[Human papillomavirus vaccination. Consensus Conference in pediatric age]

Genital human papillomavirus (HPV) infection is the most common sexually transmitted infection worldwide. Spontaneous clearance of HPV infection occurs in most cases, but chronic infection with high risk genotypes is associated with the development of cervical cancer. In particular, HPV 16 and 18 are responsible for 70% of cancers of the cervix and, in variable proportions, for cancers of the vagina, vulva, anus, penis and oropharinx. Low risk HPV genotypes, such as HPV 6 and 11, cause genital warts. Two prophylactic vaccines using virus like particles (VLPs) of L1 capside protein of HPV 16 and 18 have been developed. Of these, one also containing VLPs of HPV 6 and 11, has been approved by FDA, EMEA and AIFA for use in 9-26 year-old females. Large scale studies have shown that these vaccines are safe, well tolerated, elicits high levels of neutralizing antibodies, prevent chronic HPV infections due to genotypes present in the vaccine, and associated cervical lesions (and genital wars for the quadrivalent vaccine). To be effective the vaccines should be given prior to sexual debut. In Italy, the vaccination will be offered to 12 year-old girls. This article is the result of a targeted Consensus Conference by a panel of experts, which reviews the cornerstones of HPV infection, its association with cervical cancer, the advances in prophylactic vaccines, and the primary role of the paediatrician for the optimal adoption of this new preventive strategy.

[Budgetary impact of pneumococcal conjugate vaccination of newborns]

Pneumococcal (Pnc) disease represents a major healthcare concern being associated with severe complications. Scope of this study was to evaluate the budgetary impact effect of providing vaccination with seven-valent pneumococcal conjugate vaccine (PCV) to newborns in Lombardy (Italy). Budget impact analysis was applied to the 2004 cohort of newborns of Lombardy: efficacy data as number of pneumonia and acute otitis media (AOM) cases, and consumption of resources were derived from a large multicenter single-blind clinical study (results published) of vaccinated versus unvaccinated Italian children. Vaccinated children were administered 3 doses of PCV at 3, 5 and 11 months of age; Pnc morbidity was recorded until the 30th month of age. Economic analysis was performed in the perspective of the third party payer considering direct costs (vaccine doses, administration costs, drugs, visits and hospitalisations for management of Pnc disease complications); unit cost of resources (2006 values) was retrieved from national reimbursement tariff lists and other published sources. Our analysis suggests that the use of PCV in infants is likely to be economically justified due to savings from pneumonia and AOM cases averted, in the population of newborns of Lombardy.

Effect of highly active antiretroviral therapy (HAART) on the natural history of ocular manifestations in HIV-infected children

PURPOSE

To determine the effect of highly active antiretroviral therapy (HAART) on the natural history of ocular manifestations in HIV-infected children.

METHODS

All of the HIV-infected children attending the Institute of Pediatrics, University of Milan, Milan, Italy, between 1982 and 2004 were studied. Every 3 months, they were physically examined and underwent indirect fundoscopy conducted by an experienced ophthalmologist; if diagnosed as having eye disease, they were evaluated by the ophthalmologist every week while on specific therapy and monthly thereafter. The clinical and laboratory findings before and after the introduction of HAART were compared.

RESULTS

The cohort consisted of 117 HIV-infected children (61 males), with a follow-up ranging from 0.09 to 22.31 years (median, 16.33 years). A total of nine cases of ocular involvement (7.7%) were diagnosed between 1983 and 1994, before the introduction of HAART. All nine children died 4-24 months (median, 15 months) after the diagnosis of ophthalmic disease. No case of ocular involvement was observed after the introduction of HAART (P=0.011 vs. before HAART).

CONCLUSION

The introduction of HAART has had a significant impact on the natural history of ocular manifestations in HIV-infected children, thus suggesting that a reduction in the frequency of ophthalmologic follow-up should be considered for HAART-treated HIV-infected children with immune reconstitution and no visual symptom.

