N Engl J Med 2013; 369:2218-2225
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05 diciembre, 2013
29 noviembre, 2013
Voided Midstream Urine Culture and Acute Cystitis in Premenopausal Women
Casi nadie lo hace pero lo reforzamos...
No está indicado urocultivo en el tratamiento de cistitis en mujeres premenopáusicas sanas.
¿Cómo hicieron el estudio?
Mujeres con cistitis no complicada.
Los autores tomaron cultivos a las mismas mujeres de la siguiente manera:
Primero les pedían muestras de urocultivo por chorro medio
luego,
les colocaban una sonda y tomaban muestras de urocultivo por sonda vesical.
Se encontró que la E coli sigue siendo la principal bacteria, incluso con recuentos bajos.
Hubo MUY POCOS cultivos donde creció enterococo y STC del grupo B con la técnica del chorro medio, por lo que los autores llegan a la conclusión de que probablemente estos gérmenes poco habituales NO causen la cistitis por sí mismos.
http://www.nejm.org/doi/full/10.1056/NEJMoa1302186
Background
The cause of acute uncomplicated cystitis is determined on the basis of cultures of voided midstream urine, but few data guide the interpretation of such results, especially when gram-positive bacteria grow.Methods
Women from 18 to 49 years of age with symptoms of cystitis provided specimens of midstream urine, after which we collected urine by means of a urethral catheter for culture (catheter urine). We compared microbial species and colony counts in the paired specimens. The primary outcome was a comparison of positive predictive values and negative predictive values of organisms grown in midstream urine, with the presence or absence of the organism in catheter urine used as the reference.Results
The analysis of 236 episodes of cystitis in 226 women yielded 202 paired specimens of midstream urine and catheter urine that could be evaluated. Cultures were positive for uropathogens in 142 catheter specimens (70%), 4 of which had more than one uropathogen, and in 157 midstream specimens (78%). The presence of Escherichia coli in midstream urine was highly predictive of bladder bacteriuria even at very low counts, with a positive predictive value of 102 colony-forming units (CFU) per milliliter of 93% (Spearman's r=0.944). In contrast, in midstream urine, enterococci (in 10% of cultures) and group B streptococci (in 12% of cultures) were not predictive of bladder bacteriuria at any colony count (Spearman's r=0.322 for enterococci and 0.272 for group B streptococci). Among 41 episodes in which enterococcus, group B streptococci, or both were found in midstream urine, E. coli grew from catheter urine cultures in 61%.Conclusions
Cultures of voided midstream urine in healthy premenopausal women with acute uncomplicated cystitis accurately showed evidence of bladder E. coli but not of enterococci or group B streptococci, which are often isolated with E. coli but appear to rarely cause cystitis by themselves. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases.)29 mayo, 2013
New virus after rotavirus vaccinne in USA
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| English: Norovirus particles (Photo credit: Wikipedia) |
Norovirus and Medically Attended Gastroenteritis in U.S. Children
N Engl J Med 2013; 368:1121-1130March 21, 2013DOI: 10.1056/NEJMsa1206589
Background
Cases of rotavirus-associated acute gastroenteritis have declined since the introduction of rotavirus vaccines, but the burden of norovirus-associated acute gastroenteritis in children remains to be assessed.
Methods
We conducted active surveillance for laboratory-confirmed cases of norovirus among children younger than 5 years of age with acute gastroenteritis in hospitals, emergency departments, and outpatient clinical settings. The children resided in one of three U.S. counties during the years 2009 and 2010. Fecal specimens were tested for norovirus and rotavirus. We calculated population-based rates of norovirus-associated acute gastroenteritis and reviewed billing records to determine medical costs; these data were extrapolated to the U.S. population of children younger than 5 years of age.
Results
Norovirus was detected in 21% of young children (278 of 1295) seeking medical attention for acute gastroenteritis in 2009 and 2010, with norovirus detected in 22% (165 of 742) in 2009 and 20% (113 of 553) in 2010 (P=0.43). The virus was also detected in 4% of healthy controls (19 of 493) in 2009. Rotavirus was identified in 12% of children with acute gastroenteritis (152 of 1295) in 2009 and 2010. The respective rates of hospitalization, emergency department visits, and outpatient visits for the norovirus were 8.6, 146.7, and 367.7 per 10,000 children younger than 5 years of age in 2009 and 5.8, 134.3, and 260.1 per 10,000 in 2010, with an estimated cost per episode of $3,918, $435, and $151, respectively, in 2009. Nationally, we estimate that the average numbers of annual hospitalizations, emergency department visits, and outpatient visits due to norovirus infection in 2009 and 2010 among U.S. children in this age group exceeded 14,000, 281,000, and 627,000, respectively, with more than $273 million in treatment costs each year.
