Saturday, February 24, 2018

Laboratory diagnosis of Legionnaires’ disease

From a recent review:

Legionnaires’ disease is commonly diagnosed clinically using a urinary antigen test. The urinary antigen test is highly accurate for L. pneumophila serogroup 1, however other diagnostic tests should also be utilized in conjunction with the urinary antigen as many other Legionella species and serogroups are pathogenic. Culturing of patient specimens remains the gold standard for diagnosis of Legionnaires’ disease. Selective media, BYCE with the addition of antibiotics, allows for a high sensitivity and specificity. Culturing can identify all species and serogroups of Legionella. A major benefit of culturing is that it provides the recovery of a patient isolate, which can be used to find an environmental match. Other diagnostic tests, including DFA and molecular tests such as PCR and LAMP, are useful tests to supplement culturing. Molecular tests provide much more rapid results in comparison to culture, however these tests should not be a primary diagnostic tool given their lower sensitivity and specificity in comparison to culturing. It is recommended that all laboratories develop the ability to culture patient specimens in-house with the selective media.

Thursday, February 22, 2018

Babesiosis review

Here is a free full text review on the topic.

Points of interest:

The main species causing human disease are Babesia microti, Babesia divergens and Babesia venatorum.

It is transmitted to humans from rodents via the tick Ixodes scapularis which is the same vector that transmits anaplasmosis and Lyme disease. Coinfection with the latter two should be tested for.

Rare transmission occurs via transfusion.

Asplenia is a risk factor (and is associated with more severe disease) but is not necessary for development of disease.

It is increasingly being recognized in immunocompetent hosts.

Complications include hemolysis, cytopenias (any or all three), hemophagocytic lymphohistiocytosis, DIC, multi organ failure, splenomegaly, splenic infarct and splenic rupture. Many infections are mild and self limiting.

The intracellular forms may be confused with malaria parasites. The maltese cross, though pathognomonic, is often not seen. PCR is available but is not sensitive below 50 parasites per ml.

Wednesday, February 21, 2018

Raising magnesium awareness

Tuesday, February 20, 2018

Management of long QT

Recent findings

LQT syndrome remains the most common inherited arrhythmia and is a leading cause for sudden unexplained death accounting for up to 20–25% of cases. Rapid progress of genetic technology over the past 2 decades has significantly improved our understanding of molecular and genetic mechanisms of LQT. Despite all those novel insights, phenotype assessment and appropriate risk stratification in LQT remains challenging – even for the expert.


This review outlines our current understanding and approach to the clinical diagnosis and management of LQT as well as recent insights into genotype–phenotype correlations. Genetic testing has evolved beyond a pure diagnostic tool and is in addition increasingly integrated as complementary prognostic marker. With regard to the management of LQT, there is now evidence that the protective effect of beta-blockers is rather substance-specific than a class effect. Novel approaches – in conjunction with standard beta-blockers – are emerging including gene-specific treatment for certain subtypes of LQT. A specialized inherited arrhythmia clinic is the preferred resource for the complex risk stratification and individualized management of individuals with LQT.

Monday, February 19, 2018

Unexplained anemia in older men related to low T

Question Will testosterone treatment of older men with low testosterone levels and mild anemia improve their anemia?

Findings Testosterone treatment of older men with low testosterone levels and unexplained anemia corrected the anemia more than placebo. This treatment also corrected anemia more than placebo in men who had anemia of known causes, such as iron deficiency.

Meaning Testosterone deficiency in older men results in decreased hemoglobin levels and sometimes in mild anemia. Correcting the testosterone deficiency is associated with increased hemoglobin levels and tends to correct the anemia, even in the presence of a coexisting cause of anemia.


Sunday, February 18, 2018

Low FFR predicted events even in lesions that looked “insignificant”

Report here.