Incidence of Hospital Norovirus Outbreaks and Infections Using 2 Surveillance Methods in Sweden.

OBJECTIVE To evaluate 2 different methods of surveillance and to estimate the incidence of norovirus (NoV) outbreaks in hospitals. DESIGN Prospective observational study. SETTING All 194 hospital wards in southern Sweden during 2 winter seasons (2010-2012). METHODS Clinical surveillance based on outbreak reports of 2 or more clinical cases, with symptom onset within 5 days, was compared with laboratory surveillance based on positive NoV results among inpatients. At least 2 NoV positive patients sampled within 5 days at a ward defined a cluster. Outbreak reports including at least 1 NoV positive case and clusters including at least 1 NoV positive patient with 5 or more days from ward admission to sampling were defined as NoV outbreaks. RESULTS During the study periods 135 NoV outbreaks were identified; 74 were identified by both clinical and laboratory surveillance, 18 were identified only by outbreak reports, and 43 were identified only by laboratory surveillance. The outbreak incidence was 1.0 (95% CI, 0.8-1.2) and 0.5 (95% CI, 0.3-0.6) per 1,000 admissions for the 2 different seasons, respectively. To correctly identify NoV outbreaks, the sensitivity and positive predictive value of the clinical surveillance were 68% and 88% and of the laboratory surveillance were 86% and 81%, respectively. CONCLUSION The addition of laboratory surveillance significantly improves outbreak surveillance and provides a more complete estimate of NoV outbreaks in hospitals. Laboratory surveillance can be recommended for evaluation of clinical surveillance. Infect Control Hosp Epidemiol 2016;1-7.

No evidence of intrauterine transmission of hepatitis A virus from a mother to a premature infant.

AIM: To determine whether or not an intrauterine transmission of hepatitis A virus (HAV) occurred from an infected mother to her premature infant delivered by caesarean section. METHODS: The mother and her child were tested for HAV by serology and reverse transcription PCR. RESULTS: An outbreak of HAV infection was seen among children and a 33-year-old day-care teacher, pregnant in third trimester, at a day-care centre in southern Sweden. Due to premature labour and diminished foetal movements a caesarean section was performed and a premature girl in gestational weeks 33 + 1 was born. During the 3-week postnatal hospitalization period the child presented no clinical symptoms of HAV infection and anti-HAV IgM antibodies remained undetectable at day 14 and 109 after birth. Furthermore HAV RNA remained undetectable by reverse transcription PCR in the child's blood at birth and in throat and faeces for the first 3 and 4 weeks of life respectively. HAV RNA in the mother's blood was detected at 6 days prior to and at 17 days after delivery. HAV RNA was undetectable in breast milk when tested on day 3 after delivery. CONCLUSION: There was no evidence of intrauterine transmission of hepatitis A virus from a viraemic mother to her premature child delivered at gestational week 33 + 1 by caesarean section.

High prevalence of MRSA in household contacts.

In a 6-y period, 114 household contacts connected to newly diagnosed MRSA patients screened for MRSA in the southern part of Sweden. In 22 of 51 (43%) families, 1 to 4 household contact(s) connected to a MRSA patient were positive for MRSA. In the 22 families, 42 of 60 (70%) household contacts were positive for MRSA and transmission of MRSA occurred between adult couples, parents and children, grandparent and children and between siblings. Within a family, MRSA-positive family members had in all but 1 instance identical MRSA strain genotypes (spa types) making intrafamilial spread of MRSA highly probable. MRSA transmission among household contacts may contribute to the prevalence of MRSA in the community and failure to identify MRSA in household contacts may maintain MRSA colonization in an already known MRSA patient. MRSA screening of family members living in the same household as a known MRSA patient should therefore be considered.

Nosocomial transmission of Legionella pneumophila to a child from a hospital's cold-water supply.

Human Legionella infections mainly consist of community-acquired and nosocomial pneumonia and rarely affect children. We describe a nosocomial infection with Legionella pneumophila, serogroup 1, subgroup OLDA, in an immunocompromized 2-y-old girl at a paediatric clinic. L. pneumophila identical to that of the patient was found in the hospital's cold-water but not in the hot-water distribution system. Transmission of Legionella to the girl most probably occurred by Legionella-contaminated cold water mixed and heated by water from the hot-water system. Mixing of hot and cold water probably occurred through thermostatic water mixing valves connected to showers regulated by a handle at the shower head. Nosocomial Legionella infection might thus have occurred, although circulating hot water temperatures never dropped below 53 degrees C and cultures for surveillance of Legionella from central parts of the hot-water system have been consistently negative. Legionellae were successfully eliminated from the hospital's cold-water distribution system by hot water flushing at 73 degrees C for 1h.