Conclusions
Since the introduction of rotavirus vaccines, norovirus has become the leading cause of medically attended acute gastroenteritis in U.S. children and is associated with nearly 1 million health care visits annually. (Funded by the Centers for Disease Control and Prevention.)
23 mayo, 2013
Therapy with Omalizumab in Ireland
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| Omalizumab (Photo credit: Wikipedia) |
Via: Dr. Ivancevich.
A study into efficacy of omalizumab therapy in patients with severe persistent allergic asthma at a tertiary referral centre for asthma in Ireland
+ Author Affiliations
- Address correspondence to Dr A. Subramaniam, Department of Respiratory Medicine, The Adelaide and Meath Hospital, Belgard Road, Tallaght, Dublin 24, Ireland. email: dr.abisubra@gmail.com
- Received December 31, 2012.
- Revision received January 19, 2013.
Abstract
Background: Asthma is a
chronic airway disease characterized by airway inflammation, bronchial
hyperresponsiveness and airflow obstruction.
Patients with persistent symptoms despite maximum
standard treatment as per Global Initiative of Asthma guidelines are
considered
to have severe persistent asthma. Omalizumab is a
recombinant humanized monoclonal antibody licenced for use as an add-on
therapy in these patients. Aim: To assess the clinical benefit amongst responders to omalizumab therapy at a tertiary referral centre. Methods: This was a retrospective audit assessing the effect of omalizumab therapy on asthma control, frequency of exacerbation and
hospitalization rates over 6 months before and after therapy. Results: The study included 30 responders (14 females). There was a reduction in exacerbation and hospitalization rates following
initiation of omalizumab, 73 and 91%, respectively (P-value < 0.0001). The number of exacerbations decreased from 3.48 ± 2.20 to 0.93 ± 0.83 and the mean number of admissions
decreased from 1.07 ± 1.1 to 0.1 ± 0.40 over the study duration (P < 0.001). There was 73% reduction in the weekly need for rescue salbutamol therapy with mean of 30.33 ± 6.49 puffs to 8.23
± 1.51 puffs after omalizumab therapy (P < 0.0001). Seventy-nine per cent of patients were able to reduce their maintenance oral corticosteroid therapy. Conclusions:
Overall, responders to omalizumab therapy are less likely to experience
an asthma exacerbation and hospitalization. They
were also more likely to reduce maintenance
corticosteroid therapy and the need for rescue reliever therapy. These
data suggest
that omalizumab has proven effective in improving
health outcomes for a cohort of carefully selected patients with severe
allergic asthma in Ireland.
16 mayo, 2013
Bandolier: Genewatch: BRCA genes - potential and problems
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| Ovarian and breast cancer patients in a pedigree chart of a family (Photo credit: Wikipedia) |
 Genewatch: BRCA genes - potential and problems |
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Potential and ProblemsThe New England Journal of Medicine had a headline back in May of which Bandolier would be proud - "BRCA genes - Bookmaking, Fortunetelling, and Medical care" [1]. It pulled together information in four papers in that issue which examined new research on these genes involved with breast and ovarian cancer. The correspondence published in September is also interesting for those contemplating how to make the best use of new genetic information.Statistical propheciesThe discovery of the so-called breast cancer genes, BRCA 1 in 1994 and BRCA 2 in the following year, were clearly landmarks in the study of breast cancer. It was naturally hoped, indeed almost assumed, that such important discoveries would quickly be followed by rationally designed improvements in prevention and treatment of this dread disease. The message that a woman with a strong family history of breast and/or ovarian cancer who carries a germ line mutation in one of these genes carries a lifetime risk of breast cancer of about 85%, and about 60% for ovarian cancer, is a very frightening one. Not surprisingly the pressure created for the practical application of these discoveries was almost immediate and very great.The situation was further complicated by the potential economic returns of genetic testing and the speed with which commercial companies were able to offer their services. Although the ethical and socio-economic problems raised by this were quickly appreciated, ongoing discussions between well informed representatives of the public, patient groups and the relevant professions will be required before any consensus can be reached. It is at least of some comfort to note that government regards the situation as sufficiently important to have set up (even if only after severe pressure from the professions!) both a Human Genetic Commission and a Genetics Testing Advisory Group. Although the emerging information is of great scientific value and interest, it does have a great potential for misunderstanding and misapplication. The editorial [1] refers to the making of gene-based statistical prophecies - but not necessarily with all the evidence yet in. Inappropriate optimismOne of the papers in the NEJM issue was a study of the prevalence of BRCA1 mutations in a population of women with breast cancer. Clinical information, family histories and blood was given by 263 women, and DNA sequencing was used to identify BRCA1 mutations. Women were consecutive referrals who were referred either because there was a strong familial risk factor for breast cancer (169 women) or breast cancer was diagnosed before 40 years of age (94 women). There was an average of 4 breast cancers per family and 1.5 cases of ovarian cancer in the women with a family history. |
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BRCA 1 mutations were identified in 9/124 (7%) women where there
was a family history of breast cancer without ovarian cancer, 10/57 (18%) where
family members had bilateral breast cancer, 28/60 (47%) with family members with
both breast and ovarian cancer or a single member with both cancers.
