Prevention of nosocomial transmission of norovirus by strategic infection control measures

BACKGROUND. Nosocomial outbreaks of norovirus infection pose a great challenge to the infection control team. METHODS. Between November 1, 2009, and February 28, 2010, strategic infection control measures were implemented in a hospital network. In addition to timely staff education and promotion of directly observed hand hygiene, reverse-transcription polymerase chain reaction for norovirus was performed as an added test by the microbiology laboratory for all fecal specimens irrespective of the request for testing. Laboratory-confirmed cases were followed up by the infection control team for timely intervention. The incidence of hospitalacquired norovirus infection per 1,000 potentially infectious patient-days was compared with the corresponding period in the preceding 12 months, and the incidence in the other 6 hospital networks in Hong Kong was chosen as the concurrent control. Phylogenetic analysis of norovirus isolates was performed. RESULTS. Of the 988 patients who were tested, 242 (25%) were positive for norovirus; 114 (47%) of those 242 patients had norovirus detected by our added test. Compared with the corresponding period in the preceding 12 months, the incidence of hospital-acquired norovirus infection decreased from 131 to 16 cases per 1,000 potentially infectious patient-days (P< .001), although the number of hospitalacquired infections was low in both the study period (n=8) and the historical control periods (n=11). The incidence of hospital-acquired norovirus infection in our hospital network (0.03 cases per 1,000 patient-days) was significantly lower than that of the concurrent control (0.06 cases per 1,000 patient-days) (P=.015). Forty-three (93%) of 46 norovirus isolates sequenced belonged to the genogroup II.4 variant. CONCLUSIONS. Strategic infection control measures with an added test may be useful in controlling nosocomial transmission of norovirus. © 2011 by The Society for Healthcare Epidemiology of America. All rights reserved.published_or_final_versio

Placental transfer of SARS-CoV-2 antibodies in mother-neonate pairs: a prospective nested cohort study

Background Newborns depend on the transfer of IgG across the placenta to acquire protection against pathogens. We assessed the placental transfer of SARS-CoV-2 antibodies, primarily derived from infection, from seropositive pregnant women enrolled in a pregnancy cohort in Kilifi, Kenya. Methods The study was nested within a prospective observational multi-country cohort study. All available paired maternal delivery and cord blood samples were selected. Maternal sera were tested for SARS-CoV-2 receptor binding domain (RBD) IgM/IgG total antibodies using the Wantai assay. For positive samples, maternal and corresponding cord blood samples were tested for SARS-CoV-2 IgG antibodies against the spike (anti-spike) and nucleocapsid proteins (anti-NCP) using ELISA kits from Euroimmun. Results A total of 492 (56.1%) out of 877 maternal delivery samples were positive for RBD IgM/IgG total antibodies. Of these, 416 (84.6%) were seropositive for either anti-NCP IgG, anti-spike IgG antibodies or both. A total of 412 out of 496 (83%) cord blood samples tested positive for either anti-NCP or anti-spike antibodies. The geometric mean ratio was 1.04 (95% CI: 0.90, 1.21), indicating no significant difference between the anti-spike IgG concentration in cord and maternal blood samples. The log-transformed maternal and cord blood anti-spike IgG concentrations showed a weak positive correlation (r = 0.364, n = 496, p < 0.001). No maternal or neonatal factors were associated with the anti-spike IgG placental transfer ratio. Conclusion Placental transfer of SARS-CoV-2 antibodies was evident in a population of pregnant women whose immunity was primarily derived from infection given the low SARS-CoV-2 vaccine coverage in the study area. The positive correlation between maternal and cord blood anti-spike concentrations suggests that interventions that increase maternal antibody concentrations such as vaccination may increase passive immunity and protection against severe COVID-19 disease in neonates

Effect of human development on the relationship between generalised trust and health: an international cross-sectional investigation

Poster Abstrac

Prevention of nosocomial transmission of swine-origin pandemic influenza virus A/H1N1 by infection control bundle

After the outbreak of severe acute respiratory syndrome in Hong Kong, the importance of preventing nosocomial transmission of respiratory viruses has become a top priority in infection control. During the containment and early mitigation phases of the swine-origin influenza virus (S-OIV) A H1N1 pandemic, an infection control bundle consisting of multiple coherent measures was organised by our infection control team to minimise nosocomial transmission. This included repeated open staff forum achieving high attendance; early recognition of index cases among inpatients by liberal testing; early relief of sick staff from work; directly observed hand hygiene practice during outbreaks; and monitoring of compliance with infection control practice. During the first 100 days (from 1 May to 8 August 2009) when the first 100 laboratory-confirmed patients with S-OIV and 12 infected healthcare workers (HCWs) were identified, a total of 836 asymptomatic exposed persons (184 patients and 652 HCWs) were required to undergo a seven-day medical surveillance. The infection control nurses monitored them for the onset of symptoms. Four (0.48%) exposed persons (one house officer, two non-clinical staff, and one patient) were virologically confirmed with S-OIV. Not wearing a surgical mask either by the exposed persons during contact with the index cases (4/4 vs 264/832, P = 0.010) or vice versa (4/4 vs 300/832, P = 0.017, Fisher's exact test) were found to be significant risk factors for nosocomial acquisition of S-OIV. © 2009 The Hospital Infection Society.link_to_subscribed_fulltex