Production d’interféron alpha dans le sérum des très jeunes nourrissons lors d’infections virales

IFN-alpha detection is useful in some clinical circumstances, but its use has never been validated in young infants with viral infections.

OBJECTIVE

The authors wanted to determine it there was any difference in the assessment of IFN-alpha production between infants under or over six months of age.

PATIENTS AND METHOD

A series of 233 children with identified common viral infections who had been assessed for IFN-alpha production was retrospectively analyzed. The viral infections were enteroviral meningitis (n =103), respiratory syncytial virus infections (n =60), and rotavirus gastroenteritis (n =70). Data collected from the group of infants under six months of age (n =105) was compared to that of the older children (n =128). Qualitative and quantitative values of interferon-alpha were determined for each group.

RESULTS

Interferon-alpha was detected in very young infants (81.9% of cases) as often as in the older age group (80.3% of cases), for any of the three viral infections (P =0.3-0.63). The mean level of interferon-alpha production detected was not lower in the youngest group, and even higher in the group under six months of age with enteroviral meningitis.

CONCLUSION

Interferon-alpha detection in very young infants is efficient and may be useful to differentiate between viral and bacterial infection particularly when the etiological diagnosis appears uncertain.

Vaccination contre l'hépatite A chez l'enfant

Hepatitis A is usually considered as a mild disease and is asymptomatic in more than 80% of children less than 5 years of age. Furthermore, incidence of the disease decreased dramatically in France during the past decades. For these reasons mass routine vaccination is not required in our country. However, infected children shed the virus in the community and are responsible for secondary cases, sometimes severe. That is why, despite the cost and the absence of reimbursement of the vaccine, immunisation against hepatitis A is recommended in children attending health-care institutions, in children with chronic liver disease and in those travelling in endemic areas. Prophylaxis around an index case is the main problem because non-specific immunoglobulins, although recommended, are not available in France for this indication. Vaccination in the few days following exposition has been reported to be efficient in household contacts and small communities, including nurseries. This strategy is recommended by the British Advisory Board within the 7 days following exposition, but not in France. However, it can be proposed to the family by paediatricians.

[Parasitic diarrhea in children]

In many areas, Entamoeba histolytica and Entamoeba dispar are found together and their microscopic appearance is identical. Biochemical tests which can show cell wall differences are often falsely negative and the only possible way is to treat with metronidazole when amoebiasis is suspected. In case of clinical failure of metronidazole, a bacterial diarrhea is frequently found. Giardia is an other protozoa frequently found in stools of children in endemic areas. Diarrheas due to Giardia are possible in normal children and frequent in malnourished. They can determine severe atrophy of jejunal mucosa and must be treated. Cryptoridiosis is frequently asymptomatic but induces diarrhea in malnourished children. Diarrhea due to helminths is rare and only Strongyloides stercoralis induces severe diarrhea in malnourished child and must be treated in emergency with Ivermectin to avoid dissemination. In immune deficiency induced by corticosteroid treatment or cancer chemotherapy, a prophylactic treatment with Ivermectin against Strongyloides stercoralis must be given in endemic areas or after return, and probably also with metronidazole against Giardia.

[Hepatitis-A vaccination in children]

In France, immunization against hepatitis A is recommended for children attending health-care institutions, presenting chronic liver disease, and traveling to endemic areas. This recommendation is based on the fact that, while more than 80% of cases of hepatitis A occurring in children less than 5 years of age are asymptomatic, infected children without jaundice can shed the virus and serve as a source of infection for others. Immunization of children traveling to endemic areas protects the whole family from secondary infection that often leads to severe manifestations. Because the cost of the vaccine is not covered by health insurance, African families living in France must have children vaccinated in advance before travel to Africa. Vaccination early in childhood is possible since the protective effect is durable and perhaps definitive. The dramatic decrease of incidence in France has eliminated the need for routine vaccination except in children traveling to international destinations. The main problem is prophylaxis around index cases in situations involving single family units, small closed communities and localized outbreaks. Immediate vaccination within 7 days after exposure to the index case should be considered since the immunoglobulins are not available in France. Limited trials in families and closed communities show that this vaccination approach is effective and well tolerated even by young children attending nurseries. However this indication is currently not recognized in France even though it has often been applied and has been recommended by the British advisory board. It is the responsibility of pediatricians to inform parents of this risk and propose individual prophylaxis for the family.

[Malaria treatment in children. 2. Severe malaria]

Severe forms of Plasmodium falciparum malaria are one of the world's leading causes of infection-related death in children. The World Health Organization (WHO) has defined a set of severity criteria to improve diagnosis and speed antimalarial treatment. Although the pertinence of these criteria has not been documented in France, child travelers presenting such features require hospitalization in intensive care. The gold standard therapy is intravenous administration of quinine. According WHO recommendations, quinine therapy should begin with a loading dose barring contraindications. However French recommendations do not include the loading dose due to potentially dangerous side-effects in young children and lack of proven life-saving effect. Artemisinin derivatives have been shown to be as effective as quinine and are increasingly used in endemic zones due to good tolerance and convenience of use. However due to concerns about neurotoxicity, artemisinin derivatives are rarely used in France, except in patients with contraindications or resistance to quinine. Management of specific complications is also necessary to reduce the high mortality of severe malaria, even in Western countries, and to prevent neurological damage.

