The burden of bacteremia and invasive diseases in children aged less than five years with fever in Italy

Update on Viral Infections Involving the Central Nervous System in Pediatric Patients

Infections of the central nervous system (CNS) are mainly caused by viruses, and these infections can be life-threatening in pediatric patients. Although the prognosis of CNS infections is often favorable, mortality and long-term sequelae can occur. The aims of this narrative review were to describe the specific microbiological and clinical features of the most frequent pathogens and to provide an update on the diagnostic approaches and treatment strategies for viral CNS infections in children. A literature analysis showed that the most common pathogens worldwide are enteroviruses, arboviruses, parechoviruses, and herpesviruses, with variable prevalence rates in different countries. Lumbar puncture (LP) should be performed as soon as possible when CNS infection is suspected, and cerebrospinal fluid (CSF) samples should always be sent for polymerase chain reaction (PCR) analysis. Due to the lack of specific therapies, the management of viral CNS infections is mainly based on supportive care, and empiric treatment against herpes simplex virus (HSV) infection should be started as soon as possible. Some researchers have questioned the role of acyclovir as an empiric antiviral in older children due to the low incidence of HSV infection in this population and observed that HSV encephalitis may be clinically recognizable beyond neonatal age. However, the real benefit-risk ratio of selective approaches is unclear, and further studies are needed to define appropriate indications for empiric acyclovir. Research is needed to find specific therapies for emerging pathogens. Moreover, the appropriate timing of monitoring neurological development, performing neuroimaging evaluations and investigating the effectiveness of rehabilitation during follow-up should be evaluated with long-term studies.

Real-time polymerase chain reaction on filter paper spotted samples: a gateway to molecular diagnosis of invasive bacterial diseases for rural areas in low-income countries

BACKGROUND

Bacterial culture is the gold standard for the diagnosis of invasive bacterial diseases (IBDs) but molecular methods are more specific and sensitive. Fresh liquid samples (FLSs) show patent limitations for shipping and storage. We aimed to evaluate the sensitivity and specificity of real-time polymerase chain reaction (PCR) performed on dried sample spots (DSSs) obtained from different biological fluids compared with real-time PCR or culture performed on FLSs.

METHODS

FLSs positive for Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus, Bordetella pertussis and/or Pseudomonas aeruginosa were spotted on filter paper. Real-time PCR was performed on both FLSs and DSSs and results were compared. The stability of the DSS results over time was evaluated.

RESULTS

Real-time PCR performed on 114 DSSs showed a specificity of 99.1% and a sensitivity of 91.2% for IBD diagnosis. A positive correlation was found between FLS cycle threshold (Ct) and DSS Ct (r=0.84; r2=0.71) with the Pearson statistical test and Bland-Altman analysis showing that 95% of the specimens were within agreeable limits. Although we observed a trend towards signal reduction over time in the DSSs, there was no statistical evidence of an increase in Ct values. Real-time PCR on DSSs was 2.2 times more sensitive than culture.

CONCLUSIONS

Real-time PCR applied to DSSs may be a useful approach in different situations, such as IBD diagnosis, both for rural areas of low-income countries and family practitioners in various settings.

Adjunctive therapy to treat neonatal sepsis

Introduction: Neonatal sepsis (NS) is a very severe condition that causes significant morbidity and mortality.Areas covered: To overcome the limits of antibiotic therapy and improve NS outcomes, measures chosen among those theoretically able to improve host defenses or positively interfere with deleterious immune responses could be suggested. This paper discusses the mechanisms of action of these measures, whether their efficacy in prophylaxis justifies use in NS therapy and their impact.Expert opinion: NS remains a relevant problem despite the availability of antibiotics effective against the most common agents and the introduction of effective preventive measures such as group B Streptococcus prenatal screening and intrapartum antibiotic prophylaxis. This explains why attempts to introduce new prophylactic and therapeutic measures have been made. Unfortunately, none of the measures suggested and tested to date can be considered a definitive advance. It is highly likely that in the future, new measures will be proposed according to the increase in the knowledge of the characteristics of immune system function in preterm infants and the methods to modulate unproper immune responses.

Bacterial meningitis: new treatment options to reduce the risk of brain damage

Introduction: Bacterial meningitis (BM) is a medical emergency and its etiology varies according to the age group and geographic area. Studies have shown that brain damage, sequelae and neuropsychological deficits depend not only on the direct deleterious action of the pathogens, but also on the host defenses themselves.Areas covered: Corticosteroids (CS) were the first drugs used with the intent to limit the exaggerated host response. However, as steroid addition to antibiotics is frequently unsatisfactory, other measures have been suggested. In this study, the most important adjuvant therapies that are potentially useful to limit the neuropsychological damage of BM are discussed.Expert opinion: The pathophysiological mechanisms leading to the development of brain damage are not completely defined. Moreover, the efficacy of adjuvant therapies can vary according to the aetiologic cause of BM, and differences in immune system function of the host can play a relevant role in the expression of inflammation and related problems. It is likely that none of the measures with demonstrated efficacy in animal models can be translated into clinical practice in the next few years, suggesting that to reduce the total burden of BM, the increased use of vaccines seems to be the best solution.

Paediatric community-acquired bacteraemia, pneumococcal invasive disease and antibiotic resistance fell after the pneumococcal conjugate vaccine was introduced

AIM

This study examined the impact of the routine pneumococcal conjugate vaccination (PCV) on childhood community-acquired bacteraemia (CAB) and antibiotic resistance patterns in Israeli children.

METHODS

Israel added the PCV vaccine to its national immunisation programme in July 2009. We retrospectively analysed the medical records of all patients with CAB under 18 years at three children's hospitals in Tel Aviv and Jerusalem from 2007 to 2015. The microbiological data, clinical presentation, pneumococcal serotype distribution, antibiotic susceptibility and outcomes of infections were compared before and after the vaccine was introduced.

