Trends in hospital admission rates for whooping cough in England across five decades: database studies

Burden of selected infectious diseases covered by UK childhood vaccinations: systematic literature review

Aim: An overview of recent epidemiology and disease burden, independent of patient age, of diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis and Hemophilus influenzae invasive disease in the UK. Materials & methods: A systematic review was undertaken. Outcomes included incidence, prevalence, risk factors and cost burden. Results: 39 publications were included. Hepatitis B prevalence is high among certain risk groups. A small pertussis risk remains in pregnancy and for infants, which led to the introduction of maternal vaccination. H. influenzae invasive disease cases are limited to rare serotypes. Polio, tetanus and diphtheria are well controlled. Conclusion: The evaluated diseases are currently well controlled, thanks to a comprehensive vaccination program, with a generally low clinical and cost burden.

Low levels of detectable pertussis antibody among a large cohort of pregnant women in Canada

Newborns and infants less than 6 months of age continue to be at highest risk of severe outcomes from pertussis infection. Pertussis vaccination during the last trimester of pregnancy can confer protection to newborns as a result of trans-placental transfer of pertussis antibodies. In several countries, pertussis vaccination in pregnancy is recommended routinely and Canada's National Advisory Committee on Immunization issued similar routine recommendations in February 2018. Using second trimester biobanked plasma samples (n = 1752) collected between 2008 and 2011, we measured the pre-existing anti-pertussis toxin (PT) levels in a large cohort of second-trimester pregnant women using a commercial ELISA test. We found that 97.5% of these women had anti-PT IgG titres below 35 IU/mL. Women with higher incomes had slightly higher anti-PT levels but 96% still had titres <35 IU/ml. In conclusion, almost all of the pregnant women in this large cohort had anti-PT levels low enough to suggest susceptibility to pertussis infection in both the mothers and their newborn infants.

Trends and costs of pertussis hospitalizations in Portugal, 2000 to 2015: from 0 to 95 years old

BACKGROUND

Pertussis has caused several outbreaks and concern worldwide. Despite high vaccination coverage, people of all ages are still affected with significant morbidity and mortality. We aimed to analyse all pertussis hospitalizations in Portugal to help to delineate preventive policies.

METHODS

Data were collected from a Portuguese administrative database, which contains all registered hospitalizations in mainland Portugal. Cases were identified using the ICD-9-CM code 033.x (whooping cough) as principal or secondary diagnosis, with hospital discharges between 2000 and 2015. Data were analysed by age groups.

RESULTS

Of 2281 hospitalizations, 94% occurred in infants (<1 year). The mean and median ages were 20 and 2 months, respectively. A seasonal pattern was observed, with higher number of hospitalizations during the winter for infants, and during the summer for other age groups. Higher hospitalization rates were registered in the Southern regions. The mean and median lengths of hospital stay were 8 and 6 days, respectively. The main complications were acute respiratory failure and pneumonia. Invasive or non-invasive ventilation, or both, was required in 2.4, 1.8 and 0.6% of hospitalized cases, respectively. The overall inpatient case fatality rate was 0.7%; 0.8, 11.5 and 17.4% for the age groups 0-1 months, 18-64 years and ≥65 years, respectively. Total hospitalization costs were estimated to be 2,698,995€.

CONCLUSION

Our study emphasizes the need to adopt new preventive strategies mainly focused on infants, to reduce morbidity and costs of hospitalizations related to pertussis.

Are pertussis cases reported too late for public health interventions? Retrospective analysis of cases in London and South East England, 2010 to 2015

In the United Kingdom, pertussis guidance recommends prophylaxis for household contacts within 21 days of case symptom onset if the household includes a vulnerable contact. The aim of our study was to identify characteristics associated with cases reported late for public health action. We reviewed the epidemiology of cases reported in London and South East England for the period 2010 to 2015. We characterised risk factors associated with late reporting of cases and described public health actions taken on timely reported cases. From 2010 to 2015, 9,163 cases of pertussis were reported to health protection teams. Only 11% of cases were reported within 21 days of onset, limiting opportunities for secondary prevention. Timely reporting was associated with younger age groups, pregnancy, being a healthcare worker and being reported by schools or hospital clinicians. Late reporting was associated with older age groups and general practitioner or laboratory reporting. Delays, such as those due to insidious onset and late presentation to healthcare, may be unavoidable; however, delay in reporting once a patient presents can be reduced since cases can be reported before laboratory confirmation. Thus we recommend working with clinicians and laboratories to determine causes and improve early reporting to public health.

The French Connection: The First Large Population-Based Contact Survey in France Relevant for the Spread of Infectious Diseases

Background

Empirical social contact patterns are essential to understand the spread of infectious diseases. To date, no such data existed for France. Although infectious diseases are frequently seasonal, the temporal variation of contact patterns has not been documented hitherto.

Methods

COMES-F is the first French large-scale population survey, carried out over 3 different periods (February-March, April, April-May) with some participants common to the first and the last period. Participants described their contacts for 2 consecutive days, and reported separately on professional contacts when typically over 20 per day.

Results

2033 participants reported 38 881 contacts (weighted median [first quartile-third quartile]: 8[5–14] per day), and 54 378 contacts with supplementary professional contacts (9[5–17]). Contrary to age, gender, household size, holidays, weekend and occupation, period of the year had little influence on the number of contacts or the mixing patterns. Contact patterns were highly assortative with age, irrespective of the location of the contact, and gender, with women having 8% more contacts than men. Although most contacts occurred at home and at school, the inclusion of professional contacts modified the structure of the mixing patterns. Holidays and weekends reduced dramatically the number of contacts, and as proxies for school closure, reduced R₀ by 33% and 28%, respectively. Thus, school closures could have an important impact on the spread of close contact infections in France.

Conclusions

Despite no clear evidence for temporal variation, trends suggest that more studies are needed. Age and gender were found important determinants of the mixing patterns. Gender differences in mixing patterns might help explain gender differences in the epidemiology of infectious diseases.