Listeriosis is a rare, but serious, foodborne infection which, in the invasive form, presents as bloodstream (BS) infection, an infection of the central nervous system (CNS), a maternofetal infection or a focal infection. The disease is notifiable in Denmark. This paper reviews the results of the Danish surveillance of invasive listeriosis from 1994 to 2003, excluding maternofetal cases. In total, 299 invasive cases of listeriosis were reported. Two-thirds of the cases were caused by isolates of serogroup 1/2, and one-third by serogroup 4. Most (70%) cases had conditions known to predispose to listeriosis. More patients with BS infection were predisposed because of concurrent underlying illness than were patients with CNS infection. Half of the patients were aged > 70 years, and 21% died of the disease. There was no change in the case fatality rate (CFR) during the 10-year period. The CFR was identical for men and women. BS and CNS infection caused the same incidence of mortality, but no mortality was observed in patients with focal infections at normally sterile body sites. In a multivariate analysis, isolates belonging to serogroup 4 were associated with a higher CFR than were isolates of serogroup 1/2. In patients aged < 70 years, underlying conditions predisposing to disease were related strongly to mortality, which was not the case in patients aged > 70 years. The underlying conditions associated most strongly with mortality in the younger age group were non-haematological malignancies.

Ready-to-eat spiced meat roll from a single production facility caused this outbreak. The product, served sliced and cold, is popular among the elderly; serving it at hospitals probably contributed to the high case-fatality rate. WGS used for patient isolates and isolates from food control inspections, coupled with routine epidemiological follow-up, was instrumental in swiftly locating the source of infections, preventing further illnesses and deaths.

Background Platelets may act as vascular endothelial growth factor (VEGF) scavengers, possibly limiting neovascularization in retinopathy of prematurity (ROP). The purpose of this study was to investigate the association between thrombocytopenia (platelets <150,000/μL) and the development of type 1 ROP. Methods This was a retrospective 1:1 matched case-control study. Cases required laser; controls developed no or stage 1 ROP and were matched for birth weight within 100 g and gestational age within 1 week. Most recent platelet count prior to laser (case) and matched postmenstrual age (control) were abstracted. Conditional logistic regression was used. Results A total of 91 cases and 91 controls were reviewed. Of the cases, 25% had thrombocytopenia; of controls, 13% (P = 0.034; OR = 2.38; 95% CI, 1.04-5.43). Birth weight, gestational age, postmenstrual age, and culture-proven sepsis were not confounders in multivariate analysis. The association was significant for zone 1 (n = 16; OR = 9.00; 95% CI, 1.14-71.0) but not for zone 2 (OR = 1.43; 95% CI, 0.54-3.75) cases and controls. Conclusions Thrombocytopenia was associated with type 1 ROP, primarily among infants with zone 1 ROP. This effect may result from disease location or disease timing, as posterior disease occurs at an earlier postmenstrual age. Longitudinal studies are required to further examine the roles of cumulative platelet deficits, thresholds, or critical time windows in the observed association.

A clone of Listeria monocytogenes CC8 caused bacteremia in the elderly and a high incidence of listeriosis.

Dietary risk factors for listeriosis were examined, and the risk levels of listeriosis according to specific underlying diseases were evaluated, in order to study the basis for prevention. Questionnaires from 50 listeriosis patients and 40 matching control persons were analysed. Unpasteurized milk was a risk food for sporadic listeriosis, and an outbreak of a European epidemic strain of Listeria monocytogenes was obviously linked to a blue-mould cheese or a hard cheese. Leukaemia, AIDS and renal transplantation were found to be associated with > 1000-fold risk of acquiring listeriosis, compared with healthy persons. As a part of prevention, persons running a high risk of contracting listeriosis should be individually informed about food hygiene and risk foods.