Methods: This was a retrospective, transversal study carried-out in four Mexican hospitals. All IFIs occurring during 2016 were included. Incidence rates and estimation of antifungal therapy's expenditure for one year were calculated. Adjustments for costs of AKI were done. An analysis of factors associated with death, AKI, and LD was performed. Results: Two-hundred thirty-eight cases were included. Among all cases, AKI was diagnosed in 16%, LD in 25%, 35% required ICU stay, with a 23% overall mortality rate. AKI and LD showed higher mortality rates (39% vs 9% and 44% vs 18%, respectively, p < 0.0001). The overall incidence of IFIs was 4.8 cases (95% CI = 0.72-8.92) per 1000 discharges and 0.7 cases (95% CI = 0.03-1.16) per 1000 patients-days. Invasive candidiasis showed the highest incidence rate (1.93 per 1000 discharges, 95% CI = −1.01 to 2.84), followed by endemic IFIs (1.53 per 1000 discharges 95% CI = −3.36 to 6.4) and IA (1.25 per 1000 discharges, 95% CI = −0.90 to 3.45). AKI increased the cost of antifungal therapy 4.3-fold. The total expenditure in antifungal therapy for all IFIs, adjusting for AKI, was $233,435,536 USD (95% CI $6,224,993 to $773,810,330). Conclusions: IFIs are as frequent as HIV asymptomatic infection and tuberculosis. Costs estimations allow to assess cost-avoidance strategies to increase targeted driven therapy and decrease adverse events and their costs.

Rapid spread of an ongoing outbreak of Zika virus disease in pregnant women in a Mexican hospital

Abstract In the first nine weeks of implementation of a Zika Virus Preparedness Plan in a Mexican Public Hospital, we cared for 221 pregnant women with any signal or symptom suggesting Zika virus infection and 99 (44.8%) patients were found to be positive for Zika virus.The median age of patients was 25.3 years (range 13-49). Symptoms in PCR-positive patients were rash (91.4%) followed by headache (53.1%), myalgia (46.9%), arthralgia (45.7%), pruritus (35.8%), retroocular pain (29.6%), conjunctivitis (21%), and fever (21%). The women's epidemiologic exposure history indicates local transmission and a community outbreak.

Increasing rates of Clostridium difficile infection in Mexican hospitals

Abstract Introduction The epidemiology of Clostridium difficile infection (CDI) has changed in the last two decades. There is a lack of information regarding incidence and severity of CDI, especially in the developing world. Methods This was a retrospective and observational study from four hospitals of three Mexican cities. Patients were diagnosed with CDI when presented with loose stools and had at least one of the following tests positive: toxins assay, real-time PCR, or an endoscopic image compatible with pseudomembranous colitis. CDI was classified according to international guidelines. Demographic and clinical data as well as information regarding total hospital admissions, total length-of-hospital stay, and other variables related to hospitalization were gathered from the epidemiology and administration departments of each hospital. Results A total of 2050 hospital beds were analyzed with 288,171 patients hospitalized accumulating 1,576,446 days of hospitalization during the study period. The average rate of CDI per 1000 hospital-days was lower than the rates reported in the US and Europe, although in 2015 CDI rates were almost persistently above the mean rate for the study period. More than half of PCR positive patients were ribotype 027. Conclusion Hospital rates of CDI are increasing in Mexican hospitals with a predominance of infections caused by ribotype 027.

Molecular epidemiology of coagulase-negative bloodstream isolates: detection of Staphylococcus epidermidis ST2, ST7 and linezolid-resistant ST23

Abstract The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p < 0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence.

Sexually transmitted pathogens, coinfections and risk factors in patients attending obstetrics and gynecology clinics in Jalisco, Mexico / Patógenos de transmisión sexual, coinfecciones y factores de riesgo en pacientes que asisten a clínicas de obstetricia y ginecología en Jalisco, México

Abstract: Objective: To determine the frequency of nine sexually transmitted pathogens, coinfections and risk factors in patients attending obstetrics and gynecology clinics in Jalisco, Mexico. Materials and methods: Samples from 662 patients attending obstetrics and gynecology clinics were analyzed. Treponema pallidum, HIV, and HCV were detected by serology. HPV was detected by Polimerase Chain Reaction (PCR), and its genotype was determined by Restriction Fragment Length Polymorphism (RFLP). Trichomonas vaginalis, HSV-1, HSV-2, Mycoplasma genitalium, Neisseria gonorrhoeae and T. pallidum were detected by multiplex PCR. Results: By serology, HIV frequency was 6.8%, T. pallidum was 2.26%, and HCV was 0.15%. By PCR, HPV frequency was 13.9%, (more frequent genotype was 16, 33.7%), followed by T. vaginalis (14.2%), HSV-1 (8.5%), M. genitalium (2,41%), N. gonorrhoeae (2.11%), HSV-2 (1.8%), and T. pallidum (1.05%). Patients infected with T. vaginalis were more likely to have multiple coinfections (p = 0.01). Conclusion: The frequency of HPV, HVS-1, HSV-2, M. genitalium and T. vaginalis was lower than that reported. However, a high frequency of HIV, T. pallidum, and N. gonorrhoeae was detected.