Implication for screeningThis suggests that even when subjects are selected from families with a strong history of breast cancer only about 7 in 100 will be found to have BRCA 1 mutations. So more than 9 out of 10 tests would be negative, with 10% or fewer positive, if screening for BRCA1 mutations were instituted. The implication is that BRCA1 mutations may account for fewer than half of hereditary cases of breast cancer, not much higher figures suggested previously (see Bandolier 18 ). Routine screening, even where there is a family history, will be wasteful in that it will require enormous back up, both scientific and medical, including counselling, to undertake responsibly. Furthermore, women who do not have a mutation have to be cautioned to prevent a false sense of security, because, in the striking words of the article, "negative tests are not truly negative". That is, women with negative results for BRCA1 mutation are still at risk of cancer.BRCA1 geneScientists have already identified more than 200 different mutations in the two BRCA genes. But we do not know how these different mutations differ in their relative contributions to breast, ovarian and other cancers. Clearly some mutations are responsible for the very high risks identified in some families, but others are likely to be within the normal variations found in many genes (polymorphisms) and not be relevant to cancer. It is also likely that different mutations will determine different types of cancers with different pathologies and different outcomes. There are some very preliminary indications that mutations towards one end of the BRCA1 gene are more likely to lead to breast cancer while those towards the other end of the gene are more likely to give ovarian cancer. It is also suggested that mutations in the BRCA2 gene are less likely to be found in early onset breast cancer than are BRCA1 mutations.Moreover the same mutations may behave differently in different populations of women. This emphasises the importance of modifying factors in determining the final outcome (eg, reproductive history, hormone therapy, diet, smoking and other genes which, for example, control the metabolism of hormones). We must not forget that all cancers are ultimately determined by a combination of genetic and environmental factors and the interplay of these is one of our most urgent subjects for research. Statistical predictionThe problem of statistical prediction becomes especially worrying when irreversible decisions are based on it. The question of whether to have prophylactic mastectomies or oophorectomies for carriers of BRCA mutations is a particularly difficult one. A theoretical model [3], based on a number of statistical assumptions, estimated that prophylactic mastectomies would add 2.9 to 5.3 years of life expectancy for a 30 year old carrier of a mutation and an oophorectomy would add 0.3 to 1.7 years. Estimated gains in life expectancy decline with age, however. Gains would be minimal for a 60 year old, less than one year on average, very little more than the estimated gain in life expectancy of 8 months for a woman without a mutation. But as correspondence suggests [4], even this reported gain in life expectancy may overstate the benefit of prophylactic surgery to the patients for several reasons:
So this information should encourage a conservative approach to prophylactic surgery. But patients are individuals rather than units of a statistical study and each needs to be given individual consideration. Where this involves changes in genes which predispose to breast cancer this means access to experts who themselves are in possession of the latest information and are able to communicate this in a digestible form to worried people who do not understand the science or statistics. References:
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15 mayo, 2013
Azitromicina y mortalidad
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| The New England Journal of Medicine (Photo credit: Wikipedia) |
Fuente Martin Cañas.
El año pasado un estudio observacional
encontró que la azitromicina podría aumentar el riesgo
de muerte cardiovascular en comparación con la
amoxicilina y el no tratamiento antibiótico. Se señalo
podría deberse a efectos proarrítmicos por la
prolongación del intervalo QT. Ese estudio fue la base
para un nuevo alerta de seguridad por parte de la FDA
en marzo de este año
Este
nuevo estudio observacional publicado en el NEJM,
concluyó que el exceso de mortalidad cardiovascular
observada previamente con el uso de azitromicina es
atribuible a la infección que se está tratando, no el
antibiótico.
New
England Journal of Medicine, 2 de mayo 2013 (Full Text)
Svanström
H et al. Use of azithromycin and death from
cardiovascular causes. N Engl J Med 2013 May 2;
368:1704.
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