Cesarean sections in Brazil: will they ever stop increasing? / Cesáreas en el Brasil: ¿dejarán de aumentar alguna vez?

Objective. To describe trends, geographic distribution, and risk factors for cesarean deliveries in Brazil in 2000–2011, and to determine if efforts to curtail rates have had a measurable impact. Methods. This was an observational study using nationwide information from the Department of Informatics of the Unified Health System (DATASUS). Individual level analyses were based on data regarding maternal education, age, parity, and skin color. Ecological analyses at the level of 431 health districts investigated the relationships with health facility density and poverty level. Results. Cesarean rates increased markedly, from 37.9% in 2000 to 53.9% in 2011. Preliminary results from 2012 showed a rate of 55.8%, with the richest geographic areas showing the highest rates. Rates at the municipal level varied from 9%–96%. Cesareans were more common in women with higher education, white skin color, older age, and in primiparas. In the ecological analyses, the number of health facilities per 1 000 population was strongly and positively correlated with cesarean rates, with an increase of 16.1 percentage points (95% Confidence Interval [95%CI] = 4.3–17.8) for each facility. An increase of 1 percentage point in the poverty rate was associated with a decline of 0.5 percentage point in cesarean rates (95%CI = 0.5–0.6). Conclusions. The strong associations with maternal education and health facility density suggest that the vast majority of cesareans are not medically indicated. A number of policies and programs have been launched to counteract this trend, but have had virtually no impact.

Objetivo. Describir las tendencias, la distribución geográfica, y los factores de riesgo de parto por cesárea en el Brasil durante el período del 2000 al 2011, y determinar si las iniciativas dirigidas a reducir las tasas de cesáreas han tenido una repercusión cuantificable. Métodos. Se trata de un estudio de observación que utilizó información a escala nacional del Departamento de Informática del Sistema Unificado de Salud (DATASUS). Los análisis a nivel individual se basaron en datos sobre el nivel de formación materna, la edad, la paridad y el color de la piel. Se investigaron las relaciones con la densidad de establecimientos de salud y el nivel de pobreza mediante análisis ecológicos a nivel de 431 distritos de salud. Resultados. Las tasas de cesáreas aumentaron notablemente, de 37,9% en el 2000 a 53,9% en el 2011. Los resultados preliminares del 2012 mostraron una tasa de 55,8%, con tasas más elevadas en las zonas geográficas más ricas. Las tasas a escala municipal variaron de 9 a 96%. Los partos por cesárea fueron más frecuentes en las mujeres blancas, en las que tenían un mayor nivel de formación, en las de mayor edad y en las primíparas. En los análisis ecológicos, el número de establecimientos de salud por 1 000 habitantes se correlacionó intensa y positivamente con la tasa de cesáreas, con un incremento de 16,1 puntos porcentuales (intervalo de confianza (IC) de 95% = 4,3–17,8) para cada establecimiento. Un aumento de un punto porcentual en la tasa de pobreza se asociaba con una disminución de medio punto porcentual en la tasa de cesáreas (IC de 95% = 0,5–0,6). Conclusiones. Las intensas asociaciones con el nivel de formación materna y la densidad de establecimientos de salud indican que la mayor parte de las cesáreas no están indicadas médicamente. Se han puesto en marcha diversos programas y políticas dirigidos a contrarrestar esta tendencia, pero prácticamente no han tenido ninguna repercusión.

Virulence factor-activity relationships: workshop summary.

The concept or notion of virulence factor-activity relationships (VFAR) is an approach for identifying an analogous process to the use of qualitative structure-activity relationships (QSAR) for identifying new microbial contaminants. In QSAR, it is hypothesized that, for new chemical contaminants, their potential acute or chronic toxicity may be reasonably estimated on the basis of structural relationships to other known toxic contaminants. Thus the parallel that is being attempted for pathogenic microorganisms is that known virulence factors may be used as predictors for identifying undiscovered pathogens and microbial causes of emerging diseases. Advances in molecular biology, genomics and proteomics have led the Committee on Drinking Water Contaminants of the National Research Council, as requested by the EPA, to recommend the VFAR approach as a potentially more systematic and scientific process for the selection of microorganisms for inclusion in the Contaminant Candidate List (CCL).

Multiple treatment algorithms for successful outcomes in venous thoracic outlet syndrome.

