neumonía adquirida en la comunidad
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Community Acquired Pneumonia
Renato T. Stein, MDPorto Alegre, Brazil
Pneumonia in Developing Countries
• Incidence of pneumonia is 10 times higher in developing than in developed countries;
• ~5 million deaths occur yearly in children younger than 5 years.
• Nutritional status, age, and the presence of an underlying condition are major risk factors
MOST SIGNIFICANT RISK FACTORSEspecially in Low Income Countries
• low birth weight• malnourishment• no breast feeding• failure in vaccination schedule • low maternal education• air pollution / ETS
PneumoniaPneumonia
• Gold standards– lower Aw aspirate or lung biopsy
• Clinical dx with radiological component• Age-specific prevalent species are
important for logical approach at ethiology
Diagnosis
• Fever, cough, tachypnea (overlap w/ bronchiolitis in young children)
• WHO RR signs: sensitivity 74%, specificity 67%• PPV of clinical signs is greater in developing
countries: higher prevalence of pneumonia• NPV is greater in developed countries where
prevalence is lower• Margolis e Gadomski, JAMA, 1998; 279(4)
DIAGNOSISConsider:
• Epidemiology• Clinical presentation• Radiology• Age of child• Immune status• How infection was acquired
Diagnostic Tests
• Very low yield of positive tests; in complete trials 70% positive (serology, culture, nucleic acid amplification tests, immunofluorescence)
• Overall, respiratory viruses account for 20–45% of all infections
• S. pneumoniae is the agent in 27-44% of cases of CAP in children
• Observe local seasonal epidemics
Chest X-Ray DiagnosisChest X-Ray Diagnosis
• BTS guidelines: consider in children < 5y with fever > 39o C of unknown origin
• Interpersonal variability• Can be normal at beggining of the
infection• Alveolar/lobar infiltrates w/ air space
opacification: not sensitive but valuable
Chest X-rays
• May be useful for confirming presence of pneumonia and detecting complications such as a lung abscess or empyema
• Not useful for discriminating causative agents; cannot accurately discriminate between viral and bacterial pneumonia
• Great inter-observer variability
Indications for CXRs
• Clinical pneumonia unresponsive to standard ambulatory management
• Suspected pulmonary TB• Suspected foreign body aspiration • Hospitalized children to detect
complications
Viral and Bacterial Pneumonias
• Most pneumonias in the first 3y of lifeare viral declining afterwards(Heiskanen-Kosma T et al. Pediatr Infect Dis J 1998)
• The association of viral and bacterialpneumonias is not frequent (~5 -10%)
• Co-infection may be more frequent in non-affluent communities
Validation Score to Distinguish Bacterial from Viral Pneumonia
Moreno L. et al. Ped Pulm 2006
Moreno L. et al. Ped Pulm 2006
Viral Agents
• RSV is the major agent <2y causing viral CAP; Rhinovirus is highly prevalent thereafter
• Influenza, HMPV, Adenovirus, Paraflumay also be present
Pneumococcal Pneumonia
• Most prevalent agent in hospital admissions • Resistant strains: low to 40’s%• Typical picture
– ill appearance, fever of 39°C or higher, leukocytosis, and lobar or segmental consolidation, pleural effusions
– ~25% may have no respiratory symptoms (GI)
Impact of HIV Epidemic
• Increased the incidence, severity and case fatality of childhood pneumonia (Jadavji T et al. Can Med Ass J 1997; Zar HJ. Curr Opin Pulm Med. 2004)
• CAP accounts for between 30-40% of hospital admissions with associated case fatality rates of between 15-28%
HIV Infected Children
• Pneumocystis jiroveci pneumonia (PJP) is common and serious infection and associated with high mortality
• Infants aged 6 weeks to 6 months are at highest risk for infection
• PJP is the predominant cause of pneumonia mortality in HIV-infected children less than 6 months of age.
HIV-related Agents
• PJP has also been described in malnourished children as well as young HIV-exposed uninfected infants
• M. tuberculosis was positive in 8% of HIV infected/uninfected children hospitalized for acute pneumonia in S.A. (Zar HJ et al.Acta Paediatr 2001)
Always Consider Tuberculosis…
• Tuberculosis should always be considered as a possible diagnosis, especially in endemic areas
• May clinically mimic common viral or bacterial CAPs
Other Agents
• Routine immunization against Hib has decreased the incidence of pneumonia due to this bacterium; non-typablestrains are still responsible for a small proportion of pneumonia in South Africa (Zar HJ et al 2006)
• S. aureus causing CAP is more frequent in developing countries
Mycoplasma Pneumonia
• More prevalent over the age of 5y• Fever, cough, wheezing are most
prominent features• “No typical” radiological findings
– Pulmonary infiltrates, lobar or segmental consolidation, pleural effusions
Tx Choices
• ~20% of children with suspected viral pneumonia receive antibiotics (Friis B. et al. Arch dis child 1984)
• WHO suggest co-trimoxazole as a first choice for CAP; concerns on resistence
• Oral Amoxacilin may be the most reasonable choice for empyrical Tx
Hale KA, Isaacs, D. Paed Resp Rev 2006
Children at Risk for HIV or Symptomatic HIV disease
• Add Aminoglycoside to empirical treatment; or be covered against Gram-negative bacteria.
• If PJP is suspected add cotrimoxazole. • All HIV exposed children <6 mo should be
treated empirically for PJP if hospitalized for severe pneumonia, unless HIV infection status is confirmed to be negative and the child is not breast-fed
Special Conditions
• Empirical treatment with cotrimoxazole, amoxicillin and an aminoglycosideshould also be considered for older HIV infected children with features of severe AIDS who are not on cotrimoxazoleprophylaxis.
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