A nosocomial sapovirus-associated outbreak of gastroenteritis in adults.

The human caliciviruses norovirus and sapovirus are leading causes of acute, non-bacterial gastroenteritis. In contrast to norovirus, sapovirus is known to give infections mainly in infants and young children. We describe a nosocomial outbreak of gastroenteritis associated with sapovirus involving 23 adult patients and medical staff. The mean age of the patients and medical staff was 52 y and the major signs and symptoms were nausea, diarrhoea, vomiting, abdominal cramp, headache, myalgia and fever. More patients had diarrhoea (72%) than vomiting (56%) and the mean duration of symptoms was 6 d. A secondary attack rate of 45% was seen affecting in all 10 persons with a mean age of 29 y. Sequences of the capsid gene revealed a 97% nucleotide homology to the sapovirus genogroup IV reference strain Chiba/000671T/1999. This is one of the first reported nosocomial outbreaks of sapovirus infection among adults and shows that a diagnostic test for sapovirus should be included in investigation of gastroenteritis among adults.

A premature infant with fulminant meningococcal septicaemia.

The case is described of a 10-week-old preterm infant, a twin boy born at 34 weeks of gestational age. The day after a hernia operation he had a rapidly progressive fulminant Neisseria meningitidis serogroup B septicaemia, of which he died despite immediate and adequate treatment. No secondary cases occurred among other infants on the neonatal intensive care unit. Epidemiological investigation revealed that of 185 bacterial throat cultures performed on 17 infants on the ward, 37 close relatives to the infants and 131 medical personnel in contact with the deceased patient, 4 (2.2%) were asymptomatic carriers of N. meningitidis. Serotyping and pulsed-field gel electrophoresis of the genomic DNA of the N. meningitidis isolates revealed that the infant and his father had closely related strains.

Food-borne outbreak of gastroenteritis associated with genogroup I calicivirus.

An outbreak of gastroenteritis affecting 158 of 219 (72%) guests and employees at a hotel is described. Food served at the hotel restaurant is believed to have been the source of the outbreak and to have been contaminated by sick employees working in the restaurant. A secondary attack rate of 22% was seen involving 43 persons in all. In stool specimens from seven of eight patients, Norwalk-like viruses (NLVs) were detected by electron microscopy. While NLV-specific PCR using primers JV12 and JV13 were negative, all specimens examined with primers NVp69 and NVp110 were positive. The failure of primers JV12 and JV13 was attributed to several mismatches in the JV12 primer. Genotyping and sequence analysis revealed that all samples had identical sequences and clustered with genogroup I, and the most closely related well-characterized genotype is Desert Shield. This is the first described food-borne outbreak associated with genogroup I virus in Sweden.

Binding of human and animal immunoglobulins to the IgG Fc receptor induced by human cytomegalovirus.

Human cytomegalovirus (HCMV)-infected cells express a virus-encoded receptor that is able to bind the Fc part of IGG: Some basic binding properties of this Fc receptor (FcR) have been examined. The affinity constant (K(a)) for human IgG Fc fragment in its interaction with acetone-fixed, HCMV-infected human embryonic lung fibroblasts was estimated to be around 2 x 10(8) M(-1) and the number of binding sites was estimated to be around 2 x 10(6) per cell. Of the human IgG, IgA, IgM and IgD classes, only IgG reacted with the receptor, and all four of the IgG subclasses were reactive. IgG from rabbit, hamster, cat, swine and horse exhibited binding to the HCMV FcR, in contrast to IgG from mouse, rat, guinea pig, dog, sheep, goat, cow and chicken. Immunoglobulins with and without HCMV IgG FcR-binding properties, like IgG from rabbit and mouse, can be of value in revealing the functional importance of the receptor. When the immunoglobulins were tested against herpes simplex virus type 1-induced FcR, both similarities and differences in immunoreactivity were seen relative to the HCMV FcR, which makes it unlikely that the binding sites for these two herpesvirus FcRs on the IgG molecule are identical.