Newer agents causing pneumonitis in early infancy

Diagnostic Imaging of Neonatal Pneumonia

Respiratory infections remain a significant and formidable threat to the health and well being of the neonate despite potent antibiotics, increasingly sophisticated laboratory detection methods and technologically advanced neonatal intensive care nurseries. Although the clinical and radiological definitions of pneumonia are variable throughout medical and governmental literature, quoted incidence rates for neonatal pneumonia range between 1.5–5.0 per 1,000 live births (Keyserling 1997; Webber et el 1990).

Chlamydia and sudden infant death syndrome. A study of 166 SIDS and 30 control cases

Chlamydia inclusions could be demonstrated by an immunofluorescence assay in formalin-fixed lung sections in 32 of 166 cases (19.4%) of Sudden Infant Death Syndrome (SIDS) and in the lungs of only 1 of 30 infants with a known cause of death (3.3%). The difference is statistically significant (P = 0.04). Chlamydia trachomatis is an agent of pneumonia in 1-4 month-old infants who have acquired the disease from an infected cervix during birth, but other chlamydia species are also capable of causing pneumonia. The lung sections of the 32 chlamydia positive SIDS cases did not show typical histological signs of pneumonia. Even though chlamydia inclusions were detected in the lungs of 32 SIDS cases a causal relation between chlamydia infection and SIDS could not be demonstrated.

Pneumonia associated with infection with pneumocystis, respiratory syncytial virus, chlamydia, mycoplasma, and cytomegalovirus in children in Papua New Guinea

Paired serum samples were collected from 94 children with pneumonia admitted to Goroka Hospital, Papua New Guinea. All but three of the children were aged 1-24 months. Only nine children were malnourished, with weight for age less than 70% of the Harvard median (three had weight for age less than 60% of the Harvard median). Pneumocystis carinii antigen was detected in the serum of 23 children. Twenty two children had serological evidence of recent infection with respiratory syncytial virus. Five children were probably infected with Chlamydia trachomatis at the time of the study, and there was less convincing serological evidence of current infection in a further 11 children. Five children showed a fourfold rise in antibody to Mycoplasma pneumoniae. Although only one child showed a fourfold rise in antibody to cytomegalovirus, 86 children had this antibody. No child showed a fourfold rise in antibody to Ureaplasma urealyticum or Legionella pneumophila. P carinii, respiratory syncytial virus, C trachomatis, M pneumoniae, and cytomegalovirus may be important causes of pneumonia in children in developing countries.

Neonatal cytomegalovirus infections due to blood

Infants with very low birthweights (less than 1250g) are immunocompromised and have immature hematopoietic systems. They require frequent blood transfusions and have an increased susceptibility to infection. These very low birthweight infants who lack passively acquired antibody against CMV, acquire transfusion-associated CMV infections with a frequency of approximately 30%. These infections are associated with significant morbidity and mortality. The source of these postnatally acquired CMV infections are seropositive blood donors. These infections can be prevented by appropriate donor selection and/or blood processing. Recent but limited data suggests that all infants (regardless of birthweight or the presence of antibody against CMV) should receive CMV seronegative blood products if they are likely to receive multiple transfusions from multiple donors.