Pneumonies communautaires et infection grippale

Children without chronic or serious medical conditions are at increased risk for hospitalization during influenza seasons, mainly with respiratory tract infections. But influenza virus infections frequently remain undiagnosed, even in hospitalized patients. We prospectively studied the rate of concomitant and preceding influenza infections in children hospitalized with a community acquired pneumonia (CAP).

POPULATION AND METHODS

All 1-15-year-old children with CAP requiring hospitalization between 1st April 2000 and 2002 had nasopharyngeal aspirate for viruses, immunofluorescence and serologies for respiratory pathogens. The peak of influenza IgG measured by complement fixation (CF) is transient, and a titer of 1/64 or more indicates an acute influenza infection in the preceding weeks. Children with chronic disease were excluded and a control group of patients from outpatient clinic was measured.

RESULTS

Among 33 previously healthy children (age 4.9 years, range 1.2-14 years), 8 had a pneumococcal pneumonia, 10 a pneumonia caused by Mycoplasma pneumoniae (MP), 1 by Chlamydia pneumonia, and 8 of unknown origin. In six patients immunofluorescence was positive: Respiratory Syncitial Virus, 2, Adenovirus, 1 and Influenza A, 3 (including a patient with concomitant MP infection). Thirteen of the 33 children (39.4%) had evidence of a recent influenza A infection with CF ab > or = 1/64: with pneumococcal pneumonia, 5/10 with MP pneumonia, 3/8 with unknown origin pneumonia, 9/13 of these previous influenza infections being clinically inapparent. Only 1/30 children of control group (3.3%) had CF ab > or = 1/64.

CONCLUSION

In this study, influenza infection is the direct cause of CAP of children in 12% of cases. In other children with CAP, 39.4% of patients had an influenza infection in the preceding weeks which leads to secondary infection caused by Streptococcus pneumoniae or by MP or other pathogens.

[Information recorded by maternity ward staff in permanent pediatric health records]

OBJECTIVES

To study the frequency with which maternity ward staff complete the perinatal information section of infants' permanent pediatric health records.

METHODS

In 2000, 71 pediatricians in private practice and on staff in a general pediatric ward in a tertiary hospital in Paris carried out an observational study to assess which indicators were reported at what rates. Pediatricians were also asked which information about the perinatal admission they would find helpful in these records.

RESULTS

One thousand seven hundred and eighty-five pediatric health records were studied. The frequency of completed information varied from 5 to 100%, depending on the item. Of the items reported rarely, some, such as thoracic circumference, were obsolete, while others were very important (response to noise, light reflex). The new information desired by office-based pediatricians involved mainly risk factors for vertical infections (maternal fever during delivery, prolonged rupture of the membranes).

CONCLUSION

Although the rate of completion of information in the pediatric health record was globally good, some important data should be reported more often (sensorial screening), while other items could be deleted. New information about the pregnancy and delivery would be useful.

[Isolated intracranial hypertension due to Lyme's disease]

Lyme's borreliosis is characterized by the variety of its revealing symptoms, which may explain an often delayed diagnosis. We report on a case of a child affected by Lyme's disease, confirmed by serology, who presented a particular form consisting in an isolated intracranial hypertension. This rare form must be known and diagnosed early in order to avoid serious complications such as optic nerve atrophia in the absence of an appropriate treatment.

[Ciprofloxacin after clinical failure of beta-lactam antibiotics in children with salmonellosis]

BACKGROUND

Children with enteric fever or severe salmonella infections are usually treated with beta-lactam antibiotics, particularly ceftriaxone. Due to their poor penetration into cells, beta-lactam antibiotics, even if active in vitro, are sometimes clinically ineffective because they cannot reach the intracellular sites of Salmonella multiplication.

OBJECTIVES

To evaluate in a retrospective study usefulness, efficacy and safety of oral ciprofloxacin in patients with severe salmonellosis and clinical failure of ceftriaxone or beta-lactam antibiotics.

PATIENTS AND METHODS

From July 1, 1995 to 2000, the bacteriology laboratory of a French pediatric hospital had identified 215 patients aged between 1 month and 15 years with positive blood or stools for Salmonella sp, 113 of them requiring hospitalization due to their clinical symptoms. Three were excluded for sickle-cell disease or poor nutritional status. None of the 110 strains (including 4 S. typhi, 51 S. typhimurium, 25 S. enteritidis, 6 S. hadar and 5 S. heidelberg) isolated was resistant to ceftriaxone or ciprofloxacin. Forty-one of the 110 strains (37.3%) produced a beta-lactamase. Twelve patients had a rapid recovery without antibiotic treatment, and 98 (mean age 3.9 years) were given antibiotics (ceftriaxone in 91 and amoxicillin in 7) for dysentery (43%), shock (15%) or persistent high fever and severe diarrhea (42%).

