Olli Ruuskanen

Differentiation of bacterial and viral pneumonia in children

Background: A study was undertaken to investigate the differential diagnostic role of chest radiographic findings, total white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and serum C reactive protein (CRP) in children with community acquired pneumonia of varying aetiology. Methods: The study population consisted of 254 consecutive children admitted to hospital with community acquired pneumonia diagnosed between 1993 and 1995. WBC, ESR, and CRP levels were determined on admission. Seventeen infective agents (10 viruses and seven bacteria) were searched for. Chest radiographs were retrospectively and separately reviewed by three paediatric radiologists. Results: A potential causative agent was found in 215 (85%) of the 254 cases. Bacterial infection was found in 71% of 137 children with alveolar infiltrates on the chest radiograph, while 72% of the 134 cases with a bacterial pneumonia had alveolar infiltrates. Half of the 77 children with solely interstitial infiltrates on the chest radiograph had evidence of bacterial infection. The proportion of patients with increased WBC or ESR did not differ between bacterial and viral pneumonias, but differences in the CRP levels of >40 mg/l, >80 mg/l, and >120 mg/l were significant although the sensitivity for detecting bacterial pneumonia was too low for use in clinical practice. Conclusions: Most children with alveolar pneumonia, especially those with lobar infiltrates, have laboratory evidence of a bacterial infection. Interstitial infiltrates are seen in both viral and bacterial pneumonias.

Respiratory virus infection as a cause of prolonged symptoms in acute otitis media

We studied respiratory viruses in 22 children with acute otitis media who had failed to improve after at least 48 hours of antimicrobial therapy. The mean duration of preenrollment antimicrobial therapy was 4.8 days. For comparison we studied 66 children with newly diagnosed acute otitis media. Respiratory viruses were isolated from middle ear fluid or from the nasopharynx, or both, significantly more often in the patients unresponsive to initial antimicrobial therapy than in the comparison patients (68% vs 41%, p less than 0.05). Viruses were recovered from the middle ear fluid in 32% of the study patients and from 15% of the comparison group. Bacteria were isolated from the middle ear fluid of four (18%) children in the study group; one child had an isolate resistant to initial antimicrobial therapy. All four children with bacteria in the middle ear fluid had evidence of concomitant respiratory virus infection. Our results indicate that respiratory virus infection is often present in patients with acute otitis media unresponsive to initial antimicrobial therapy, and may explain the prolongation of symptoms of infection. Resistant bacteria seem to be a less common cause of failure of the initial treatment.

Induced sputum in the diagnosis of childhood community-acquired pneumonia

Background: The usefulness of induced sputum in searching for causative agents of pneumonia in children has not been studied. Methods: The study involved 101 children, aged 6 months to 15 years, treated for community-acquired pneumonia at Turku University Hospital (Turku, Finland) from January 2006 to April 2007. Nasopharyngeal aspirate samples were first collected through both nostrils. Sputum production was then induced by inhalation of 5.0% hypertonic saline for 5–10 min and a sputum sample was either aspirated or expectorated. The presence and amount of bacteria and viruses in paired nasopharyngeal aspirate and sputum specimens was analysed and compared using semiquantitative bacterial culture and quantitative PCR techniques. Results: A good quality sputum specimen was obtained from 76 children. The possible causative agent was found in 90% of cases. Streptococcus pneumoniae (46%) and rhinovirus (29%) were the most common microbes detected. Newly discovered viruses human bocavirus and human metapneumovirus were detected in 18% and 13% of the children, respectively. One-quarter of all bacterial findings were only detected in sputum, and the amount of bacteria in the remainder of the sputum specimens compared with nasopharyngeal aspirate was higher in 14% and equal in 70%. The amount of rhinovirus in sputum was higher than in nasopharyngeal aspirate in 82%. Conclusions: Sputum induction provides good quality sputum specimens with high microbiological yield in children with community-acquired pneumonia. Induced sputum analysis can be useful in the microbiological diagnosis of childhood community-acquired pneumonia.

