Viral pneumonia

Department of Paediatrics, Turku University Hospitals, Turku, Finland.
The Lancet (Impact Factor: 45.22). 03/2011; 377(9773):1264-75. DOI: 10.1016/S0140-6736(10)61459-6
Source: PubMed


About 200 million cases of viral community-acquired pneumonia occur every year-100 million in children and 100 million in adults. Molecular diagnostic tests have greatly increased our understanding of the role of viruses in pneumonia, and findings indicate that the incidence of viral pneumonia has been underestimated. In children, respiratory syncytial virus, rhinovirus, human metapneumovirus, human bocavirus, and parainfluenza viruses are the agents identified most frequently in both developed and developing countries. Dual viral infections are common, and a third of children have evidence of viral-bacterial co-infection. In adults, viruses are the putative causative agents in a third of cases of community-acquired pneumonia, in particular influenza viruses, rhinoviruses, and coronaviruses. Bacteria continue to have a predominant role in adults with pneumonia. Presence of viral epidemics in the community, patient's age, speed of onset of illness, symptoms, biomarkers, radiographic changes, and response to treatment can help differentiate viral from bacterial pneumonia. However, no clinical algorithm exists that will distinguish clearly the cause of pneumonia. No clear consensus has been reached about whether patients with obvious viral community-acquired pneumonia need to be treated with antibiotics. Apart from neuraminidase inhibitors for pneumonia caused by influenza viruses, there is no clear role for use of specific antivirals to treat viral community-acquired pneumonia. Influenza vaccines are the only available specific preventive measures. Further studies are needed to better understand the cause and pathogenesis of community-acquired pneumonia. Furthermore, regional differences in cause of pneumonia should be investigated, in particular to obtain more data from developing countries.

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Available from: Olli Ruuskanen, Jan 13, 2014
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    • "Clinical signs and symptoms of bacterial and viral pneumonia are highly variable and overlap, and there is no clinical or radiologic algorithm that can discriminate between the two causes of CAP [12]. Some attempts at differentiation based on biomarkers have been made, and it is now well established that CRP and, especially, PCT show higher levels in bacterial than in viral (or atypical) pneumonia [12-14]. Lack of viral PCT response to viral infection is thought to be related to post-infection release of interferon, which inhibits PCT synthesis [15]. "
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    ABSTRACT: Background The role of mixed pneumonia (virus + bacteria) in community-acquired pneumonia (CAP) has been described in recent years. However, it is not known whether the systemic inflammatory profile is different compared to monomicrobial CAP. We wanted to investigate this profile of mixed viral-bacterial infection and to compare it to monomicrobial bacterial or viral CAP. Methods We measured baseline serum procalcitonin (PCT), C reactive protein (CRP), and white blood cell (WBC) count in 171 patients with CAP with definite etiology admitted to a tertiary hospital: 59 (34.5%) bacterial, 66 (39.%) viral and 46 (27%) mixed (viral-bacterial). Results Serum PCT levels were higher in mixed and bacterial CAP compared to viral CAP. CRP levels were higher in mixed CAP compared to the other groups. CRP was independently associated with mixed CAP. CRP levels below 26 mg/dL were indicative of an etiology other than mixed in 83% of cases, but the positive predictive value was 45%. PCT levels over 2.10 ng/mL had a positive predictive value for bacterial-involved CAP versus viral CAP of 78%, but the negative predictive value was 48%. Conclusions Mixed CAP has a different inflammatory pattern compared to bacterial or viral CAP. High CRP levels may be useful for clinicians to suspect mixed CAP.
    Full-text · Article · Jul 2014 · BMC Pulmonary Medicine
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    • "There are approximately 150 million cases of childhood CAP reported each year [2]. Although death from CAP is rare in industrialized countries, lower respiratory tract infection is one of the leading causes of childhood mortality in developing countries [3]. "
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    ABSTRACT: Community-acquired pneumonia (CAP) is one of the five leading causes of death among children in developing countries, accounting for approximately three million deaths per year. Identification of the modifiable risk factors of CAP may help to reduce the burden of this disease. In this study, the impact of the socioeconomic status (SES) on the severity and outcome of CAP among Egyptian children was studied. This was a prospective longitudinal cohort study which included 1,470 children diagnosed with CAP, aged two to 15 years (median age 5.4 years). The diagnosis of CAP was based on clinical and radiological findings. A structured questionnaire and the patients' medical records were used for the data collection. The subjects were divided into two groups: mild and severe CAP. Social and demographic variables were compared, and a multivariate logistic regression analysis was performed. THE MULTIVARIATE ANALYSIS SHOWED THAT A LOW MATERNAL EDUCATION LEVEL (OR: 3.8; 95% CI: 2.12 -6.70; P = .0001), unavailability of adequate medical care (OR: 3.1; 95% CI: 1.99 -4.88; P = .0001), a low family income (OR: 2.2; 95% CI: 0.99 -4.78; P = .047), and parents' smoking habits (OR: 2.0; 95% CI: 1.15 -3.55; P = .014) were significant independent predictive risk factors for severe CAP among Egyptian children. Public health measures against these socio-demographic risk factors should be identified as priorities in order to help reduce the disease burden of deaths from severe CAP among Egyptian children.
    Full-text · Article · Apr 2014 · Infectious Diseases of Poverty
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    • "Acute respiratory tract infections (ARIs) represent a leading cause of human acute illnesses worldwide and an important contributing factor of childhood morbidity and mortality, especially under the age of 5 [1-3]. Besides the issue of bacterial pneumonia, which represents a frequent cause of mortality in paediatric populations of developing countries, there is an increasing interest in the epidemiology and characterization of Influenza Like Illnesses (ILIs), which are predominantly of viral aetiology [4]. First, ILIs are responsible for a large number of cases in all age groups (with a specifically high frequency in children) and despite their frequent association with a mild clinical presentation, their medical and socio-economical impact is enormous [5]. "
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    ABSTRACT: Acute respiratory infections represent a serious public health issue worldwide but virological aetiologies of Influenza Like Illnesses (ILIs) remain largely unknown in developing countries. This study represents the first attempt to characterise viral aetiologies of ILIs in Bolivia. It was performed in Santa Cruz city from January 2010 to September 2012, based on 564 naso-pharyngeal swabs collected in a National Reference Laboratory and real-time PCR techniques, viral cultures and phylogenetic analyses. 50.2% of samples were positive for at least one virus with influenza viruses (Flu A: ~15%; Flu B: ~9%), rhinoviruses (~8%), coronaviruses (~5%) and hRSV (~4%) being the most frequently identified. The pattern of viral infections varied according to age groups. The elucidation rate was the highest (>60%) amongst patients under 10 yo and the lowest (<40%) amongst patients >=60 yo. Nearly 3% of samples showed dual viral infections. Epidemiological peaks were associated with a predominant virus but generally included 30-50% of infections by different viruses. Unexpectedly, the frequency of influenza in the 0-4 yo population was very low and a complete hRSV eclipse occurred in 2011. Genetic analyses indicated that distinct evolutionary lineages of Flu A(H1N1)pdm2009, Flu A/H3N2 and Flu B have co-circulated in Bolivia in the study period, originating from Central and North America, Europe, Asia and Australia. Our results emphasise the requirement for a reinforced epidemiological and genetic follow-up of influenza and other ILIs in Bolivia to further inform the preparation of vaccines used in the region, guide vaccination campaigns and improve the medical management of patients.
    Full-text · Article · Feb 2014 · Virology Journal
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