RESULTS

In 72 children (mean age = 3.6 years) ceftriaxone treatment (amoxicillin in 5) for 5 or 7 days was rapidly effective: apyrexia was obtained in 1.5 day after the start of treatment and the number of stools per day was 4 or less in 2.2 days. Two to 3 weeks after clinical recovery, asymptomatic carriage was present in 22/38 patients. In the 26 other patients ceftriaxone (amoxicillin in 2) treatment was clinically ineffective, despite good in vitro activity, and was switch for oral ciprofloxacin (20 mg kg(-1) d(-1), 5 days) after 2 to 7 days of lasted fever and/or severe diarrhea. Clinical improvement with ciprofloxacin was obtained in less than 48 h. The strains involved in these 26 patients included the 4 S. typhi and 15 S. typhimurium (P < 0.05), 13/15 (P < 0.01) producing beta-lactamase. Asymptomatic carriage was found in 5/22 patients (P < 0.05) after recovery. None of the patient treated with ciprofloxacin had side effect.

CONCLUSION

In severe salmonellosis, the clinical failure of treatment with ceftriaxone is not rare, particularly in S. typhimurium producing beta-lactamase infection and short treatment with oral ciprofloxacin is safe and allows to obtain a rapid recovery.

Thrombocytopenia and Plasmodium falciparum malaria in children with different exposures

We studied thrombocytopenia during acute Plasmodium falciparum malaria in 64 traveller children from Paris (France), 85 children from Dakar (Senegal) with an intermittent exposure (69 with severe attack or cerebral malaria), and 81 children from Libreville (Gabon) with a perennial exposure (43 with severe attack or cerebral malaria). Initial thrombocytopenia was present in 43-58% of children with P falciparum malaria but was not more frequent in severe outcome or cerebral malaria. Low parasitaemia may lead to the misdiagnosis of malaria and delayed treatment when there is associated thrombocytopenia

Parasitic diarrhea in normal and malnourished children

Diarrhea is only one of the many manifestations of intestinal parasites. Environmental influences are inescapable, regardless of an individual's state of health: in a highly endemic region, intestinal parasitic colonization is almost the rule. The clinical expression of the parasitoses, however, is largely determined by host defenses; and when they are weakened, parasitic diarrhea is frequent and severe. Protein-energy malnutrition is by far the most important cause of immune deficiency in developing countries. Diarrhea caused by Strongyloides or Giardia is common and severe in malnourished children, while well-nourished children remain healthy carriers. These parasites require specific treatment in the malnourished; and the well-nourished should have preventive treatment when they are to receive corticosteroids or immunosuppressive agents. Diarrhea caused by Cryptosporidium spp. may be severe in malnourished or immunodeficient children, and recovery is achieved only after renutrition or treatment of the immunodeficiency.

[Parasitic diarrhea in eutrophic and malnourished children]

Almost all children living in endemic zones are infected by gastrointestinal parasites. However only 3 to 5% develop diarrhea directly related to parasite infection. Entamoeba hystolytica and Entamoeba dispar coexist in many areas. In the past Entamoeba dispar was called non-pathogenic ameba. The vegetating forms are microscopically identical and detection of wall differences using biochemical tests is unreliable. Thus since it is rarely possible to determine whether or not a vegetating ameba found in stools is hematophagous treatment using metronidazole is the only alternative. Failure of such treatment indicates that dysentery is probably due to a cause other than amibiasis, e.g., bacterial infection in most cases. Another protozoan commonly found in endemic areas is Giardia. Giardia can cause diarrhea and this is frequently the case in undernourished children. Giardia infection leads to severe atrophic villosity requiring appropriate specific treatment. In children cryptosporidioses may be asymptomatic or lead to diarrhea especially in cases associated with malnutrition or immunodeficiency related in particular to AIDS. Helminths are a rare cause of significant diarrhea except Anguillula in undernourished children. In children presenting severe malnutrition, anguilluliasis can lead to serious consequences and requires immediate treatment using ivermectin. To avoid severe diarrhea in children presenting immunodeficiency induced by corticotherapy or chemotherapy for cancer, prophylaxis is mandatory against anguilluliasis using ivermectin and usually against giardiasis using metronidazole.

[Fluoroquinolones in children]

The only currently recommended pediatric use of fluoroquinolones involves ciprofloxacine for treatment of pyocyanic infection in children with cystic fibrosis. The main contraindication for use of fluoroquinolones in children is arthrotoxicity. Notwithstanding they are occasionally used for serious infections when there is no other therapeutic alternative. In addition to cystic fibrosis, potential pediatric indications include multidrug-resistant salmonella and shigellosis, certain enterobacterial infections in newborns, complicated urinary tract infections, and severe multidrug-resistant bacterial infection especially in immunocompromised subjects. The availability of new quinolones against pneumococcus should have little impact on current therapeutic strategies for upper or lower respiratory tract infections since potential indications in children are limited. However when the new generation reaches the market, fluoroquinolones should offer new alternatives for treatment of penicillin-resistant pneumococcal meningitis. Studies comparing children and adults have shown that arthrotoxicity is approximately the same or only slightly higher. The main problem for assessment of adverse effects is that pediatricians often fail to report the limited number of cases in which fluoroquinoles have been prescribed. Regardless fluoroquinolones must remain a second or third line agent for treatment of severe infection in cases in which no other alternative especially by the oral route is available. Use must be restricted to situations in which the risks are outweighed by potential benefits. Limiting pediatric use will slow down the emergence of resistant bacteria.