C-reactive protein in respiratory virus infections

Les recherches effectuees chez 176 enfants atteints de diverses infections virales ont mis en evidence des taux de CRP superieurs a 40 mg/l et une leucocytose superieure a 15×10 9 /l dans la plupart des infections a adenovirus tandis que dans la plupart des infections a virus grippal, parainfluenza ou syncytial respiratoire, la CRP etait <40 mg/l et la leucocytose < a 15×10 9 /l, ce qui est typique des maladies virales et les oppose classiquement aux infections bacteriennes ou le taux serique de CRP est notablement eleve

MALIGNANT HISTIOCYTOSIS Histiocytic Medullary Reticulosis

ABSTRACT. Three cases of malignant histiocytosis occurring in children aged 2 months, 10 months and 14 years, are described. In all children the diagnosis was based on anaemia, granulocytopenia or thrombocytopenia, splenomegaly and marked erythrophagocytosis by bone marrow and lymph node atypical histiocytes. Two children aged 10 months and 14 years, underwent splenectomy after which combined chemotherapy with cyclophosphamide, vincristine and prednisone (COP) was started. In the older child a complete remission was achieved. The younger child died soon after the onset of the treatment. The youngest child was treated with bleomycin, adriamycin, cyclophosphamide, vincristine and prednisone (BACOP). He died of pneumonia and sepsis two months after the start of the treatment.

Rhinovirus in acute otitis media

Low positive results were somewhat easier to distinguish by EIA than LA, because the minimal color change produced in the EIA was more apparent than the few agglutinated latex particles in the LA test. However, some of the low positive Abbott Testpack Strep A and Cards Strep A plus and minus endpoints had an irregularly or partially filled vertical line that was neither clearly positive nor clearly negative, making interpretation difficult. The Icon Strep A tests resulted in the presence or absence of a clearly outlined central dot on a white background, giving unequivocal results, with only minimal experience required for interpretation.

Childhood bacterial meningitis: initial symptoms and signs related to age, and reasons for consulting a physician

The relationship of symptoms and signs to age and the reasons for consulting a physician were analyzed in 110 cases of culture-proven childhood bacterial meningitis. H. influenzae caused 74, meningococci 28, pneumococci 6 and streptococci 2 of the cases. Apart from fever (present in 94%), the most common symptoms according to age were as follows: 1–5 months: irritability (85%), 6–11 months: impaired consciousness (79%), 12 months or more: vomiting (82%) and neck rigidity (78%). Absence of neck rigidity at diagnosis was associated with young age (<12 months, P<0.001) and, in older children, to a short duration of symptoms (P<0.01) but not to the degree of CSF pleocytosis. Symptoms of meningitis caused by H. influenzae differed from those of meningococcal meningitis. Meningitis should be suspected in irritable or lethargic febrile children despite absence of neck rigidity. Fever and vomiting were the most frequent reasons for consulting a physician (60% and 31%, respectively). Despite the frequency and alarming character of irritability, impaired consciousness and neck rigidity, their presence led infrequently to a consultation (6%, 22% and 3%, respectively). Parental ignorance of such symptoms or of their importance may cause treatment delay, despite readily available medical services.

Nonsuppression of cortisol in depression and immune function

Eighteen depressive patients and twenty-five healthy control subjects were studied using a comprehensive immunological test system and the dexamethasone suppression test (DST) as well as some additional neuroendocrine parameters. In addition, immune functions of six of the patients were studied serially three times at 1-2 months intervals. The OKT 4+/8+ ratio (OKT 4+ = helper/inducer phenotype; OKT 8+ = suppressor/cytotoxic phenotype) was slightly higher in those ten depressive patients showing suppression in the DST than in healthy controls, but there were no significant differences between the nonsuppressor and suppressor groups or between the nonsuppressor and suppressor groups or between nonsuppressors and control subjects. Lymphocyte transformation responses induced by phytohaemagglutinin (PHA) were similar in the nonsuppressors and suppressors, but lower in both groups than in control subjects. The number of Ig-secreting cells measured in the absence and presence of pokeweed mitogen (PWM) were similar in the nonsuppressor and suppressor groups. Four of the depressive patients tested repeatedly exhibited an abnormal response in the DST at the beginning of the study. During the follow-up period two of them recovered completely from depression as well as the patients with a normal suppression in the DST. The proportions of T and B lymphocytes and regulatory T lymphocyte subsets as well as the functions of T and B lymphocytes of the nonsuppressors and suppressors in the DST were within normal ranges before and after recovery from depression and comparable to healthy controls in repeated testing. The results indicate that in spite of the importance of cortisol in immunoregulation, the increased cortisol secretion and typical resistance to dexamethasone suppression in endogenously depressive patients is not profoundly and consistently reflected in immune functions. Neither does normalization of cortisol responses induce any major changes in immune status during a patients recovery from depression. Previous work indicates that suppressed immunity may play an important role in the increased morbidity and mortality associated with bereavement. In the light of present findings we suggest that endogenous depression differs also in this respect from grief reactions.

