A multicenter study on the epidemiology of complicated parapneumonic effusion in the era of currently available pneumococcal conjugate vaccines

BACKGROUND

Parapneumonic effusion (PPE) is a common complication of pneumonia. Streptococcus pneumoniae is the most common cause of bacterial pneumonia. A reduction in pneumonia hospitalizations has been observed since the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). Despite this apparent benefit, an increase in the incidence of PPE was recorded in some countries following PCV7 implementation. As the 13-valent pneumococcal conjugate vaccine (PCV13) was expected to provide a wider protection against PPE, the aim of the present study was to evaluate the impact of PCV13 introduction on the epidemiology of complicated parapneumonic effusion (c-PPE) among children in the Athens greater area.

METHODS

All cases of community-acquired pneumonia (CAP) with PPE requiring chest tube insertion (complicated PPE, c-PPE) hospitalized in the 3 public Children's hospitals in Athens between 01/01/2004 and 31/12/2019 were included in the study.

RESULTS

A total of 426 cases of c-PPE associated with pneumonia were recorded of which 198 were admitted during 2004-2010 (period A, prePCV13/PCV -7 introduction period) and 228 during 2011-2018 (period B, post - PCV13 period). A definite bacterial etiology was established in 44.4 % of all cases and of those 25.4 % were caused by S. pneumoniae. An increasing trend in c-PPE incidence was observed during period A; although, a significant decrease on c-PPE annual rates was observed during the period B (p = 0.011), a remarkable increase in serotype 3 cases was recorded.

CONCLUSION

A decreasing time trend in c-PPE cases among children was shown after the introduction of PCV13 in our area. However, serotype 3 is nowadays a common cause of PPE. Hence, continuous surveillance is imperative in order to follow c-PPE epidemiology over time.

Methicillin-resistant Staphylococcus aureus transmission and hospital-acquired bacteremia in a neonatal intensive care unit in Greece

BACKGROUND

Staphylococcus aureus is a common pathogen causing hospital acquired infections (HAIs) in neonates. In this study, the epidemiology of methicillin-resistant S. aureus (MRSA) colonization and infections in a 30-bed, level III university-affiliated neonatal intensive care unit (NICU) located in a children's hospital was retrospectively investigated for the period 2014-2018.

METHODS

Genes encoding Panton-Valentine Leukocidin (lukS/lukF-PV, PVL), toxic shock syndrome toxin (tst), exfoliative toxins (eta, etb), and the resistance genes mecA, mecC and fusB, were defined in 46 representative strains by PCRs. Relatedness of strains was assessed by MLST.

RESULTS

Of 1538 neonates, 77 (5%) had a positive culture for MRSA (23/77 were NICU-acquired and 54/77 imported cases). Four MRSA bacteremias occurred. Most isolates were multi-resistant. One major clone was identified, ST225, among 40 tested neonatal strains (23/40, 58%). Of these, 14/23 were imported from the same maternity hospital (MH). Another clone, ST217, was predominant (4/6) among health care workers (HCWs), found colonized. Four isolates classified as ST80 were PVL-positive. Additional four strains carried tst (10%), belonging to ST30 and ST225 (two strains each), and two etb. The implicated MH was notified for the problem, decolonization treatment was successfully performed in HCWs and neonates. Strengthening of infection control measures with emphasis on hand hygiene was applied.

CONCLUSIONS

Uncovering reservoirs for on-going MRSA transmission in NICUs has proved challenging. Well known nosocomial MRSA clones are being constantly introduced and transmitted via MHs and HCWs. Effective infection prevention and control requires constant vigilance.

Acute diarrhoea in children treated in an outpatient setting in Athens, Greece

OBJECTIVE

To describe the epidemiology and aetiology of acute diarrhoea among children treated exclusively in an outpatient setting in Greece.

METHODS

During 1999, children with acute diarrhoea who attended the emergency department of our hospital were prospectively studied. Patients requiring hospitalization were excluded. Stool specimens were tested microscopically, for bacterial enteropathogens by standard and selective medium cultures and for rotavirus and adenovirus by latex agglutination test.

RESULTS

One hundred and thirty-two children (median age: 2 years) were included in the study; an enteropathogen was detected in 63 (48%) of them. Isolates included rotavirus (19 patients), Salmonella sp (12), Campylobacter sp (10), Aeromonas sp (9), enteropathogenic Escherichia coli (6), adenovirus (6), Giardia lamblia (4), Yersinia enterocolitica (2) and Shigella sp (1). Half of the bacterial cases occurred from August to October, and two rotavirus-associated peaks occurred during February and August. Acute diarrhoea caused by viruses affected exclusively children under six years of age, mainly those attending day care centres. Macroscopic blood in stools was reported only among patients with a bacterial infection. Socioeconomic characteristics were not helpful in differentiating disease due to specific enteropathogens.

CONCLUSIONS

Bacterial enteropathogens account for a significant proportion of acute diarrhoea in children treated in the outpatient setting in Greece. Rotavirus is also a frequent cause affecting mostly younger children and those attending day care centers. The presence of blood in stools and the seasonality of bacterial infections may enable their presumptive diagnosis.