[Nosocomial bacteremias in pediatrics]

OBJECTIVES

To identify pathogenic microorganisms responsible for hospital-acquired bloodstream infections and to evaluate the associated risk factors in pediatric units, in a case-control study over 30 months from January 1st 1997 to June 30th 1999.

RESULTS

Forty-six of 855 (5.4%) positive blood cultures were attributed to nosocomial infections. They were related to 32 infectious episodes in 28 patients hospitalized for more than 48 hours. The incidence rate was 0.11 per 100 admissions. Gram-positive cocci (n = 14; 38.8%) were the most frequently isolated pathogens (7 cases of Staphylococcus aureus, 5 of coagulase-negative staphylococci), followed by enterobacteria (n = 9; 25%), Pseudomonas aeruginosa (n = 5; 13.8%) and yeasts (n = 5; 13.8%). The major risk factors for hospital-acquired bloodstream infections were: length of stay before positive blood culture (32 +/- 51 days in cases vs 15 +/- 43 days in controls, p < 0.01), presence of central venous catheter [odds ratio (OR): 6.05, 95% confidence interval (CI): 1.87-20.42], number of days with central venous catheter (p < 0.001) and parenteral nutrition (OR: 9.44, 95% CI: 2.03-50.05).

CONCLUSION

Central venous catheter use, length of stay, parenteral nutrition and particularly intravenous lipids are major risk factors for the acquisition of bloodstream infection in hospitalized children.

[Procalcitonin and viral meningitis: reduction of unnecessary antibiotics by measurement during an outbreak]

OBJECTIVE

Viral meningitis are often treated with antibiotics in emergency because routine analysis of CSF is not always efficient for distinguishing between viral and bacterial infection. The aim of the study was to evaluate the usefulness of procalcitonin (PCT) to reduce antibiotic treatments.

METHODS AND RESULTS

A blood PCT level < 0.5 ng/mL was prospectively used for the diagnosis of viral origin of meningitis in 58 patients (two months-14 years), in which enterovirus was isolated by culture or PCR during an outbreak (May-June 2000). CSF cells range was 10 to 2800/mL (m: 244), PMN 5 to 2464/mL and CSF proteins range was 0.19 to 0.92 mg/dL (m: 0.37). Seventeen patients received antibiotic therapy in admission. In nine patients, PCT (dosage was routinely measured 3/week) result < 0.5 ng/mL was obtained in 24 h and in 48 h in six: treatment was then stopped and children led hospital. In two patients, PCT was > 1 ng/mL because of bacterial coinfection. CSF and PCT values were similar to those of an already published control group.

CONCLUSION

PCT dosage allowed to shorten hospitalization of 4.47 (controls) to 2.06 (patients) days in patients receiving unnecessary antibiotic treatments. During this outbreak, PCT dosage allowed to reduce 40 days of hospitalization.

[Community-acquired pneumonia in children: etiology and treatment]

Due to their very different etiological agents, community-acquired pneumoniae in children frequently require empiric antibiotic therapy in emergency. Streptococcus pneumoniae represents between 15 to 30% of the etiologies and has unspecific diagnostic procedures; as a matter of fact radiological lobar consolidation is seen in less than half of cases, and laboratory data, except for high procalcitonin level, are poorly reliable. Pneumonia due to Mycoplasma pneumoniae is frequent after 2 years of age, reaching 40 to 60% of causes in ambulatory teenagers; it must be treated with macrolides as sequellae are possible. The exact number of viral pneumonia is difficult to establish because of the lack of reliable diagnostic methods. If bacterial superinfections are probably overestimated during acute phase, viral infections may lead to bacterial pneumonia 2 to 4 weeks after the initial episode. Empiric antibiotic treatment must take into account pneumococci and their penicillin-resistant strains. Amoxicillin is the antibiotic of choice, having a higher efficacy on resistant pneumococci than oral cephalosporins. In case of clinical failure of amoxicillin, mycoplasma infection must be considered and patient must receive macrolides. Future epidemiology will be affected by anti-pneumococcal immunisation but difficulties in diagnosis and empiric antibiotic treatment will probably remain. Studies in immunised children are needed to evaluate the importance of pneumococcal infections due to serotypes not included in the vaccine.

[Hospitalization for acute community-acquired rotavirus gastroenteritis: a 4-year survey]

OBJECTIVE

To evaluate the number of hospitalizations due to community-acquired rotavirus acute gastroenteritis in a general pediatric unit during a four-year survey.

