Diagnosis and outcomes of enterovirus infections in young infants

BACKGROUND: Enterovirus (EV) infections commonly cause fever in infants younger than 90 days of age. The polymerase chain reaction (PCR) has improved our ability to diagnose EV infections. OBJECTIVE: To evaluate the utility of blood and cerebrospinal fluid (CSF) specimens for the diagnosis of EV infections by PCR and to describe a large cohort of EV-infected infants. DESIGN/METHODS: Febrile infants younger than 90 days of age evaluated for sepsis at Primary Children's Medical Center in Salt Lake City, UT, were enrolled in a prospective study designed to identify viral infections from December 1996 to June 2002. All patients had bacterial cultures of blood, urine and CSF. Testing for EV was performed by PCR and/or viral cultures. Patients who were positive for EV were identified for this study. RESULTS: Of 1779 febrile infants enrolled, 1061 had EV testing and 214 (20%) were EV-positive. EV infections were diagnosed by PCR of blood, CSF or both in 93% of infants. PCR testing was positive in blood in 57%, and blood was the only positive specimen for 22% of EV infected infants. PCR of CSF was positive in 74%. The mean age of infants with EV infection was 33 days, with 18% younger than 14 days and 5% younger than 7 days. Fifty percent of EV-positive infants had CSF pleocytosis. Of EV PCR-positive infants, 91% were admitted, and 2% required intensive care. Possible serious EV disease was diagnosed in <1%, and there were no deaths. Twelve infants (5.6%) had concomitant urinary tract infection, and 3 (1%) had bacteremia. CONCLUSIONS: EV infections are common in febrile infants younger than 90 days. Blood and CSF are equally likely to yield positive results by PCR, but the combination of both specimens improved the diagnostic yield.     

Sciatic nerve injuries associated with traumatic posterior hip dislocations

This study was undertaken to test the hypothesis that patients transferred between hospitals with a dislocated hip have a greater incidence of sciatic nerve injury than patients who have their hip reduced at the first facility. One hundred six dislocated hips were included in this 12-year retrospective study. Sixty-nine hips were relocated at the first hospital and 36 patients were transferred with the hip still dislocated to LDS Hospital. There was a higher incidence of major sciatic nerve injury (complete sciatic or peroneal motor deficit) in patients transferred with the hip still dislocated (P =.0453). Time to relocation was significantly longer in patients with major motor nerve injury (P =.016). The presence of an associated fracture had no influence on sciatic nerve injury rates. The length of time a hip remains dislocated influences the incidence and severity of major sciatic nerve injury.     

Evaluation of the Prodesse Hexaplex multiplex PCR assay for direct detection of seven respiratory viruses in clinical specimens

We evaluated the Hexaplex assay (Prodesse, Waukesha, WI) for the detection of 7 respiratory viruses (influenza A and B, parainfluenza 1-3, and respiratory syncytial virus [RSV] A and B). The Hexaplex assay was performed on 300 respiratory samples during the 1999-2000 respiratory virus season. Results of this assay were compared with shell vial cell culture and/or direct fluorescent antibody stain. The overall sensitivity and specificity of the assay were 96.6% and 94.1%, respectively. The respective sensitivity and specificity of the Hexaplex assay for detection of specific virus groups were as follows: influenza A, 98.6% and 97.8%; influenza B, 100% and 100%; and for parainfluenza viruses (1-3), 100% and 99.1%. The assay did not perform as well with patients infected with RSV: sensitivity and specificity were 91.0% and 98.6%, respectively. There are 2 major drawbacks to this assay: it is technically demanding (3-4 hours hands-on time), and it is expensive ($80-$90 direct cost). Nevertheless, because of the excellent sensitivity and specificity, the Hexaplex assay may be valuable in the diagnosis of respiratory viral infections in immunocompromised patients.     

