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1.  Parameters for the Mathematical Modelling of Clostridium difficile Acquisition and Transmission: A Systematic Review 
PLoS ONE  2013;8(12):e84224.
Introduction
Mathematical modelling of Clostridium difficile infection dynamics could contribute to the optimisation of strategies for its prevention and control. The objective of this systematic review was to summarise the available literature specifically identifying the quantitative parameters required for a compartmental mathematical model of Clostridium difficile transmission.
Methods
Six electronic healthcare databases were searched and all screening, data extraction and study quality assessments were undertaken in duplicate. Results were synthesised using a narrative approach.
Results
Fifty-four studies met the inclusion criteria. Reproduction numbers for hospital based epidemics were described in two studies with a range from 0.55 to 7. Two studies provided consistent data on incubation periods. For 62% of cases, symptoms occurred in less than 4 weeks (3-28 days) after infection. Evidence on contact patterns was identified in four studies but with limited data reported for populating a mathematical model. Two studies, including one without clinically apparent donor-recipient pairs, provided information on serial intervals for household or ward contacts, showing transmission intervals of <1 week in ward based contacts compared to up to 2 months for household contacts. Eight studies reported recovery rates of between 75% - 100% for patients who had been treated with either metronidazole or vancomycin. Forty-nine studies gave recurrence rates of between 3% and 49% but were limited by varying definitions of recurrence. No study was found which specifically reported force of infection or net reproduction numbers.
Conclusions
There is currently scant literature overtly citing estimates of the parameters required to inform the quantitative modelling of Clostridium difficile transmission. Further high quality studies to investigate transmission parameters are required, including through review of published epidemiological studies where these quantitative estimates may not have been explicitly estimated, but that nonetheless contain the relevant data to allow their calculation. [Systematic review reference: CRD42012003081]
doi:10.1371/journal.pone.0084224
PMCID: PMC3869946  PMID: 24376797
2.  Multi-Centre Observational Study of Transplacental Transmission of Influenza Antibodies following Vaccination with AS03A-Adjuvanted H1N1 2009 Vaccine 
PLoS ONE  2013;8(1):e47448.
Introduction
Illness and death from influenza increase during pregnancy. In the United Kingdom pregnant women were targeted in a national programme for vaccination during the H1N1 2009–10 pandemic.
Methods
In this study, pregnant women were recruited in labour from November 9, 2009 to March 10, 2010. Pandemic vaccination status was determined. Venous cord blood collected at delivery was evaluated for transplacental transfer of antibodies by measurement of haemagglutination inhibition and microneutralization titres.
Results
Samples were collected from 77 vaccinated and 27 unvaccinated women. Seroprotection (HI titre ≥1∶40) was detected in 58 (75.3%, 95% CI 64.2–84.4) cord blood samples from vaccinated women and 5 (18.5%, 95% CI 6.3–38.1) from unvaccinated women (P<0.0001). There was evidence of transplacental seroprotection 8 days after maternal immunization (77.9%, 95 CI 66.2–87.1), maintained in most cases for at least 16 weeks.
Discussion
Immunization of pregnant women with AS03A-adjuvanted vaccine is followed by transplacental transfer of passive immunity at titres consistent with clinical protection in three-quarters of new-born infants. The findings support national and international pandemic H1N1 2009 recommendations for immunization during pregnancy.
doi:10.1371/journal.pone.0047448
PMCID: PMC3553100  PMID: 23372640
3.  Influenza Vaccination for Immunocompromised Patients: Systematic Review and Meta-Analysis from a Public Health Policy Perspective 
PLoS ONE  2011;6(12):e29249.
Background
Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events.
Methodology/Principal Findings
Electronic databases and grey literature were searched and records were screened against eligibility criteria. Data extraction and risk of bias assessments were performed in duplicate. Results were synthesised narratively and meta-analyses were conducted where feasible. Heterogeneity was assessed using I2 and publication bias was assessed using Begg's funnel plot and Egger's regression test. Many of the 209 eligible studies included an unclear or high risk of bias. Meta-analyses showed a significant effect of preventing influenza-like illness (odds ratio [OR] = 0.23; 95% confidence interval [CI] = 0.16–0.34; p<0.001) and laboratory confirmed influenza infection (OR = 0.15; 95% CI = 0.03–0.63; p = 0.01) through vaccinating immunocompromised patie nts compared to placebo or unvaccinated controls. We found no difference in the odds of influenza-like illness compared to vaccinated immunocompetent controls. The pooled odds of seroconversion were lower in vaccinated patients compared to immunocompetent controls for seasonal influenza A(H1N1), A(H3N2) and B. A similar trend was identified for seroprotection. Meta-analyses of seroconversion showed higher odds in vaccinated patients compared to placebo or unvaccinated controls, although this reached significance for influenza B only. Publication bias was not detected and narrative synthesis supported our findings. No consistent evidence of safety concerns was identified.
Conclusions/Significance
Infection prevention and control strategies should recommend vaccinating immunocompromised patients. Potential for bias and confounding and the presence of heterogeneity mean the evidence reviewed is generally weak, although the directions of effects are consistent. Areas for further research are identified.
doi:10.1371/journal.pone.0029249
PMCID: PMC3245259  PMID: 22216224
4.  Public health professionals' perceptions toward provision of health protection in England: a survey of expectations of Primary Care Trusts and Health Protection Units in the delivery of health protection 
BMC Public Health  2006;6:297.
Background
Effective health protection requires systematised responses with clear accountabilities. In England, Primary Care Trusts and the Health Protection Agency both have statutory responsibilities for health protection. A Memorandum of Understanding identifies responsibilities of both parties, but there is a potential lack of clarity about responsibility for specific health protection functions. We aimed to investigate professionals' perceptions of responsibility for different health protection functions, to inform future guidance for, and organisation of, health protection in England.
Methods
We sent a postal questionnaire to all health protection professionals in England from the following groups: (a) Directors of Public Health in Primary Care Trusts; (b) Directors of Health Protection Units within the Health Protection Agency; (c) Directors of Public Health in Strategic Health Authorities and; (d) Regional Directors of the Health Protection Agency
Results
The response rate exceeded 70%. Variations in perceptions of who should be, and who is, delivering health protection functions were observed within, and between, the professional groups (a)-(d). Concordance in views of which organisation should, and which does deliver was high (≥90%) for 6 of 18 health protection functions, but much lower (≤80%) for 6 other functions, including managing the implications of a case of meningitis out of hours, of landfill environmental contamination, vaccination in response to mumps outbreaks, nursing home infection control, monitoring sexually transmitted infections and immunisation training for primary care staff. The proportion of respondents reporting that they felt confident most or all of the time in the safe delivery of a health protection function was strongly correlated with the concordance (r = 0.65, P = 0.0038).
Conclusion
Whilst we studied professionals' perceptions, rather than actual responses to incidents, our study suggests that there are important areas of health protection where consistent understanding of responsibility for delivery is lacking. There are opportunities to clarify the responsibility for health protection in England, perhaps learning from the approaches used for those health protection functions where we found consistent perceptions of accountability.
doi:10.1186/1471-2458-6-297
PMCID: PMC1712342  PMID: 17156421

Results 1-4 (4)