BACKGROUND: We sought to determine the outcomes in patients presenting with venous thoracic outlet syndrome. METHODS: Prospectively collected data from 67 patients between October 2003 and December 2007. The average age was 31 years (range, 16-54); the 37 males and 30 females presented on average 9.2 months (range, 1 month-6 years) after acute thrombosis. Four treatment algorithms were utilized. RESULTS: In group 1, 3 patients presented with acute occlusion and received tissue plasminogen activator (tPA) and immediate first rib resection with scalenectomy (FRRS). One vein rethrombosed and was treated by intravenous tPA postoperatively. In group 2, 39 patients presented with stenotic subclavian veins an average of 22 weeks after their initial thrombosis, all of whom underwent FRRS followed by a venogram 2 weeks postoperatively: 25 had a tight stenosis and underwent venoplasty with anticoagulation; 13 had patent, nonstenotic subclavian veins, and 1 patient required tPA and venoplasty owing to rethrombosis. Two patients had their subclavian vein thrombose after venoplasty and were treated with anticoagulation, tPA, and venoplasty. In group 3, 11 patients presented with intermittent venous obstruction without thrombosis and underwent FRRS; 3 underwent venograms because of concerns of residual stenosis, 2 of whom required venoplasty postoperatively. Finally, in group 4, 14 patients presented with occluded subclavian veins and underwent FRRS with long-term anticoagulation. Eleven have recanalized at an average of 6 months (range, 2-12). CONCLUSION: Overall, 64 of 67 patients have patent subclavian veins after a median follow-up of 10 months, and all patients are asymptomatic for a success rate of 96%. Tailored treatment algorithms including FRRS, postoperative venograms with or without intervention, and the use of long-term anticoagulation seems to be required in this complicated group of young patients to achieve optimal results.

Surgical intervention for thoracic outlet syndrome improves patient's quality of life.

OBJECTIVE: To assess long-term quality of life outcomes in patients following transaxillary first-rib resection and scalenectomy for thoracic outlet syndrome (TOS). METHODS: This was a prospective observational study using the Short-Form 12 (SF-12) and Disability of Arm, Hand, and Shoulder (DASH) instruments between February 2005 and March 2008 in patients with TOS presenting to an academic medical center for preoperative surgical evaluation after failing physical therapy protocol. Surveys were conducted preoperatively and then again at 3, 6, 12, 18, and 24 months after surgery. Longitudinal data analysis was performed with population-averaged models using generalized estimating equations (GEE) method for average rate of recovery. Kaplan-Meier method was used to analyze time to return to work. RESULTS: A total of 70 out of 105 eligible patients (66.7%) completed the study protocol (44 neurogenic; 26 venous), returning 243 valid SF-12 surveys (162 neurogenic; 81 venous) and 188 valid DASH surveys (124 neurogenic; 64 venous). Half (50%) of the neurogenic patients and 77% of the venous patients returned to full-time work or activity within the study follow-up, with half of them doing so by 4 months and 75% of them by 5 months. There was no statistically significant difference in return to work between the neurogenic or venous patients. Neurogenic patients had baseline SF-12 Physical Component Scores (PCS) similar to chronic heart failure patients and were significantly worse than venous patients (33.8 vs 43.6, P < .001). In contrast, no difference existed in Mental Component Scores (MCS) (44.5 vs 43.5, P = .78). In follow-up, on average, PCS scores for neurogenic patients improved 0.24 points (P < .001) and MCS scores improved 0.15 points per month (P = .01); while PCS scores for venous patients improved 0.40 points (P = .004) and MCS scores improved 0.55 points per month (P < .001). Additionally, neurogenic patients had baseline DASH scores that were similar to patients with rotator cuff tears, and they were also significantly worse than venous patients (50.2 vs 25.0, P < .001). DASH scores, on average, also improved 0.85 points (P < .001) for neurogenic patients and 0.81 points (P < .001) for venous patients per month. CONCLUSION: The use of the SF-12 and DASH instruments in patients with TOS demonstrated significant improvement in patients postoperatively. Venous TOS patients typically improved both physical and mental scores in shorter periods of time than their neurogenic counterparts. Neurogenic and venous TOS patients returned to full-time work/activity within the same length of time postoperatively. However, neurogenic patients required more secondary interventions. We conclude that in appropriately selected patients with either neurogenic or venous TOS, surgical intervention can improve their quality of life over time.

First rib resection and scalenectomy for chronically occluded subclavian veins: what does it really do?

First rib resection and scalenectomy is an acceptable therapy for those with axillosubclavian vein thrombosis who have responded to lytic therapy and demonstrated subclavian vein patency. However, the treatment for those patients who present with a chronically occluded subclavian vein is controversial. We present four such patients who underwent first rib resection and scalenectomy and whose subclavian vein spontaneously opened within the first year following surgery while anticoagulated, as well as the ultrasound protocol we employ at our institution to identify such reopening. The average age of these patients was 20 (range 17-23) years; three were male and one was female. The average time interval prior to surgery when the initial thrombosis occurred was 25 (12-34) weeks. All patients were symptomatic and underwent a transaxillary first rib resection and scalenectomy with attention to incise the subclavius tendon. All were maintained on warfarin postoperatively and surveilled by duplex scan. In all four patients the subclavian vein subsequently opened after an average of 7 (2-11) months and anticoagulation was stopped. The resultant patent subclavian vein correlated with improvement in symptoms in all four patients. All patients were asymptomatic in the postoperative follow-up period at an average of 14 (2-33 months). In conclusion, selective symptomatic patients with subclavian vein occlusion can be aggressively treated with first rib resection and scalenectomy along with anticoagulation that will lead to recanalization and opening of vein over time. This treatment correlates with improvement of their symptoms.

UV inactivation of Cryptosporidium hominis as measured in cell culture.