Human metapneumovirus in paediatric patients

Acute respiratory tract infections (ARTIs) are a leading cause of morbidity and mortality in children worldwide, but the aetiology of many ARTIs is still unknown. In 2001, researchers in The Netherlands reported the discovery of a previously unidentified pathogen called human metapneumovirus (hMPV). Since its initial description, hMPV has been associated with ARTI in Europe (Italy, France, Spain, the UK, Germany, Denmark, Finland and Norway), America (the USA, Canada, Argentina and Brazil), Asia (India, Japan, China and Singapore), Australia and South Africa in individuals of all ages. The incidence of infection varies from 1.5% to 25%, indicating that hMPV is a ubiquitous virus with a worldwide distribution. hMPV seems to play an important role as a cause of paediatric upper and lower respiratory tract infection, with similar, but not identical, epidemiological and clinical features to those of respiratory syncytial virus and influenza virus. Moreover, the socio‐economic impact of hMPV‐infected children on their families seems to be considerable, which suggests that, like influenza virus, hMPV infection may be a substantial public health problem for the community. It may be associated with significant morbidity and mortality in pre‐term infants and children with underlying clinical conditions, although more adequately controlled studies are needed to confirm its importance in such patients. Many fundamental questions concerning the pathogenesis of hMPV disease and the host's specific immune response remain to be answered. Further studies are also required to properly define hMPV diagnosis, treatment and prevention strategies.

Clinical and socio-economic impact of influenza and respiratory syncytial virus infection on healthy children and their households

This prospective study compared the clinical and socio-economic impact of laboratory-confirmed influenza and respiratory syncytial virus (RSV) infection on healthy children and their families. Among 1,520 otherwise healthy children aged< 15 years attending the Emergency Department for acute conditions other than trauma, influenza viruses and RSV were found in 234 (15.4%) and 116 (7.6%; p<0.0001) patients, respectively. The fact that influenza has a similar global clinical impact on the community to that of RSV infection, but represents a greater socio-economic burden, may contribute to broadening the acceptance of influenza vaccination.

Burden of influenza in healthy children and their households

OBJECTIVE

A prospective, multicentre study was conducted to evaluate the burden of laboratory confirmed influenza in healthy children and their household contacts.

METHODS

The patients were enrolled in four emergency departments (EDs) and by five primary care paediatricians (PCPs) in different Italian municipalities 2 days a week between November 1, 2001 and April 30, 2002. The study involved 3771 children less than 14 years of age with no chronic medical conditions who presented with a respiratory tract infection in EDs or PCP outpatient clinics during the study period. Nasopharyngeal swabs were collected for the isolation of influenza viruses and RNA detection. Information was also collected concerning respiratory illnesses and related morbidities among the study children and their household contacts.

RESULTS

Influenza virus was demonstrated in 352 cases (9.3%). In comparison with the influenza negative children, those who were influenza positive had an older mean age, were more often attending day care centres or schools, more frequently experienced fever and croup, received more antipyretics, and had a longer duration of fever and school absence. Furthermore, their parents and siblings had more respiratory illnesses, received more antipyretics and antibiotics, needed more medical visits, missed more work or school days, and needed help at home to care for the ill children for a longer period of time.

CONCLUSIONS

Influenza has a significant clinical and socioeconomic impact on healthy children and their families. Prevention strategies should also focus on healthy children regardless of their age because of their role in disease transmission.

Recurrent respiratory tract infections in pediatric age: a population-based survey of the therapeutic role of macrolides

In order to evaluate the efficacy of macrolides in pediatric patients with recurrent respiratory tract infections (RRTIs), we enrolled 1,706 children (783 females) aged between 6 months and 14 years (median: 4 years) with an acute respiratory infection and a history of RRTIs (> or = 8 episodes per year if aged < 3 years; > or = 6 episodes per year if aged > or = 3 years). The therapies were chosen by the primary care pediatricians and their effects on respiratory relapses were blindly analyzed. Regardless of age and clinical diagnosis, the children treated with macrolides showed a significantly higher rate of short- and long-term clinical success than those receiving beta-lactams (p<0.0001) or symptomatics alone (p<0.0001). These data show that macrolide therapy of acute respiratory infections influences the natural history of RRTIs, probably because of their elective activity on atypical bacteria. They also suggest the possible importance of these pathogens in causing recurrences of respiratory infections in children and show that the infections they cause may have a more complicated course unless treated with adequate antibacterial drugs.

