Influence of pneumococcal vaccine on the incidence of empyema:

Invasive pneumococcal disease in children under 60 months before and after availability of 13-valent conjugate vaccine

BACKGROUND

Invasive pneumococcal disease (IPD) is the most important bacterial infection in young children, and the introduction of pneumococcal conjugate vaccines has changed its presentation. This study compared the incidence, characteristics and serotype distribution of IPD before and after the introduction of the pneumococcal conjugate vaccine (PCV13).

METHODS

Prospective enrolment of patients with IPD aged less than 60 months and admitted to either of 2 tertiary care hospitals between January 2007 and December 2009 (pre-PCV13 period) and January 2012 and June-2016 (PCV13 period).

RESULTS

We identified 493 cases, 319 in the pre-PCV13 period and 174 in the PCV13 period. The incidence of IPD decreased from 89.7 to 34.4 casos per 100 000 habitantes ( -62%; P < .001). This decrease was observed in all forms of disease except necrotising pneumonia (increase from 0.8 to 3.7 casos/100 000 population). There was a significant reduction in all serotypes included in the PCV13 and not included in the PCV7. We did not find significant differences in length of stay, mortality or the frequency of sequelae between both periods, but in the PCV13 period, the length of stay in the paediatric intensive care unit and the duration of mechanical ventilation were longer (P = .00). The incidence of serotype 3 decreased from 10.4 to 6.9 casos per 100 000 population, although it was the serotype involved most frequently in patients with severe disease.

CONCLUSIONS

After the introduction of the PCV13, there has been a significant decrease in IPD cases. Serotype 3 continues to be an important cause of severe IPD.

[Invasive pneumococcal disease in children under 60 months before and after availability of 13-valent conjugate vaccine]

BACKGROUND

Invasive pneumococcal disease (IPD) is the most important bacterial infection in young children, and the introduction of pneumococcal conjugate vaccines has changed its presentation. This study compared the incidence, characteristics and serotype distribution of IPD before and after the introduction of the pneumococcal conjugate vaccine (PCV13).

METHODS

Prospective enrolment of patients with IPD aged less than 60 months and admitted to either of 2 tertiary care hospitals between January 2007 and December 2009 (pre-PCV13 period) and January 2012 and June-2016 (PCV13 period).

RESULTS

We identified 493 cases, 319 in the pre-PCV13 period and 174 in the PCV13 period. The incidence of IPD decreased from 89.7 to 34.4 cases per 100,000 population (-62%; P<.001). This decrease was observed in all forms of disease except necrotising pneumonia (increase from 0.8 to 3.7 cases/100,000 population). There was a significant reduction in all serotypes included in the PCV13 and not included in the PCV7. We did not find significant differences in length of stay, mortality or the frequency of sequelae between both periods, but in the PCV13 period, the length of stay in the paediatric intensive care unit and the duration of mechanical ventilation were longer (P=.00). The incidence of serotype 3 decreased from 10.4 to 6.9 cases per 100,000 population, although it was the serotype involved most frequently in patients with severe disease.

CONCLUSIONS

After the introduction of the PCV13, there has been a significant decrease in IPD cases. Serotype 3 continues to be an important cause of severe IPD.

Trends in Hospital Treatment of Empyema in Children in the United States

OBJECTIVE

To evaluate trends in procedures used to treat children hospitalized in the US with empyema during a period that included the release of guidelines endorsing chest tube placement as an acceptable first-line alternative to video-assisted thoracoscopic surgery.

STUDY DESIGN

We used National Inpatient Samples to describe empyema-related discharges of children ages 0-17 years during 2008-2014. We evaluated trends using inverse variance weighted linear regression and characterized treatment failure using multivariable logistic regression to identify factors associated with having more than 1 procedure.

RESULTS

Empyema-related discharges declined from 3 in 100 000 children to 2 in 100 000 during 2008-2014 (P = .04, linear trend). There was no significant change in the proportion of discharges having 1 procedure (66.1% to 64.1%) or in the proportion having 2 or more procedures (22.1% to 21.6%). The proportion coded for video-assisted thoracoscopic surgery as the only procedure declined (41.4% to 36.2%; P = .03), and the proportions coded for 1 chest tube (14.6% to 20.9%; P = .04) and 2 chest tube procedures (0.9% to 3.5%; P < .01) both increased. The median length of stay for empyema-related discharges remained unchanged (9.3 days to 9.8 days; P = .053). Having more than 1 procedure was associated with continuous mechanical ventilation (adjusted OR, 2.7; 95% CI, 1.8-4.1) but not with age, sex, payer, chronic conditions, transfer admission, hospital size, or census region.

CONCLUSIONS

The use of video-assisted thoracoscopic surgery to treat children in the US hospitalized with empyema seems to be decreasing without associated increases in length of stay or need for additional drainage procedures.

