Summertime Bacillus cereus colonization of hospital newborns traced to contaminated, laundered linen.

BACKGROUND: Routine screening of premature newborns for haemolytic streptococci, Staphylococcus aureus and enteric Gram-negative bacteria done at birth using umbilical swabs identified clustering of babies colonized with Bacillus cereus in summers of 2009 and 2010 at a 400-bedded UK general hospital. AIM: To determine the source of this organism by focusing on the clinical environment. METHODS: Umbilical swab screening was extended to all newborns and the labour ward environment, including construction-related dust, was sampled for B. cereus. FINDINGS: During the summer of 2009, 65% of newborns had umbilical swabs which were culture positive for B. cereus. Blood agar and B. cereus selective agar impression plates of unused labour ward linen, and freshly received linen from the hospital's external laundry, gave mainly confluent growth of B. cereus in >85% of items sampled. In-use and exposed healthcare products including liquid handwashing agents, paper hand-towels, vaginal lubricants, labour ward dust and air were culture negative. Linen contamination and umbilical swab culture positivity both approached zero in autumn. B. cereus colonization of newborn umbilici recurred in summer 2010 and unused laundered linen was again found to be as contaminated. Washing linen at the laundry in a washer-extractor, with higher dilution than the continuous tunnel washer normally used, coincided with lowering of detectable B. cereus numbers in unused washed linen and no clustering in newborns the following summer (2011). CONCLUSION: Freshly laundered linen can be contaminated with B. cereus with subsequent spread and colonization of newborns. This contamination appears to be associated with low-dilution washing and high ambient temperatures.

The evaluation of ventricular function using gated myocardial imaging with Tc-99m MIBI.

Left ventricular function is an important prognostic indicator in patients with coronary artery disease. We have assessed a method of providing this information as an adjunct to myocardial perfusion imaging using Tc-99m MIBI (2-methoxy-2-methyl-isopropyl-1-isonitrile). Two separate studies, at rest and during exercise, were performed following an injection of 400-600 M Bq of Tc-99m MIBI in 62 patients. Cardiac gating permitted excellent myocardial edge definition during the cardiac cycle. Radionuclide fractional shortening (RFS) was calculated from the anteroposterior (AP) and the septum to lateral wall (SL) axes in diastole and systole. Results were compared with echocardiographic fractional shortening (EFS) and the ejection fraction (EF) obtained from the gated equilibrium blood pool using Tc-99m-labelled red blood cells. The RFS in the AP axis correlated closely with echocardiographic FS (r = 0.89, P less than 0.001). The RFS in both axes was averaged to provide a global RFS. Global RFS correlated closely with LV radionuclide EF (r = 0.83, P less than 0.001). Inter- and intra-observer reproducibility studies have shown a variability for the procedure of less than 10%. In conclusion, gated perfusion imaging with Tc-99m MIBI, provides useful functional information as an adjunct to perfusion imaging.

Comparison of effects of ingested medium- and long-chain triglyceride on gallbladder volume and release of cholecystokinin and other gut peptides.

In a double-blind, crossover study of the effect of ingested medium-chain triglyceride (MCT) and long-chain triglyceride (LCT) in six normal subjects, the gallbladder did not contract after ingestion of MCT but instead had significantly increased in volume at 2 hr after the meal. Plasma cholecystokinin (CCK) increased after the MCT meal, but gastrin, motilin, pancreatic polypeptide (PP), and GIP were unaffected. The long-chain triglyceride meal evoked a brisk and sustained gallbladder contraction, higher levels of CCK, and a significant increase in plasma PP and GIP levels.

Use of an exercise QRS score and radionuclide left ventricular ejection fraction in assessing prognosis after myocardial infarction.