RESULTS

From January 1997 to December 2000, 725 patients were admitted for acute gastro-enteritis to the general paediatric unit of a Parisian children hospital (nosocomial diarrhoea excluded) and 706 (97.5%) of these patients had had a stool microbiologic examination. Diarrhoea was caused by rotavirus in 359 patients (50.89%) and Salmonella sp in 61 (8.6%). Children and infants hospitalized for rotavirus acute gastroenteritis were younger (26% had three months or less, and 50.03% had six months or less) than in other European studies.

CONCLUSION

This study is the first in France reporting a systematic survey of hospitalized gastroenteritis during four years. More than half of hospitalized community-acquired gastroenteritis were due to rotavirus in this Parisian area. The young age of patients should be investigated in other French areas, searching for risk factors and rotavirus strains.

[Severe cutaneous Streptococcus pyogenes infections in the child: results of a multicenter survey]

To assess pediatric cases of severe cutaneous infections due to Streptococcus pyogenes. Since the beginning of 1980, the incidence of cellulitis and necrotizing fasciitis due to S. pyogenes has increased in adults. Serotyping of obtained isolates are in most cases M1, M3 or M5 protein.

PATIENTS AND METHOD

A retrospective (1990-2000) survey was carried out in pediatric hospital centers.

RESULTS

Three cases of necrotizing fasciitis and 15 of cellulitis were observed. In 30% of the cases, vancella lesions were associated; in the other cases, minor wounds were the site of the infection. Bacteriologic diagnosis was made by local samples in 14 cases; blood cultures were positive in four cases. In 11 cases, initial intravenous treatment consisted of third generation cephalosporin, in six cases of penicillin M or G and in one case of fusidic acid. In the second time, penicillin M was perfused in the majority of the cases. Mean duration of intravenous antibiotics perfusion was 15 days. There were no sequelae or death in this survey.

CONCLUSIONS

Despite this study had limited epidemiological characteristics, it confirms that these two infections are rare. The frequency is probably underestimated, due to the difficulty in performing a diagnosis. The major site of infection was the varicella lesion. These two infections are so similar that it is frequent to mistake one infection for the other. Nonsteroidal anti-inflammatory drugs and site of infections did not influence prognosis. The treatment of cellulitis is penicillinotherapy whereas in necrotizing fasciitis early major surgery is often correlated with the rate of survival.

Fluoroquinolones in paediatrics

The fluoroquinolones are an important group of antibiotics, which are widely used in adult patients because of their high penetration in tissues and bactericidal activity. However, they are not licensed for paediatric use (except the limited indication of Pseudomonas infection in cystic fibrosis) because of their potential to cause joint toxicity (observed in experiments using juvenile animal models). In recent years, there has been a change in the susceptibility of pathogens to widely used antibiotics; however, many of these pathogens remain sensitive to the fluoroquinolones (agents which can often be administered orally to treat severe infections). Fluoroquinolones have a number of potential indications in children: cystic fibrosis, intestinal infections due to resistant strains of Salmonella spp. and Shigella spp., severe infections due to Enterobacteriaceae (including the neonatal period), complicated urinary tract infections, the immunocompromised host, and some mycobacterial infections. The third generation fluoroquinolones have improved activity against Gram-positive bacteria and could be useful in respiratory tract, and ear, nose and throat infections in adult patients. Their potential role in routine use for paediatric patients will remain limited because of potential joint complications and the availability of other treatment options. However, available clinical data does indicate that the incidence of arthrotoxicity in children treated with ciprofloxacin appears to be the same as that in adult patients. The use of other fluoroquinolones is too rare to obtain meaningful information on their toxicity in children. For future fluoroquinolones, pneumococcal meningitis will probably be a potential indication. Despite their important activity, fluoroquinolones remain a second-line treatment in children, for use following the failure of a well established antibiotic treatment, to avoid potential adverse effects and the emergence of resistant strains.

Isoniazid pharmacokinetics in children according to acetylator phenotype

The pharmacokinetics of isoniazid (INH) was studied in children (0-196 months old) according to their acetylator phenotype, estimated from the metabolic acetyl INH/INH molar plasma concentration ratio (MR) measured 3 h after INH oral administration. There were 17 slow (MR < 0.48) and 17 fast acetylators (MR > or = 0.48). The mean apparent plasma clearance was significantly lower, the mean apparent volume of distribution higher and the half-life longer in the slow acetylator group (C1, 0.298 +/- 0.099 L/h/kg; Vd, 1.56 +/- 0.65 L/kg; t1/2, 3.88 +/- 01.89 h) than in the fast acetylator group (Cl, 0.528 +/- 0.234 L/h/kg; Vd, 1.06 +/- 0.45; t1/2, 1.64 +/- 1.1 h). The half-life decreased with age. An impaired isoniazid elimination was suggested in children less than three months old, which may be in favour of an individual dose adjustment in this population.