Changes in empyema among U.S. children in the pneumococcal conjugate vaccine era

BACKGROUND

Parapneumonic empyema, a serious complication of pneumonia, started increasing among U.S. children before the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2000, and continued afterwards. This increase was due in part to pneumococcal serotypes not included in PCV7 that were included in the new 13-valent (PCV13) vaccine introduced in 2010. We assessed changes in the incidence of empyema hospitalizations among U.S. children after PCV13 introduction.

METHODS

We calculated annualized empyema hospitalization rates among U.S. children <18years using Nationwide Inpatient Sample and Census data (1997-2013) for four periods based on PCV7 and PCV13 introductions. Relative rates (RR) and 95% confidence intervals (CI) were calculated by age group and sex, comparing PCV7 [early-PCV7 (2001-2005) and late-PCV7 (2006-2009)] and PCV13 (2011-2013) periods with the pre-PCV7 period (1997-1999). Secondary analyses examined changes in pneumococcal, streptococcal, staphylococcal and unspecified empyema.

RESULTS

Among children <18years of age, annualized empyema hospitalization rates peaked at 3.6 per 100,000 in the late-PCV7 period compared with 2.1 per 100,000 in the pre-PCV7 period [RR: 1.70 (95% CI: 1.11-2.60)]. However, annualized rates in the post-PCV13 period declined to 2.0 per 100,000, similar to rates in the pre-PCV7 period. Empyema rates among children <2years were lower in the post-PCV13 period compared to the pre-PCV7 period [RR: 0.77 (95% CI: 0.61-0.96)], but rates in the two periods among children 2-4 and 5-17years were similar. Most empyema were of unspecified etiology. Pneumococcal and unspecified empyema declined after PCV13 introduction.

CONCLUSIONS

Although empyema hospitalization rates among U.S. children peaked after PCV7 introduction, rates decreased substantially following the introduction of PCV13.

Incidence, aetiology and outcome of pleural empyema and parapneumonic effusion from 1998 to 2012 in a population of New Zealand children

AIM

To document rising incidence rates of childhood empyema and parapneumonic effusion (PPE) in South Auckland, New Zealand between 1998 and 2012; to compare epidemiology, pathogens and outcomes of children with empyema and PPE; and to ascertain whether primary care antibiotic prescribing, delayed presentation, or bacterial epidemiology might account for the rising incident rates.

METHODS

Children aged 0 to14 years hospitalised with pleural empyema or PPE were retrospectively identified. Empyema was defined by ultrasound and pleural tap criteria. PPE was defined as the presence of pleural fluid on chest xray not fulfilling empyema criteria. Epidemiology, clinical features, microbiology and outcomes of empyema and PPE were compared and incidence rates analysed.

RESULTS

Of 184 cases identified, 104 met the criteria for empyema. Empyema incidence increased from 1 per 100 000 children aged 0 to 14 years in 1998 to 10 per 100 000 in 2012, with a peak incidence of 13 per 100 000 in 2009. Staphylococcus aureus was most frequently detected (n=38), followed by Streptococcus pneumoniae (n=31). Cases of S. aureus empyema increased 4 fold over the 15 years. Dominant S. pneumoniae serotypes were 1 and 14. Thirty-five percent of empyema and 53% of PPE cases received pre-hospital antibiotics. Children who received pre-hospital antibiotics were more than 40% less likely to require surgical intervention than those not pre-treated.

CONCLUSIONS

Childhood empyema incidence has increased markedly in South Auckland. Paediatric S. aureus empyema is becoming increasingly common in South Auckland. Pre-hospital antibiotic prescribing may mitigate the need for surgical intervention in our population.

The increasing incidence of empyema

PURPOSE OF REVIEW

The aim of this review is to highlight recent changes concerning the incidence of empyema. In this article we have focused on community-acquired empyema

RECENT FINDINGS

The incidence of empyema seems to have been increasing both in children and adults worldwide in the past decades, mainly in healthy young adults and in older patients. The bacteriology of pleural infection is changing as well. In children, the most common microorganism that causes empyema continues to be Streptococcus pneumoniae. Interestingly, the widespread use of the seven valent conjugate vaccine has produced a replacement phenomenon with the emergence of some pneumococcal serotypes such as serotypes 1, 3 and 19A, which have a higher propensity to cause empyema. Moreover increases in the incidence of empyema due to Staphylococcus aureus have also been observed. In adults, increases in the rate of empyema due to Streptococcus milleri group and S. aureus have been reported.

SUMMARY

Continued surveillance in the epidemiology of empyema is needed. Progress in new strategies of prevention, such as a new generation of conjugate pneumococcal vaccines and protein-based vaccines, could become an important step in the control of this important complication.