[Efficacy of the heptavalent pneumococcal vaccine against meningitis, pneumonia and acute otitis media in pediatric age. Theoretical coverage offered by the heptavalent conjugate vaccine in Italy]

All the clinical trials carried out to evaluate the heptavalent pneumococcal conjugate vaccine have clearly demonstrated that it is safe, well tolerated and, despite some differences in the different diseases, effective in the prevention of all the pneumococcal illnesses. Considering that the available data demonstrate that the serotypes involved in the determination of pneumococcal diseases are, in Italy, the same found in the U.S.A. where the vaccine has been formulated, it is reasonable to think that it will be very effective also in our country. We hope that this vaccine can be systematically prescribed also in Italy: this could permit to reduce the number of both common and severe pneumococcal diseases at the moment largely present among italian children.

[Epidemiology of meningitis, pneumonia and acute otitis due to Streptococcus pneumoniae in pediatric in Italy]

Streptococcus pneumoniae is one of the most important bacterial pathogens in pediatrics, both from a quantitative and from a qualitative point of view. It can cause severe diseases such as occult bacteremia, sepsis, meningitis and it is also involved in the determination of a relevant part of very common illnesses such as pneumonia, acute otitis media and rhinosinusitis. However, most of the data regarding the epidemiology of pneumococcal infections in pediatrics have been collected in the U.S.A. and in other industrialized Countries different from Italy. In Italy only studies concerning meningitis and the carrier state of pneumococcus are at the moment available. They indicate that also in Italy S. pneumoniae seems to play a significant role in the determination of several pediatric diseases and that quite similar are the group of serotypes mainly involved in the determination of both invasive and not invasive diseases.

Emerging role of Mycoplasma pneumoniae in children with acute pharyngitis

In order to define the role, the risk factors, and the clinical and laboratory characteristics of Mycoplasma pneumoniae infection in children with pharyngitis, 184 patients with acute non-streptococcal pharyngitis (102 males; median age, 5.33 years) were studied. Acute Mycoplasma pneumoniae infection was demonstrated in 44 (23.9%) patients. A history of recurrent episodes of pharyngitis (defined as at least 3 acute episodes of pharyngitis in the 6 months preceding enrollment) appeared to be the more useful parameter for differentiating Mycoplasma pneumoniae pharyngitis from non-streptococcal non- Mycoplasma pneumoniae pharyngitis ( P<0.05 in multivariate analysis). These data, which highlight the emerging role of Mycoplasma pneumoniae in acute pharyngitis, must be taken into account in the diagnosis and treatment of this clinical manifestation in children.

Upper GI bleeding in healthy full-term infants: a case-control study

OBJECTIVE

The aim of this case-control study was to evaluate the frequency and the type of mucosal lesions in newborn babies with upper GI bleeding (UGIB), the diagnostic role and safety of upper GI endoscopy, and the recognition of risk factors associated with the hemorrhagic event.

METHODS

A population of 5180 infants born from June, 1988 to May, 1997 was examined. A case was defined as any patient who had UGIB within 4 days of delivery. The diagnosis was made by endoscopic examination in an endoscopy room. The following parameters were determined: amniotic fluid features, funicular blood pH, Apgar index at 5 min, neonatal weight, body length, gestational age, and the presence of other pathologies. Biochemical profiles were also evaluated. Clinical and demographic data of the mothers of the newborn babies were analyzed. Sera of cases and the respective parents were tested for gastrin and pepsinogen. As a control group, 53 full-term healthy infants matched for sex and age were randomly selected from the population of infants born in our pediatric department.

RESULTS

Sixty-four of 5180 newborn babies (1.23%) suffered from UGIB within 26.5 +/- 20 h of life. In 53 of 64 cases (mean age = 24.2 +/- 25.5 h) it was possible to carry out an endoscopic examination. In one case, endoscopy was limited to the esophagus because of the presence of multiple mucosal ulcers and substenosis of the viscus. Esophageal damage was observed in 24/53 patients. The esophageal lesions were isolated in nine cases, and occurred jointly with gastric or duodenal damage in 14 cases and one, respectively. Gastric and duodenal lesions were seen in 43/52 and 1/52 patients, respectively. There were 17 cases of gastric ulcers and one case of duodenal ulcer. Blood clots were observed in 14 gastric ulcer patients; in one case there was evidence of active bleeding at the margins of a gastric ulcer. There was no significant difference with regard to the demographic and clinical characteristics of the cases and controls. Median values of serum gastrin of the cases and controls were similar. Median serum pepsinogen was significantly higher in the case group.

