Invasive Group A Streptococcus Outbreaks Associated with Home Healthcare, England, 2018-2019.

Healthcare-associated invasive group A Streptococcus (iGAS) outbreaks are common worldwide, but only England has reported outbreaks associated with home healthcare (HHC). We describe 10 outbreaks during 2018-2019 in England. A total of 96 iGAS cases (range 2-39 per outbreak) and 28 deaths (case-fatality rate 29%) occurred. Outbreak duration ranged from 3-517 days; median time between sequential cases was 20.5 days (range 1-225 days). Outbreak identification was difficult, but emm typing and whole-genome sequencing improved detection. Network analyses indicated multiple potential transmission routes. Screening of 366 HHC workers from 9 outbreaks identified group A Streptococcus carriage in just 1 worker. Outbreak control required multiple interventions, including improved infection control, equipment decontamination, and antimicrobial prophylaxis for staff. Transmission routes and effective interventions are not yet clear, and iGAS outbreaks likely are underrecognized. To improve patient safety and reduce deaths, public health agencies should be aware of HHC-associated iGAS.

Review of vaccination in pregnancy to prevent pertussis in early infancy.

Maternal pertussis vaccination has been introduced in several countries to protect infants from birth until routine infant vaccination takes place. This review assesses existing evidence on the effectiveness and safety of immunization in pregnancy. The search was finalized in April 2017 and was based on searches using several databases. The selection criteria included any experimental or observational study reporting on the immunogenicity, effectiveness or safety of vaccination with a pertussis-containing vaccine in pregnant women and their infants. Following de-duplication and exclusions, we identified 8395 studies, which were reduced to 46 for inclusion. The overall risk of bias was low, with the exception of some early studies and pharmacovigilance safety data. The evidence demonstrates efficient transplacental transfer of maternal antibodies in infants whose mothers were vaccinated with Tdap or Tdap/IPV in pregnancy, with good evidence that this protects against disease in young infants. Safety studies covering more than 150 000 women vaccinated mostly in the late second or third trimesters are generally consistent and provide reassurance of no significant increased risk of recognized maternal conditions or of adverse events (including congenital anomalies) in infants born to vaccinated women. The clinical significance of reduced seroconversion to pertussis following routine immunization is not yet clear, but no increased risk of pertussis in infants whose mothers were vaccinated in pregnancy was found following primary immunizations in North American and English studies. Most post-booster studies suggest that any blunting effect is short-lived and that longer-term protection in infants from active immunization is not compromised.

Impact assessment of mass measles vaccination.

OBJECTIVE: The mass measles vaccination campaign was conducted in the slums of Surat City, in Gujarat State, as a part of urban measles control initiative in India. One dose each of the vaccine was administered to children in the age range of 9-59 months residing in these slums, regardless of their previous vaccination status. METHODS: One year later, (October 2000), the present study was carried out in order to assess the impact of the mass vaccination campaign on the vaccination coverage and on the incidence of measles by comparing the findings with those of the baseline survey carried out in May 98. This was a retrospective study with a recall period of the preceding year. 3,147 children under five were studied in thirty slum clusters selected by the cluster sampling method. The parents/caretakers of these children were interviewed for information on any episode of fever with rash conforming to the case definition. RESULT: The incidence rate for measles declined from 7.7 percent reported in the baseline (May 1998) to 3.5 percent in the impact assessment study. The incidence was 8 times higher in unvaccinated children. The mean and median age at contracting the illness increased from 26 +/- 14.2 months and 26 months in the baseline to 30.9 +/- 14.7 months and 30 months respectively in the impact assessment. The vaccination coverage had improved from 48.3 percent to 73.7 percent following the campaign. CONCLUSION: The compaign increased vaccination coverage decreased disease incidence and caused a shift towards higher age-groups in vaccinated children.