Cristiana M. Nascimento-Carvalho

The role of respiratory viral infections among children hospitalized for community-acquired pneumonia in a developing country.

We report an investigation for 16 bacteria and viruses among 184 children hospitalized with pneumonia in Salvador, Brazil. Etiology was established in 144 (78%) cases. Viral, bacterial, and mixed infections were found in 110 (60%), 77 (42%), and 52 (28%) patients, respectively. Rhinovirus (21%) and Streptococcus pneumoniae (21%) were the most common pathogens. Our results demonstrate the importance of viral and pneumococcal infections among those patients.

Prevalence and risk factors for nasopharyngeal carriage of Streptococcus pneumoniae among adolescents

Data on the prevalence of pneumococcal nasopharyngeal carriage and its risk factors among adolescents are scarce. The aim of this study was to provide such information. A cross-sectional, population-based prospective study was conducted. Participants were 1013 adolescents (age range 10-19 years) randomly recruited in 22 public schools. Those schools were randomly chosen among 307 public schools from 11 Sanitary Districts of Salvador, Brazil. Nasopharyngeal samples were assessed by standard procedures to recover and identify Streptococcus pneumoniae. Data on potential risk factors were gathered by confidential interview based on a standardized questionnaire. Pneumococci were recovered from 8.2 % [83/1013, 95 % confidence interval (CI) 6.6-10.0]. By stepwise logistic regression, pneumococcal colonization was independently associated with younger age [odds ratio (OR) 0.85, 95 % CI 0.77-0.94, P=0.001], being male (OR 1.78, 95 % CI 1.11-2.85, P=0.02), exposure to passive smoke in the household (OR 1.76, 95 % CI 1.10-2.79, P=0.02), having an upper respiratory infection during recruitment (OR 2.67, 95 % CI 1.67-4.28, P<0.001) and having a history involving an episode of acute asthma during the last year (OR 2.89, 95 % CI 1.18-7.08, P=0.03). The estimated probability of pneumococcal colonization decreased with age (chi(2) for trend=8.52, P=0.003). These findings provide tools for increasing the use of prevention strategies for pneumococcal diseases, such as pneumococcal vaccination among asthmatic patients and public health measures to stop smoking.

Penicillin resistant pneumococcus and risk of treatment failure in pneumonia

Objective: To determine whether the presence of in vitro penicillin-resistant Streptococcus pneumoniae increases the risk of clinical failure in children hospitalised with severe pneumonia and treated with penicillin/ampicillin. Design: Multicentre, prospective, observational study. Setting: 12 tertiary-care centres in three countries in Latin America. Patients: 240 children aged 3–59 months, hospitalised with severe pneumonia and known in vitro susceptibility of S pneumoniae. Intervention: Patients were treated with intravenous penicillin/ampicillin after collection of blood and, when possible, pleural fluid for culture. The minimal inhibitory concentration (MIC) test was used to determine penicillin susceptibility of the pneumococcal strains isolated. Children were continuously monitored until discharge. Main outcome measures: The primary outcome was treatment failure (using clinical criteria). Results: Overall treatment failure was 21%. After allowing for different potential confounders, there was no evidence of association between treatment failure and in vitro resistance of S pneumoniae to penicillin according to the Clinical Laboratory Standards Institute (CLSI)/National Committee for Clinical Laboratory Standards (NCCLS) interpretative standards (adjRR = 1.03; 95%CI: 0.49–1.90 for resistant S pneumoniae). Conclusions: Intravenous penicillin/ampicillin remains the drug of choice for treating penicillin-resistant pneumococcal pneumonia in areas where the MIC does not exceed 2 μg/ml.

Etiology of childhood community acquired pneumonia and its implications for vaccination

Pneumonia is an important cause of morbidity and mortality among children throughout the world. Vaccines are available for some organisms, but they are underutilized and/or still in development. To evaluate the potential impact of vaccines, we review studies in which the etiology of childhood community-acquired pneumonia was recorded. In North America and Europe (9 studies), the etiology of pneumonia was established in 62% of studied children (range 43%-88%) by use of noninvasive specific methods for microbiologic diagnosis. The most often identified agents were S. pneumoniae (22%), respiratory syncytial virus (RSV) (20%), Haemophilus influenzae (7%), and Mycoplasma pneumoniae (15%). In Africa and South America (8 studies), bacteria were recovered from 56% (range 32%-68%) of severely ill children studied by lung aspirate. The most often isolated bacteria were Streptococcus pneumoniae (33%) and Haemophilus influenzae (21%). A high percentage of H. influenzae strains were not serotype b. Throughout the world, children requiring hospitalization were most likely to have infection caused by pneumococcus, H. influenzae or RSV. Out patients also had Mycoplasma pneumoniae. Countries in Africa and Asia recorded 2 to 10 times more children with pneumonia (7 to 40/100 annually) than in the USA. Widespread use of pneumococcal and H. influenzae type b conjugate vaccines could reduce the frequency of childhood pneumonia by one-third. Further reduction will require development of non-type b H. influenzae, RSV and M. pneumoniae vaccines. This could result in a > 50% reduction of pneumonia in children. This goal should be sought and achieved as soon as possible.