Procalcitonin is useful in identifying bacteraemia among children with pneumonia.

Abstract Empirical antibiotic use is prescribed in managing children with pneumonia worldwide. We assessed the usefulness of procalcitonin (PCT) and interferon-alpha (IFN-α) in differentiating viral from bacterial pneumonia. Among 159 hospitalized children, pneumonia was diagnosed based on clinical complaints plus pulmonary infiltrate. Aetiology was investigated for 9 viruses and 4 atypical and 3 typical bacteria. PCT and IFN-α were measured in the serum sample collected on admission. Eight patients had bacteraemic infections, 38 had non-bacteraemic typical infections, and 19 patients had atypical bacterial infections. Viral and unknown aetiology was established in 57 (36%) and 34 (21%) cases, respectively. Three patients with bacterial infection without collected blood culture were excluded. IFN-α (IU/ml) was detectable in 20 (13%) cases. The difference among median PCT values of the bacteraemic (4.22; 1.56–7.56), non-bacteraemic typical bacterial (1.47; 0.24–4.07), atypical bacterial (0.18; 0.06–1.03) and only viral (0.65; 0.11–2.22) subgroups was significant (p = 0.02). PCT was ≥2 ng/ml in 52 (33%) cases. The presence of IFN-α was associated with PCT <2 ng/ml (90% vs. 64%, p = 0.02). The negative predictive value (95% confidence interval) of PCT ≥2 ng/ml was 95% (89–100%), 89% (78–100%), 93% (85–100%) for differentiation of bacteraemic from viral, atypical bacterial and non-bacteraemic typical bacterial infection, respectively, and 58% (49–68%) for differentiation between bacterial and viral infection. PCT may be useful in identifying bacteraemia among children hospitalized with community-acquired pneumonia. IFN-α was uncommonly detected.

Human bocavirus infection diagnosed serologically among children admitted to hospital with community-acquired pneumonia in a tropical region.

Human bocavirus (HBoV) is a human virus associated with respiratory disease in children. Limited information is available on acute infection with HBoV among children admitted to hospital with community‐acquired pneumonia in tropical regions and the current diagnosis is inadequate. The aims were to diagnose and describe acute HBoV infections among children hospitalized for community‐acquired pneumonia. In Salvador, Brazil, 277 children with community‐acquired pneumonia were prospectively enrolled. Paired serum samples were tested by IgG, IgM, and IgG‐avidity enzyme immunoassays (EIAs) using recombinant HBoV VP2. HBoV DNA was detected in nasopharyngeal aspirates and serum by a quantitative polymerase‐chain reaction (PCR). HBoV DNA was detected in nasopharyngeal aspirates of 62/268 (23%) children and 156/273 (57%) were seropositive. Acute primary HBoV infection was reliably diagnosed (bearing at least two acute markers: Positive IgM, a fourfold increase/conversion of IgG, low IgG avidity or viremia) in 21 (8%) of 273 patients, 90% of 20 had HBoV DNA in nasopharyngeal aspirates, 83% with a high DNA load. The median age of infection with HBoV was 16 months, range 5–36. Community‐acquired pneumonia was confirmed radiographically in 85% of 20 patients with acute HBoV infection diagnosed serologically. HBoV DNA was found in nasopharyngeal aspirates of 42/246(17%) children without an acute primary HBoV infection and available nasopharyngeal aspirate. Four children with HBoV secondary immune responses were detected, lacking both IgM and viremia. HBoV infection was diagnosed accurately in children aged 5–36 months with community‐acquired pneumonia confirmed radiographically. PCR of nasopharyngeal aspirates is not a reliable marker of acute HBoV infection. J. Med. Virol. 84:253–258, 2012.