RESULTS

There were 511 904 emergency department visits and 125 922 children were hospitalised. Of those, 238 had CAB before vaccination was introduced (mean age 17 months) and 316 had CAB after the introduction (mean age 21 months). Emergency department presentations for CAB fell from 141.8 to 91.8 per 100 000 visits: a relative risk reduction (RRR) of 35%. Hospitalisations for CAB decreased from 430 to 337 per 100 000 admissions: an RRR of 22%. Hospitalisations due to Staphylococcus aureus increased significantly and penicillin nonsusceptible blood Streptococcus pneumoniae isolates decreased significantly.

CONCLUSION

Introducing national pneumococcal conjugate vaccination significantly changed the epidemiology of CAB, with reduced antibiotic-resistant Streptococcus pneumoniae and increased hospitalisation rates for Staphylococcus aureus infections.

Blood-Brain Barrier in a Haemophilus influenzae Type a In Vitro Infection: Role of Adenosine Receptors A2A and A2B

The blood-brain barrier (BBB) is mainly made up of tightly connected microvascular endothelial cells (BMECs), surrounded by pericytes (BMPCs) which regulate BBB tightness by providing soluble factors that control endothelial proliferation. Haemophilus influenzae type a (Hia) is able to reach the BBB, crossing it, thus causing meningitis. In this study, by using an in vitro model of BBB, performed with human BMECs and human BMPCs in co-culture, we demonstrated that, after Hia infection, the number of hBMPCs decreased whereas the number of hBMECs increased in comparison with non-infected cells. SEM and TEM images showed that Hia was able to enter hBMECs and reduce TEER and VE-cadherin expression. When the cells were infected in presence of SCH58261 and PSB603 but not DPCPX, an increase in TEER values was observed thus demonstrating that A_2A and A_2B adenosine receptors play a key role in BBB dysfunction. These results were confirmed by the use of adenosine receptor agonists CGS21680, CCPA, and NECA. In infected co-cultures cAMP and VEGF increased and TEER reduction was counter-balanced by VEGF-R1 or VEGF-R2 antibodies. Moreover, the phosphorylated CREB and Rho-A significantly increased in infected hBMECs and hBMPCs and the presence of SCH58261 and PSB603 significantly abrogated the phosphorylation. In conclusion, this study demonstrated that the infection stimulated A_2A and A_2B adenosine receptors in hBMECs and hBMPCs thus inducing the pericytes to release large amounts of VEGF. The latter could be responsible for both, pericyte detachment and endothelial cell proliferation, thus provoking BBB impairment.

Progress in pediatrics in 2015: choices in allergy, endocrinology, gastroenterology, genetics, haematology, infectious diseases, neonatology, nephrology, neurology, nutrition, oncology and pulmonology

This review focuses key advances in different pediatric fields that were published in Italian Journal of Pediatrics and in international journals in 2015. Weaning studies continue to show promise for preventing food allergy. New diagnostic tools are available for identifying the allergic origin of allergic-like symptoms. Advances have been reported in obesity, short stature and autoimmune endocrine disorders. New molecules are offered to reduce weight gain and insulin-resistance in obese children. Regional investigations may provide suggestions for preventing short stature. Epidemiological studies have evidenced the high incidence of Graves' disease and Hashimoto's thyroiditis in patients with Down syndrome. Documentation of novel risk factors for celiac disease are of use to develop strategies for prevention in the population at-risk. Diagnostic criteria for non-celiac gluten sensitivity have been reported. Negative effect on nervous system development of the supernumerary X chromosome in Klinefelter syndrome has emerged. Improvements have been made in understanding rare diseases such as Rubinstein-Taybi syndrome. Eltrombopag is an effective therapy for immune trombocytopenia. Children with sickle-cell anemia are at risk for nocturnal enuresis. Invasive diseases caused by Streptococcus pyogenes are still common despite of vaccination. No difference in frequency of antibiotic prescriptions for acute otitis media between before the publication of the national guideline and after has been found. The importance of timing of iron administration in low birth weight infants, the effect of probiotics for preventing necrotising enterocolitis and perspectives for managing jaundice and cholestasis in neonates have been highlighted. New strategies have been developed to reduce the risk for relapse in nephrotic syndrome including prednisolone during upper respiratory infection. Insights into the pathophysiology of cerebral palsy, arterial ischemic stroke and acute encephalitis may drive advances in treatment. Recommendations on breastfeeding and complementary feeding have been updated. Novel treatments for rhabdomyosarcoma should be considered for paediatric patients. Control of risk factors for bronchiolitis and administration of pavilizumab for preventing respiratory syncytial virus infection may reduce hospitalization. Identification of risk factors for hospitalization in children with wheezing can improve the management of this disease. Deletions or mutations in genes encoding proteins for surfactant function may cause diffuse lung disease.

Emerging resistant serotypes of invasive Streptococcus pneumoniae

BACKGROUND

Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7).

METHODS

A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005.

RESULTS

The most common serotypes for all age groups were 3 (12.70%), 14 (11.90%), 1 (11.90%), 19A (9.00%), 9V (5.20%), 23F (5.20%), and 19F (4.50%). Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10), and the 13-valent conjugated vaccine (PCV-13) were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2-5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6-64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46%) were multidrug resistant (MDR) and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in cefotaxime nonsusceptible strains from 3.55% to 16.66%.

CONCLUSION

Invasive pneumococcal strains and the emergence of MDR serotypes is a global burden that must be addressed through multiple strategies, including vaccination, antibiotic stewardship, and continuous surveillance.