We have compared the prognostic value of a predischarge post-infarction QRS score derived at rest and at submaximal exercise with ejection fraction measured by gated radionuclide left ventriculography in 65 patients. Seventeen patients died or had heart failure (group 1) and 48 were well or had angina (group 2) six months after infarction. The mean QRS score derived from the resting electrocardiogram for group 1 was significantly greater than that for group 2 (P less than 0.01) but the QRS scores at peak exercise did not differ significantly between the two groups. The mean ejection fraction for group 2 was significantly greater than that for group 1 (P less than 0.001). Both the rest and peak exercise QRS scores correlated weakly but significantly with ejection fraction (P less than 0.001). The QRS score at rest had a greater sensitivity and specificity in predicting cardiac death and heart failure than the QRS score at peak exercise. A sensitivity of 88% was achieved with a resting ejection fraction less than 50% and a resting QRS score greater than 4. At these values the specificities were 58% and 63% respectively. Combining the blood pressure response to exercise with the QRS score and ejection fraction improved the sensitivity of both with no loss of specificity. Therefore, the resting QRS score is comparable to ejection fraction as a predictor of serious cardiac events after infarction and the sensitivity of both may be improved by including an assessment of the blood pressure response to exercise. Because a 12-lead electrocardiogram is cheap and widely available, this QRS score may be used in risk stratification after infarction.

Superiority of radionuclide over oximetric measurement of left to right shunts.

In 100 children with suspected left to right shunts the ratio of pulmonary to systemic flow was measured both by oximetry and first pass radionuclide angiography. The pulmonary time activity curve from the radionuclide study was analysed by the method of gamma variate fits. There was strong correlation between the two techniques; weaker correlation was found when the shunt was at atrial rather than ventricular level. This difference can be explained only by problems with the oximetric rather than the radionuclide technique. Although there are important limitations to the radionuclide method, it is the more precise and less invasive of the two and is to be preferred when the accurate measurement of left to right shunts is required.

First-pass measurement of left ventricular function in infants and children.

The left ventricular ejection fraction was measured in 57 infants and children with congenital heart disease by both first-pass radionuclide angiography and left ventricular cineangiography. The correlation coefficient for the two sets of measurements was 0.79. In subgroups without left to right shunts (n = 21) and with left to right shunts (n = 36) it was 0.93 and 0.37, respectively. It is concluded that measurement of the left ventricular ejection fraction by the first-pass method is valid in children, provided there is no left-to-right shunt.

Radionuclide measurement of left ventricular ejection fraction in infants and children.

The left ventricular ejection fraction was measured in 60 infants and children with congenital heart disease by both the equilibrium gated radionuclide technique and biplane left ventricular cineangiography. The median age of the patients studied was 2.25 years, and 17 were less than 1 year old. The correlation coefficient for the two sets of measurements was good and did not deteriorate in subgroups under 1 year old and with a large left to right shunt. In those infants with a right to left shunt the correlation was weak. Equilibrium gated radionuclide angiography is a valid and clinically valuable method of measuring left ventricular function in infants and children with congenital heart disease.

Ventricular function in thyrotoxicosis complicated by atrial fibrillation.

The radionuclide gated ventriculogram was used to study the association between thyrotoxic atrial fibrillation and underlying ischaemic heart disease. Comparison between ten patients with atrial fibrillation induced by thyrotoxicosis which reverted to sinus rhythm after return to a euthyroid state, and ten age-matched controls with treated hyperthyroidism who never developed atrial fibrillation, showed no significant difference in the incidence of underlying ischaemic heart disease. This study suggests that further investigation for underlying coronary arterial disease is not indicated in simple, reversible, thyrotoxic atrial fibrillation.

Investigating the adenocarcinoma of unknown origin (ACUP): a cost benefit analysis.

This paper attempts to assess three approaches to the investigation of a patient with histological metastatic adenocarcinoma when the primary tumour of origin is not clear on the initial presentation. These different approaches are evaluated semi-quantitatively. Estimated costs and morbidity of investigations and treatment, increased survival, and improvement in quality of life are taken into account in this analysis. A sample schema of investigation which will maximise the potential benefit as well as minimise the cost to the health service resources and the human cost to the patient is proposed.

Clinical indications for optimal use of the radionuclide brain scan.

427 radionuclide brain scans, performed in 1981 at Guy's Hospital Nuclear Medicine Department, were reviewed retrospectively to define clinical circumstances in which the study provided useful information. It was concluded that the radionuclide brain scan was the appropriate first line investigation in patients with known non-cerebral malignancy, in whom the possibility of cerebral metastases exists; and in patients with a low to moderate probability of subdural haematoma. The radionuclide brain scan can provide a valuable alternative to computed tomography studies:--(1) in patients without known underlying disease who develop localising signs; (2) in patients with focal fits; (3) in patients with underlying vascular disease and gradual onset of localising signs; and (4) in patients with suspected inflammatory conditions of the central nervous system. Outside these groups, the radionuclide brain scan rarely provided useful information.