Israel Medical Association Journal

Background: Respiratory syncytial virus (RSV)-related bronchiolitis is a common cause of morbidity in young infants. The recommendations for its passive prevention by palivizumab are currently under intensive debate.

Objectives: To elucidate the optimal prevention strategy by studying the morbidity of RSV disease under the current recommendations for palivizumab prophylaxis in Israel.

Methods: We collected demographic and clinical data of all children hospitalized with microbiologically confirmed RSV bronchiolitis during 2015–2016 at Schneider Children's Medical Center. The seasonality of RSV disease was also studied for the period 2010–2017 in sentinel clinics scattered throughout Israel.

Results: Of the 426 hospitalized children, 106 (25%) had underlying diseases but were not eligible for palivizumab prophylaxis according to the current criteria in Israel. Their course was severe, with a mean hospital stay of 6.7 days and a 12% admission rate to the pediatric intensive care unit (PICU). Palivizumab-eligible children who did not receive the prophylaxis before hospitalization had the most severe course, with 22% admitted to the PICU. More children were diagnosed with RSV disease in October than in March among both hospitalized and ambulatory children; 44% of the palivizumab-eligible hospitalized children were admitted in the last 2 weeks of October, before 1 November which is the recommended date for starting palivizumab administration in Israel.

Conclusions: According to the results of the present study we suggest advancing RSV prophylaxis in Israel from 1 November to mid-October. The precise palivizumab-eligible categories should be reconsidered.

Background: Upper respiratory tract infection (URTI) occurs frequently in the general population and is considered a benign self-limited disease. Dialysis patients constitute a high risk population whose morbidity and mortality rate as a result of URTI is unknown. 

Objectives: To assess the local incidence, morbidity and mortality of URTI in dialysis patients compared to the general population. 

Methods: In this retrospective cohort study we reviewed the charts of all chronic dialysis patients diagnosed with URTI at Meir Medical Center, Kfar Saba, Israel during the 2014–2015 winter season. 

Results: Among 185 dialysis patients, 40 were found to be eligible for the study. The average age was 66.1 ± 15.7 years, and the co-morbidity index was high. Influenza A was the most common pathogen found, followed by rhinovirus, respiratory syncytial virus and para-influenza. Of the 40 patients 21 (52.5%) developed complications: pneumonia in 20%, hospitalization in 47.5%, and respiratory failure requiring mechanical ventilation in 12.5%. Overall mortality was 10%. General population data during the same seasonal period showed a peak pneumonia incidence of 4.4% compared to 20% in the study population (P < 0.0001). 

Conclusions: The study findings show that compared to the general population, URTI in dialysis patients is a much more severe disease and has a higher complication rate. Influenza A, the most common pathogen, is associated with a worse prognosis. 

 

Background: Exposure to air pollution in the form of particulate matter smaller than 10 µm in diameter (PM10) has been associated with increased morbidity and mortality. However, since air pollution is correlated with confounding factors that might otherwise affect health, identifying the causal link has proven challenging. 

Objectives: To identify the effect of PM10 on hospital admissions due to respiratory illnesses. 

Methods: We used the Instrumental Variable (IV) methodology to control for confounding factors affecting hospital admissions. Exploiting the timing of sandstorms as an instrumental variable allows for a better estimate of the relationship between PM10 and hospital admissions. Data on PM concentrations and hospital admissions rates were compiled for Israel’s two largest cities, Jerusalem and Tel Aviv, for 2007–2009. We compared our IV estimates to those derived from a Poisson regression, which is commonly used in the existing literature. 

Results: Sandstorms led to an increase of 307 µg/m3 of PM10 concentrations. A 10 µg/m3 increase in PM10 is associated with a 0.8% increase in hospital admissions due to respiratory conditions, using Poisson regression. The same finding was noted using the IV methodology. 

Conclusions: The association between PM10 and hospital admission reflects a primarily causal relationship. Instrumental variable methodology could be applied to analysis of the effect of air pollution on hospital admissions. 

 

Background: Several studies have identified associations between low vitamin D concentrations and risk of upper respiratory infections (URI). T lymphocytes have a major anti-viral role, are affected by vitamin D metabolism, and may mediate the link between vitamin D and URIs. Competitive swimmers have a relatively high rate of URIs, alongside a high prevalence of low vitamin D concentration. 

Objectives: To examine the associations linking T cell receptor excision circles (TREC, markers of thymus activity), circulating 25(OH)D concentrations and the effect of vitamin D supplementation, and URI symptoms in young competitive swimmers.