The Cryptosporidium spp. UV disinfection studies conducted to date have used Cryptosporidium parvum oocysts. However, Cryptosporidium hominis predominates in human cryptosporidiosis infections, so there is a critical need to assess the efficacy of UV disinfection of C. hominis. This study utilized cell culture-based methods to demonstrate that C. hominis oocysts displayed similar levels of infectivity and had the same sensitivity to UV light as C. parvum. Therefore, the water industry can be confident about extrapolating C. parvum UV disinfection data to C. hominis oocysts.

Diversity of nitrifying bacteria in full-scale chloraminated distribution systems.

Chloramination for secondary disinfection of drinking water often promotes the growth of nitrifying bacteria in the distribution system due to the ammonia introduced by chloramine formation and decay. This study involved the application of molecular biology techniques to explore the types of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) present in several full-scale chloraminated systems. The results of AOB community characterization indicated the ubiquitous detection of representatives from the Nitrosomonas genus, with Nitrosospira constituting a negligible or small fraction of the AOB community in all but one sample. Cloning and sequencing demonstrated the presence of AOB representatives within the Nitrosomonas oligotropha cluster, a phylogenetic subgroup of AOB from which isolates demonstrate a high affinity for ammonia. For the NOB communities, Nitrospira were detected in most of the samples, while Nitrobacter were only detected in a few samples. These results provide insight into the types of AOB responsible for nitrification episodes in full-scale chloraminated systems, which should help direct future studies aimed at characterizing relevant AOB growth and inactivation properties. Furthermore, the detection of NOB in most of the samples suggests a need to evaluate the contribution of biological nitrite oxidation relative to chemical oxidation in these systems.

Comparison of in vitro cell culture and a mouse assay for measuring infectivity of Cryptosporidium parvum.

In vitro cell cultures were compared to neonatal mice for measuring the infectivity of five genotype 2 isolates of Cryptosporidium parvum. Oocyst doses were enumerated by flow cytometry and delivered to animals and cell monolayers by using standardized procedures. Each dose of oocysts was inoculated into up to nine replicates of 9 to 12 mice or 6 to 10 cell culture wells. Infections were detected by hematoxylin and eosin staining in CD-1 mice, by reverse transcriptase PCR in HCT-8 and Caco-2 cells, and by immunofluorescence microscopy in Madin-Darby canine kidney (MDCK) cells. Infectivity was expressed as a logistic transformation of the proportion of animals or cell culture wells that developed infection at each dose. In most instances, the slopes of the dose-response curves were not significantly different when we compared the infectivity models for each isolate. The 50% infective doses for the different isolates varied depending on the method of calculation but were in the range from 16 to 347 oocysts for CD-1 mice and in the ranges from 27 to 106, 31 to 629, and 13 to 18 oocysts for HCT-8, Caco-2, and MDCK cells, respectively. The average standard deviations for the percentages of infectivity for all replicates of all isolates were 13.9, 11.5, 13.2, and 10.7% for CD-1 mice, HCT-8 cells, Caco-2 cells, and MDCK cells, respectively, demonstrating that the levels of variability were similar in all assays. There was a good correlation between the average infectivity for HCT-8 cells and the results for CD-1 mice across all isolates for untreated oocysts (r = 0.85, n = 25) and for oocysts exposed to ozone and UV light (r = 0.89, n = 29). This study demonstrated that in vitro cell culture was equivalent to the "gold standard," mouse infectivity, for measuring the infectivity of C. parvum and should therefore be considered a practical and accurate alternative for assessing oocyst infectivity and inactivation. However, the high levels of variability displayed by all assays indicated that infectivity and disinfection experiments should be limited to discerning relatively large differences.

Development of a Molecular Method for the Detection of Enteric Viruses in Oysters.

Detection of enteric virus contamination of shellfish is limited by current methodology, which is time-consuming, tedious, and lacking in sensitivity due to reliance on cell culture infectivity. Alternative detection methods based on nucleic acid amplification have been hampered by high sample volumes and the presence of enzymatic inhibitors. The goal of this study was to develop methods to purify and concentrate intact virions from oyster extracts to a volume and quality compatible with viral genomic nucleic acid amplification by reverse transcriptase-polymerase chain reaction (RT-PCR). Fifty-gram oyster samples were homogenized and processed by standard adsorption-elution precipitation methodology and then seeded with 105 PFU of poliovirus 1 (PV1) or hepatitis A virus (HAV). Seeded viruses were concentrated by fluorocarbon extraction, polyethylene glycol (PEG) precipitation, chloroform extraction, and cetyltrimethyl ammonium bromide (CTAB) precipitation to a volume of 100 µl with removal of RT-PCR inhibitors. Virus recovery after elution of PEG precipitates was 50% for PVI and IS to 20% for HAV as evaluted by cell culture infectivity. The CTAB precipitation step yielded a concentrated sample which was directly compatible with RT-PCR reactions and capable of detecting about 100 placque=forming units (PFU) of PVl or HAV. When 50-g oyster extracts were seeded and processed by the entire concentration and purification scheme, direct RT-PCR detection of viral genomic RNA was possible at initial inoculum levels of 104 PFU of HAV and 103 PFU of PV1, with recoveries of 1 to 5% of seeded viruses.