血液感染性安全问题的现状与展望

输血和大多数临床治疗技术一样，存在着一定的风险，输血风险主要由免疫性输血风险和输血感染性风险两大类相关的安全问题。20世纪80年代开始，由于艾滋病的发现迫使输血相关的安全问题更进一步成为公众关注的焦点。随着输血用血医学的不断发展，在已经获得很好治疗效果的同时，如何更加科学的安全用血是挑战当今公共卫生事业发展的一项大课题。     

Dynamic holographic imaging of the beating human heart

Background--Currently, the reporting and archiving of echocardiographic data suffer from the difficulty of representing heart motion on printable 2-dimensional (2D) media. Methods and Results--We studied the capability of holography to integrate motion into 2D echocardiographic prints. Images of normal human hearts and of a variety of mitral valve function abnormalities (mitral valve prolapse, systolic anterior motion of the mitral leaflets, and obstruction of the mitral valve by a myxoma) were acquired digitally on standard echocardiographic machines. Images were processed into a data format suitable for holographic printing. Angularly multiplexed holograms were then printed on a prototype holographic "laser" printer, with integration of time in vertical parallax, so that heart motion became visible when the hologram was tilted up and down. The resulting holograms displayed the anatomy with the same resolution as the original acquisition and allowed detailed study of valve motion with side-by-side comparison of normal and abnormal findings. Comparison of standard echocardiographic measurements in original echo frames and corresponding hologram views showed an excellent correlation of both methods (P<0.0001, r2=0.979, mean bias=2.76 mm). In this feasibility study, both 2D and 3D holographic images were produced. The equipment needed to view these holograms consists of only a simple point-light source. Conclusions--Holographic representation of myocardial and valve motion from echocardiographic data is feasible and allows the printing on a 2D medium of the complete heart cycle. Combined with the recent development of online holographic printing, this novel technique has the potential to improve reporting, visualization, and archiving of echocardiographic imaging.     

Intraventricular haemorrhage in the preterm infant without hyaline membrane disease

The clinicopathological associations of 33 singleton infants who died with intraventricular haemorrhage (IVH) without hyaline membrane disease (HMD) ('IVH only') were compared with those of 39 infants who died with IVH+HMD over the same gestation range in order to determine what factors other than those related to HMD may contribute to the pathogenesis of IVH. The incidence of 'IVH only' was inversely related to gestational age in the Hammersmith birth population, whereas the incidence of IVH+HMD rose to a peak at 28-29 weeks' gestation. Infants with 'IVH only' lived longer on average than those with IVH+HMD despite a lower birthweight and shorter gestation. Infants who died in the first 12 hours from 'IVH only' had suffered severe birth asphyxia but in those who died later the main symptom was recurrent apnoea. Fewer infants with asphyxia but in those who died later the main symptom was.recurrent apnoea. Fewer infants with 'IVH only' were given alkali therapy or were connected to the ventilator as compared to those with IVH+HMD, but there were no differences in alkali therapy in those who lived for 12 hours or more. In the 'IVH only' group there was a high incidence of haemorrhage from other sites and of bacterial infections. It is suggested that, in the absence of HMD, extreme immaturity is the main factor determining the occurrence of IVH. Birth asphyxia, apnoeic attacks, haemorrhage, and infections may play subsidiary roles, possibly through development of metabolic acidosis.     

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992

BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.     

Obstructive sleep apnea: diagnosis with ultrafast CT

Patients with sleep-disordered breathing often have physiologic and anatomic abnormalities of the upper airway that are demonstrable while awake. An ultrafast computed tomographic (CT) scanner was used to measure the oropharyngeal and nasopharyngeal cross-sectional areas of 11 patients with obstructive sleep apnea. Twenty-four healthy volunteers served as control subjects. The percentage of change in cross-sectional area during quiet tidal breathing was used as a measure of airway compliance. Compared with weight-matched control subjects, patients with obstructive sleep apnea had smaller oropharyngeal airways (40.4 vs 177.8 mm2) (P less than .001) and smaller nasopharyngeal airways (31.3 vs 134.2 mm2) (P less than .001). In addition, their oropharyngeal airways were significantly more compliant (75% vs 27%) (P less than .001). Patients with obstructive sleep apnea are characterized by a small, collapsible oropharyngeal airway and by nasopharyngeal airway narrowing. These abnormalities can cause sleep-disordered breathing. Ultrafast CT scanning allows rapid, noninvasive assessment of airway variables.