[Impact of bacterial resistance on severe infections]

Since many years, the antimicrobial resistance increases as well as for community-acquired as for nosocomial infections. Antibiotic-resistant pneumococci are neither more nor less virulent susceptible strains. Except for immunocompromised patients, the outcome of penicillin-resistant pneumococcal infections have been similar to those in patients who are infected by susceptible ones. Current levels of S. pneumoniae resistance to penicillin and cephalosporin are not associated to an increase in mortality in children with meningitis if adequate doses of antibiotics are given. Because empiric therapy has changed, antibiotic resistance has not been associated with increased mortality. This statement can be extended to Meningococcus, for which 32 to 50% of the strains have a decreased susceptibility to penicillin. For nosocomial infections, S. aureus is the main studied pathogen. Several studies report that in patients with severe diseases (bacteremia or pneumonia) methicillin resistance of S. aureus had no significant impact on patient outcome after adjustment for different confounders. The main risk factor for mortality is the severe underlying diseases rather than the resistance as well for methicillin--resistant S. aureus, as for vancomycin resistant enterococci, Klebsiella with extended spectrum beta lactamase and Enterobacters. Recommendations for controlling epidemiologic surveillance, using barrier precautions and limiting the use of antibiotics as well in the hospital as in the community must be undertaken.

Nasopharyngeal colonization by Haemophilus influenzae in children living in an orphanage

AIM

To study colonization and transmission of Haemophilus influenzae in a cohort of children <2 years old living in the unique epidemiologic conditions of a closed community of an orphanage.

METHODS

Fifty-three children, ages 0 to 24 months, were followed for 1 year. All children >2 months were vaccinated against H. influenzae serotype b. Nasopharyngeal cultures were collected monthly or, in children <6 months of age, every 2 weeks. Antibiotic susceptibility, serotype, biotype and genotype (pulsed field gel electrophoresis) of each isolate were determined. As control, 39 H. influenzae isolates were recovered from various regions in France.

RESULTS

The mean monthly rate of carriage was 45% ranging from 17 to 70%. Most isolates belonged to biotype II (62%), 4 isolates to serotype f (3.6%) and none to serotype b, and 60% of the 111 isolates produced beta-lactamase. A complete concordance was found among biotype, serotype, pulsotype and antimicrobial susceptibility. On average children were sequentially colonized by 3 different isolates. The mean duration of carriage for a given isolate was approximately 1.4 months. In younger children the mean age of primary colonization was 2 months. Contrasting with the high genetic heterogeneity of 39 control isolates, most isolates (82%) belonged to only 5 pulsotypes. Three main H. influenzae clones rapidly spread in the community and colonized children in waves.

CONCLUSION

During early life nasopharyngeal colonization by H. influenzae is a dynamic phenomenon with sequential carriage of various clones spreading in the community.

[Cardiac rhythm disturbances and prolonged QT interval with halofantrine]

OBJECTIVE

To determine the importance of prolonged QT interval and electrocardiographic changes in children treated with halofantrin for an acute malaria attack.

RESULTS

Out of 25 children treated with halofantrin, nine had an increase of QTc interval < 440 ms and ten a QTc > 440 ms on control 24 h after the first dose. A 9-year-old girl, treated with halofantrin, had bradycardia and increase of QTc interval for six days, with a normal halofantrin blood level.

CONCLUSION

These data show that cardiac monitoring during halofantrin treatment is mandatory in children as in adults. Contraindications of halofantrin treatment must be respected, particularly a long congenital QT interval.

Procalcitonin in children admitted to hospital with community acquired pneumonia

AIMS

To assess the sensitivity, specificity, and predictive value of procalcitonin (PCT) in differentiating bacterial and viral causes of pneumonia.

METHODS

A total of 72 children with community acquired pneumonia were studied. Ten had positive blood culture for Streptococcus pneumoniae and 15 had bacterial pneumonia according to sputum analysis (S pneumoniae in 15, Haemophilus influenzae b in one). Ten patients had Mycoplasma pneumoniae infection and 37 were infected with viruses, eight of whom had viral infection plus bacterial coinfection. PCT concentration was compared to C reactive protein (CRP) concentration and leucocyte count, and, if samples were available, interleukin 6 (IL-6) concentration.

RESULTS

PCT concentration was greater than 2 microg/l in all 10 patients with blood culture positive for S pneumoniae; in eight of these, CRP concentration was above 60 mg/l. PCT concentration was greater than 1 microg/l in 86% of patients with bacterial infection (including Mycoplasma and bacterial superinfection of viral pneumonia). A CRP concentration of 20 mg/l had a similar sensitivity but a much lower specificity than PCT (40% v 86%) for discriminating between bacterial and viral causes of pneumonia. PCT concentration was significantly higher in cases of bacterial pneumonia with positive blood culture whereas CRP concentration was not. Specificity and sensitivity were lower for leucocyte count and IL-6 concentration.

CONCLUSIONS

PCT concentration, with a threshold of 1 microg/l is more sensitive and specific and has greater positive and negative predictive values than CRP, IL-6, or white blood cell count for differentiating bacterial and viral causes of community pneumonia in untreated children admitted to hospital as emergency cases.