CONCLUSIONS

UGIB in the newborn babies is often associated with clinically relevant mucosal lesions of the upper GI tract. The evolution, after treatment with antisecretory drugs, is generally rapid and favorable, with clinical recovery usually obtained within 24-48 h. The higher serum pepsinogen levels may only represent a significant risk factor of mucosal lesions and complications.

Emerging role of Mycoplasma pneumoniae and Chlamydia pneumoniae in paediatric respiratory-tract infections

Increased use of specialised diagnostic techniques over the past 10 years has allowed considerable new information to be obtained concerning Mycoplasma pneumoniae and Chlamydia pneumoniae infections. In children, these pathogens seem to have a more important role in causing respiratory-tract infections than previously thought; they have been associated with wheezing, and they are also frequent in children aged under 5 years. Contrary to original belief, no clinical, laboratory, or radiological findings seem to be unique to M. pneumoniae or C. pneumoniae; furthermore, there is no rapid and cost-effective diagnostic test capable of identifying these pathogens. Appropriate antimicrobial treatment of the infections they cause is needed to reduce the recurrent episodes of wheezing and other respiratory symptoms, to decrease morbidity, and to avoid the spread of the pathogens. However, a number of therapeutic issues remain unsolved.

Use of antimicrobial agents for community-acquired lower respiratory tract infections in hospitalised children

Data collected from 613 children aged 2-14 years who had been hospitalized for acute bronchitis, wheezing, or pneumonia were analysed to evaluate the prescribing practices of pediatricians treating community-acquired lower respiratory tract infection. Antibiotics were prescribed for 92.1% of the children: 85% had acute bronchitis, 72% had wheezing, and 97.9% had pneumonia. A high frequency of antibiotic overuse and inappropriate prescriptions was noted. In order to contain costs and limit the risk of resistant bacteria emerging, it is urgent that pediatricians and parents be educated in the proper use of antibiotics.

Markers of cell death-activation in lymphocytes of vertically HIV-infected children naive to highly active antiretroviral therapy: the role of age

BACKGROUND

Apoptosis plays a major role in depleting CD4(+) lymphocytes during infection with HIV-1. Few data exist on its role during HIV infection of children. Sensitivity of peripheral blood lymphocytes (PBLs) to apoptotic stimuli and the importance of the patient's age remain unclear.

OBJECTIVES

We sought to analyze the following: (1) markers of cell death-activation (CD95, CD45 isoforms, and CD28) in PBLs from vertically HIV-infected children of different ages before highly active antiretroviral therapy; (2) changes in other PBL populations; (3) PBL sensitivity to cell death and mitochondrial damages; and (4) role of age during progression of infection.

METHODS

Cell culture techniques and flow cytometry were used to analyze surface antigens, PBL susceptibility to apoptosis, or PBL susceptibility to change of mitochondrial membrane potential.

RESULTS

Donor age had a strong negative correlation with numbers of CD4(+) and CD8(+) T cells. Virgin T lymphocyte (CD45RA(+), CD95(-)) levels and those of CD95(+) cells showed no correlation with the children's clinical status but did show a correlation with patient age. CD28(-) T lymphocytes were markedly augmented in HIV-infected children but were unrelated to stage of infection or age. A relevant decrease in B lymphocytes and an increase in natural killer cells were also found. Finally, PBLs from HIV-positive children had a marked tendency to undergo apoptosis and mitochondrial damage.

CONCLUSION

Changes in PBL phenotype, increased expression of CD95, and high sensitivity to apoptosis suggest that a precocious aging of the immune system occurs in HIV-infected children.

Asthma in children: are chlamydia or mycoplasma involved?