Neuroschistosomiasis due to Schistosoma mansoni: a review of pathogenesis, clinical syndromes and diagnostic approaches

Neuroschistosomiasis (NS) is the second most common form of presentation of infection by the trematode, Schistosoma mansoni. Granulomatous inflammatory reaction occurs as a result of schistosome eggs being transmitted to spinal cord or brain via the vascular system, or by inadvertent adult worm migration to these organs. The two main clinical syndromes are spinal cord neuroschistosomiasis (acute or subacute myelopathy) and localized cerebral or cerebellar neuroschistosomiasis (focal CNS impairment, seizures, increased intracranial pressure). Presumptive diagnosis of NS requires confirming the presence of S. mansoni infection by stool microscopy or rectal biopsy for trematode eggs, and serologic testing of blood and spinal fluid. The localized lesions are identified by signs and symptoms, and confirmed by imaging techniques (contrast myelography, CT and MRI). Algorithms are presented to allow a stepwise approach to diagnosis.

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.

The burden of childhood pneumonia in the developed world: A review of the literature

Background: Estimates of the disease burden from childhood pneumonia are available for most developed countries, but they are based mainly on models. Measured country-specific pneumonia burden data are limited to a few nations and differ in case definitions and case ascertainment methods. This review describes pneumonia disease burden in developed countries. Methods: We reviewed studies describing childhood pneumonia incidence in North America, Europe, Australia, New Zealand and Japan. Available estimates suggest that each year in developed countries there are up to 2.6 million cases of pneumonia, including 1.5 million hospitalized cases and around 3000 pneumonia deaths (compared with approximately 640 annual deaths from meningitis) in children <5 years of age. Results: Data to inform policy decisions would be improved by information on burden and etiology of severe pneumonia, population-based incidence of ambulatory visits and hospitalizations and prevalence of complications and sequelae.

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.

Seasonal patterns of viral and bacterial infections among children hospitalized with community-acquired pneumonia in a tropical region

Abstract Community-acquired pneumonia (CAP) is a common cause of morbidity among children. Evidence on seasonality, especially on the frequency of viral and bacterial causative agents is scarce; such information may be useful in an era of changing climate conditions worldwide. To analyze the frequency of distinct infections, meteorological indicators and seasons in children hospitalized for CAP in Salvador, Brazil, nasopharyngeal aspirate and blood were collected from 184 patients aged <5 y over a 21-month period. Fourteen microbes were investigated and 144 (78%) cases had the aetiology established. Significant differences were found in air temperature between spring and summer (p = 0.02) or winter (p < 0.001), summer and fall (p = 0.007) or winter (p < 0.001), fall and winter (p = 0.002), and on precipitation between spring and fall (p = 0.01). Correlations were found between: overall viral infections and relative humidity (p = 0.006; r = 0.6) or precipitation (p = 0.03; r = 0.5), parainfluenza and precipitation (p = 0.02; r = −0.5), respiratory syncytial virus (RSV) and air temperature (p = 0.048; r = −0.4) or precipitation (p = 0.045; r = 0.4), adenovirus and precipitation (p = 0.02; r = 0.5), pneumococcus and air temperature (p = 0.04; r = −0.4), and Chlamydia trachomatis and relative humidity (p = 0.02; r = −0.5). The frequency of parainfluenza infection was highest during spring (32.1%; p = 0.005) and that of RSV infection was highest in the fall (36.4%; p < 0.001). Correlations at regular strength were found between several microbes and meteorological indicators. Parainfluenza and RSV presented marked seasonal patterns.

Clinical and cerebrospinal fluid (CSF) profile and CSF criteria for the diagnosis of spinal cord schistosomiasis

OBJECTIVES To describe the clinical and CSF findings among patients with presumptive neuroschistosomiasis (NS) and to suggest a classification for the CSF diagnosis of presumptive NS. METHOD The charts of all patients whose CSF exam was performed at the CSF Lab, Jos Silveira Foundation, Salvador, Brazil, from 1988 to 2002 were reviewed. Those with clinically suspected NS whose indirect fluorescent antibody test (IFA) and or hemagglutination-inhibiting antibodies test (HAI) were positive to S. mansoni were identified. RESULTS Of 377 patients, 67.9% were males; the median age was 36 years (mean 37 + 16 yrs, range 3-82 yrs). The most frequent complaints were paraparesis (59.9%), urinary retention (36.2%), lower limb pain (22.8%). WBC of CSF (count/mm ) was > 4 in 66.0% (mean 83 + 124, median 40, range 4.3-1,100), protein (mg/dl) was > 40 in 84.6% (mean 185 + 519, median 81, range 41-6,800) and eosinophils were present in 46.9%. IFA and HAI were positive in 75.3%. WBC > 4 and presence of eosinophils were associated with IFA and HAI positive (67.3% versus 51.4%, p 0.014; 49.1% versus 23.0%, p 0.0001, respectively) and protein > 40 was not (85.4% versus 77.0%, p 0.09). Presence of WBC > 4, protein > 40 and eosinophils was associated with IFA and HAI positive (71.6% versus 38.2%, p 0.0003) but presence of eosinophils and any other combination of WBC and protein were not. CONCLUSION NS should be considered as a possible diagnosis in patients who had had contact with schistosome-infected water and present with spinal cord compromising. Presence of IFA and HAI positive to S. mansoni, WBC > 4, protein > 40 and presence of eosinophils in the CSF may be considered as a criterium of highly probable presumptive diagnosis.