Reduced lung diffusion capacity after Mycoplasma pneumoniae pneumonia

BACKGROUND

Mycoplasma pneumoniae is a frequent but underdiagnosed cause of community-acquired pneumonia (CAP) in children, and appropriate macrolide treatment is often given late. The aim of this work was to estimate the frequency of pulmonary involvement in children 6 months after a clinical episode of Mycoplasma CAP.

METHODS

We measured carbon monoxide diffusion capacity (TLCO) and conducted spirometric tests in 35 children without asthma or chronic lung disease (ages 4.5 to 15 years), 6 months and 1 year after acute CAP caused by M. pneumoniae (23 children), pneumococci (5 children) or viruses (7 children). Only 11 of 23 patients with M. pneumoniae CAP required hospitalization, whereas all the patients with pneumococcal or viral pneumonia were admitted to hospital.

RESULTS

Lung volumes and spirometric tests were normal for all children. TLCO was normal 6 months after pneumococcal or viral pneumonia (87 to 112% of expected values for height and sex). After acute M. pneumoniae CAP, 11 of 23 patients (48%) had TLCO values <80% of the expected value. The extent of change in lung diffusion capacity was correlated with the delay to diagnosis and treatment: TLCO was low in 8 of 11 patients given macrolide treatment 10 days or more after the onset of acute symptoms vs. only 3 of 10 patients given appropriate treatment in the first 10 days. TLCO was low in 7 of 7 who received macrolide therapy for <2 weeks. TLCO had increased slightly after 1 year in the 5 patients retested after a new course of macrolide treatment. TLCO reached the lower normal range in 2 patients controlled after 3 years.

CONCLUSIONS

The abnormal TLCO values suggest that some children with Mycoplasma pneumonia have reduced pulmonary gas diffusion after recovery from the illness. The reduction is related to delay and short macrolide therapy.

Sequential colonization by Streptococcus pneumoniae of healthy children living in an orphanage

A prospective study of nasopharyngeal colonization by Streptococcus pneumoniae in the exceptional conditions of a closed community of abandoned children was done over a 1-year period; 71 children (age <24 months) were studied monthly. S. pneumoniae was isolated from 58 (81.7%), and 94.5% of the 111 isolates were resistant to penicillin. The mean rate of carriage was estimated at 57.4%, ranging from 42.8% to 70.4%. Children were sequentially colonized by a mean of 3 different isolates. The mean duration of carriage for a given isolate was approximately 2.2 months. Serotyping and molecular typing by pulsed-field gel electrophoresis showed that children were colonized by a limited number of clones belonging to only 4 serotypes and 4 pulsotypes. These clones rapidly spread in the community and colonized the children in waves, with a rapid turnover of S. pneumoniae isolates, facilitated by close contact between children.

[Urinary tract infection and biological markers: C-reactive protein, interleukins and procalcitonin]

Serum C reactive protein (CRP) remains a good marker of the severity of urinary tract infections in children, despite false negative results. Serum IL-6 is not a better marker; urinary IL-6 might have a better prognostic value as it is higher in patients with renal lesions due to infection, but low values are found in some cases. Serum procalcitonin levels are correlated with the importance of renal scars at scintigraphy, with less than 10% of false negative results. Further studies are needed to confirm the sensitivity and sensibility of these markers, especially for procalcitonin.

[Procalcitonin in pediatric emergencies: comparison with C-reactive protein, interleukin-6 and interferon alpha in the differentiation between bacterial and viral infections]

OBJECTIVE

Procalcitonin concentration increases in bacterial infections but remains low in viral infections and inflammatory diseases. The change is rapid and the molecule is stable making it a potentially useful marker for distinguishing between bacterial and viral infections.

PATIENTS AND METHODS

Procalcitonin (PCT) was determined with an immunoluminometric assay on plasma collected at admission in 436 infants and children hospitalized for bacterial or viral infection. It was compared with C reactive protein, interleukin-6 and interferon-alpha measured on the same sample.

RESULTS

PCT was 41.3 +/- 77.4 micrograms/l in children with septicemia or bacterial meningitis (n = 53), 0.39 +/- 0.57 microgram/l in children with viral infection (n = 274) and 3.9 +/- 5.9 micrograms/l in children with a localized bacterial infection who had a negative blood culture (n = 109). PCT was > 1 microgram/l in 126 children with a localized or systemic bacterial infection (sensitivity 78%). PCT was < 1 microgram/l in 258 children with a viral infection (specificity 94%). For differenciation between viral and bacterial infections, CRP value > or = 20 mg/l, IL-6 > 100 pg/ml and interferon-alpha > 0 Ul/ml have 85, 48 and 76% sensitivity and 73, 85 and 92% specificity respectively.

CONCLUSIONS

In this study, a PCT value of 1 microgram/l or greater had better specificity, sensitivity and predictive value than CRP, IL-6 and interferon-alpha in children for distinguishing between viral and bacterial infections. PCT may be useful in pediatric emergency room for making decision about antibiotic treatments.