Asthma aetiology is complex, involving interactions between genetic susceptibility, allergen exposure and external aggravating factors such as air pollution, smoking and respiratory tract infections. Available evidence supports a role for acute Chlaymdia pneumoniae or Mycoplasma pneumoniae respiratory tract infection as a trigger for 5 to 30% of wheezing episodes and asthma exacerbations. It also appears that acute infections with C. pneumoniae and M. pneumoniae can initiate asthma in some previously asymptomatic patients; however, the quantitative role for these atypical bacteria as asthma initiators is unknown at the present time. Whether chronic infections with these agents play an important role in persistent asthma symptoms and/or to asthma severity is unclear and additional information should be acquired before definite conclusions can be reached. Improvement in asthma symptoms after antimicrobial therapy active against C. pneumoniae and M. pneumoniae has been observed. In some studies C. pneumoniae seems to be more important for asthma pathogenesis and exacerbations than M. pneumoniae; in other reports the role of M. pneumoniae appears to be more significant. However, a number of questions remain unanswered. Carefully controlled randomised trials are clearly warranted to determine whether infection with atypical bacteria is really associated with asthma and to define the appropriate role of antimicrobial treatment.

Long-term pertussis-specific immunity after primary vaccination with a combined diphtheria, tetanus, tricomponent acellular pertussis, and hepatitis B vaccine in comparison with that after natural infection

The aim of this study was to compare pertussis-specific humoral and cellular immunity in children 5 years after a primary vaccination with a combined diphtheria, tetanus, tricomponent acellular pertussis, and hepatitis B vaccine (DTaP-HBV; InfanrixHepB; SmithKline Beecham) with immunity after natural infection. The subjects were 38 children aged 5 to 6 years who received DTaP-HBV at 3, 5, and 11 months of life and 21 subjects of similar ages and sex who acquired pertussis in the first year of life. Immunoglobulin G (IgG) antibody titers against Bordetella pertussis antigens, peripheral blood mononuclear cell-specific proliferation, and the secretion of cytokines were evaluated. After 5 years, only a small proportion of vaccinated and infected children had significant specific concentrations of IgG in serum against all three B. pertussis antigens, and T-cell responses persisted in a minority of subjects. A preferential type 1 cytokine response with the secretion of gamma interferon was observed in the pertussis group, whereas a type 2 skewed response was observed in the vaccinated children; however, the quantitative differences in the cytokines produced by DTaP-HBV and natural infection were minimal. In conclusion, our results show that the immune responses induced by primary pertussis vaccination are qualitatively and quantitatively similar to those seen in children who recovered from natural infection and highlight the need for booster immunization with pertussis vaccines in order to maintain adequate levels of a specific immune response to B. pertussis.

Role of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community-acquired lower respiratory tract infections

In order to evaluate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae, we studied 613 children aged 2-14 years who were hospitalized for community-acquired lower respiratory tract infections (LRTIs). The patients were enrolled in the study by 21 centers in different regions of Italy from May 1998 through April 1999. Paired serum samples were obtained on admission and after 4-6 weeks to assay the titers of M. pneumoniae and C. pneumoniae antibodies. Nasopharyngeal aspirates for the detection of M. pneumoniae and C. pneumoniae were obtained on admission. Acute M. pneumoniae infections in 210 patients (34.3%) and acute C. pneumoniae infections in 87 (14.1%) were diagnosed. Fifteen of the 18 children with M. pneumoniae and/or C. pneumoniae infections whose treatments were considered clinical failures 4-6 weeks after enrollment had not been treated with macrolides. Our study confirms that M. pneumoniae and/or C. pneumoniae plays a significant role in community-acquired LRTIs in children of all ages and that such infections have a more complicated course when not treated with adequate antimicrobial agents.