Resumen: Objetivo: Determinar la frecuencia de nueve patógenos de transmisión sexual, coinfecciones y factores de riesgo en pacientes que acudieron a una consulta de ginecología y obstetricia en Jalisco, México. Material y métodos: Se analizaron muestras de 662 pacientes que asistieron a la consulta de ginecología y obstetricia. Se detectaron Treponema pallidum, VIH y VHC mediante serología. Se detectó VPH por Reacción de Cadena de Polimerasa (PCR) y sus genotipos se detectaron por Polimorfismos de Longitud de Fragmentos de Restricción (RFLP). Se detectaron Trichomonas vaginalis, VHS-1,VHS-2, Mycoplasma genitalium, Neisseria gonorrhoeae y T. pallidum por PCR múltiple. Resultados: Por serología, la frecuencia deVIH fue 6.8%, de T. pallidum fue 2.26% y deVHC fue 0.15%. Por PCR, la frecuencia más alta fue deVPH (13.9%, el genotipo más frecuente fue el 16, 33.7%), seguida deT. vaginalis (14.2%), VHS-1 (8.5%), M. genitalium (2.41%), N. gonorrhoeae (2.11%), VHS-2 (1.8%) y T. pallidum (1.05%). Los pacientes infectados con T. vaginalis presentaron más probabilidades de tener múltiples coinfecciones (p = 0.01). Conclusiones: La frecuencia de infección por VPH, VHS-1,VHS-2, M.genitalium y T. vaginalis fue menor a lo reportado. Sin embargo, se detectó una alta frecuencia de VIH, T. pallidum, y N. gonorrhoeae.

Application of the ATLAS score for evaluating the severity of Clostridium difficile infection in teaching hospitals in Mexico

Background: For clinicians, a practical bedside tool for severity assessment and prognosis of patients with Clostridium difficileinfection is a highly desirable unmet medical need.Setting: Two general teaching hospitals in northeast Mexico.Population: Adult patients with C. difficileinfection.Methods: Prospective observational study.Results: Patients included had a median of 48 years of age, 54% of male gender and an average of 24.3 days length of hospital stay. Third generation cephalosporins were the antibiotics most commonly used prior to C. difficileinfection diagnosis. Patients diagnosed with C. difficileinfection had a median ATLAS score of 4 and 56.7% of the subjects had a score between 4 and 7 points. Patients with a score of 8 through 10 points had 100% mortality.Conclusion: The ATLAS score is a potentially useful tool for the routine evaluation of patients at the time of C. difficileinfection diagnosis. At 30 days post-diagnosis, patients with a score of ≤3 points had 100% survival while all of those with scores ≥8 died. Patients with scores between 4 and 7 points had a greater probability of colectomy with an overall cure rate of 70.1%.

Purple urine bag syndrome in end-stage chronic kidney disease

Introduction: When faced with violet, purple or purplish-blue urine, clinicians should consider urinary tract infection in their differential diagnosis. Case report: A 60-year-old woman with end-stage kidney disease and non-adherence to renal replacement therapy was admitted to our hospital for placement of hemodialysis catheter. During her hospitalization she had purple urine, and purple urine bag syndrome (PUBS) was diagnosed. She was effectively treated with antibiotics and her urine returned to a dark yellow color. Discussion: Although this condition is often easily treated, diagnosing PUBS in chronic renal patients probably means an increased serum concentration of indoxyl sulfate, metabolite that is involved in the progression of both CKD and cardiovascular disease. Conclusion: Hence, in the context of our renal patients, perhaps PUBS is not as benign as supposed. .

Enfermedad asociada a Clostridium difficile en América Latina / Clostridum difficile associated disease in Latin America

La enfermedad asociada a Clostridium difficile (EACD) se ha incrementado de manera sostenida en todo el mundo durante los últimos 10 años. Sin embargo, son pocos los estudios en América Latina que abordan el tema. En una revisión bibliográfica en las bases de datos documentales de los países latinoamericanos, encontramos solo siete artículos recientes en los cuales se describen las características clínicas, los factores de riesgo y, en algunos, el desenlace de la infección. De estos artículos solo uno fue prospectivo, mientras que los restantes fueron retrospectivos, transversales o de casos y controles. Esta revisión estuvo orientada fundamentalmente hacia la población adulta en hospitalización, aunque la edad de los pacientes va de los 13 años en algunos trabajos. En dos análisis recientes se realizó cultivo celular para determinar efecto citopático y en el resto la determinación fue por inmunoensayo. En todos, el empleo de antibióticos (fluoroquinolonas, clindamicina y cefalosporinas) tuvo asociación con la EACD, y el tratamiento de la enfermedad incluyó casi siempre metronidazol por vía oral; únicamente en un centro se utilizó vancomicina. La mortalidad atribuible fue menor (4%) a la informada en países desarrollados. Dado que en América Latina existen escasas investigaciones de EACD con pocos pacientes y casi todas retrospectivas, se percibió la necesidad de determinar la frecuencia de esta enfermedad, conocer mejor los factores de riesgo y las verdaderas tasas de mortalidad global y atribuible.

Clostridium difficile associated disease (CDAD) has shown a sustained increase worldwide over the last ten years. However, there are few studies on this topic in Latin America. We conducted a comprehensive literature review using medical databases of Latin American countries. We found only seven recent papers in which clinical characteristics and risk factors were analyzed; some included outcome variables. Of these articles, only one was prospective, while the rest were either retrospective, cross-sectional or case-control studies. Most studies were done among hospitalized adult patients, even though patients 13+ years were also included in some reports. Only two recent clinical studies used cell culture to determine a cytopathic effect and the rest included immunoenzymatic assays. In general, all the studies we reviewed showed that the use of fluorquinolones, clindamycin, and cephalosporins were the antibiotics mostly associated with CDAD. Treatment schedules generally included metronidazol, although vancomycin was reported in one. Attributable mortality was lower than the mortality described in previous reports from hospitals in developed countries. Studies where this outcome was included did not surpass 4%, a significant difference from the findings from developed countries. In Latin America there are few studies that describe this clinical problem, they generally include small sample sizes and most are retrospective. There is a clear need to design and carry out prospective studies that will allow us to determine the true prevalence of this health problem