Methods: We tested 82 adolescent swimmers for serum 25(OH)D and TREC concentrations and found that 55 had vitamin D insufficiency. Randomized supplementation of either vitamin D3 or placebo was given for 12 winter weeks. URI symptoms were recorded weekly. The associations between TREC copy numbers, vitamin D and URI burden were examined.

Results: TREC concentrations decreased with the participants’ age (r = -0.346, P = 0.003), with no significant between-gender difference. TREC concentrations did not materially differ among subjects with normal, insufficient or deficient vitamin D status, and were not affected by vitamin D supplementation. No significant correlations were found between TREC levels or their changes during the study period, and mean URI severity or duration. 

Conclusions: Thymus activity, represented by higher TREC levels, was not related to vitamin D concentrations or status, and was not affected by vitamin D supplementation in adolescent swimmers. TREC concentrations were not associated with URI severity or duration in this population.

 

Studies of the respiratory effects of air pollution in Israel published in peer-reviewed journals have been infrequent. Most empiric evidence relates to the association between air pollution and childhood asthma; other air pollution effects on other illnesses are less thoroughly studied. Our evaluation provides a possible explanation for the quite contradictory results demonstrated in the various studies. Actual effect estimates appear to differ considerably, ranging from no air pollution effect to a reasonably strong association detected between PM10 and asthma. We attribute these discrepancies to different research methodologies and different types of data used in various studies.

Objectives: To evaluate if fetal reduction of triplets to twins improves outcome.

Methods: We analyzed the outcome of 80 triplet gestations cared for at Rambam Health Care Campus in the last decade; 34 families decided to continue the pregnancy as triplets and 46 opted for MFPR to twins.

Results: The mean gestational age at delivery was 32.3 weeks for triplets and 35.6 weeks for twins after MFPR. Severe prematurity (delivery before 32 gestational weeks) was experienced in 37.5% of triplets and in 7% of twins. Consequently, the rate of severe neonatal morbidity (respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage) and of neonatal death was significantly higher in unreduced triplets, as was the length of hospitalization in the neonatal intensive care unit (31.4 vs. 15.7, respectively). Overall, the likelihood of a family with triplets to take home all three neonates was 80%; the likelihood to take home three healthy babies was 71.5%.

Conclusions: MFPR reduces the risk of severe prematurity and the neonatal morbidity of triplets. A secondary benefit is the reduction of cost of care per survivor. Our results indicate that MFPR should be offered in triplet gestations.

Objective: To assess the impact of multiple births on the severity of RSV infection and define risk factors for acquiring RSV infection in infants of multiple birth.

Methods: Clinical data on infants hospitalized with RSV infection between 2008 and 2010 were retrospectively collected.

Results: Twins comprised 7.6% (66/875) of hospitalized infants with RSV bronchiolitis during the study period. Infants in the twin group were younger (122.4 ± 131.7 vs. 204.5 ± 278.8 days, P = 0.014), had a lower mean gestational age (35.3 ± 2.6 vs. 38.6 ± 2.5 weeks, P < 0.001), and were more likely to have been born prematurely compared with singleton infants (65.6% vs. 13%, P < 0.001). On a multivariable logistic regression analysis, young age, early gestational age and male gender were the only variables identified as risk factors for pediatric intensive care unit admission (P < 0.001, P < 0.001 and P = 0.03, respectively). In contrast, the mere fact of a child being a twin was not found to be a significant risk factor for disease severity. In addition, if one twin is hospitalized due to RSV infection, the other has a 34% chance of also being hospitalized with bronchiolitis. Young age was a significant risk factor for hospitalization of the second twin (P < 0.001).

Conclusions: Our findings suggest that twins hospitalized with RSV bronchiolitis do not have an increased risk for severe infection as compared to singletons. However, a twin of an infant hospitalized with RSV infection has a considerable risk of also being hospitalized with bronchiolitis, thus close monitoring is recommended. 

Background: During an influenza pandemic, clinicians need easily available clinical and laboratory criteria to distinguish influenza from similar respiratory illnesses. We compared A/H1N1/2009-polymerase chain reaction (PCR)-positive and matched PCR-negative hospitalized patients with suspected H1N1 influenza to identify factors that could assist physicians at patient admission.

Objectives: To identify factors significantly associated with A/H1N1/2009 infection.

Methods: A group of 145 patients with PCR-confirmed A/H1N1 2009 influenza admitted between 27 May 2009 and 3 December 2009 was matched with 145 PCR-negative patients by age, epidemiological week and pregnancy status. Epidemiological and clinical parameters and radiological findings on initial chest X-ray were compared between the two groups.