Mycoplasma pneumoniae and Chlamydia pneumoniae infections in children with pneumonia. Mowgli Study Group

The most common clinical signs, host responses and radiographic patterns were studied in 203 Italian children hospitalized for community-acquired pneumonia in order to clarify the role of clinical and radiological characteristics in the diagnosis of Mycoplasma pneumoniae and/or Chlamydia pneumoniae infections. Antibody measurements in paired sera and polymerase chain reaction on nasopharyngeal aspirates were used to establish the diagnoses of acute M. pneumoniae and C. pneumoniae infection, and the aetiologic data were correlated with the clinical, laboratory and radiographic data obtained on admission. No significant association was observed between evidence of M. pneumoniae and/or C. pneumoniae infection and periods of episode during the year, mean age of the study subjects, individual symptoms, physical findings or laboratory test results. Furthermore, no significant correlation was observed in relation to the radiological findings and M. pneumoniae and/or C. pneumoniae infection. This study shows that neither clinical findings nor laboratory parameters distinguished Mycoplasma pneumoniae and/or Chlamydia pneumoniae infection in children with pneumonia. Radiological findings also have a limited capacity to differentiate aetiologic agents. The priorities for future research include the development of rapid, easily accessible and cost-effective diagnostic tests useful for each episode of pneumonia in children.

Epidemiology of Streptococcus pneumoniae in Italian children

In Italy, data regarding the aetiological role, antibiotic resistance, and serotype distribution of isolates of Streptococcus pneumoniae are scarce and based on very small population samples. We found that S. pneumoniae caused about 30% of lower respiratory tract infections and 15% of acute otitis media infections in Italian children. The incidence of S. pneumoniae meningitis in subjects aged 0-4y was 1.1 x 100,000. In children <5 y of age with meningitis, the most common S. pneumoniae serotypes were, in rank order, 14, 6, 23, 1 and 4; among 53 nasopharyngeal carriers the most frequent serotypes were 6 and 19. The actual percentage of resistance of S. pneumoniae to penicillin is 10.2%, while for macrolides it reaches 25.5%. More data on the distribution of serotypes in Italian children are urgently needed in order to obtain a better understanding of the impact of the new pneumococcal vaccines.

Importance of acute Mycoplasma pneumoniae and Chlamydia pneumoniae infections in children with wheezing

In order to evaluate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae in reactive airway disease, 71 children aged 2-14 yrs with an acute episode of wheezing and 80 age-matched healthy children were studied. Sera for the determination of specific antibody levels and nasopharyngeal aspirates for the detection of M. pneumoniae and C. pneumoniae deoxyribonucleic acid were obtained on admission and after 4-6 weeks. All children with wheezing received a standard therapy with inhaled corticosteroids and bronchodilators for 5-7 days; when antibiotic was added on the basis of the judgement of the paediatrician in charge, clarithromycin 15 mg.kg body weight(-1).day(-1) for 10 days was used. Acute M. pneumoniae and C. pneumoniae infections were detected significantly more often in children with wheezing than in controls. In patients infected with one of the two pathogens, a history of recurrent wheezing was significantly more frequent than in those without either infection. During a 3-month follow-up period, among nonantibiotic-treated children, those with acute M. pneumoniae and/or C. pneumoniae infection showed a significantly higher recurrence of wheezing than those without acute M. pneumoniae and/or C. pneumoniae infection (p=0.03). These results highlight the apparently significant relationship of Mycoplasma pneumoniae and Chlamydia pneumoniae with wheezing in children, particularly in subjects with a history of recurrent episodes, and the possible improvement in the course of reactive airway disease within paediatric patients with acute Mycoplasma pneumoniae and/or Chlamydia pneumoniae infection.

A prospective study on mother-to-infant transmission of hepatitis C virus

To assess the rate of mother-to-infant transmission of hepatitis C virus (HCV) and to identify potential risk factors for transmission, we followed up (mean 22.4 months, range 1-7.5 years) a cohort of 291 babies born to anti-HCV-positive mothers, 40 of whom were also HIV coinfected. Seventeen (5.8%) babies acquired HCV infection, but none became icteric. All babies developed chronic HCV infection with 16 babies showing elevated levels of ALT. The rate of transmission was higher in babies born to mothers coinfected with HIV than in those born to mothers with HCV alone (22.5 vs. 3.2%, p < 0.0001). No association was seen between a specific maternal HCV genotype and an increased risk of neonatal infection. The median level of HCV-RNA was higher in mothers who transmitted infection than in those who did not, although the ranges overlapped. In this study, maternal history of chronic liver disease, mode of delivery and type of feeding were not predictive of HCV infection.