Legionnaires' disease in Ireland--a cause for concern?

Legionnaires' disease is a multi-system illness that can have widespread clinical symptoms, though the principle manifestation is pneumonia. A review of all legionnaires' disease case notifications in Ireland in the 4 year period 1998-2001 was undertaken to assess the degree of concern health authorities here should have in relation to this disease. There were 17 cases of legionnaires' disease (all were legionella pneumophila serogroup 1) notified to the National Disease Surveillance Centre in the period 1998-2001. Nine cases were travel-associated cases with the majority of cases occurring during the summer months. There were 2 deaths. It would appear that legionnaires' disease is rare in Ireland but when compared with other European countries Ireland is conspicuous by its low rate. This would suggest that a major degree of under diagnosis and under reporting of legionnaires' disease currently exists in Ireland.     

Intra-alveolar haemorrhage in sudden infant death syndrome: a cause for concern?

BACKGROUND: The "Back to Sleep" campaign in 1991 resulted in a dramatic decrease in the incidence of sudden infant death syndrome (SIDS). The proportion of presumed SIDS deaths being actually suspicious deaths from airway obstruction is likely to have become relatively greater. There is usually little pathological evidence to suggest smothering, but intra-alveolar haemorrhage appears to be more prominent in cases where interference with the airway is suspected. AIM: To attempt to quantify intra-alveolar haemorrhage to see whether it could be used as a marker to distinguish between smothering/overlaying and SIDS. METHODS: Intra-alveolar haemorrhage was quantified using digital image analysis on haematoxylin/eosin stained sections taken from the lungs of 62 consecutive infants who had died suddenly and unexpectedly. Cases were initially classified according to the original cause of death. After quantitation, the case histories were critically reviewed. Three pathologists independently made microscopic assessments of the degree of intra-alveolar haemorrhage in the first 24 cases to see whether these accurately reflected the quantitative results. RESULTS: 73% of those infants with a history suggesting possible involuntary overlaying and 45% of those with a history suspicious of smothering had significant intra-alveolar haemorrhage (> 5% of total lung surface area assessed). From the history, the cause of death in 11 cases initially classified as SIDS would better have been given as "Unascertained." Simple microscopic assessments underestimated the true extent of the haemorrhage in 33% (8/24). CONCLUSIONS: If a moderate degree (at least 5%) of pulmonary parenchymal haemorrhage is observed, this may be an indicator of airway obstruction for a significant period, either from overlaying or possibly smothering. The diagnosis of SIDS may be being used inappropriately in such cases.     

Acquisition of human cytomegalovirus infection in infants via breast milk: natural immunization or cause for concern?

Since the recognition in the 1960s that human cytomegalovirus (HCMV) infections could be transmitted by breast milk, there has been relatively little attention paid to the potential medical consequences of such infections. Indeed, since HCMV infections acquired by healthy newborn infants appear to be largely asymptomatic in nature, there has been no real incentive to develop or implement strategies to prevent transmission by this route. However, recent studies have identified a significant risk for low-birth weight, premature infants for the development of HCMV disease following acquisition of infection via breast milk. Such infections may cause considerable short-term morbidity and, in some cases, severe, life-threatening illness. There is little consensus amongst neonatologists on the approach to prevention and management of such infections. This review summarises the epidemiology and natural history of HCMV infections acquired via breast milk, and outlines available strategies for prevention and management of such infections, as well as opportunities for future clinical research on this understudied topic.     

Methicillin-resistant Staphylococcus aureus in HIV patients: Risk factors associated with colonization and/or infection and methods for characterization of isolates – a systematic review

Staphylococcus aureus is an important cause of infections and HIV-infected individuals are frequently susceptible to this pathogen. The aim of this study was to perform a systematic review to identify both the risk factors associated with colonization/infection by methicillin-resistant S. aureus in HIV patients and the methods used for characterization of isolates. An electronic search of articles published between January 2001 and December 2013 was first conducted. Among 116 studies categorized as being at a quality level of A, B or C, only 9 studies were considered to have high methodological quality (level A). The majority of these studies were retrospective (4/9 studies). The risk factors associated with colonization/infection by S. aureus were use of antimicrobials (4/9 studies), previous hospitalization (4/9 studies) and low CD4+ T lymphocyte counts (<200 cells/μl) (3/9 studies). Culture in mannitol salt agar (3/9 studies) and the latex agglutination test (5/9 studies) were the main methods used for bacterial phenotypic identification. Genotypic profiles were accessed by pulsed-field gel electrophoresis (6/9 studies) and USA300 was the most prevalent lineage (5/9 studies). Most isolates were resistant to erythromycin (3/9 studies) and susceptible to vancomycin (4/9 studies). Ultimately, use of antimicrobials and previous hospitalization were the main risk factors for colonization/infection by methicillin-resistant S. aureus in HIV-infected individuals. However, the numbers of evaluated patients, the exclusion and inclusion criteria and the characterization of the S. aureus isolates were not uniform, which made it difficult to establish the characteristics associated with HIV patients who are colonized/infected by S. aureus.     

Stress in obesity: cause or consequence?

Obesity is a global public health challenge that increases the risk of various diseases including type 2 diabetes mellitus, hypertension and cancer, and will in the future cause further increases in the incidence of chronic disease. Understanding the mechanisms of obesity is critical if we are to prevent and treat this pandemic challenge. Diet and physical activity have traditionally been the major tasks in preventing and treating obesity. However, other mechanisms are now also being considered in the quest for knowledge and understanding of obesity, including the body’s stress system and cortisol release. While it seems evident that stress is a cause of obesity, whether stress is also a consequence of obesity has up to now only briefly been discussed. The aim of this article is to elucidate how stress and obesity might be linked and discuss the cause/consequence relationship between the stress response and obesity. Our hypothesis is that stress and obesity interfere by positive feedback. This may be an important issue in both our understanding and coping of obesity.     

Are B lymphocytes of importance in severe Staphylococcus aureus infections?

To investigate the role of B cells in experimental, superantigen-mediated Staphylococcus aureus arthritis and sepsis, we used gene-targeted B-cell-deficient mice. The mice were inoculated intravenously with a toxic shock syndrome toxin 1 (TSST-1)-producing S. aureus strain. The B-cell-deficient and thus agamma-globulinemic mice showed striking similarities to the wild-type control animals with respect to the development of arthritis, the mortality rate, and the rate of bacterial clearance. Surprisingly, we found that the levels of gamma interferon in serum were significantly lower (P < 0. 0001) in B-cell-deficient mice than in the controls, possibly due to impaired superantigen presentation and a diminished expression of costimulatory molecules. In contrast, the levels of interleukin-4 (IL-4), IL-6, and IL-10 in serum were equal in both groups. Our findings demonstrate that neither mature B cells nor their products significantly contribute to the course of S. aureus-induced septic arthritis.     

Ceftriaxone for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia: a matter of dosages?

European Journal of Clinical Microbiology & Infectious Diseases -     

Are Nasal Carriers of Staphylococcus aureus More Likely To Become Colonized or Infected with Methicillin-Resistant Staphylococcus aureus on Admission to a Hospital?

Of 840 patients at hospital admission, 2.7% were positive for methicillin-resistant Staphylococcus aureus (MRSA) and 22.3% were positive for methicillin-susceptible S. aureus (MSSA). During the next 8 months, 4.8% of the MSSA-positive patients acquired MRSA with no lineage association. A total of 5.2% of noncarriers acquired MRSA. We find no evidence that colonized hosts are more susceptible to acquiring MRSA.