Rapid improvement of intracranial tuberculomas after addition of ofloxacin to first-line antituberculosis treatment

Reported here is the case of a 9-year-old girl presenting with disseminated tuberculosis, the manifestations of which included mediastinal adenopathy, an osteolytic parietal lesion with a large associated scalp abscess, cerebral empyema, meningoencephalitis, and tuberculomas. No clear improvement was observed after 4 weeks of first-line antituberculosis treatment (10 mg/kg rifampin, 15 mg/kg isoniazid, 30 mg/kg ethambutol, 30 mg/kg pyrazinamide). The isolation of an isoniazid-resistant organism prompted institution of ofloxacin. Introduction of this drug was associated with dramatic improvement. Its good penetration into the central nervous system and its distribution into macrophages suggest that this drug may be of interest for the treatment of intracranial tuberculomas, particularly those due to isoniazid-resistant strains.

Comparison of procalcitonin with C-reactive protein, interleukin 6 and interferon-alpha for differentiation of bacterial vs. viral infections

BACKGROUND

Procalcitonin (PCT) concentration increases in bacterial infections but remains low in viral infections and inflammatory diseases. The change is rapid and the molecule is stable, making it a potentially useful marker for distinguishing between bacterial and viral infections.

METHODS

PCT concentration was determined with an immunoluminometric assay on plasma collected at admission in 360 infants and children hospitalized for bacterial or viral infection. It was compared with C-reactive protein (CRP), interleukin 6 and interferon-alpha measured on the same sample.

RESULTS

The mean PCT concentration was 46 microg/l (median, 17.8) in 46 children with septicemia or bacterial meningitis. PCT concentration was > 1 microg/l in 44 of 46 in this group and in 59 of 78 children with a localized bacterial infection who had a negative blood culture (sensitivity, 83%). PCT concentration was > 1 microg/l in 16 of 236 children with a viral infection (specificity, 93%). PCT concentration was low in 9 of 10 patients with inflammatory disease and fever. A CRP value > or =20 mg/l was observed in 61 of 236 patients (26%) with viral infection and in 105 of 124 patients (86%) with bacterial infection. IL-6 was > 100 pg/ml in 14% of patients infected with virus and in 53% with bacteria. A secretion of interferon-alpha was found in serum in 77% of viral infected patients and in 8.6% of bacterial infected patients.

CONCLUSIONS

In this study a PCT value of 1 microg/l or greater had better specificity, sensitivity and predictive value than CRP, interleukin 6 and interferon-alpha in children for distinguishing between viral and bacterial infections. PCT values are higher in invasive bacterial infections, but the cutoff value of 1 microg/l indicates the severity of the disease in localized bacterial infection and helps to decide antibiotic treatment in emergency room. PCT may be useful in an emergency room for differentiation of bacterial vs. viral infections in children and for making decisions about antibiotic treatments.

[Coincidental outbreaks of rotavirus and respiratory syncytial virus in Paris: a survey from 1993 to 1998]

PATIENTS AND METHODS

In a pediatric hospital of Paris, from 1993 to 1998, respiratory secretions were positive for respiratory syncytial virus (RSV) in 26.3% of 4,738 children (0-5 years) examined or hospitalized for lower respiratory tract infections. Rotavirus detection was positive in stools of 23.7% of the 8,537 children of the same age with acute diarrhea.

RESULTS

The RSV epidemic peak occurred annually in Paris in December and the rotavirus outbreak peaks were observed in December/January. The winter seasonal peaks remained constant for both pathogens and the temporal appearance of these peaks was constant from 1993 to 1998. Fifty to sixty-one percent of rotavirus and 77 to 92% of RSV infections were observed in November, December or January. These simultaneous outbreaks provoked important problems in hospital organization and prevention of nosocomial infections.

CONCLUSION

The coincidence of RSV and rotavirus peaks is not found in all countries. The epidemic patterns have to be checked in other parts of France and Europe because this could be important when active immunization programs will be available for these two pathogens.

Interferon-alpha in viral and bacterial gastroenteritis: a comparison with C-reactive protein and interleukin-6

The aim of the study was to identify serum markers able to differentiate bacterial and viral origin in acute diarrhoea. Interferon-alpha (INF-alpha), C-reactive protein (CRP) and interleukin-6 were determined on admission in the sera of 119 children aged between 1 mo and 14 y who were hospitalized for rotavirus (n = 60) or bacterial diarrhoea (Salmonella spp. 39 cases, Shigella spp. 15 cases, Campylobacter jejuni 5 cases). CRP concentration was >10 mg/l in 48.3% of children with viral gastroenteritis and 86.4% of children with bacterial gastroenteritis. IL6 concentration was >100 pg/ml in 11.7% and 26.3% of cases, respectively. INF-alpha was detected in 79.1% of children with rotavirus (sens 79%) and in 3.5% (spec 93%) with bacterial gastroenteritis. However the INF-alpha assay takes 48 h and pathogens are often identified from stools before interferon results are available. We found that serum markers are not discriminating enough to differentiate between viral and bacterial gastroenteritis in emergency cases.