Results: Asthma (PCR+ 26%, PCR- 12%, P = 0.006) and military service (PCR+ 13%, PCR- 4%, P = 0.15) were associated with PCR-positive status in non-pregnant patients. At presentation, fever, cough, myalgia and fulfilling the pandemic influenza case definition were significantly more frequent in non-pregnant PCR+ patients (62/90/43/59% in PCR+ versus 38/69/30/35% in PCR-). In pregnant patients, fever and fulfilling the case definition were significantly associated with PCR-positive status. Mean leukocyte and absolute lymphocyte counts were significantly lower in both pregnant and non-pregnant PCR-positive patients. Significantly more PCR-negative non-pregnant patients (43% vs. 22% PCR+, P = 0.004) had abnormal chest X-ray (CXR) findings on presentation. In PCR-positive patients, patchy consolidation and interstitial infiltrates were the most common abnormalities.

Conclusions: Under the conditions generated by the A/H1N1/2009 pandemic, radiological findings did not distinguish reliably between influenza and other febrile respiratory illnesses. Asthma, military service, the pandemic case definition (particularly fever, cough and myalgia) and lymphopenia were associated with confirmed H1N1 infection.
 

Background: Most studies on asbestos-related diseases describe the associations between exposure and disease and the factors influencing that association. It is recognized that there is a long latency period between exposure and disease, but the health status of affected individuals after long-term non-exposure is uncertain.

Objectives: To describe the changes in pulmonary function tests (PFTs) and computed tomographic imaging of the thorax over a 15 year period after cessation of exposure to asbestos in a cohort of Israeli power plant workers.

Methods: Israeli power plant workers whose PFTs and thoracic CT imaging between 1993 and 1998 revealed asbestos-related disease underwent a second clinical, functional and imaging evaluation up to 15 years later. The two sets of results were compared.

Results: Of the original cohort of 59 males, 35 were still alive, and 18 of them agreed to take part in the current study. The mean length of their exposure was 30 ± 10.06 years (range 7–43 years). Comparison of the initial and follow-up examination findings revealed a significant increase in calcification of the pleural plaques (from 37% to 66%, P = 0.008) and a deterioration in PFTs (P = 0.04). Of the 24 men who died, malignant disease was the cause of death in 53%, mostly in sites other than the respiratory system.

Conclusions: PFTs declined and CT findings worsened in subjects who were formerly exposed to asbestos and had not been exposed to it for over a decade. Continued monitoring of individuals exposed to asbestos, even decades after the cessation of exposure, is recommended.
 

Background: Exacerbations of chronic obstructive pulmonary disease (COPD) are a major problem worldwide and are usually the main indication for mechanical ventilation (MV), especially in the intensive care unit (ICU). The rate of weaning failure is also high and prolonged MV leads to complications of intubation. The goal is to wean these patients as soon as possible.

Objective: To determine the optimal time necessary to start the weaning process.

Methods: In an attempt to determine the length of MV and stay in the ICU, we compared the length of MV, weaning, re-intubations and discharge during a 10 month period. This study included 122 patients on MV due to severe exacerbation of COPD who were not suitable for non-invasive ventilation. For each patient serial arterial blood gases were measured at admission and during hospitalization. PeCO₂ (mixed expired CO₂) was tested using a Datex S/5 instrument at follow-up.

Results: The study population comprised all patients who required MV; of these 122, 108 were ventilated from 6 to 140 hours (average 48 ± 42), 9 needed more than 168 hours, and 5 died due to severe ventilation-associated pneumonia. No correlation was found between pH, PCO₂ and length of MV; these findings did not contribute to evaluation of the patient’s condition nor did they enable us to predict the length of treatment necessary.

Conclusion: Most of the patients (93%) ventilated for acute respiratory failure due to COPD required MV for only 6–90 hours.

Pathological gambling is classified in the DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders) and in the ICD-10 (International Classification of Disease) as an impulse control disorder. The association between impulsivity and pathological gambling remains a matter of debate: some researchers find high levels of impulsivity within pathological gamblers, others report no difference compared to controls, and yet others even suggest that it is lower. In this review we examine the relationship between pathological gambling and impulsivity assessed by various neurocognitive tests. These tests – the Stroop task, the Stop Signal Task, the Matching Familiar Figures Task, the Iowa Gambling Task, the Wisconsin Card Sorting Test, the Tower of London test, and the Continuous Performance Test – demonstrated less impulsivity in gambling behavior. The differences in performance between pathological gamblers and healthy controls on the neurocognitive tasks could be due to addictive behavior features rather than impulsive behavior.